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6.1 Automated systems

6.1.1 Sensors, microprocessors and actuators
An automated system is a combination of software and hardware that is designed and
programmed to work automatically without the need of any human intervention.

» Sensors are input devices that take readings from their surroundings and send this data to a
microprocessor or computer. If the data is analogue, it is first converted into a digital format by
an analogue-digital converter (ADC).

» The microprocessor will process the data and take the necessary action based on
programming.

» This will involve some form of output, usually involving signals sent to actuators to control
motors, wheels, solenoids, and so on.

6.1.2 Advantages and disadvantages of automated systems

Industrial applications
Example 1: A nuclear power station
A key use of automated systems is in the control and monitoring of a nuclear power station

At the centre of the system is a distributed control system (DCS).

DCS is essentially a powerful computer that has been programmed to monitor and control the
whole process with no human interaction required:
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1. Data from a number of sensors is sent to a DCS (computer) – if the data is analogue, it
must first be converted into digital format using an ADC.
2. The DCS will have access to a large database containing operational data and
parameters.
3. If any action needs to be taken, then signals will be sent to the appropriate actuators to
operate pumps, valves or even an emergency shutdown system.
4. The key here is that the system is fully automated. A human operator (the supervisor)
will sit in a remote control room where a schematic of the process will show on a large
screen.
5. While the process is fully automatic, the supervisor can still override the DCS and shut
down the process.

The main advantages of this automated system are:

» much faster than a human operator to take any necessary action

» much safer

» the process is more likely to run under optimum conditions since any small changes needed
can be identified very quickly and action taken

» in the long run, it is less expensive

The main disadvantages of this automated system are:

» expensive to set up in the first place and needs considerable testing

» always possible for a set of conditions to occur that were never considered during testing
which could have safety implications

» any computerised system is subject to cyberattacks no matter how good the system

» automated systems always need enhanced maintenance which can be expensive.

Example 2: Manufacture of paracetamol

1. This automated system also depends on sensors, a computer, actuators and software.
2. Process 1 is the manufacture of the paracetamol.
3. Process 2 is the making of the solid tablets.
4. Both processes are monitored by a number of sensors that send their data back to a
central computer.
5. The computer consults its database to ensure both processes are operating within
correct parameters.
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6. Any necessary action is taken by the computer, sending signals to the appropriate
actuator to operate pumps, valves, heaters, stirrers or pistons to ensure both processes
can operate without any human intervention.
7. Again, this system uses a remote monitoring station manned by an operator.
8. The system is fully automated, but the operator can override the central computer
system if necessary.

The main advantages of this automated system are:

» much faster than a human operator to take any necessary action

» much safer

» the process is more likely to run under optimum conditions since any small changes needed
can be identified very quickly and action taken

» in the long run, it is less expensive

» more efficient use of materials

» higher productivity

» more consistent results.

The main disadvantages of this automated system are:

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» expensive to set up in the first place and needs considerable testing

» always possible for a set of conditions to occur that were never considered during testing
which could have safety implications

» automated systems always need enhanced maintenance which can be expensive

» any computerised system is subject to cyberattacks no matter how good the

system.

Transport:
As with industrial processes, many of the automated systems in transport refer to robotic
systems.

Example 3: Self-parking cars

1. The driver goes along the row of parked cars.

2. On-board sensors and cameras gauge the size of any parking spaces, and the on-board
computer warns the driver if a suitable space has been found.
3. The driver then selects auto-parking and the on-board computer takes over.
4. Actuators are used to operate the steering rack, brakes and throttle under the full
control of the computer.
5. This allows the car in Figure 6.4 to go from Step 1 to Step 2 automatically and complete
the parking manoeuvre with no driver intervention.
6. Sensors in the bumpers of the car are both transmitters and receivers.
7. The sensors transmit signals that bounce off objects and are reflected back.
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8. The car’s on-board computer uses the amount of time it takes for the signal to return to
the sensor to calculate the position of any objects.
9. The sensors give the computer a 3D image of its surroundings.
10. This allows the car to fit into its parking space automatically with no driver intervention.

The main advantages of this automated system are:

» allows the same number of cars to use fewer parking spaces

» avoids traffic disruption in cities

» cars can fit into smaller spaces

» fewer dents and scratches to cars

» safer system since sensors monitor all objects, including young children

» very consistent results.

The main disadvantages of this automated system are:

» over-reliance on automated systems by the driver (loss of skills)

» faulty/dirty sensors or cameras can send false data/images to the on-board computer which
could lead to a malfunction

» kerbing of wheels is a common problem since the sensors may not pick-up low kerbs

» expensive option that doesn’t really save the driver any money

» requires additional maintenance to ensure it functions correctly at all times.

Example 4: Adaptive cruise control

1. The driver will set a cruising speed on his touch screen in the car.
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2. Lasers are used to send out signals constantly.
3. The lasers bounce off the vehicle in front of the car and are reflected back to the car’s
sensors.
4. The time taken for the signal to bounce back is used by the on-board computer to
calculate the distance between the two vehicles.
5. If the car is getting too close to the vehicle in front, the computer will send signals to
slow the car down.
6. This is done by actuators applying the brakes and/or reducing the throttle.
7. If the distance between vehicles is greater than the safe distance, the computer will
check to see if the current speed equals the value set by the driver.
8. If the speed is different to the set speed, the computer sends signals to the actuators to
increase or decrease the throttle.

Agriculture
There are many examples of the use of automated systems in agriculture. Again, many of the
systems involve robotics.
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Example 5: Automated system used in the Brazil irrigation system

1. The watering of crops (irrigation) is fully automatic and also involves considerable
amounts of wireless transmission.
2. This allows the system to be used in very remote areas that are vast in size – some of the
fields are more than 10 km2 in area.
3. Data from an automatic weather station is received by the controller every ten minutes.
4. This is particularly important if very wet or very dry conditions are being predicted or
detected by the weather station.
5. Ultrasonic water level sensors are used in the crop fields that measure the amount of
water in the irrigation channels.
6. The sensors send their data back via wireless transmitters.
7. This data is then picked up by the wireless receiver, which sends the data back to the
controller.
8. The controller then uses this data, together with the data from the weather station, to
decide whether it is necessary to stop or start a series of water pumps.
9. This is done by sending signals to actuators, which operate the pumps.
10. Although the whole system is fully automatic, a supervisor still monitors the process
remotely.
11. Using a schematic of a number of processes on a computer screen and via internet links
to the controllers, the supervisor can oversee several irrigation processes from one
central point.
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12. If the supervisor wishes to further increase or reduce the water supply in any of the
irrigation systems, they can override the controller if necessary.

The main advantages of this automated system are:

1. reduced labour costs since the system only needs a supervisor to monitor vast areas
2. better and more efficient control of the irrigation process
3. better control of precious resources, such as water
4. faster response than a human having to manually check many kilometres of irrigation
channels
5. safer
6. different crops may require different irrigation requirements it is possible to program the
controllers so that different growing conditions can be maintained simultaneously.

The main disadvantages of this automated system are:

1. expensive to set up initially
2. very high maintenance costs are associated with automated systems
3. increased need to maintain the water channels to ensure the system works correctly at
all times

Weather (stations):
Automated weather stations are designed to save labour and to gather information from
remote regions or where constant weather data is a requirement.

Automated weather stations require a microprocessor, storage (database), battery (usually with
solar-powered charging) and a range of sensors:

» thermometer (to measure temperature)

» anemometer (to measure wind speed)

» hygrometer (to measure humidity)

» barometer (to measure air pressure)

» level sensor (to measure rain fall)

» light sensor (to measure hours of daylight).

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1. The data from sensors is all sent to a microprocessor; any calculations are then done.
2. The data from the sensors and the calculated values are then stored on a central
database.
3. Some automated weather stations are sited near airports, where reports are sent out
automatically every five minutes to pilots in the vicinity of the airport.
4. The only part of the weather station that needs to use actuators is the ‘tipping bucket
rain gauge’.
5. At a pre-determined time interval, a signal is sent from the microprocessor to an
actuator to operate a piston, which tips a bucket that was collecting rain water.
6. The water is tipped into a vessel where level sensors are then used to measure the
amount of rainfall that fell during the required time interval.
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Gaming
Gaming devices involve sensors to give a degree of realism to games:

» accelerometers

» proximity sensors

Embedded accelerometers and proximity sensors (together with a microcontroller) in games

consoles allow increased human interaction with the game. This allows players to take actions
that simulate real events happening, giving a more immersive games experience.

Lighting
» light sensors (to automatically switch lights on or off depending on the ambient lighting)

» motion sensors (to automatically turn lights on in a room when somebody enters)

» infrared sensors (to be used either as a motion detector or as part of the security system).

The example we will consider here is used in a house:

» where lights in the garden are turned on automatically when someone enters the garden or it
turns dark

» where a lighting show is part of a microprocessor-controlled water fountain display; the

lighting only comes on when it becomes dark.

Example 6: Lighting system in a house

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1. As it becomes dark, the light sensor value will change, and the microprocessor will send
signals to the interface to control the array of LED lights around the garden.
2. Data from the infrared sensor would also be used (during day and night) as a security
device whenever the house is unoccupied.
3. Also, as it becomes dark, the lighting show in the fountain could also be initiated.
4. This could involve a pre-programmed display involving changing colours under the
control of the microprocessor.
5. The fountain display itself will also be under microprocessor control with signals being
sent to actuators to turn water pumps on and off according to the installed program.
6. The whole system will be fully automated.

The main advantages of this automated system are:

» it is possible to control light sources automatically

» a reduced energy consumption

» wireless connections can be chosen which are much safer

» longer bulb life

» possible to program new light displays for various occasions.

The main disadvantages of this automated system are:

» expensive to set the system up in the first place

» if wireless connections chosen, they can be less reliable than wired systems

» to ensure consistent performance, the automated system will require more maintenance.

Science
Automated systems in scientific research are widely used.

Example 7: Chemical process in a laboratory

1. Imagine an experiment in a pharmaceutical laboratory where two chemicals are reacted
together in a vessel.
2. One of the chemicals is being added from a piece of equipment (‘A’) known as a burette
to a reaction vessel (‘B’).
3. Once the reaction is complete, it turns a bright orange colour (see Figure 6.11).
4. The whole process is under microprocessor control:
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5. The level sensors measure how much liquid is being added from ‘A’; this data is sent to a
microprocessor.
6. Readings are also sent to the microprocessor from a colorimeter next to vessel ‘B’.
7. The microprocessor controls the opening and closing of the tap in ‘A’; this is done by
sending signals to an actuator that operates the tap.
8. This means the microprocessor has automatic control of the experiment with no human
interaction needed.
9. This type of automated system is of great benefit to pharmaceutical companies when
developing new drugs and vaccines.

The main advantages of this automated system are:

» more consistent results

» less dangerous

» faster results

» automatic analysis of the results is possible

» fewer highly trained staff needed for each experiment

» results/experiments can be monitored anywhere in the world in real time.

The main disadvantages of this automated system are:

» less flexible than when using human technicians
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» security risks are always present if the data is being shared globally

» equipment can be expensive to buy and set up in the first place.

Finally, there are many automated systems being used in both industry and

scientific research that incorporate artificial intelligence (AI). It is therefore

worth considering the generic advantages of using AI in these automated

systems:

» ability to access and store vast amounts of facts (very important in research)

» they are able to learn from huge amounts of available data that would

overwhelm humans

» they are able to see patterns in results that could be missed by humans.

While all of this is positive, there are a few disadvantages in this approach:

» a change in skills set

» AI is dependent on the data which trains it.

6.2 Robotics
6.2.1 What is robotics?
Robotics is a branch of (computer) science that brings together the design, construction and
operation of robots.

Isaac Asimov even composed his three laws of robotics:

1. a robot may not injure a human through action or inaction
2. a robot must obey orders given by humans, unless it comes into conflict with law 1
3. a robot must protect itself, unless this conflicts with law 1.

Robots can be found in:

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» factories
– welding parts together
– spray-painting panels on a car
– fitting windscreens to cars
– cutting out metal parts to a high precision
– bottling and labelling plants
– warehouses (automatic location of items)

» in the home
– autonomous floor sweepers (see Figure
6.13)
– autonomous lawn mower
– ironing robots
– pool cleaning
– automatic window cleaners
– entertainment (‘friend’ robots)

» drones
– unmanned aerial vehicles (UAVs) are
drones that are either remotely controlled
or totally autonomous using embedded
systems
– can be used in reconnaissance (for
example, taking aerial photographs)
– can be used to make parcel deliveries

6.2.2 Characteristics of a robot

1. Ability to sense their surroundings
2. Have a degree of movement
3. Programmable
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It is important to realize that robotics and artificial intelligence (AI) are almost two entirely
different field.

TWO IMPORTANT NOTES:

1. Many robots don’t possess artificial intelligence (AI) since they tend to do repetitive
tasks rather than requiring adaptive human characteristics.

2. It is important not to confuse physical robots with software robots such as:

– search engine bots or WebCrawlers (these ‘robots’ roam the internet scanning websites,
categorising them for search purposes)

– chat bots (these are programs that pop up on websites that seem to enter some form of
conversation with the web user)

According to our definition above, software robots are not true robots.

Physical robots can be classified as independent or dependent:

» Independent robots:
– have no direct human control

– can replace the human activity totally

» Dependent robots:
– have a human who is interfacing directly with the robot

– can supplement, rather than totally replace, the human activity

6.2.3 The role of robots and their advantages and disadvantages

We will now consider the use of robots in a number of areas, together with the advantages and
disadvantages of using robots in each of these areas:

» industry

» transport

» agriculture

» medicine

» domestic (home) use

» entertainment.
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Industry

Advantages Disadvantages
robots are capable of working in conditions robots can find it difficult to do ‘non-
that may be hazardous to humans standard’ tasks
robots are less expensive in the long run robots can lead to higher manual labour tasks
robots are more productive than humans there is a risk of deskilling when robots take
over certain tasks
robots are better suited to boring, repetitive factories can now be moved to anywhere in
tasks than humans the world where operation costs are lower
there will be less cost in heating and lighting robots are expensive to buy and set up in the
first place

Transport

Advantages of autonomous vehicles Disadvantages of autonomous vehicles

safer since human error is removed leading very expensive system to set up in the first
to fewer accidents place
better for the environment since vehicles will the ever-present fear of hacking into the
operate more efficiently vehicle’s control system
increased lane capacity security and safety issues
reduced travel times driver and passenger reluctance to use the
new technology
stress-free parking for motorists reduction in the need for taxis could lead to
unemployment

Autonomous trains

Advantages of autonomous trains Disadvantages of autonomous trains

this improves the punctuality of the trains the ever-present fear of hacking into the
vehicle’s control system
reduced running costs system doesn’t work well with very busy
services
improves safety since human error is high capital costs and operational costs
removed initially
it is possible to increase the frequency of passenger reluctance to use the new
trains technology
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Autonomous (unpiloted) airplanes:
Some of the main features of a control system on

a pilotless airplane would include:

» sensors to detect turbulence to ensure smooth flights

» an increase in self-testing of all circuits and systems

» sensors that would automatically detect depressurisation in the cabin; thus allowing for quick
stabilisation of the airplane

» use of GPS for navigation and speed calculations

» use of actuators to control, for example, throttle, flaps (on the wings) and the rudder.

Advantages of pilotless airplanes Disadvantages of pilotless airplanes

improvement in passenger comfort security aspects if no pilots on-board
reduced running costs emergency situations during the flight may
be difficult to deal with
improved safety hacking into the system
improved aerodynamics at the front of the passenger reluctance to use the new
airplane since there would no longer be the technology
need to include a cockpit for the pilots
software glitches

Agriculture:
Robots could replace slow, repetitive and dull tasks allowing farmers to concentrate

on improving production yields.

We will consider the following five areas where robotics could play a big role:

» harvesting/picking of vegetables and fruit

» weed control

» phenotyping (plant growth and health)

» seed-planting and fertiliser distribution

» autonomous labour-saving devices.

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Harvesting and picking:

» robots have been designed to do this labour-intensive work; they are more accurate and much
faster at harvesting

» for the reasons above, this leads to higher yields and reduces waste

» a second camera in vegebot guides an arm to remove the lettuce from its stalk with no
damage.

Weed control:
» weed management robots can distinguish between a weed and crop using AI

» examples of weed control robots are being used in to remove weeds between grape vines in
their vineyards; this saves considerably on labour costs and improves vine growth

» weed control robots use GPS tracking to stay on course to move along the rows of vines and
remove the weeds; a weed removal blade is operated by an actuator under the control of the
controller (microprocessor) in the robot

Phenotyping:
» phenotyping is the process of observing physical characteristics of a plant in order to assess its
health and growth

» robots designed to do phenotyping are equipped with sensors (including spectral sensors and
thermal cameras) that can create a 3D image/model of the plant, thus allowing it to be
monitored for health and growth

» machine learning (see Section 6.3) is used to recognise any issues with leaves so that the
robot can convey this back to the farmer

» these robots are much more accurate and faster at predicting problems than when done
manually.

Seed-planting drones and fertiliser distribution

» drones (flying robots) can produce an aerial image of a farm sending back a ‘bird’s eye view’ of
the crops and land

» they allow seed-planting to be done far more accurately

» they also allow for more efficient fertiliser-spreading to reduce waste and improve coverage
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» drones can also be used in cloud seeding where the drone can add silver iodide crystals to a
cloud forcing it to give up its rainwater

» the drones use a very complex camera system to target seeding and allow fertiliser spraying.

Autonomous agriculture devices

Several of the devices described above could be referred to as autonomous. The following list
summarises some of the devices that can work independently of humans:

» grass mowers/cutters

» weeding, pruning and harvesting robots

» seeding robots

» fertiliser spraying

» all of these devices use sensors and cameras to go around obstacles, or they can even be
programmed to ‘go to sleep’ if the weather turns bad.

Domestic robots:
» autonomous vacuum cleaners:
– these use proximity sensors and cameras to avoid bumping into obstacles and allows them to
cover a whole room automatically
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– these robots have a microprocessor to control the overall operation of the device; this also
allows the user to program the device

– actuators are used to control motors which allow movement forward/backward and from side
to side

» autonomous grass cutters (mowers):

– these use the same type of sensor, camera, microprocessor and actuator set up as vacuum
cleaners

» personal assistants (such as ‘Vector’):

– this is a robot controlled by a micro-processor that also uses cloud connectivity to connect to
the internet

– it understands voice commands (using a microphone) and will answer any questions it is asked

– it also makes use of an HD camera, utilising computer vision, allowing it to recognise

somebody’s face as well as navigate a room to steer around objects in its way.

Robots used in entertainment:

The use of robots in the entertainment industry is increasing. They are now found in areas such
as:

» entertainment parks and arenas/venues

» the film and TV industry.

» theme parks are now using autonomous robots to entertain visitors to the

park;

» music festivals are much more immersive for the audience; robotic methods are used to
control lighting

» use of robots to control camerasrobots are capable of producing special effects with a
precision, speed and coordination which is beyond human capabilities