C01 Introduction To MPC
C01 Introduction To MPC
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                                        Chapter 1
                                        Introduction to Model Predictive Control
                                        Abstract This Chapter is an introduction to the field of MPC. Its basic idea and the
                                        rudimentary MPC optimisation problems are defined, at first for Single-Input Single-
                                        Output (SISO) processes and next for Multiple-Input Multiple-Output (MIMO) ones.
                                        A method to cope with infeasibility problems caused by constraints imposed on the
                                        predicted controlled variables is presented. Next, parameterisation of the decision
                                        variables using Laguerre functions in order to reduce the number of actually opti-
                                        mised variables is described. Classification of MPC algorithms is given and com-
                                        putational complexity issues are discussed. Finally, some example applications of
                                        MPC algorithms in different fields are reported.
                                        The objective of a good control algorithm is to calculate repeatedly on-line the value
                                        of the manipulated variable (or the values of many manipulated variables) that leads
                                        to good process behaviour [36]. Let us discuss the term good process behaviour
                                        using two examples.
                                            The first process example is a residential building equipped with an underfloor
                                        radiant heating system based on electric heating foils [99]. From the point of view
                                        of control engineering, the process is very simple since it has only one manipulated
                                        variable (process input) which is the value of the current (or the voltage) applied
                                        to the foils and only one controlled variable (process output) which is the average
                                        temperature inside the building. There are two objectives of the controller:
                                                                                                                            3
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                                        a) it must increase the temperature quickly when the user increases the temperature
                                           set-point, i.e. the value of the required temperature,
                                        b) it must stabilise the temperature when the outside temperature drops.
                                        The first objective is set-point tracking, i.e. the process output must follow changes of
                                        its set-point. The second objective is compensation of disturbances, i.e. the process
                                        output must be (approximately) constant when the process is affected by external
                                        disturbances, also called uncontrolled process inputs. In our simple example, it is
                                        only possible to increase the temperature by increasing the current (or the voltage),
                                        but it is impossible to reduce the temperature. It means that it works fine in the
                                        two above situations, but when the user wants to reduce the set-point or the outside
                                        temperature increases, the only possible action is to reduce heating, switch it off or
                                        simply ventilate the building. Of course, in more advanced solutions, it is possible
                                        to both heat and cool. Furthermore, it may be necessary to stabilise not only tem-
                                        perature but also humidity. An important application of such a control system may
                                        be found in greenhouses, where it is necessary to maintain constant temperature and
                                        humidity values for the proper growth of plants. Different parts of the greenhouse
                                        may be heated separately to obtain different local temperature conditions. In such
                                        a case, there are many manipulated, controlled and disturbance variables. In addi-
                                        tion to set-point tracking and compensation of disturbances, the calculated values of
                                        the manipulated signals must satisfy some constraints. Typically, they have limited
                                        values and rates of change caused by the physical limits of actuators. Moreover,
                                        one may imagine that some constraints are imposed on the controlled variables, e.g.
                                        temperature and humidity should be in some ranges.
                                            The second process example is a car. Its control is significantly much more
                                        complicated than the simple temperature control task discussed above. It is because
                                        a driver must manipulate numerous variables, such as the accelerator, clutch and
                                        brake pedals, the wheel and the gear lever. There are many controlled variables,
                                        such as position on the road, speed, acceleration. The driver controls the car in
                                        such a way that position, speed and acceleration set-point trajectories are followed.
                                        Moreover, the influence of many external disturbances is compensated, e.g. variable
                                        road slope, type of surface, side wind. Unlike the first process example, the driver
                                        not only controls the process but also calculates the set-point trajectories on-line, i.e.
                                        adjusts them to the current road conditions. Of course, there are numerous constraints
                                        which must be taken into account during calculation of the values of the manipulated
                                        variables and adjusting the trajectories. Both manipulated and controlled variables
                                        must be constrained in this example.
                                            The classical Proportional-Integral-Derivative (PID) controller in continuous-
                                        time domain is described by the following rule
                                                                                     1                   de(t)
                                                                                        ∫ t                   
                                                            u(t) = u0 + K e(t) +             e(τ)dτ + Td                    (1.1)
                                                                                     Ti 0                 dt
                                        The control error is defined as the difference between the set-point and the current
                                        measured value of the controlled variable, i.e. e(t) = y sp (t) − y(t). The value of
                                        the manipulated variable u for the current time t is a linear function of three parts:
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                                        the proportional part, which takes into account the current control error, e(t), the
                                        integral part, which takes into account the past errors, and the derivative part, which
                                        takes into account the rate of change of the error. The tuning parameters are: the
                                        proportional gain K, the integration time-constant Ti and the derivative time-constant
                                        Td . Using Euler’s backward differentiation and trapezoidal integration, in discrete-
                                        time domain, the value of the manipulated variable for the current sampling instant
                                        k is
                                                         u(k) = u(k − 1) + r0 e(k) + r1 e(k − 1) + r2 e(k − 2)             (1.2)
                                        where e(k), e(k − 1) and e(k − 2) denote the values of the control error at the
                                        sampling instants k, k − 1 and k − 2, respectively, u(k − 1) is the value of the
                                        manipulated variable at the sampling instant k − 1, r0 , r1 , r2 are parameters. They are
                                        calculated for the settings K, Ti , Td and the chosen sampling time of the controller.
                                        If properties of the process are (approximately) linear, the PID controller proves to
                                        be very efficient in numerous applications. Nevertheless, the PID controller has the
                                        following limitations:
                                        1. The PID control law (1.1) or (1.2) is linear. In the case of nonlinear processes,
                                           the possible quality of control may be not satisfactory, in particular when the
                                           set-point changes are significant and fast or the external disturbances are strong.
                                        2. The PID controller works fine when the process delay is not significant. Con-
                                           versely, PID control of delayed dynamical systems is usually not good.
                                        3. In its basic version, the PID controller does not include constraints. Although
                                           simple limiters may easily enforce limits of the manipulated variable and con-
                                           straints on its rate of change, there is no systematic way to enforce satisfaction of
                                           constraints imposed on the controlled variable.
                                        4. The PID controller is a natural choice when the controlled process has one ma-
                                           nipulated variable and one controlled one. In the case of a dynamical process with
                                           many inputs and many outputs, the basic problem is finding out which manipu-
                                           lated variable has the strongest influence on each controlled one. Next, several
                                           classical single-loop PID controllers are used. Such an approach works correctly
                                           when the consecutive manipulated variables strongly impact the consecutive con-
                                           trolled ones, but when one process input impacts two or more outputs, such a
                                           control structure does not work. Moreover, the number of process inputs and
                                           outputs must be equal.
                                        5. It is interesting that the current value of the manipulated variable generated by
                                           the PID controller depends on the current and past errors. It is clear when we
                                           consider the discrete-time implementation (1.2). The derivative part tries to use
                                           some information of the future control error but using only its current and previous
                                           measurements.
                                        6. The PID controller is tuned in practice using some simple rules, e.g. the famous
                                           Ziegler and Nichols procedure, or simply by the trial and error approach. Although
                                           interpretation of the continuous-time parameters K, Ti and Td is straightforward,
                                           the parameters r0 , r1 and r2 of the discrete-time controller have no physical
                                           interpretation.
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                                        Fig. 1.1 Situations on the road and the driver’s A decisions for three example time instants t1 , t2 , t3
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                                        is calculated on-line. The symbol 4u(k + p|k) denotes the increment of the manipu-
                                        lated variable for the sampling instant k + p calculated at the current sampling instant
                                        k, Nu is the control horizon which defines the number of decision variables (1.3).
                                        The first increment is
                                                                     4u(k |k) = u(k |k) − u(k − 1)                         (1.4)
                                        and the following ones are
                                        for p = 1, . . . , Nu − 1. The symbol u(k + p|k) denotes the value of the manipulated
                                        variable for the sampling instant k + p calculated at the current sampling instant k,
                                        u(k − 1) is the value of the manipulated variable used (applied to the process) at the
                                        previous sampling instant. In the simplest case, the vector of decision variables (1.3)
                                        is calculated on-line from an unconstrained optimisation problem
                                        Typically, the minimised objective function (the cost-function) consists of two parts
                                                            N                                           Nu −1
                                        The first part of the MPC cost-function measures the predicted quality of control
                                        since the differences between the set-point trajectory and the predicted trajectory
                                        of the output variable (i.e. the predicted control errors) over the prediction horizon
                                        N ≥ Nu are taken into account. The set-point value for the sampling instant k + p
                                        known at the current sampling instant k is denoted by y sp (k + p|k), the predicted
                                        value of the output variable for the sampling instant k + p calculated at the current
                                        instant is denoted by ŷ(k + p|k). The future values of the set-point are usually
                                        not known, hence only the scalar set-point value for the current sampling instant,
                                        denoted by y sp (k), is used, i.e. y sp (k + 1|k) = . . . = y sp (k + N |k) = y sp (k). Such
                                        an approach is typically used in control of industrial processes in which changes
                                        of the set-point are very rare, but the controller must compensate for changes of
                                        the disturbances. However, in some applications, e.g. in autonomous vehicles and
                                        robotics, the set-point trajectory may be not constant over the prediction horizon.
                                        The second part of the MPC cost-function is a penalty term. It is used to reduce
                                        excessive changes of the manipulated variable; λ > 0 is a weighting coefficient. The
                                        greater its value, the lower the increments of the manipulated variable and, hence, the
                                        slower control. Because in practice the control horizon is shorter than the prediction
                                        one, it is assumed that u(k + p|k) = u(k + Nu − 1|k) for p = Nu, . . . , N, which means
                                        that 4u(k + Nu |k) = . . . = 4u(k + N |k) = 0.
                                           Although at each sampling instant as many as Nu future increments of the ma-
                                        nipulated variable (1.3) are calculated, only the first element of this sequence is
                                        actually applied to the process, i.e. the increment for the current sampling instant k.
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                                        Let the optimal vector calculated from the MPC optimisation problem be denoted
                                        by 4u opt (k). The current optimal value of the manipulated variable is applied to the
                                        process
                                                                     u(k) = 4uopt (k |k) + u(k − 1)                      (1.8)
                                        where 4uopt (k |k) is the first element of the vector 4u opt (k). In the next sampling
                                        instant (k +1) the output value of the process is measured (the state variables may also
                                        be measured or estimated), the prediction horizon is shifted one step forward and the
                                        whole procedure described above is repeated. As a result, the MPC algorithm works
                                        in the closed-loop, i.e. with feedback from the measured process output. Fig. 1.2
                                        depicts the general structure of the MPC algorithm. It is assumed that the time
                                        necessary to solve the MPC optimisation problem is much shorter than the sampling
                                        time.
                                           In practical applications, it is necessary to take into account existing constraints.
                                        First of all, the magnitude of the manipulated variable may be constrained. Such
                                        constraints result from the physical limits of the actuator
                                        where umin and umax are the minimal and maximal values of the manipulated variable,
                                        respectively. It is interesting to notice the fact that all calculated values of the
                                        manipulated variable over the whole control horizon are limited, not only the value
                                        for the current sampling instant, i.e. u(k |k). Secondly, the rate of change of the
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                                        where 4umin and 4umax are the maximal negative and maximal (positive) changes
                                        of the manipulated variable, respectively (usually 4umin = −4umax ). All calculated
                                        increments of the manipulated variable over the whole control horizon are limited,
                                        not only the increment for the current sampling instant, i.e. 4u(k |k). Thirdly, the
                                        predicted values of the process output variable may also be limited, which is usually
                                        enforced by some technological reasons
                                        where y min and y max are the minimal and maximal values of the predicted output
                                        variable, respectively. All predictions over the prediction horizon N are constrained.
                                        When the constraints are present, the vector of decision variables (1.3) is calculated
                                        at each sampling instant from an optimisation problem in which the cost-function
                                        (1.7) is minimised and all the constraints (1.9), (1.10) and (1.11) are taken into
                                        account. Hence, the rudimentary MPC constrained optimisation problem is
                                                                N                                           Nu −1                    
                                                                       (y sp (k + p|k) − ŷ(k + p|k))2 + λ           (4u(k + p|k))2
                                                                 Õ                                           Õ
                                              min
                                                    
                                                                                                                                     
                                                                                                                                      
                                                        J(k) =
                                              4u(k)                                                                                  
                                                                p=1                                         p=0                      
                                             subject to                                                                                (1.12)
                                             umin ≤ u(k + p|k) ≤ umax, p = 0, . . . , Nu − 1
                                             4umin ≤ 4u(k + p|k) ≤ 4umax, p = 0, . . . , Nu − 1
                                             y min ≤ ŷ(k + p|k) ≤ y max, p = 1, . . . , N
                                                                                                                                               PD
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                                        is hence of length nu Nu . The minimised MPC cost-function for the MIMO case is
                                                                       ny
                                                                     N Õ
                                                                     Õ
                                                                                        sp                                 2
                                                            J(k) =             µ p,m ym (k + p|k) − ŷm (k + p|k)
                                                                     p=1 m=1
                                                                         Nu −1 Õ
                                                                               nu
                                                                                    λ p,n (4un (k + p|k))2
                                                                         Õ
                                                                     +                                                                (1.13)
                                                                         p=0 n=1
                                        In comparison with the SISO case (Eq. (1.7)), in the first part of the cost-function
                                        (1.13), we consider the predicted control errors for all ny controlled variables over
                                        the whole prediction horizon. Similarly, in the second part of the cost-function,
                                        increments of all nu manipulated variables are taken into account over the whole
                                        control horizon. The weighting coefficients µ p,m ≥ 0 make it possible to differentiate
                                        the influence of the predicted control errors of the consecutive outputs within the
                                        prediction horizon. The coefficients λ p,n > 0 are used not only to differentiate the
                                        influence of the control increments of the consecutive inputs of the process within
                                        the control horizon but to establish the necessary scale between both parts of the
                                        cost-function.
                                            The MPC cost-function and the resulting optimisation problems may be con-
                                        veniently and compactly derived, formulated and implemented using vector-matrix
                                        notation rather than scalars. The cost-function (1.13) may be expressed in the fol-
                                        lowing form
                                                      N                                                  Nu −1
                                                              sp
                                                                                        p|k)k 2M p               k4u(k + p|k)k 2Λ p
                                                      Õ                                                  Õ
                                             J(k) =         k y (k + p|k) − ŷ(k +                   +                                (1.14)
                                                      p=1                                                p=0
                                        Now, the set-point vector for the sampling instant k + p known at the current sampling
                                        instant k is denoted by y sp (k + p|k), the predicted vector of the output variables for
                                        the sampling instant k + p calculated at the current sampling instant k is denoted by
                                        ŷ(k + p|k), both vectors are of length ny . The matrix M p = diag(µ p,1, . . . , µ p,ny ) ≥
                                        0 is of dimensionality ny × ny , the matrix Λ p = diag(λ p,1, . . . , λ p,nu ) > 0 is of
                                        dimensionality nu × nu .
                                            For the process with nu manipulated variables, the magnitude constraints are
                                                 umin                 max
                                                  n ≤ un (k + p|k) ≤ un , p = 0, . . . , Nu − 1, n = 1, . . . , nu                    (1.15)
                                              4umin                   max
                                                n ≤ 4un (k + p|k) ≤ 4un , p = 0, . . . , Nu − 1, n = 1, . . . , nu                    (1.16)
                                        where 4umin
                                                 n and 4un
                                                           max are the maximal negative and maximal (positive) changes of
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                                        where ym min and y max are the minimal and maximal values of the predicted variable
                                                           m
                                        ym , respectively. If we use the vector notation, the constraints are defined by the
                                        following vectors of length nu
                                                          umin           umax            4umin           4umax 
                                                          1              1               1               1 
                                             umin      =  ...  , umax =  ...  , 4umin =  ...  , 4umax =  ...                (1.18)
                                                                                                               
                                                          umin           umax            4umin           4umax 
                                                                                                               
                                                          nu             nu              nu              nu 
                                        and the following vectors of length ny
                                                                                     y min    y max 
                                                                                     1        1 
                                                                                     ..  max  .. 
                                                                          y min   =  . , y  = .                                 (1.19)
                                                                                     min      max 
                                                                                     yn       yn 
                                                                                     y        y 
                                        We may notice that the above 3 scalar constraints given by Eqs. (1.15), (1.16) and
                                        (1.17) may be rewritten in the same way it is done for the SISO case, i.e. by Eqs.
                                        (1.9), (1.10) and (1.11).
                                           Now we may formulate the general MPC optimisation problem for MIMO pro-
                                        cesses. Using the cost-function (1.14), the scalar constraints (1.15), (1.16), (1.17)
                                        and the definitions (1.18)-(1.19), we have
                                                            N                                     Nu −1
                                                  (                                                                       )
                                                                  sp                        2                         2
                                                           Õ                                      Õ
                                            min J(k) =         k y (k + p|k) − ŷ(k + p|k)k M p +       k4u(k + p|k)k Λ p
                                              4u(k)
                                                                 p=1                                        p=0
                                             subject to                                                                             (1.20)
                                                 min                      max
                                             u         ≤ u(k + p|k) ≤ u      , p = 0, . . . , Nu − 1
                                                  min
                                             4u          ≤ 4u(k + p|k) ≤ 4umax, p = 0, . . . , Nu − 1
                                             y min ≤ ŷ(k + p|k) ≤ y max, p = 1, . . . , N
                                                                                                                                     PD
                                or
                                                                                                                                                                     or
                           !
                                                                                                                                                                !
                        W
                                                                                                                                                             W
                       O
                                                                                                                                                            O
                       N
                                                                                                                                                            N
                   Y
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                   U
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                                                                                                                                               d f- x            e.
                   chang                                                                                                                                chang
                                           In the case of the MIMO constrained MPC algorithm, at each sampling instant k
                                        the following steps are performed on-line:
                                        1. The current values of the controlled variables, y1 (k), . . . , yny (k), are measured;
                                           the state variables may be measured or estimated when necessary.
                                        2. The future sequence of increments of the manipulated variables is calculated from
                                           the optimisation problem (1.20).
                                        3. The first nu elements of the determined sequence are applied to the process (Eq.
                                           (1.8)).
                                           Now, let us find a more compact representation of the rudimentary MIMO MPC
                                        optimisation problem (1.20). Let us define the set-point trajectory vector
                                                                                   y sp (k + 1|k) 
                                                                                            ..
                                                                                                   
                                                                       y sp (k) =           .                             (1.21)
                                                                                                   
                                                                                                    
                                                                                   y sp (k + N |k) 
                                                                                                   
                                                                                                   
                                        and the predicted output trajectory vector
                                                                                  ŷ(k + 1|k) 
                                                                                         ..
                                                                                               
                                                                         ŷ(k) =         .                                (1.22)
                                                                                               
                                                                                                
                                                                                               
                                                                                  ŷ(k + N |k) 
                                                                                               
                                        Both vectors are of length ny N. The MPC cost-function (1.14) may be rewritten in
                                        the following compact form
                                                                                                                                          PD
                                or
                                                                                                                                                                          or
                           !
                                                                                                                                                                     !
                        W
                                                                                                                                                                  W
                       O
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                       N
                                                                                                                                                                 N
                   Y
                                                                                                                                                             Y
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            to
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     .p
          d f- x            e.                                                                                                                 .p
                                                                                                                                                    d f- x            e.
                   chang                                                                                                                                     chang
                                        where
                                                                                    u(k |k)     
                                                                                        .
                                                                                                
                                                                       u(k) =          ..                              (1.27)
                                                                                                
                                                                                                 
                                                                                u(k + Nu − 1|k) 
                                                                                                
                                                                                                
                                        is a vector of length nu Nu that corresponds to the vector of increments 4u(k). Using
                                        Eq. (1.26), the scalar constraints (1.15) may be expressed compactly
                                                                                                                                   PD
                                or
                                                                                                                                                                   or
                           !
                                                                                                                                                              !
                        W
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          d f- x            e.                                                                                                          .p
                                                                                                                                             d f- x            e.
                   chang                                                                                                                              chang
                                                            subject to                                                   (1.35)
                                                                min                             max
                                                            u         ≤ J4u(k) + u(k − 1) ≤ u
                                                                 min
                                                            4u         ≤ 4u(k) ≤ 4u max
                                                            y min ≤ ŷ(k) ≤ y max
                                           Since a mathematical model of the controlled process is used on-line for prediction
                                        and optimisation of the control policy, the MPC algorithms have the following
                                        advantages:
                                        1. It is possible to control MIMO processes efficiently. When a series of classical
                                           single-loop PID controllers are used for the MIMO process, the consecutive
                                           controllers work independently; each of them has only one objective, i.e. control
                                           of only one controlled variable. When cross-couplings in the process (interactions
                                           of the consecutive manipulated variables with the consecutive controlled ones)
                                           are strong, such single-loop PID controllers do not work properly. Conversely,
                                           due to using a model for prediction, the MPC “knows” all interactions between
                                           process variables and calculates the best possible control policy.
                                        2. The MPC algorithms may be used when the number of process inputs is different
                                           from the number of outputs. In such a case, it is practically impossible to use a
                                           set of single-loop PID controllers.
                                        3. It is possible to take into account constraints imposed on both manipulated and
                                           predicted controlled variables in a simple way (MPC optimisation is simply
                                           carried out subject to all necessary constraints).
                                        4. It is possible to control “difficult” processes, i.e. with significant time-delays or
                                           with the inverse step-response.
                                        Additional advantages of MPC are:
                                        1. Tuning of MPC algorithms is relatively easy. It is only necessary to select ap-
                                           propriate horizons and some weighting coefficients. All these parameters have a
                                           clear physical interpretation.
                                        2. It is possible to take into account the measured disturbances of the process, i.e.
                                           the uncontrolled inputs (the feed-forward action).
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                           !
                                                                                                                                                                 !
                        W
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                       N
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                   chang                                                                                                                                 chang
                                        3. Unlike the PID algorithm, future changes of the set-point trajectory over the
                                           prediction horizon may be easily taken into account.
                                        4. The core idea of MPC is straightforward, which is important when advanced
                                           methods are introduced in industry [112, 177].
                                            Let us emphasise the very significant role of the process model in MPC. The
                                        model is used for prediction. Intuitively, the better the model, the better (potentially)
                                        the resulting control accuracy. Moreover, without the model, it is impossible to use
                                        MPC at all. Let us also mention some other advanced model-based computational
                                        methods: fault diagnosis [81, 83, 145, 192] and fault-tolerant control [118, 145, 192].
                                            An important question is how to assess the quality of control. In addition to
                                        typically used indicators, such as the sum of squared errors, overshoot and setting
                                        time, we can use more sophisticated indices, including fractal and entropy measures
                                        [36]. Effectiveness of such methods is discussed in [38, 39, 41] (for MPC algorithms
                                        based on linear models) and in [40, 42] (for nonlinear MPC algorithms). A review
                                        of control performance assessment methods for MPC is given in [37].
                                            We have presented above the classical formulation of MPC. In the next parts of
                                        the book, we will detail computationally efficient nonlinear approaches. At this point
                                        we have to mention a few important extensions of MPC. In numerous industrial
                                        applications, when the objective is maximisation of production profits, set-point
                                        optimisation that cooperates with MPC [50, 91, 89, 177, 181] and economic MPC
                                        [49, 48, 107, 132] must be used. An excellent review of possible architectures
                                        for distributed and hierarchical MPC is given in [163]. MPC algorithms may also
                                        offer fault-tolerant control [118, 145, 167], which means that safe process operation
                                        is guaranteed in the case of some faults, e.g. when a sensors’ or an actuators’
                                        malfunction occurs. It is also possible to take into account in MPC not only control
                                        accuracy and economic issues but also the remaining useful life of the system
                                        considered (health-aware MPC) [150]. An important direction of theoretical research
                                        is concerned with stable and robust versions of MPC algorithms [128, 129]. Different
                                        versions of such approaches are presented in [58, 117, 146, 144, 145, 174, 159, 182].
                                        In the last years MPC schemes for fractional-order systems have gained popularity
                                        [43, 44, 45, 46, 135, 169]. The fractional-order approach makes it possible to control
                                        processes for which classical differential (or difference) equations are insufficient as
                                        models used for prediction in MPC.
                                        In this work three different classes of constraints are taken into account in MPC
                                        optimisation taks (1.12), (1.20) and (1.35). The constraints may be imposed on:
                                        the values of the manipulated variables, the corresponding increments of those
                                        variables and on the predicted values of the controlled variables. The first two
                                        classes of constraints simply limit the feasible set of possible solutions of the MPC
                                        optimisation task. The third type of constraints may cause some important problems.
                                        Let us imagine that we require no overshoot. In order to achieve that, we use the
               hange E                                                                                                                                                           hange E
          XC               di                                                                                                                                               XC               di
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                                                                                                                                                                  PD
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                                                                                                                                                                                                  or
                           !
                                                                                                                                                                                             !
                        W
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                       N
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                                        constraints
                                                                             ŷ(k + p|k) ≤ y sp (k), p = 1, . . . , N                                    (1.36)
                                        If the model used for prediction is precise and there are no external disturbances,
                                        such constraints may work correctly provided that the constraints imposed on the
                                        manipulated variables are not too restrictive. It is also possible that the constraints
                                        (1.36) may be not satisfied because of the constraints imposed on the manipulated
                                        variables, even in the case of a perfect model and no disturbances. When the model
                                        is only a rough approximation of the process, which frequently happens, and/or the
                                        process is affected by a strong disturbance, it is very likely that it is impossible
                                        to calculate a decision variable vector which leads to satisfaction of the constraints
                                        (1.36). When such problems occur, the feasible set of the MPC optimisation problem
                                        is empty. In such a case, one may use for control at the current sampling instant the
                                        signals applied to the process at the previous sampling instant, i.e. u(k − 1), or
                                        the signals calculated at the previous sampling instant for the current sampling, i.e.
                                        u(k |k − 1). A more mathematically sound approach is to use soft output constraints
                                        [112, 177]. The original hard constraints (in the vector notation for a general MIMO
                                        process)
                                                               y min ≤ ŷ(k + p|k) ≤ y max, p = 1, . . . , N            (1.37)
                                        are relaxed when they cannot be satisfied. It means that the predicted values of
                                        the controlled variables may temporarily violate the hard constraints. As a result,
                                        the feasible set is not empty. Using the soft constraints, the rudimentary MPC
                                        optimisation problem (1.20) becomes
                                                                          N
                                                                 (
                                                                            k y sp (k + p|k) − ŷ(k + p|k)k 2M p
                                                                          Õ
                                                        min        J(k) =
                                                             4u(k)
                                                                                       p=1
                                                      ε min (k), ε max (k)
                                                                                         N u −1
                                                                                                   k4u(k + p|k)k 2Λ p
                                                                                         Õ
                                                                                       +
                                                                                            p=0                                                      )
                                                                                             min        min         2    max        max          2
                                                                                       + ρ          ε         (k)       +ρ     kε         (k)k
                                                   subject to                                                                                            (1.38)
                                                       min                            max
                                                   u         ≤ u(k + p|k) ≤ u              , p = 0, . . . , Nu − 1
                                                         min
                                                   4u          ≤ 4u(k + p|k) ≤ 4umax, p = 0, . . . , Nu − 1
                                                   y min − ε min (k) ≤ ŷ(k + p|k) ≤ y max + ε max (k), p = 1, . . . , N
                                                   ε min (k) ≥ 0ny ×1, ε max (k) ≥ 0ny ×1
                                        When the original hard constraints (1.37) cannot be satisfied, they are temporarily
                                        violated. It is done by relaxing the minimal and maximal predicted values of the
                                        controlled variables by ε min (k) and ε max (k), respectively. The MPC algorithm cal-
                                        culates not only the future control increments 4u(k) but also the vectors ε min (k) and
                                        ε max (k) of length ny . Because it is natural that the original hard output constraints
                                        should be relaxed only when necessary, the degree of violations of the hard con-
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                           !
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                                        straints is minimised in the cost-function by additional penalty terms; ρmin, ρmax > 0
                                        are penalty coefficients. Additionally, the last two constraints require that the de-
                                        gree of constraints’ violation is non-negative. The number of decision variables
                                        of the optimisation problem (1.38) is nu Nu + 2ny , the number of constraints is
                                        4nu Nu + 2ny N + 2ny .
                                           Using the vector-matrix notation, the rudimentary MPC optimisation problem
                                        with soft output constraints (1.38) may be easily transformed to the following task
                                        in a compact vector-matrix notation, similar to the task (1.35)
                                                    subject to                                                                    (1.39)
                                                        min                              max
                                                    u         ≤ J 4u(k) + u(k − 1) ≤ u
                                                         min
                                                    4u         ≤ 4u(k) ≤ 4u max
                                                    y min − ε min (k) ≤ ŷ(k) ≤ y max + ε max (k)
                                                    ε min (k) ≥ 0ny ×1, ε max (k) ≥ 0ny ×1
                                        The vectors of additional decision variables of the MPC optimisation task are now
                                                                     ε min (k + 1|k)                  ε max (k + 1|k) 
                                                                               ..                                ..
                                                                                                                       
                                                        ε min (k) = 
                                                                                        max
                                                                                .       , ε (k) =                .               (1.42)
                                                                                                                        
                                                                                                                         
                                                                     ε min (k + N |k)                 ε max (k + N |k) 
                                                                                                                       
                                                                                                                       
                                        Unfortunately, the number of decision variables increases to nu Nu +2ny N, the number
                                        of constraints is 4nu Nu + 4ny N. In practical applications of MPC, the assumption
                                        that the output constraints are relaxed by the same degree for the whole prediction
                                        horizon (for the consecutive controlled variables) and only 2ny additional variables
                                        are used gives very good results, very close to those possible when as many as 2ny N
                                        additional variables are necessary [96].
               hange E                                                                                                                             hange E
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                           !
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                                        Laguerre, Kautz and other orthonormal functions may be successfully used for mod-
                                        elling of dynamical systems in linear [137] and nonlinear [138] cases, respectively.
                                        Application of orthonormal Laguerre functions to parameterise the calculated future
                                        sequence of the manipulated variables may be used in MPC algorithms based on
                                        linear state-space models: in continuous-time [186] and discrete-time [187] versions,
                                        respectively, as well as in the DMC algorithm, in which a step-response model is
                                        used for prediction [178]. A systematic tuning methodology to find parameters of
                                        Laguerre functions in parameterised MPC is discussed in [61, 75]. MPC algorithms
                                        with Laguerre parameterisation have been developed for different technological pro-
                                        cesses. Example applications include: buildings [19], wave energy converters [69],
                                        magnetically actuated satellites [76], wind turbines [84], hexacopters [104] and
                                        power systems [202]. All cited MPC algorithms use linear models for prediction. In
                                        this book, the Laguerre functions are used to parameterise the decision vector of all
                                        discussed nonlinear MPC algorithms, i.e. to reduce the number of decision variables
                                        that are actually optimised on-line.
                                            At first, let us consider the SISO case. Let l1 (k),. . . ,lnL (k) denote nL Laguerre
                                        functions. The transfer function of the Laguerre function of the order n is [185]
                                                                               1 − (aL )2 1 − aL z n−1
                                                                             p                    
                                                                   G n (z) =                                               (1.43)
                                                                               z − aL      z − aL
                                        where aL is a scaling factor, often named a Laguerre pole. For stability, the condition
                                        0 ≤ aL < 1 must be satisfied. The transfer functions G n (z) satisfy the following
                                        orthonormality conditions
                                                              1
                                                                 ∫ π
                                                                      G n (e jω )G n (e jω )∗ dω = 1                     (1.44)
                                                             2π −π
                                                              1
                                                                ∫ π
                                                                      G m (e jω )G n (e jω )∗ dω = 0 for m , n           (1.45)
                                                             2π −π
                                                                                                                                           PD
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                           !
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                                                                                                                                                 d f- x            e.
                   chang                                                                                                                                  chang
                                        For the whole vector of future increments of the manipulated variable over the control
                                        horizon, we have
                                                                            4u(k) = Lc(k)                               (1.56)
                                        where the matrix of dimensionality Nu × nL is
                                                               l1 (0)          l2 (0)             ...       lnL (0)   
                                                                                                   ...
                                                                                                                      
                                                               l1 (1)          l2 (1)                       lnL (1)   
                                                            L=       ..           ..              ..           ..           (1.57)
                                                                                                                      
                                                                       .            .                 .          .
                                                                                                                       
                                                                                                                      
                                                               l1 (Nu − 1) l2 (Nu − 1)            . . . lnL (Nu − 1) 
                                                                                                                      
                                                              
                                        In parameterised MPC the vector of decision variables is c(k), not 4u(k). Since
                                        nL < Nu , the number of decision variables used in the MPC optimisation problem
                                        solved on-line is reduced. Having calculated the optimal vector copt (k) from the MPC
                                        optimisation problem, using Eq. (1.56) and taking into account the structure of the
                                        matrix L given by Eq. (1.57), the current optimal value of the manipulated variable
                                        is calculated from
                                                                                                                                              PD
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                           !
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          d f- x            e.                                                                                                                     .p
                                                                                                                                                        d f- x            e.
                   chang                                                                                                                                         chang
                                                                    L 1 0 N ×n2 0 N ×n3
                                                                                  u      u
                                                                                                        . . . 0 Nu ×n nu   
                                                                                     L      L                        L    
                                                                   0
                                                                    Nu ×nL1      L 2 0 Nu ×n3          . . . 0 Nu ×n nu   
                                                                                             L                        L    
                                                              L =  0 Nu ×nL1 0 Nu ×nL2 L3             . . . 0 Nu ×n nu            (1.64)
                                                                                                                          
                                                                                                                      L
                                                                                                                           
                                                                         ..        ..     ..            ..         ..
                                                                                                                           
                                                                          .         .      .                .       .
                                                                                                                          
                                                                                                                          
                                                                                                        . . . L nu
                                                                                                                          
                                                                    0 N ×n1 0 N ×n2 0 N ×n3                               
                                                                    u        L   u     Lu         L                       
                                        where the consecutive submatrices of dimensionality Nu × nLn are
                                                                                                                                    PD
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                   chang                                                                                                                               chang
                                        In the simplest case, a linear model is used in MPC for prediction and no constraints
                                        are taken into account. A few different such MPC methods have been developed, with
                                        different structures of linear models. To name the most important MPC approaches
                                        based on linear models, we have to mention the following ones:
                                        1. The Predictive Functional Control (PFC) algorithm (also known under the name
                                           Model Heuristic Predictive Control (MHPC)) [156, 157] in which the impulse-
                                           response process representations are used.
                                        2. The Dynamic Matrix Control (DMC) algorithm [29] in which the step-response
                                           models are used.
                                        3. The Generalized Predictive Control (GPC) algorithm [27] in which the discrete-
                                           time transfer functions are used.
                                        4. The MPC algorithm with state-space models (MPCS) [112, 177] in which the
                                           classical linear state-space models are used.
                                        The use of a linear model implies that the predicted trajectory of the manipulated
                                        variables (Eq. (1.22)) is a linear function of the decision variable vector (1.3).
                                        Remembering that the typical minimised MPC cost-function is of the quadratic type
                                        (Eq. (1.13)), we obtain an unconstrained quadratic optimisation problem. It may
                                        be solved analytically, without on-line optimisation. The future increments of the
                                        manipulated variables are linear functions of the following: the model parameters,
                                        some values of the manipulated variables computed at the previous sampling instants
                                        and the values of the process controlled variables measured at the previous sampling
                                        instants. Hence, such unconstrained MPC methods are named unconstrained linear
                                        explicit MPC algorithms.
                                           If a linear model is used for prediction, but the constraints must be taken into
                                        account, at each sampling instant, it is necessary to solve on-line a quadratic op-
                                        timisation task (a quadratic minimised cost-function and linear constraints). Such
                                        methods are named constrained linear MPC algorithms or, better, constrained MPC
                                        algorithms based on linear models since in the constrained case, the explicit linear
                                        solution does not exist, the optimal solution is obtained as a result of on-line opti-
                                        misation. Depending on the model used, we obtain constrained MHPC, DMC, GPC
                                        and MPCS algorithms. For linear models, provided that µ p,m ≥ 0 and λ p,n > 0, the
                                        optimisation task has only one solution, which is the global one. Different approaches
                                        may be used to find the solution of the quadratic optimisation MPC problem [171]:
                                        the active-set methods, the interior-point ones and the first-order ones. It is necessary
                                        to point out that many very computationally efficient quadratic optimisation solvers
                                        are available, e.g. qpOASES [52], CVXGEN [126] and OSQP [171]. To speed up
                                        calculations, advanced quadratic optimisation algorithms may be specially tailored
                                        for MPC, i.e. the special form of the MPC optimisation task may be exploited. They
                                        may be used not only for industrial control applications [13] but also in embedded
                                        systems [16, 78, 158], for which sampling times are very short, of the order of
                                        hundreds, teens or even single milliseconds.
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                                        make it possible to carry out parallel calculations [31, 199]. When the model used
                                        for prediction is comprised of a set of differential-algebraic equations, specialised
                                        optimisation methods must be used [33]. An excellent review of possible approaches
                                        to nonlinear optimisation in MPC is given in [34]. Very infrequently, for nonlinear
                                        optimisation other algorithms may be used, e.g. the golden section method [114, 193]
                                        or the branch-and-bound approach [195].
                                            When the process dynamics is slow, which makes it possible to use relatively
                                        long sampling periods, we may use heuristic global optimisation algorithms. For
                                        example, applications of genetic algorithms to solve the constrained nonlinear MPC
                                        optimisation task may be found in [103, 149]. Specialised genetic operators (mutation
                                        and crossover) are used, tailored for the nature of MPC. An alternative is to use the
                                        particle swarm optimisation algorithm [25, 191]. Another option is to use simulated
                                        annealing for nonlinear optimisation [1]. It must be stressed that application of
                                        heuristic optimisation methods is limited.
                                            There are, however, some deterministic global optimisation methods [164] that
                                        may be used in MPC [47]. The cited method is based on a convex relaxation of the
                                        MPC cost-function. It is reported to significantly reduce dimensionality of the MPC
                                        optimisation task, which lower the overall computational burden. To further reduce
                                        computational complexity, a neural multi-model is used rather than one dynamical
                                        model applied recurrently.
                                            In practice, fuzzy MPC is a very important alternative. To control a nonlinear
                                        process, a set of simple local MPC controllers is used. The local controllers are
                                        switched on-line, taking into account the current operating point of the process
                                        and/or the set-point. Both the unconstrained linear explicit MPC methods and the
                                        constrained MPC algorithms based on linear models may be used as local controllers.
                                        It is important that the local controllers are developed off-line. During on-line control,
                                        it is only necessary to combine the values of the manipulated variables computed
                                        by the local controllers in a fuzzy way. Fuzzy DMC algorithms [30, 119, 125]
                                        and fuzzy GPC methods are given as examples of the described approach [177].
                                        Advanced methods utilised for prediction generation in the fuzzy DMC algorithm
                                        are discussed in [123, 124]. A similar idea is to use multi-linear models for prediction
                                        in MPC [200]. A specialised procedure is used to determine the multi-linear process
                                        representation from nonlinear Hammerstein or Wiener models.
                                            There are numerous attempts to simplify the general nonlinear MPC optimisation
                                        task that must be solved at each sampling instant on-line. The following methods are
                                        reported in the literature:
                                        1. The first nu elements of the future control policy are computed from a nonlinear
                                           optimisation task, whereas the remaining ones are found from an explicit control
                                           law [201]. As a result, the optimisation problem is still nonlinear, but the number
                                           of decision variables is equal to nu , not to nu Nu as in the rudimentary approach.
                                        2. The technique named move blocking may be used [21]. The degree of freedom
                                           is reduced by fixing the manipulated variables or their derivatives to be constant
                                           over several time-steps. Some of such methods guarantee stability and satisfaction
                                           of constraints.
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                                         3. Compression of the constraint set is possible [102]. It simplifies the MPC opti-
                                            misation task. Such an approach may be used together with the move blocking
                                            technique.
                                         4. The domain of the calculated manipulated variable may be discretised [115] (in the
                                            cited approach, the control horizon is equal to 1). A simple procedure determines
                                            its best value and on-line optimisation is not necessary. A more advanced graph
                                            search method for finding the control policy is used in [155].
                                         5. In the case of the cascade models, the inverse of the static part of the model
                                            may be used to make an attempt to cancel the effect of nonlinearity. It makes
                                            it possible to formulate the classical quadratic optimisation MPC problem. For
                                            the Hammerstein structure, such an approach is discussed in [54], for the Wiener
                                            structure in [4, 23, 70, 133, 134, 168]. The same method may also be used for
                                            cascade models with 3 blocks, e.g. the Hammerstein-Wiener ones as described
                                            in [35, 63, 147]. As pointed out in Section 3.1, the discussed approach has
                                            important structural disadvantages and limitations. Moreover, as demonstrated
                                            in simulations discussed in this book, it is very sensitive to model errors and
                                            disturbances.
                                         6. In the fast MPC algorithm [190] the MPC optimisation task is not solved precisely
                                            but in an approximate way. Although it may have a negative effect on the resulting
                                            control quality, the time of calculations necessary at each sampling instant is likely
                                            to be significantly reduced. As proved in [165], for stability, it is sufficient to use
                                            a feasible control strategy, i.e. the one that satisfies all the existing constraints,
                                            not the optimal one.
                                         7. The numerical optimisation procedure used in the MPC algorithm may be re-
                                            placed by a specially designed neural network which acts as a neural optimiser.
                                            There are a few neural structures which solve the quadratic optimisation problem
                                            [109, 188]. The network described in [109] is used for optimisation in an MPC
                                            algorithm based on a linear model [141] and in an MPC algorithm with on-line
                                            model linearisation [140].
                                         8. The MPC algorithm may be replaced by a specially designed neural network
                                            which acts as a neural approximator that attempts to mimic the whole MPC
                                            algorithm [2, 142]. At first, the classical nonlinear MPC algorithm is developed
                                            and run on-line (or off-line in simulations) for different operating conditions and
                                            set-points. A data set is collected and next used to train a neural approximator. For
                                            a given operating point of the process, determined by measurements of the process
                                            input and output variables, as well as the set-point, the approximator finds the
                                            current values of the manipulated variables. An approximator may also be used
                                            to find the initial solution of the MPC optimisation problem [180]. Finding the
                                            initial solution is likely to significantly shorten the calculation time in embedded,
                                            microprocessor-based systems [77].
                                         9. The prediction and control horizons may be equal to 1 and the current value of
                                            the manipulated variable may be computed by a simple binary search algorithm
                                            [160].
                                        10. The Experience-driven Predictive Control (EPC) algorithm constructs a database
                                            of feedback controllers that are parameterised by the system dynamics [32].
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                                              When, for given conditions, the control law does not exist, it is calculated by
                                              a conventional MPC algorithm based on a linear model. In order to obtain a
                                              quadratic optimisation task, for prediction Locally-Weighted Projection Regres-
                                              sion (LWPR) models are used, which allow for easy on-line model adaptation.
                                        11.   The nonlinear optimisation MPC problem is relaxed into a Mixed Integer Linear
                                              Programming (MILP) one. Next, the solution of the MILP problem is taken as a
                                              starting point of the nonlinear one [189].
                                        12.   Constrained explicit nonlinear MPC algorithms are possible [57, 71]. Unfortu-
                                              nately, a huge number of local control laws may be necessary.
                                        13.   A specialised model may be used in which the output values for the consecutive
                                              sampling instants within the prediction horizon are linear functions of the calcu-
                                              lated future manipulated variables, but they are nonlinear functions of the past (the
                                              quasi-linear model) [106]. Such an approach results in a quadratic optimisation
                                              MPC task. Neural networks are used for modelling.
                                        14.   When Linear Parameter Varying (LPV) models are used for prediction, the general
                                              nonlinear optimisation problem is replaced by a convex Linear Matrix Inequal-
                                              ities (LMIs) optimisation task [203, 205, 204]. Neural networks may calculate
                                              coefficients of the LPV models.
                                        15.   Model convexity may be achieved when Input Convex Neural Networks (ICNNs)
                                              are used [8]. ICNNs are obtained by explicitly constraining the model outputs to
                                              be convex functions of the inputs during model development. As a result, convex
                                              MPC optimisation problems are obtained: unconstrained [26] or constrained ones
                                              [196].
                                        16.   A class of linear predictors may be used to describe a nonlinear system [127]. The
                                              key step in obtaining such accurate predictions is to lift (or embed) the nonlinear
                                              dynamics into a higher dimensional space in which its evolution of this lifted state
                                              is (approximately) linear. The idea corresponds to the Koopman operator [79, 80].
                                              When such a model is used in MPC, we obtain a quadratic MPC optimisation
                                              task [82, 127]. An alternative method, named polyflows, is discussed in [72].
                                             Finally, on-line linearisation must be discussed as the method which makes it
                                         possible to significantly reduce computational burden of nonlinear MPC. Details of
                                         numerous such MPC methods are presented in Chapters 3 and 7 for input-output
                                         and state-space Wiener process descriptions, respectively. Let us now only give a
                                         short literature review. In general, two categories of computationally efficient MPC
                                         algorithms may be distinguished: with on-line model linearisation and with on-line
                                         trajectory linearisation. In both cases, we obtain computationally simple quadratic
                                         optimisation problems, the necessity of on-line nonlinear optimisation is eliminated.
                                             In the simplest approach, a linear approximation of the nonlinear model is com-
                                         puted on-line for the current operating point of the process. Typically, model lineari-
                                         sation is performed at each sampling instant but, for some “less nonlinear” processes
                                         or when changes of the set-point are slow and infrequent, model linearisation may
                                         be repeated less frequently. Next, the obtained linearised model is used to calculate
                                         the predicted trajectory of the controlled variables. Thanks to linearisation, the pre-
                                         dicted trajectory is a linear function of the vector of decision variables (1.3), which
                                         is a characteristic feature of the classical MPC algorithms based on linear models.
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                                        Hammerstein [95] (for a heat exchanger) structures. Although all cited works are
                                        concerned with the input-output process representation, the MPC algorithm with
                                        trajectory linearisation is, of course, possible for the state-space representation [101]
                                        (implementation details for the Wiener model are given).
                                            Finally, let us mention computationally efficient MPC algorithms with on-line
                                        linearisation and approximation. The approximator is used in order to eliminate
                                        some calculations that must be repeated at each sampling instant. They are neces-
                                        sary in the classical MPC algorithms with on-line linearisation. Successive model
                                        linearisation and prediction calculation may be simplified using an approximator
                                        which directly estimates, at each sampling instant, the time-varying matrix of step
                                        response coefficients of the linearised model [91]. An application of that approach to
                                        a simulated distillation column is detailed in [90]. The same approximation method
                                        may be used in the nonlinear DMC algorithm [86, 91]. A significant reduction of
                                        computational complexity in comparison with the classical MPC algorithms with
                                        on-line linearisation may be obtained when explicit unconstrained versions of the
                                        discussed algorithms are considered. It may be proved [91, 92] that in such a case,
                                        the optimal vector of the decision variable vector (1.3) is a linear function of the
                                        set-point, model parameters and some past measurements. The time-varying vector
                                        of coefficients of the control law is determined on-line by a neural approximator
                                        for the current operating point. As a result, on-line model linearisation and some
                                        other calculations are not necessary, which significantly speeds up calculations. A
                                        simulation study concerned with a high-pressure distillation process is presented in
                                        [91, 92]. In all mentioned cases, neural networks are used as approximators, although
                                        other structures are also possible.
                                        MPC is regarded as the only one among the advanced control techniques, defined
                                        as more advanced than the classical PID controller, which is successfully used in
                                        numerous industrial applications [152]. Let us cite a number of typical applications.
                                        Traditionally, MPC algorithms may be successfully used for controlling the following
                                        industrial processes:
                                        –   chemical reactors [64, 166, 175, 198],
                                        –   distillation columns [11, 65, 111, 74, 116, 148, 184],
                                        –   combustion in pulverized-coal-fired boilers (in power plants) [62],
                                        –   greenhouses [60],
                                        –   hydraulic systems [12],
                                        –   solar power stations [9, 55],
                                        –   waste water treatment plants [131],
                                        –   electromagnetic mills [136],
                                        –   cement kilns [170].
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                                        Typically, the sampling period of industrial MPC algorithms used in process con-
                                        trol is quite long, of the order of seconds, a dozens of seconds or even minutes.
                                        Programmable Logic Controllers (PLCs) are used for implementation of MPC al-
                                        gorithms in industrial process control. In addition to that, thanks to availability of
                                        fast microcontrollers, it is possible to develop MPC algorithms for fast dynamical
                                        systems (in embedded systems). In contrast to the mentioned industrial applications,
                                        they require short sampling times, shorter than one second, typically of millisecond
                                        order. Example applications of fast MPC include:
                                        –    fuel cells [59],
                                        –    active vibration attenuation [176],
                                        –    combustion engines [28, 73, 154],
                                        –    robots [183, 22, 139],
                                        –    servomotors [24],
                                        –    quadrotors [7],
                                        –    stratospheric airships [108],
                                        –    power converters [194],
                                        –    electrical inverters [110],
                                        –    induction machines [51].
                                           Many research works are concerned with automotive applications. A few exam-
                                        ples are: autonomous driving [105, 173], autonomous racing [6], traction control
                                        [68], vehicle roll-over [67].
                                           There are some applications of MPC in medicine, e.g. muscle relaxant anaesthesia
                                        [114] and artificial pancreas [66].
                                           In addition to industrial and embedded applications of MPC, it is interesting to
                                        mention a few original and less frequent applications in which MPC algorithms also
                                        turn out to be very efficient:
                                        –    drinking water transport networks [143],
                                        –    supermarket refrigeration systems [161],
                                        –    traffic on highways [14],
                                        –    high energy physics accelerators [18],
                                        –    inventory management in hospitals [113].
                                           Important applications of MPC are concerned with building control. Typically,
                                        only temperature control (stabilisation despite changes of the outside temperature,
                                        which is a disturbance) is considered [56, 172]. In more advanced solutions, thermal
                                        comfort is controlled [197], i.e. temperature, humidity and other factors. MPC may
                                        cooperate with on-line energy optimisation which determines optimal set-points for
                                        MPC [10].
                                           It is important to emphasise that all cited works in Chapter 1.5 discuss real
                                        applications only. In addition to that, hundreds or even thousands of works annually
                                        discuss simulation results.
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References 31
References
                                          1. Aggelogiannaki, E., Sarimveis, H.: A simulated annealing algorithm for prioritized multiob-
                                             jective optimization–implementation in an adaptive model predictive control configuration.
                                             IEEE Transactions on Systems, Man and Cybernetics–Part B: Cybernetics 37, 902–915
                                             (2007)
                                          2. Åkesson, B.M., Toivonen, H.T., Waller, J.B., Nyström, R.H.: Neural network approximation
                                             of a nonlinear model predictive controller applied to a pH neutralization process. Computers
                                             & Chemical Engineering 29, 323–335 (2005)
                                          3. Akpan, V.A., Hassapis, G.D.: Nonlinear model identification and adaptive model predictive
                                             control using neural networks. ISA Transactions 50, 177–194 (2011)
                                          4. Al-Duwaish, H., Karim, M., Chandrasekar, V.: Use of multilayer feedforward neural net-
                                             works in identification and control of Wiener model. IEE Proceedings: Control Theory and
                                             Applications 143, 255–258 (1996)
                                          5. Al Seyab, R.K., Cao, Y.: Nonlinear model predictive control for the ALSTOM gasifier. Journal
                                             of Process Control 16, 795–808 (2006)
                                          6. Alcalá, E., Puig, V., Quevedo, J., Rosolia, U.: Autonomous racing using linear parameter
                                             varying-model predictive control (LPV-MPC). Control Engineering Practice 95, 104270
                                             (2020)
                                          7. Alexis, K., Nikolakopoulos, G., Tzes, A.: Switching model predictive attitude control for a
                                             quadrotor helicopter subject to atmospheric disturbances. ISA Transactions 19, 1195–1207
                                             (2011)
                                          8. Amos, B., Xu, L., Kolter, J.Z.: Input convex neural networks. In: Proceedings of the 34th
                                             International Conference on Machine Learning, pp. 146–155. Sydney, NSW, Australia (2017)
                                          9. Arahal, M.R., M., B., F., C.E.: Neural identification applied to predictive control of a solar
                                             plant. Control Engineering Practice 6, 333–344 (1998)
                                         10. Ascione, F., Bianco, N., De Stasio, C., Mauro, G.M., Vanoli, G.P.: Simulation-based model
                                             predictive control by the multi-objective optimization of building energy performance and
                                             thermal comfort. Energy and Buildings 111, 131–144 (2016)
                                         11. Assandri, A.D., de Prada, C., Rueda, A., Martínez, J.S.: Nonlinear parametric predictive
                                             temperature control of a distillation column. Control Engineering Practice 21, 1795–1806
                                             (2013)
                                         12. Bakhshande, F., Spiller, M., King, Y.L., Söffker, D.: Computationally efficient model predic-
                                             tive control for real time implementation experimentally applied on a hydraulic differential
                                             cylinder. IFAC-PapersOnLine 53, 8979–8984 (2020)
                                         13. Bartletta, R.A., Biegler, L.T., Backstromb, J., Gopal, V.: Quadratic programming algorithms
                                             for large-scale model predictive control. Journal of Process Control 12, 775–795 (2002)
                                         14. Bellemans, T., De Schutter, B., De Moor, B.: Model predictive control for ramp metering of
                                             motorway traffic: a case study. Control Engineering Practice 14, 757–767 (2006)
                                         15. Bemporad, A., Morari, M., Dua, V., Pistikopoulos, E.: The explicit linear quadratic regulator
                                             for constrained systems. Automatica 38, 3–20 (2002)
                                         16. Bemporad, A., Patrinos, P.: Simple and certifiable quadratic programming algorithms for
                                             embedded linear model predictive control. IFAC Proceedings Volumes 45, 14–20 (2012)
                                         17. Berenguel, M., Arahal, M.R., Camacho, E.F.: Modelling the free response of a solar plant for
                                             predictive control. Control Engineering Practice 6, 1257–1266 (1998)
                                         18. Blanco, E., de Prada, C., Cristea, S., Casas, J.: Nonlinear predictive control in the LHC
                                             accelerator. Control Engineering Practice 17, 1136–1147 (2009)
                                         19. Bosschaerts, W., Van Renterghem, T., Hasan, O.A., Limam, K.: Development of a model
                                             based predictive control system for heating buildings. Energy Procedia 122, 519–528 (2017)
                                         20. Byrd, R.H., Hribar, M.E., Nocedal, J.: An interior point algorithm for large-scale nonlinear
                                             programming. SIAM Journal on Optimization 9, 877–900 (1999)
                                         21. Cagienard, R., Grieder, P., Kerrigan, E.C., Morari, M.: Move blocking strategies in receding
                                             horizon control. In: Proceedings of the 43rd IEEE Conference on Decision and Control (CDC
                                             2004), pp. 2023–2028. Nassau, Bahamas (2004)
               hange E                                                                                                                                      hange E
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                                or
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                           !
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                        W
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                       O
                                                                                                                                                                    O
                       N
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                   Y
                                                                                                                                                                Y
                   U
                                                                                                                                                                U
               B
                                                                                                                                                            B
            to
                                                                                                                                                         to
          k
                                                                                                                                                       k
     lic
                                                                                                                                                  lic
ww
                                                                                                                                             ww
                                om
                                                                                                                                                                             om
     C
                                                                                                                                                  C
 w                                  c                                                                                                         w                                  c
     .p
          d f- x            e.                                                                                                                    .p
                                                                                                                                                       d f- x            e.
                   chang                                                                                                                                        chang
                                        22. Castañeda, L.Á., Guzman-Vargas L. Chairez, I., Luviano-Juárez, A.: Output based bilateral
                                            adaptive control of partially known robotic systems. Control Engineering Practice 98, 104362
                                            (2020)
                                        23. Cervantes, A.L., Agamennoni, O.E., Figueroa, J.L.: A nonlinear model predictive control
                                            system based on Wiener piecewise linear models. Journal of Process Control 13, 655–666
                                            (2003)
                                        24. Chaber, P., Ławryńczuk, M.: Fast analytical model predictive controllers and their implemen-
                                            tation for STM32 ARM microcontroller. IEEE Transactions on Industrial Informatics 15,
                                            4580–4590 (2019)
                                        25. Chen, L., Du, S., He, Y., Liang, M., Xu, D.: Robust model predictive control for greenhouse
                                            temperature based on particle swarm optimization. Information Processing in Agriculture 5,
                                            329–338 (2018)
                                        26. Chen, Y., Shi, Y., Zhang, B.: Optimal control via neural networks: a convex approach. In:
                                            Proceedings of the International Conference on Learning Representations. New Orleans, USA
                                            (2019)
                                        27. Clarke, D.W., Mohtadi, C., Tuffs, P.S.: Generalized predictive control–part i. the basic algo-
                                            rithm. Automatica 23, 137–148 (1987)
                                        28. Colin, G., Chamaillard, Y., Bloch, G., Corde, G.: Neural control of fast nonlinear systems–
                                            application to a turbocharged SI engine with VCT. IEEE Transactions on Neural Networks
                                            18, 1101–1114 (2007)
                                        29. Cutler, C.R., Ramaker, B.L.: Dynamic matrix control–a computer control algorithm. In:
                                            Proceedings of the AIChE National Meeting. Houston, Texas, USA (1979)
                                        30. D., D., D., C.: A practical multiple model adaptive strategy for single-loop MPC. Control
                                            Engineering Practice 11, 141–159 (2003)
                                        31. Deng, H., Ohtsuka, T.: A parallel newton-type method for nonlinear model predictive control.
                                            Automatica 109, 108560 (2019)
                                        32. Desaraju, V.R., Nathan, M.: Leveraging experience for computationally efficient adaptive non-
                                            linear model predictive control. In: Proceedings of the 2017 IEEE International Conference
                                            on Robotics and Automation (ICRA 2017), pp. 5314–5320. Singapore (2017)
                                        33. Diehl, M., Bock, H.G., Schlöder, J.P., Findeisen, R., Nagy, Z., Allgöwer, F.: Real-time op-
                                            timization and nonlinear model predictive control of processes governed by differential-
                                            algebraic equations. Journal of Process Control 12, 577–585 (2002)
                                        34. Diehl, M., Ferreau, H.J., Haverbeke, N.: Efficient numerical methods for nonlinear mpc and
                                            moving horizon estimation. In: L. Magni, D.M. Raimondo, F. Allgöwer (eds.) Nonlinear
                                            model predictive control, Lecture Notes in Control and Information Sciences, vol. 384, pp.
                                            391–417. Springer, Berlin, Heidelberg (2009)
                                        35. Ding, B., Ping, X.: Dynamic output feedback model predictive control for nonlinear systems
                                            represented by Hammerstein-Wiener model. Journal of Process Control 22, 1773–1784
                                            (2012)
                                        36. Domański, P.D.: Control Performance Assessment: Theoretical Analyses and Industrial Prac-
                                            tice, Studies in Systems, Decision and Control, vol. 245. Springer, Cham (2020)
                                        37. Domański, P.D.: Performance assessment of predictive control—A survey. Algorithms 13,
                                            97 (2020)
                                        38. Domański, P.D., Ławryńczuk, M.: Assessment of predictive control performance using fractal
                                            measures. Nonlinear Dynamics 89, 773–790 (2017)
                                        39. Domański, P.D., Ławryńczuk, M.: Assessment of the GPC control quality using non-gaussian
                                            statistical measures. International Journal of Applied Mathematics and Computer Science
                                            27, 291–307 (2017)
                                        40. Domański, P.D., Ławryńczuk, M.: Control quality assessment for processes with asymmetric
                                            properties and its application to pH reactor. IEEE Access 8, 94535–94546 (2020)
                                        41. Domański, P.D., Ławryńczuk, M.: Multi-criteria control performance assessment method for
                                            a multivariate MPC. In: Proceedings of the American Control Conference (ACC 2020), pp.
                                            1968–1973. Denver, Colorado, USA (2020)
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                   Y
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               B
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            to
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                                                                                                                                                    lic
ww
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                                om
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     C
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 w                                  c                                                                                                           w                                  c
     .p
          d f- x            e.                                                                                                                      .p
                                                                                                                                                         d f- x            e.
                   chang                                                                                                                                          chang
References 33
                                         42. Domański, P.D., Ławryńczuk, M.: Quality assessment of nonlinear model predictive control
                                             using fractal and entropy measures. In: W. Lacarbonara, B. Balachandran, J. Ma, J. Tenreiro
                                             Machado, G. Stepan (eds.) Nonlinear Dynamics and Control, pp. 147–156. Springer, Cham
                                             (2020)
                                         43. Domek, S.: Switched state model predictive control of fractional-order nonlinear discrete-time
                                             systems. Asian Journal of Control 15, 658–668 (2013)
                                         44. Domek, S.: Fractional-order model predictive control with small set of coincidence points.
                                             In: K. Latawiec, M. Łukaniszyn, R. Stanisławski (eds.) Advances in Modelling and Control of
                                             Non-integer-Order Systems, Lecture Notes in Electrical Engineering, vol. 320, pp. 135–144.
                                             Springer, Cham (2015)
                                         45. Domek, S.: Model-plant mismatch in fractional order model predictive control. In: S. Domek,
                                             P. Dworak (eds.) Theoretical Developments and Applications of Non-Integer Order Systems,
                                             Lecture Notes in Electrical Engineering, vol. 357, pp. 281–291. Springer, Cham (2016)
                                         46. Domek, S.: Switched fractional state-space predictive control methods for non-linear frac-
                                             tional systems. In: A.B. Malinowska, D. Mozyrska, Ł. Sajewski (eds.) Advances in Non-
                                             Integer Order Calculus and Its Applications, Lecture Notes in Electrical Engineering, vol.
                                             3559, pp. 113–127. Springer, Cham (2020)
                                         47. Doncevic, D.T., Schweidtmann, A.M., Vaupel, Y., Schäfer, P., Caspari, A., Mitsos, A.: Deter-
                                             ministic global nonlinear model predictive control with recurrent neural networks embedded.
                                             IFAC-PapersOnLine 53, 5273–5278 (2020)
                                         48. Ellis, M., Christofides, P.D.: On finite-time and infinite-time cost improvement of economic
                                             model predictive control for nonlinear systems. Automatica 50, 2561–2569 (2014)
                                         49. Ellis, M., Durand, H., Christofides, P.D.: A tutorial review of economic model predictive
                                             control methods. Journal of Process Control 24, 1156–1178 (2014)
                                         50. Engell, S.: Feedback control for optimal process operation. Journal of Process Control 17,
                                             203–219 (2007)
                                         51. Englert, T., Graichen, K.: Nonlinear model predictive torque control and setpoint computation
                                             of induction machines for high performance applications. Control Engineering Practice 99,
                                             104415 (2016)
                                         52. Ferreau, H.J., Kirches, C., Potschka, A., Bock, H.G., Diehl, M.: qpOASES: a parametric
                                             active-set algorithm for quadratic programming. Mathematical Programming Computation
                                             6, 327–363 (2014)
                                         53. Frasch, J.V., Sager, S., Diehl, M.: A parallel quadratic programming method for dynamic
                                             optimization problems. Mathematical Programming Computatione 7, 289–329 (2015)
                                         54. Fruzzetti, K.P., Palazoğlu, A., A., M.K.: Nonlinear model predictive control using Hammer-
                                             stein models. Journal of Process Control 7, 31–41 (1997)
                                         55. Gallego, A.J., Merello, G.M., Berenguel, M., Camacho, E.F.: Gain-scheduling model predic-
                                             tive control of a Fresnel collector field. Control Engineering Practice 82, 1–13 (2019)
                                         56. Gorni, D., del Mar Castilla, M., Visioli, A.: An efficient modelling for temperature control of
                                             residential buildings. Building and Environment 103, 86–98 (2016)
                                         57. Grancharova, A., Johansen, T.A.: Explicit Nonlinear Model Predictive Control, Lecture Notes
                                             in Control and Information Sciences, vol. 429. Springer, Berlin (2012)
                                         58. Griffith, D.W., Biegler, L.T., Patwardhan, S.C.: Robustly stable adaptive horizon nonlinear
                                             model predictive control. Journal of Process Control 70, 109–122 (2018)
                                         59. Gruber, J.K., Doll, M., Bordons, C.: Design and experimental validation of a constrained mpc
                                             for the air feed of a fuel cell. Control Engineering Practice 17, 874–885 (2009)
                                         60. Gruber, J.K., Guzmán, J.L., Rodríguez, F., Bordons, C., Berenguel, M., Sánchez, J.A.: Non-
                                             linear mpc based on a Volterra series model for greenhouse temperature control using natural
                                             ventilation. Control Engineering Practice 19, 354–366 (2011)
                                         61. Gutiérrez-Urquídez, R.C., Valencia-Palomo, G., Rodríguez-Elias, O.M., Trujillo, L.: System-
                                             atic selection of tuning parameters for efficient predictive controllers using a multiobjective
                                             evolutionary algorithm. Applied Soft Computing 31, 326–338 (2015)
                                         62. Havlena, V., Findejs, J.: Application of model predictive control to advanced combustion
                                             control. Control Engineering Practice 13, 671–680 (2005)
               hange E                                                                                                                                          hange E
          XC               di                                                                                                                              XC               di
     F-                         t                                                                                                                     F-                         t
PD
                                                                                                                                                 PD
                                or
                                                                                                                                                                                 or
                           !
                                                                                                                                                                            !
                        W
                                                                                                                                                                         W
                       O
                                                                                                                                                                        O
                       N
                                                                                                                                                                        N
                   Y
                                                                                                                                                                    Y
                   U
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               B
                                                                                                                                                                B
            to
                                                                                                                                                             to
          k
                                                                                                                                                           k
     lic
                                                                                                                                                      lic
ww
                                                                                                                                                 ww
                                om
                                                                                                                                                                                 om
     C
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 w                                  c                                                                                                             w                                  c
     .p
          d f- x            e.                                                                                                                        .p
                                                                                                                                                           d f- x            e.
                   chang                                                                                                                                            chang
                                        63. Hong, M., Cheng, S.: Hammerstein-Wiener model predictive control of continuous stirred
                                            tank reactor. In: W. Hu (ed.) Electronics and Signal Processing, Lecture Notes in Electric
                                            Engineering, vol. 97, pp. 235–242. Springer, Berlin, Heidelberg (2011)
                                        64. Hosen, M.A., Hussain, M.A., Mjalli, F.S.: Control of polystyrene batch reactors using neural
                                            network based model predictive control (NNMPC): An experimental investigation. Control
                                            Engineering Practice 19, 454–467 (2011)
                                        65. Huyck, B., De Brabanter, J., De Moor, B., Van Impe, J.F., Logist, F.: Online model predictive
                                            control of industrial processes using low level control hardware: A pilot-scale distillation
                                            column case study. Control Engineering Practice 28, 34–48 (2014)
                                        66. Incremona, G.P., Messori, M., Toffanin, C., Cobelli, C., Magni, L.: Model predictive control
                                            with integral action for artificial pancreas. Control Engineering Practice 77, 86–94 (2019)
                                        67. Jalali, M., Hashemi, E., Khajepour, A., Chen, S.K., Litkouhi, B.: Model predictive control of
                                            vehicle roll-over with experimental verification. Control Engineering Practice 77, 256–266
                                            (2018)
                                        68. Jalali, M., Khajepour, A., Chen, S.K., Litkouhi, B.: Integrated stability and traction control for
                                            electric vehicles using model predictive control. Control Engineering Practice 54, 256–266
                                            (2016)
                                        69. Jama, M., Wahyudie, A., Noura, H.: Robust predictive control for heaving wave energy
                                            converters. Control Engineering Practice 77, 138–149 (2018)
                                        70. Jia, L., Li, Y., Li, F.: Correlation analysis algorithm-based multiple-input single-output Wiener
                                            model with output noise. Complexity p. 9650254 (2019)
                                        71. Johansen, T.A.: Approximate explicit receding horizon control of constrained nonlinear sys-
                                            tems. Automatica 40, 293–300 (2004)
                                        72. Jungers, R.M., Tabuada, P.: Non-local linearization of nonlinear differential equations via
                                            polyflows. In: Proceedings of the American Control Conference (ACC 2019), pp. 1906–1911.
                                            Philadelphia, Pensylwania, USA (2019)
                                        73. Kaleli, A.: Development of the predictive based control of an autonomous engine cooling
                                            system for variable engine operating conditions in SI engines: design, modeling and real-time
                                            application. Control Engineering Practice 100, 104424 (2020)
                                        74. Kawathekar, R., Riggs, J.B.: Nonlinear model predictive control of a reactive distillation
                                            column. Control Engineering Practice 15, 231–239 (2007)
                                        75. Khan, B., Rossiter, J.A.: Alternative parameterisation within predictive control: a systematic
                                            selection. International Journal of Control 86, 1397–1409 (2013)
                                        76. Kim, J., Jung, Y., Bang, H.: Linear time-varying model predictive control of magnetically
                                            actuated satellites in elliptic orbits. Acta Astronautica 151, 791–804 (2018)
                                        77. Klaučo, M., Kalúz, M., Kvasnica, M.: Machine learning-based warm starting of active set
                                            methods in embedded model predictive control. Engineering Applications of Artificial Intel-
                                            ligence 77, 1–8 (2019)
                                        78. Kögel, M., Findeisen, R.: A fast gradient method for embedded linear predictive control.
                                            IFAC Proceedings Volumes 44, 1362–1367 (2011)
                                        79. Koopman, B.: Hamiltonian systems and transformation in Hilbert space. Proceedings of the
                                            National Academy of Sciences of the United States of America 17, 315–318 (1931)
                                        80. Koopman, B., von Neuman, J.: Dynamical systems of continuous spectra. Proceedings of the
                                            National Academy of Sciences of the United States of America 18, 255–263 (1932)
                                        81. Korbicz, J., Kościelny, J.M., Kowalczuk, Z.: Fault diagnosis: models, artificial intelligence,
                                            applications. Springer, Heidelberg (2004)
                                        82. Korda, M., Mezić, I.: Linear predictors for nonlinear dynamical systems: Koopman operator
                                            meets model predictive control. Automatica 93, 149–160 (2018)
                                        83. Kościelny, J.M.: Fault Diagnosis of Automated Industrial Processes. Academic Publishing
                                            House EXIT, Warsaw (2001). In Polish
                                        84. Lasheen, A., Saad, M.S., Emara, H.M., Elshafei, A.L.: Continuous-time tube-based explicit
                                            model predictive control for collective pitching of wind turbine. Energy 118, 1222–1233
                                            (2017)
               hange E                                                                                                                                        hange E
          XC               di                                                                                                                            XC               di
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                           !
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                        W
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                       O
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                       N
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                   Y
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                   U
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               B
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            to
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 w                                  c                                                                                                           w                                  c
     .p
          d f- x            e.                                                                                                                      .p
                                                                                                                                                         d f- x            e.
                   chang                                                                                                                                          chang
References 35
                                         85. Ławryńczuk, M.: A family of model predictive control algorithms with artificial neural
                                             networks. International Journal of Applied Mathematics and Computer Science 17, 217–232
                                             (2007)
                                         86. Ławryńczuk, M.: Neural Dynamic Matrix Control algorithm with disturbance compensation.
                                             In: N. García Pedrajas, F. Herrera, C. Fyfe, J.M. Benítez, A. M. (eds.) Proceedings of the
                                             23th International Conference on Industrial, Engineering & Other Applications of Applied
                                             Intelligent Systems (IEA-AIE 2010), Cordoba, Spain, Lecture Notes in Artificial Intelligence,
                                             vol. 6098, pp. 52–61. Springer, Berlin (2010)
                                         87. Ławryńczuk, M.: Nonlinear predictive control based on multivariable neural Wiener models.
                                             In: A. Dobnikar, U. Lotrič, B. Šter (eds.) Proceedings of the 10th International Conference on
                                             Adaptive and Natural Computing Algorithms (ICANNGA 2011), Lecture Notes in Computer
                                             Science, vol. 6593, pp. 31–40. Springer, Berlin (2011)
                                         88. Ławryńczuk, M.: On improving accuracy of computationally efficient nonlinear predictive
                                             control based on neural models. Computers Engineering Science 66, 5253–5267 (2011)
                                         89. Ławryńczuk, M.: On-line set-point optimisation and predictive control using neural Ham-
                                             merstein models. Chemical Engineering Journal 166, 269–287 (2011)
                                         90. Ławryńczuk, M.: Predictive control of a distillation column using a control-oriented neural
                                             model. In: A. Dobnikar, U. Lotrič, B. Šter (eds.) Proceedings of the 10th International
                                             Conference on Adaptive and Natural Computing Algorithms (ICANNGA 2011), Lecture
                                             Notes in Computer Science, vol. 6593, pp. 230–239. Springer, Berlin (2011)
                                         91. Ławryńczuk, M.: Computationally Efficient Model Predictive Control Algorithms: a Neural
                                             Network Approach, Studies in Systems, Decision and Control, vol. 3. Springer, Cham (2014)
                                         92. Ławryńczuk, M.: Explicit nonlinear predictive control algorithms with neural approximation.
                                             Neurocomputing 129, 570–584 (2014)
                                         93. Ławryńczuk, M.: Nonlinear predictive control for Hammerstein-Wiener systems. ISA Trans-
                                             actions 55, 49–62 (2015)
                                         94. Ławryńczuk, M.: Modelling and predictive control of a neutralisation reactor using sparse
                                             support vector machine Wiener models. Neurocomputing 205, 311–328 (2016)
                                         95. Ławryńczuk, M.: Nonlinear predictive control of dynamic systems represented by Wiener-
                                             Hammerstein models. Nonlinear Dynamics 86, 1193–1214 (2016)
                                         96. Ławryńczuk, M.: Nonlinear predictive control of a boiler-turbine unit: A state-space approach
                                             with successive on-line model linearisation and quadratic optimisation. ISA Transactions 67,
                                             476–495 (2017)
                                         97. Ławryńczuk, M.: Constrained computationally efficient nonlinear predictive control of Solid
                                             Oxide Fuel Cell: Tuning, feasibility and performance. ISA Transactions 99, 270–289 (2020)
                                         98. Ławryńczuk, M.: Nonlinear model predictive control for processes with complex dynamics:
                                             a parameterisation approach using Laguerre functions. International Journal of Applied
                                             Mathematics and Computer Science 30, 35–46 (2020)
                                         99. Ławryńczuk, M., Ocłoń, P.: Model Predictive Control and energy optimisation in residential
                                             building with electric underfloor heating system. Energy 182, 1028–1044 (2019)
                                        100. Ławryńczuk, M., Söffker, D.: Wiener structures for modeling and nonlinear predictive control
                                             of proton exchange membrane fuel cell. Nonlinear Dynamics 95, 1639–1660 (2019)
                                        101. Ławryńczuk, M., Tatjewski, P.: Offset-free state-space nonlinear predictive control for Wiener
                                             systems. Information Sciences 511, 127–151 (2020)
                                        102. Li, S.E., Jia, Z., Li, K., Cheng, B.: Fast online computation of a model predictive controller
                                             and its application to fuel economy-oriented adaptive cruise control. IEEE Transactions on
                                             Industrial Informatics 16, 1199–1209 (2015)
                                        103. Li, Y., Shen, J., Lu, J.: Constrained model predictive control of a solid oxide fuel cell based
                                             on genetic optimization. Journal of Power Sources 196, 5873–5880 (2011)
                                        104. Ligthart, J.A.J., Poksawat, P., Wang, L., Nijmeijer, H.: Experimentally validated model pre-
                                             dictive controller for a hexacopter. IFAC-PapersOnLine 50, 4076–4081 (2017)
                                        105. Lima, P.F., Pereira, G.C., Mårtensson, J., Wahlberg, B.: Experimental validation of model
                                             predictive control stability for autonomous driving. Control Engineering Practice 81, 244–255
                                             (2018)
               hange E                                                                                                                                        hange E
          XC               di                                                                                                                            XC               di
     F-                         t                                                                                                                   F-                         t
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                                                                                                                                               PD
                                or
                                                                                                                                                                               or
                           !
                                                                                                                                                                          !
                        W
                                                                                                                                                                       W
                       O
                                                                                                                                                                      O
                       N
                                                                                                                                                                      N
                   Y
                                                                                                                                                                  Y
                   U
                                                                                                                                                                  U
               B
                                                                                                                                                              B
            to
                                                                                                                                                           to
          k
                                                                                                                                                         k
     lic
                                                                                                                                                    lic
ww
                                                                                                                                               ww
                                om
                                                                                                                                                                               om
     C
                                                                                                                                                    C
 w                                  c                                                                                                           w                                  c
     .p
          d f- x            e.                                                                                                                      .p
                                                                                                                                                         d f- x            e.
                   chang                                                                                                                                          chang
                                        106. Liu, G.P., Kadirkamanathan, V., Billings, S.A.: Predictive control for non-linear systems using
                                             neural networks. International Journal of Control 71, 1119–1132 (1998)
                                        107. Liu, S., Liu, J.: Economic model predictive control with extended horizon. Automatica 73,
                                             180–192 (2016)
                                        108. Liu, S., Sang, Y., Jin, H.: Robust model predictive control for stratospheric airships using
                                             LPV design. Control Engineering Practice 81, 231–243 (2018)
                                        109. Liu, S., Wang, J.: A simplified dual neural network for quadratic programming with its KWTA
                                             application. IEEE Transactions on Neural Networks 17, 1500–1510 (2006)
                                        110. Liu, Y., Ge, B., Abu-Rub, H., Sun, H., Peng, F.Z., Xue, Y.: Model predictive direct power
                                             control for active power decoupled single-phase quasi-Z-source inverter. IEEE Transactions
                                             on Industrial Informatics 12, 1550–1559 (2016)
                                        111. Lopez-Negrete, R., D’Amato, F.J., Biegler, L.T., Kumar, A.: Fast nonlinear model predictive
                                             control: Formulation and industrial process applications. Computers & Chemical Engineering
                                             51, 55–64 (2013)
                                        112. Maciejowski, J.: Predictive control with constraints. Prentice Hall, Harlow (2002)
                                        113. Maestre, J.M., Fernández, M.I., Jurado, I.: An application of economic model predictive
                                             control to inventory management in hospitals. Control Engineering Practice 71, 120–128
                                             (2018)
                                        114. Mahfouf, M., Linkens, D.A.: Non-linear generalized predictive control (NLGPC) applied to
                                             muscle relaxant anaesthesia. International Journal of Control 71, 239–257 (1998)
                                        115. Makarow, A., Keller, M., Rösmann, C., Bertram, T.: Model predictive trajectory set con-
                                             trol with adaptive input domain discretization. In: Proceedings of the American Control
                                             Conference (ACC 2018), pp. 3159–3164. Milwaukee, USA (2018)
                                        116. Martin, P.A., Odloak, D., Kassab, F.: Robust model predictive control of a pilot plant distil-
                                             lation column. Control Engineering Practice 21, 231–241 (2013)
                                        117. Martins, M.A.F., Odloak, D.: A robustly stabilizing model predictive control strategy of stable
                                             and unstable processes. Automatica 67, 132–143 (2016)
                                        118. Marusak, P.M.: Oeasily reconfigurable analytical fuzzy predictive controllers: Actuator faults
                                             handling. In: L. Kang, Z. Cai, X. Yan, Y. Liu (eds.) Advances in Computation and Intelligence,
                                             Lecture Notes in Computer Science, vol. 5370, pp. 396–405. Springer, Berlin, Heidelberg
                                             (2008)
                                        119. Marusak, P.M.: Advantages of an easy to design fuzzy predictive algorithm in control systems
                                             of nonlinear chemical reactors. Applied Soft Computing 9, 1111–1125 (2009)
                                        120. Marusak, P.M.: Application of fuzzy Wiener models in efficient MPC algorithms. In:
                                             M. Szczuka, M. Kryszkiewicz, S. Ramanna, R. Jensen, Q. Hu (eds.) Rough Sets and Cur-
                                             rent Trends in Computing, Lecture Notes in Artificial Intelligence, vol. 6086, pp. 669–677.
                                             Springer, Berlin, Heidelberg (2010)
                                        121. Marusak, P.M.: On prediction generation in efficient MPC algorithms based on fuzzy Ham-
                                             merstein models. In: L. Rutkowski, R. Scherer, R. Tadeusiewicz, L.A. Zadeh, J.M. Zurada
                                             (eds.) Artificial Intelligence and Soft Computing, Lecture Notes in Computer Science, vol.
                                             6113, pp. 136–143. Springer, Berlin, Heidelberg (2010)
                                        122. Marusak, P.M.: Efficient MPC algorithms based on fuzzy Wiener models and advanced meth-
                                             ods of prediction generation. In: L. Rutkowski, M. Korytkowski, R. Scherer, R. Tadeusiewicz,
                                             L.A. Zadeh, J.M. Zurada (eds.) Artificial Intelligence and Soft Computing, Lecture Notes in
                                             Computer Science, vol. 7267, pp. 292–300. Springer, Berlin, Heidelberg (2012)
                                        123. Marusak, P.M.: Numerically efficient fuzzy MPC algorithm with advanced generation of
                                             prediction—application to a chemical reactor. Algorithms 13, 143 (2020)
                                        124. Marusak, P.M.: Advanced construction of the dynamic matrix in numerically efficient fuzzy
                                             MPC algorithms. Algorithms 14, 25 (2021)
                                        125. Marusak, P.M.: A numerically efficient fuzzy MPC algorithms with fast generation of the
                                             control signal. International Journal of Applied Mathematics and Computer Science 31,
                                             59–71 (2021)
                                        126. Mattingley, J., Boyd, S.: CVXGEN: a code generator for embedded convex optimization.
                                             Optimization and Engineering 13, 1–27 (2012)
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References 37
                                        127. Mauroy, A., Mezić, I., Susuki, Y. (eds.): The Koopman Operator in Systems and Control: Con-
                                             cepts, Methodologies, and Applications, Lecture Notes in Control and Information Sciences,
                                             vol. 484. Springer, Cham (2020)
                                        128. Mayne, D.Q.: Model predictive control: Recent developments and future promise. Automatica
                                             50, 2967–2986 (2014)
                                        129. Mayne, D.Q., Rawlings, J.B., Rao, C.V., Scokaert, P.O.M.: Constrained model predictive
                                             control: Stability and optimality. Automatica 36, 789–814 (2000)
                                        130. Mu, J., Rees, D., Liu, G.P.: Advanced controller design for aircraft gas turbine engines.
                                             Control Engineering Practice 13, 1001–1015 (2005)
                                        131. Mulas, M., Tronci, S., Corona, F., Haimi, H., Lindell, P., Heinonen, M., Vahala, R., Baratti, R.:
                                             Predictive control of an activated sludge process: An application to the Viikinmäki wastewater
                                             treatment plant. Control Engineering Practice 35, 89–100 (2015)
                                        132. Müller, M.A., Grüne, L.: Economic model predictive control without terminal constraints for
                                             optimal periodic behavior. Automatica 70, 128–139 (2016)
                                        133. Norquay, S.J., Palazoğlu, A., Romagnoli, J.A.: Model predictive control based on Wiener
                                             models. Chemical Engineering Science 53, 75–84 (2016)
                                        134. Norquay, S.J., Palazoğlu, A., Romagnoli, J.: Application of wiener model predictive control
                                             (WMPC) to an industrial C2 splitter. Journal of Process Control 9, 461–473 (1999)
                                        135. Ntouskas, S., Sarimveis, H., Sopasakis, P.: Model predictive control for offset-free reference
                                             tracking of fractional order systems. Control Engineering Practice 71, 26–33 (2018)
                                        136. Ogonowski, S., Bismor, D., Ogonowski, Z.: Control of complex dynamic nonlinear loading
                                             process for electromagnetic mill. Archives of Control Sciences 30, 471–500 (2020)
                                        137. Oliveira, G.H.C., da Rosa, A., Campello, R.J.G.B., Machado, J.B., Amaral, W.C.: An intro-
                                             duction to models based on Laguerre, Kautz and other related orthonormal functions – part
                                             I: linear and uncertain models. International Journal of Modelling, Identification and Control
                                             14, 121–132 (2011)
                                        138. Oliveira, G.H.C., da Rosa, A., Campello, R.J.G.B., Machado, J.B., Amaral, W.C.: An intro-
                                             duction to models based on Laguerre, Kautz and other related orthonormal functions – part
                                             II: Non-linear models. International Journal of Modelling, Identification and Control 16,
                                             1–14 (2012)
                                        139. Ortega, J.G., Camacho, E.F.: Mobile robot navigation in a partially structured static environ-
                                             ment, using neural predictive control. Control Engineering Practice 4, 1669–1679 (1996)
                                        140. Pan, Y., Wang, J.: Nonlinear model predictive control using a recurrent neural network. In:
                                             Proceedings of the International Joint Conference on Neural Networks (IJCNN 2008), pp.
                                             2296–2301. Hong Kong (2008)
                                        141. Pan, Y., Wang, J.: Two neural network approaches to model predictive control. In: Proceedings
                                             of the American Control Conference (ACC 2008), pp. 1685–1690. Washington, USA (2008)
                                        142. Parisini, T., Zoppoli, R.: A receding-horizon regulator for nonlinear systems and a neural
                                             approximation. Automatica 31, 1443–1451 (1995)
                                        143. Pascual, J., Romera, J., Puig, V., Cembrano, G., Creus, R., Minoves, M.: Operational predictive
                                             optimal control of Barcelona water transport network. Control Engineering Practice 21,
                                             1020–1034 (2013)
                                        144. Patan, K.: Two stage neural network modelling for robust model predictive control. ISA
                                             Transactions 72, 56–65 (2018)
                                        145. Patan, K.: Robust and Fault-Tolerant Control: Neural-Network-Based Solutions, Studies in
                                             Systems, Decision and Control, vol. 197. Springer, Cham (2019)
                                        146. Patan, K., Korbicz, J.: Nonlinear model predictive control of a boiler unit: a fault tolerant
                                             control study. International Journal of Applied Mathematics and Computer Science 22,
                                             225–237 (2012)
                                        147. Patikirikorala, T., Wang, L., Colman, A., Han, J.: Hammerstein-Wiener nonlinear model
                                             based predictive control for relative QoS performance and resource management of software
                                             systems. Control Engineering Practice 20, 49–61 (2012)
                                        148. Porfírio, C., Odloak, D.: Optimizing model predictive control of an industrial distillation
                                             column. Control Engineering Practice 19, 1137–1146 (2011)
               hange E                                                                                                                                            hange E
          XC               di                                                                                                                                XC               di
     F-                         t                                                                                                                       F-                         t
PD
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                                or
                                                                                                                                                                                   or
                           !
                                                                                                                                                                              !
                        W
                                                                                                                                                                           W
                       O
                                                                                                                                                                          O
                       N
                                                                                                                                                                          N
                   Y
                                                                                                                                                                      Y
                   U
                                                                                                                                                                      U
               B
                                                                                                                                                                  B
            to
                                                                                                                                                               to
          k
                                                                                                                                                             k
     lic
                                                                                                                                                        lic
ww
                                                                                                                                                   ww
                                om
                                                                                                                                                                                   om
     C
                                                                                                                                                        C
 w                                  c                                                                                                               w                                  c
     .p
          d f- x            e.                                                                                                                          .p
                                                                                                                                                             d f- x            e.
                   chang                                                                                                                                              chang
                                        149. Potočnik, P., Grabec, I.: Nonlinear model predictive control of a cutting process. Neurocom-
                                             puting 43, 107–126 (2002)
                                        150. Pour, F.K., Puig, V., Ocampo-Martinez, C.: Multi-layer health-aware economic predictive
                                             control of a pasteurization pilot plant. International Journal of Applied Mathematics and
                                             Computer Science 28, 97–110 (2018)
                                        151. Powell, M.J.D.: A fast algorithm for nonlinearly constrained optimization calculations. In:
                                             G.A. Watson (ed.) Numerical Analysis, Lecture Notes in Mathematics, vol. 630, pp. 144–157.
                                             Springer, Dundee (1978)
                                        152. Qin, S.J., Badgwell, T.A.: A survey of industrial model predictive control technology. Control
                                             Engineering Practice 11, 733–764 (2003)
                                        153. Rao, C.V., Wright, S.J., Rawlings, J.B.: Application of interior-point methods to model
                                             predictive control. Journal of Optimization Theory and Applications 99, 723–757 (1998)
                                        154. Raut, A., Irdmousa, B.K., Shahbakhti, M.: Dynamic modeling and model predictive control
                                             of an rcci engine. Control Engineering Practice 81, 129–144 (2018)
                                        155. Reese, B.M., Collins, E.G.: A graph search and neural network approach to adaptive nonlinear
                                             model predictive control. Engineering Applications of Artificial Intelligence 55, 250–268
                                             (2016)
                                        156. Richalet, J., O’Donovan, D.: Predictive Functional Control: Principles and Industrial Appli-
                                             cations. Springer, London (2009)
                                        157. Richalet, J.A., Rault, A., Testud, J.L., Papon, J.: Model predictive heuristic control: application
                                             to an industrial processes. In: Proceedings of the AIChE National Meeting, vol. 14, pp. 413–
                                             428 (1979)
                                        158. Richter, S., Morari, M., Jones, C.N.: Towards computational complexity certification for
                                             constrained MPC based on Lagrange relaxation and the fast gradient method. In: Proceedings
                                             of the 2011 IEEE 50th Annual Conference on Decision and Control (CDC) and European
                                             Control Conference (ECC), pp. 5223–5229. Orlando, Florida, USA (2011)
                                        159. Rodrigues, M.A., Odloak, D.: An infinite horizon model predictive control for stable and
                                             integrating processes. Computers & Chemical Engineering 27, 1113–1128 (2003)
                                        160. Saeed, J., Hasan, A.: Unit prediction horizon binary search-based model predictive control
                                             of full-bridge DC-DC converter. IEEE Transactions on Control Systems Technology 26,
                                             463–474 (2018)
                                        161. Sarabia, D., Capraro, F., Larsen, L.F.S., de Prada, C.: Hybrid NMPC of supermarket display
                                             cases. Control Engineering Practice 17, 428–441 (2009)
                                        162. Saraswati, S., Chand, S.: Online linearization-based neural predictive control of air-fuel ratio
                                             in SI engines with PID feedback correction scheme. Neural Computing and Applications 19,
                                             919–933 (2010)
                                        163. Scattolini, R.: Architectures for distributed and hierarchical model predictive control – a
                                             review. Journal of Process Control 19, 723–731 (2009)
                                        164. Schweidtmann, A.M., Mitsos, A.: Deterministic global optimization with artificial neural
                                             networks embedded. Journal of Optimization Theory and Applications 180, 925–948 (2019)
                                        165. Scokaert, P.O.M., Mayne, D.Q., Rawlings, J.B.: Suboptimal model predictive control (feasi-
                                             bility implies stability). IEEE Transactions on Automatic Control 44, 648–654 (1999)
                                        166. Seki, H., Ogawa, M., Ooyama, S., Akamatsu, K., Ohshima, M., Yang, W.: Industrial applica-
                                             tion of a nonlinear model predictive control to polymerization reactors. Control Engineering
                                             Practice 9, 819–828 (2001)
                                        167. Seybold, L., Witczak, M., Majdziek, P., Stetter, R.: Towards robust predictive fault-tolerant
                                             control for a battery assembly unit. International Journal of Applied Mathematics and
                                             Computer Science 25, 849–862 (2015)
                                        168. Shafiee, G., M., A.M., Jahed-Motlagh, M.R., Jalali, A.A.: Nonlinear predictive control of
                                             a polymerization reactor based on piecewise linear Wiener model. Chemical Engineering
                                             Journal 143, 282–292 (2008)
                                        169. Sopasakis, P., Sarimveis, H.: Stabilising model predictive control for discrete-time fractional-
                                             order systems. Automatica 75, 24–31 (2017)
                                        170. Stadler, K.S., Poland, J., Gallestey, E.: Model predictive control of a rotary cement kiln.
                                             Control Engineering Practice 19, 1–9 (2011)
               hange E                                                                                                                                         hange E
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     .p
          d f- x            e.                                                                                                                       .p
                                                                                                                                                          d f- x            e.
                   chang                                                                                                                                           chang
References 39
                                        171. Stellato, B., Banjac, G., Goulart, P., Bemporad, A., Boyd, S.: OSQP: an operator splitting
                                             solver for quadratic programs. Mathematical Programming Computation (2020). In press
                                        172. Sturzenegger, D., Gyalistras, D., Morari, M., Smith, R.S.: Model predictive climate control of
                                             a Swiss office building: implementation, results, and cost–benefit analysis. IEEE Transactions
                                             on Control system technology 24, 1–12 (2016)
                                        173. Suh, J., Yi, K., Jung, J., Lee, K., Chong, H., Ko, B.: Design and evaluation of a model
                                             predictive vehicle control algorithm for automated driving using a vehicle traffic simulator.
                                             Control Engineering Practice 51, 256–266 (2016)
                                        174. Sun, J., Kolmanovsky, I.V., Ghaemi, R., Chen, S.: A stable block model predictive control
                                             with variable implementation horizon. Automatica 43, 1945–1953 (2007)
                                        175. Tahir, F., Mercer, E., Lowdon, I., Lovett, D.: Advanced process control and monitoring of a
                                             continuous flow micro-reactor. Control Engineering Practice 77, 225–234 (2018)
                                        176. Takács, G., Batista, G., Gulan, M., Rohal’-Ilkiv, B.: Embedded explicit model predictive
                                             vibration control. Mechatronics 36, 54–62 (2016)
                                        177. Tatjewski, P.: Advanced control of industrial processes, structures and algorithms. Springer,
                                             London (2007)
                                        178. Tatjewski, P.: DMC algorithm with Laguerre functions. In: A. Bartoszewicz, J. Kabziński,
                                             J. Kacprzyk (eds.) Advanced, Contemporary Control, Advances in Intelligent Systems and
                                             Computing, vol. 1196, pp. 1006–1017. Springer, Cham (2020)
                                        179. Tøndel, P., Johansen, T.A., Bemporad, A.: An algorithm for multi-parametric quadratic
                                             programming and explicit mpc solutions. Automatica 39, 489–497 (2003)
                                        180. Vaupel, Y., Hamacher, N.C., Caspari, A., Mhamdi, A., Kevrekidis, I.G., Mitsos, A.: Accel-
                                             erating nonlinear model predictive control through machine learning. Journal of Process
                                             Control 92, 261–270 (2020)
                                        181. Vega, P., Revollar, S., Francisco, M., Martın, J.M.: Integration of set point optimization tech-
                                             niques into nonlinear mpc for improving the operation of WWTPs. Computers & Chemical
                                             Engineering 68, 78–95 (2014)
                                        182. Vermillion, C., Menezes, A., Kolmanovsky, I.: Stable hierarchical model predictive control
                                             using an inner loop reference model and λ-contractive terminal constraint sets. Automatica
                                             50, 92–99 (2014)
                                        183. Vivas, A., Poignet, P.: Predictive functional control of a parallel robot. Control Engineering
                                             Practice 13, 863–874 (2005)
                                        184. Volk, U., Kniese, D.W., Hahn, R., Haber, R., Schmitz, U.: Optimized multivariable predictive
                                             control of an industrial distillation column considering hard and soft constraints. Control
                                             Engineering Practice 13, 913–927 (2005)
                                        185. Wahlberg, B.: System identification using Laguerre models. IEEE Transactions on Automatic
                                             Control 36, 551–562 (1991)
                                        186. Wang, L.: Continuous time model predictive control design using orthonormal functions.
                                             International Journal of Control 74, 1588–1600 (2001)
                                        187. Wang, L.: Discrete model predictive controller design using Laguerre functions. Journal of
                                             Process Control 14, 131–142 (2004)
                                        188. Wang, L.X., Wan, F.: Structured neural networks for constrained model predictive control.
                                             Automatica 37, 1235–1243 (2001)
                                        189. Wang, X., Mahalec, V., F., Q.: Globally optimal nonlinear model predictive control based on
                                             multi-parametric disaggregation. Journal of Process Control 52, 1–13 (2017)
                                        190. Wang, Y., Boyd, S.: Fast model predictive control using online optimization. IEEE Transac-
                                             tions on Control Systems Technology 18, 267–278 (2010)
                                        191. Wang, Y., Luo, L., Zhang, F., Wang, S.: GPU-based model predictive control for continuous
                                             casting spray cooling control system using particle swarm optimization. Control Engineering
                                             Practice 84, 349–364 (2019)
                                        192. Witczak, M.: Fault Diagnosis and Fault-Tolerant Control Strategies for Non-Linear Systems:
                                             Analytical and Soft Computing Approaches, Lecture Notes in Electrical Engineering, vol.
                                             266. Springer, Cham (2014)
                                        193. Wu, X., Zhu, X., Cao, G., Tu, H.: Predictive control of sofc based on a GA-RBF neural
                                             network model. Journal of Power Sources 179, 232–239 (2008)
               hange E                                                                                                                                                      hange E
          XC               di                                                                                                                                          XC               di
     F-                         t                                                                                                                                 F-                         t
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                           !
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                        W
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                       O
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                   Y
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                   U
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               B
                                                                                                                                                                            B
            to
                                                                                                                                                                         to
          k
                                                                                                                                                                       k
     lic
                                                                                                                                                                  lic
ww
                                                                                                                                                             ww
                                om
                                                                                                                                                                                             om
     C
                                                                                                                                                                  C
 w                                  c                                                                                                                         w                                  c
     .p
          d f- x            e.                                                                                                                                    .p
                                                                                                                                                                       d f- x            e.
                   chang                                                                                                                                                        chang
                                                    194. Xia, C., Liu, T., Shi, T., Song, Z.: A simplified finite-control-set model-predictive control for
                                                         power converters. IEEE Transactions on Industrial Informatics 10, 991–1002 (2014)
                                                    195. Yang, J., Li, X., Mou, H., Jian, L.: Predictive control of solid oxide fuel cell based on an
                                                         improved takagi-sugeno fuzzy model. Journal of Power Sources 193, 699–705 (2009)
                                                    196. Yang, S., Bequette, B.W.: Optimization-based control using input convex neural networks.
                                                         Computers & Chemical Engineering 144, 107143 (2020)
                                                    197. Yang, S., Wan, M.P., Ng, B.F., Zhang, T., Babu, S., Zhang, Z., Chen, W., Dubey, S.: A
                                                         state-space thermal model incorporating humidity and thermal comfort for model predictive
                                                         control in buildings. Energy and Buildings 170, 25–39 (2018)
                                                    198. Yu, D.L., Gomm, J.B.: Implementation of neural network predictive control to a multivariable
                                                         chemical reactor. Control Engineering Practice 11, 1315–1323 (2003)
                                                    199. Yu, Z., Biegler, L.T.: Advanced-step multistage nonlinear model predictive control: robustness
                                                         and stability. Journal of Process Control 85, 15–29 (2020)
                                                    200. Zhang, J., Chin, K.S., Ławryńczuk, M.: Multilinear model decomposition and predictive
                                                         dontrol of MIMO two-block cascade systems. Industrial & Engineering Chemistry Research
                                                         56, 14101–14114 (2017)
                                                    201. Zheng, A.: A computationally efficient nonlinear MPC algorithm. In: Proceedings of the
                                                         American Control Conference (ACC 1997), pp. 1623–1627. Albuquerque, New Mexico,
                                                         USA (1997)
                                                    202. Zheng, Y., Zhou, J., Xu, Y., Zhang, Y., Qian, Z.: A distributed model predictive control based
                                                         load frequency control scheme for multi-area interconnected power system using discrete-time
                                                         Laguerre functions. ISA Transactions 68, 127–140 (2017)
                                                    203. Zhou, F., Peng, H., Zeng, X., Tian, X., Peng, X.: RBF-ARX model-based robust MPC for
                                                         nonlinear systems with unknown and bounded disturbance. Journal of the Franklin Institute
                                                         354, 8072–8093 (2017)
                                                    204. Zhou, F., Peng, H., Zhang, G., Zeng, X.: A robust controller design method based on parameter
                                                         variation rate of RBF-ARX model. IEEE Access 7, 160284–160294 (2019)
                                                    205. Zhou, F., Peng, H., Zhang, G., Zeng, X., Peng, X.: Robust predictive control algorithm based
                                                         on parameter variation rate information of functional-coefficient ARX model. IEEE Access
                                                         7, 27231–27243 (2019)