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Laboratory Activity
8
Finals
Feedback and Control Systems
Submitted to:
Engr. Joey P. Sarmiento
Submitted by:
Monsalud, Robert Russell N.
February 26, 2019
%Monsalud_Exercise1_A_B_LA8
disp('Open Loop Transfer Function')
disp('Answer for letter a and b')
num = 5;
denum = [1 3 4 2];
transfunc = tf (num, denum) %G(s)H(s) (open loop transfer function)
nyquist(transfunc) %Nyquist Plot%
Open Loop Transfer Function
Answer for letter a and b
transfunc =
5
---------------------
s^3 + 3 s^2 + 4 s + 2
Continuous-time transfer function.
Published with MATLAB® R2016b
1
%Monsalud_Exercise1_B_C_LA8
disp('Open Loop Transfer Function')
disp('Answer for letter b and c')
num = 5;
denum = [1 3 4 2];
transfunc = tf (num, denum) %G(s)H(s) (open loop transfer function)
pzmap(transfunc) %P (number of open loop poles located at the RHP)
Open Loop Transfer Function
Answer for letter b and c
transfunc =
5
---------------------
s^3 + 3 s^2 + 4 s + 2
Continuous-time transfer function.
Published with MATLAB® R2016b
1
%Monsalud_Exercise1_F_LA8
disp('Closed Loop Transfer Function')
disp('Answer for letter f')
num = 5;
denum = [1 3 4 2];
transfunc = tf (num, denum)
feedback(transfunc, 1)
pzmap(feedback(transfunc, 1))
disp('Stability of the system = Stable')
Closed Loop Transfer Function
Answer for letter f
transfunc =
5
---------------------
s^3 + 3 s^2 + 4 s + 2
Continuous-time transfer function.
ans =
5
---------------------
s^3 + 3 s^2 + 4 s + 7
Continuous-time transfer function.
Stability of the system = Stable
1
Published with MATLAB® R2016b
2
%Monsalud_Exercise2_A_B_LA8
disp('Open Loop Transfer Function')
disp('Answer for letter a and b')
num = 20;
denum = [1 4 1 -6];
transfunc = tf (num, denum) %G(s)H(s) (open loop transfer function)
nyquist(transfunc) %Nyquist Plot%
Open Loop Transfer Function
Answer for letter a and b
transfunc =
20
-------------------
s^3 + 4 s^2 + s - 6
Continuous-time transfer function.
Published with MATLAB® R2016b
1
%Monsalud_Exercise2_B_C_LA8
disp('Open Loop Transfer Function')
disp('Answer for letter b and c')
num = 20;
denum = [1 4 1 -6];
transfunc = tf (num, denum) %G(s)H(s) (open loop transfer function)
pzmap(transfunc) %P (number of open loop poles located at the RHP)
Open Loop Transfer Function
Answer for letter b and c
transfunc =
20
-------------------
s^3 + 4 s^2 + s - 6
Continuous-time transfer function.
Published with MATLAB® R2016b
1
%Monsalud_Exercise2_F_LA8
disp('Closed Loop Transfer Function')
disp('Answer for letter f')
num = 20;
denum = [1 4 1 -6];
transfunc = tf (num, denum)
feedback(transfunc, 1)
pzmap(feedback(transfunc, 1))
disp('Stability of the system = Unstable')
Closed Loop Transfer Function
Answer for letter f
transfunc =
20
-------------------
s^3 + 4 s^2 + s - 6
Continuous-time transfer function.
ans =
20
--------------------
s^3 + 4 s^2 + s + 14
Continuous-time transfer function.
Stability of the system = Unstable
1
Published with MATLAB® R2016b
2
Conclusion:
Experiment 8 is about Frequency Response. Frequency Response is the dependence on signal
frequency of the output–input ratio of an amplifier or other device. Throughout the activity, the
Nyquist plot and pzmap plot of an open loop system have been performed. The pzmap plot of a
closed loop system is also identified. By using MATLAB, the frequency response of a system can
be determined through plot. Moreover, the stability of the system whether it is an open loop or
closed loop can be identified.
