Standard Grade Computing Studies
Automated Systems
Frank Frame
AUTOMATED SYSTEMS
Acknowledgement
Thanks to Dorothy Tedman for her contribution to the review of the content.
First published 2004
© Learning and Teaching Scotland 2004
This publication may be reproduced in whole or in part for educational purposes by schools and
colleges in Scotland provided that no profit accrues at any stage.
ISBN 1 84399 039 3
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Contents
Introduction
iv
The Reasons for Using Automated Systems
1
Computer-Aided Design (CAD)
4
Computer-Aided Manufacture (CAM)
5
Virtual Reality
6
Using Software
6
Analogue to Digital
8
Using ROM Chips
10
Using Real-time Processing
10
The Glasgow Science Centre Tower
10
The Costs of Automated Systems
11
Retraining
12
Designing a Modern Workplace
12
Safety Systems
13
Automated Systems Questions
14
Automated Systems Answers
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AUTOMATED SYSTEMS
Introduction
This publication is part of a series of publications to support Standard Grade
Arrangements in Computing Studies (March 2004). The titles in the series are:
•
•
•
•
•
General Purpose Packages
Communications and Networks
Computer Systems
Automated Systems
Commercial Data Processing.
The first two packs, General Purpose Packages and Communications and
Networks, provide complete coverage of the content as specified in the updated
arrangements for Standard Grade Computing Studies.
The other three packs, Computer Systems, Automated Systems, and Commercial
Data Processing have been produced to support the three programmes featured
on the DVD. The content of these materials has been written to relate directly
to the programmes on the DVD and may not cover all the content as specified
in the course arrangements.
Automated Systems
The materials contained in this pack support the programme on the DVD
entitled Dreaming in Digital. The materials cover automated systems at a
variety of different companies and organisations such as Aberdeen Traffic
Control Systems, Department of Informatics at Edinburgh University, Glasgow
Science Centre, Linn Systems and Torness Nuclear Power Station. The
materials cover the following content as specified in the course arrangements.
Note: Credit level is marked in this document with shading.
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AUTOMATED SYSTEMS
Automated Systems –
Content covered in support materials
Main Aspect
F/G/C
G/C
C
Need
• speed
• hazardous environment
• repetitive tasks
• efficiency
• accuracy
• adaptability
Hardware
and Software
• sensors
• feedback
• robots:
– anatomy
– motor
– programmable
– stationary/mobile
– tools
• CAD/CAM
• analogue I/O
• interface guides
– magnetic and light
• simulation
• virtual reality
• real-time processing
• A to D and D
to A converters
• control language
• ROM software
• embedded systems
• intelligent robots
• retraining
• employment:
– changes in nature of job
• industrial automation
• design of workplace
• safety precautions
• modern factory
• high initial cost
• long term savings
• replacement costs
Implications
– Social
– Technical
– Economic
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The Reasons for
Using Automated Systems
As this table shows, the programme makes clear the reasons why automated
systems are needed.
Reason for using automated system
Example from the programme
They operate at high speed.
Linn Systems uses automated
systems to produce circuit boards at
very high speeds.
They can handle repetitive tasks
without making mistakes.
Aberdeen Traffic Control centre
uses automated systems to
monitor traffic flow by repeatedly
counting vehicles as they pass
through road junctions.
They are accurate.
The automated systems in Torness
power station use sensors accurately to
monitor and control the use of nuclear
energy to produce electricity.
They work in dangerous places where Automated systems work in areas
it is unsafe for people to work.
of Torness nuclear power plant
where it would be very dangerous
for people to work, monitoring
electrical voltages, radiation levels
and the acidity levels in the water
purification plant.
Adaptability
Automated systems are very adaptable because they can be reprogrammed and, in the case of robot arms, fitted with different tools to
enable them to carry out different tasks.
In the programme a good example of this is Linn Systems where the
robot arms can be quickly re-programmed to work on different types of
circuit board.
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AUTOMATED SYSTEMS
Automated systems use sensors to gather data and feed it back to the processor.
In the programme you saw a wide range of sensors being used.
Sensor
Example from the programme
Pressure sensor
Front of
the mobile
robot
Infra-red sensor
Aberdeen Traffic
Control points
at traffic lights
Edinburgh
University robots
Magnetic sensor
Linn Systems Mobile robots
Induction loop: electromagnetic sensor
Aberdeen Traffic Control points at
traffic lights
Light sensor
Edinburgh University robots
Radiation sensor
Torness Nuclear Power plant
Sensors detecting the levels of acidity in
a water purification plant
Torness Nuclear Power plant
There are two main types of robot you need to know about: stationary robots
and mobile robots. There are examples of both in the programme.
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Stationary robots
These are robot arms that are fixed in
position. The diagram below shows a
large-scale stationary robot arm. It has
mobile joints called ‘the wrist’, ‘the
elbow’, ‘the waist’ and ‘the shoulder’.
Changing the tools on a
robot arm
A whole range of tools can be fitted to
the end of a robot arm, for example a
spray gun, a welding gun, a gripper, etc.
In the Linn Systems factory the robot arms were relatively small, were fitted to
the production line and had a tool fitted to enable them to place parts on the
circuit boards. This tool could be changed to enable the arm to place a range
of different electronic parts on the circuit board.
Mobile robots
Mobile robots move around using wheels or tracks and are usually powered
by electric motors.
Guiding mobile robots
Two ways of guiding a mobile robot
are magnetic guides and light guides.
Magnetic guides
Magnetic guides work as follows.
1.
2.
3.
A cable buried in the floor gives
off a magnetic field.
Sensors suspended underneath
the robot detect the magnetic
field and feed the data back to
the processor controlling the
robot.
The processor then uses this information to send out signals to control
the direction of the robot’s wheels.
In the Linn Systems factory the mobile robots, which are used to carry
materials around the factory floor, used magnetic guides to follow the cables
buried in the factory floor.
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AUTOMATED SYSTEMS
Light guides
Using this method the robot follows a path marked out by a white line painted
on the floor as follows:
1.
2.
3.
The robot shines a light on to the floor.
This light is reflected back off the white line and is picked up by light
sensors that are positioned underneath the robot.
The information about reflected light is fed from the sensors back to the
processor. Then, just as with magnetic guides, the processor then uses this
information to send out signals to control the movement of the robot.
Computer-Aided Design (CAD)
CAD systems are used to produce designs and plans of everything from
buildings to aeroplanes, from conservatories to mobile phones.
Why use CAD systems?
Reasons
Example from the programme
It is much easier to produce complex
drawings using a CAD system than it
is to do it by hand.
Linn Systems used CAD to design
their circuit boards.
Altering a drawing is a simple process
of making the change and saving the
new version to disk. By hand the whole
drawing would have to be done again.
Producing multiple copies of a design is
straightforward: it is simply a matter of
printing out as many copies as are
needed by sending them to the printer.
What kind of hardware do CAD systems need?
•
•
•
•
•
High resolution monitors
Powerful processors
High-capacity backing storage
Graphics tablet
Plotter
You can find out more about hardware in the Computer Systems programme
and support notes.
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Computer-Aided Manufacture (CAM)
In industry many factories use computers to control machinery during manufacture.
Some industries have an
integrated CAD/CAM
system where objects are
designed using a CAD
system. This design is then
fed directly to the computer
that controls the machinery
and robots are used to cut
out the parts or assemble
the finished product. Linn
Systems uses a CAD/CAM
system to produce its circuit
boards. Once the designs for
the circuit boards are completed using the CAD system, they are transferred directly
to the computer systems that control the robot arms. The robot arms then assemble
the circuit boards.
Simulation
A computer simulation is the use of the computer system to mimic a
complicated activity in the real world such as driving a train or flying a plane.
A simulation will allow the user to input control signals, for example using a
joystick to control a simulation of a plane flight. The signals are then processed
by the system, which reacts to the signals by changing the display on the
screen, for example, the plane starts to dive to the ground.
Computer simulations are used:
•
•
to teach people skills in a
safe environment. You can
learn to drive a train or fly a
plane on a simulator without
any danger to yourself, or
anyone else. In the
programme you can see how
Torness nuclear power plant
uses a simulated control
room, which is identical to
the real control room, to
train its operators
for games.
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AUTOMATED SYSTEMS
Virtual Reality
Virtual reality systems use stereo vision screens and surround sound to make
the user feel as if they are actually inside the computer’s world.
Virtual reality systems even let the user move around the virtual world and
manipulate it by touching and moving
objects. This is done by building
sensors into the gloves, helmet and
even suits that the user wears while in
the virtual world.
Glasgow Science Centre has a virtual
reality theatre that can be used by
designers to inspect their virtual
CAD models.
Using Software
Automated systems are controlled using software.
This controlling software contains instructions about what an automated
system has to do. Take the example of the robots being developed at
Edinburgh University: the actions of the robots and the way they react to the
data being fed to them by their sensors are controlled by the instructions in the
controlling software.
These instructions are written using a control language that has features such
as special commands for controlling robot movements, for specifying the
degrees of rotation of robots arms, and special input/output facilities.
Control language has instructions that the programmer can use to tell a robot
which way to turn, how high to lift up the gripper, how far to travel or even to
control the speed of the motor.
Using embedded systems
Embedded systems are found in machines. An embedded system is a single
processor that has a few simple functions to carry out. Modern car engines
have embedded systems as have mobile phones and other electronic
equipment such as digital cameras and games consoles.
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An embedded system gives the user a simple control interface such as a touch
screen with a simple menu and/or a couple of control buttons. Embedded
systems are based on the use of microprocessors such as the Intel Pentium’s
‘M’ processor, which is specially designed for low-power embedded systems.
Intelligent robots
Intelligent robots have a range of sensors attached to them as well as their own
powerful onboard processors, and significant memory capacity. All of which
enables them to mimic the capacities of the human senses.
How can they mimic human senses?
•
•
•
•
•
They can ‘hear’ commands using microphones and sound and/or voice
recognition systems.
They can use sonar beams and sensors to detect objects.
They can see objects using optical sensors.
They can, using tactile sensors, tell the differences between various types
of surface, for example tiled floors, soft carpets.
Some even move about using human-like legs.
These sensors, combined with powerful onboard processors and large
memory capacity means that robots of this type are very flexible and can react
to the environment they are working in. This in turn means that they can be
used for a wide range of complex functions that require the robot to gather,
process and react to stimuli.
Where are they used?
In space exploration, in undersea work, for example on undersea pipelines.
They are commonly used to clean out swimming pools.
In the programme we saw a range of experimental intelligent robots being
developed at Edinburgh University.
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AUTOMATED SYSTEMS
Robot
Illustrating
The robot that followed a person
around a room
The ability to mimic
the human ability
to ‘see’.
The robot that moved towards
a sound.
The ability to
mimic the human
ability to ‘hear’.
The robot that used infra-red
sensors to avoid objects.
The ability to
mimic the human
abillity to ‘see’ and
detect obstacles.
Analogue to Digital
To understand how sensors feed data back to a processor, let us look at the
example of the magnetic sensor attached to the mobile robots in Linn
Systems.
As a robot moves along the factory floor, the sensor detects the magnetic field
and, as levels rise and fall, it sends an electrical current back to the processor.
This current rises and falls along with the strength of the magnetic field. Because
it rises and falls continuously this signal is known as an analogue signal.
If we were to draw an analogue signal it would look like a rising and falling wave.
An interface is used to change the analogue signal into digital form so that the
processor can deal with it.
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An A to D converter is an interface that changes analogue signals into digital
form. It does this by sampling the incoming analogue signal thousands of
times per second and changing the samples into digital numbers. A to D
converters are used to change the analogue signals coming from the magnetic
sensors attached to the mobile robots in the programme into the digital form
that the controlling processor can accept and understand.
A D to A converter is an interface that changes digital information to
analogue form, reversing the process of an A to D converter. The D to A
converter is used when the processor is sending signals out, for example, to
control the speed of a mobile robot or to change the direction of its wheels.
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AUTOMATED SYSTEMS
Using ROM Chips
Automated systems often store the controlling software and the software that
carries out the A to D–D to A conversion on ROM chips. The advantage of
this is that the instructions in the software are immediately available to the
processor without having to be loaded from backing storage.
Using Real-time Processing
In real-time processing the system reacts instantly to data fed back to the
processor from sensors. Take the example of how the Aberdeen traffic control
system operates.
1.
2.
The incoming analogue signals from the infra-red traffic sensors are
converted into digital form.
This digital data is then sent to the controlling computer system, which
processes it and reacts instantly to control the traffic lights and keep the
traffic flowing.
Real time processing enables the traffic control system to react instantly to
control the lights and regulate the flow of traffic.
The Glasgow Science Centre Tower
Glasgow Science Centre Tower is a spectacular
example of an automated system. The giant tower
has a viewing platform that you can reach by a lift.
From there you can see a panoramic view of the
city of Glasgow and the surrounding countryside.
The tower has two special features.
•
•
It has a special streamlined shape so that it
can face directly into the prevailing wind.
It can be rotated to face into the wind.
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How is an automated system involved?
It rotates the tower according to the prevailing wind speed and direction.
•
•
•
The tower sits on large rollers which are turned by powerful electric motors.
The motors are controlled by a computerised control unit.
Sensors on two weather stations, one at the top of the tower and one
near the bottom, gather information about wind speed and direction,
temperature, humidity and rainfall. The data from the wind speed and
direction sensors is fed to the control unit at the base of the tower by
using radio modems.
The control unit then processes this data before sending control signals to the
motors to adjust the position of the tower.
The Costs of Automated Systems
Initial costs
It takes a lot of money to set up an automated system. The following list gives
you an idea of some of the things that might need to be paid for:
•
•
•
•
•
•
Sstationary robots
Mobile robots
Guidance systems for the mobile robots
Sensors, software
Computer systems
Installation of cables, etc.
Linn Systems, Aberdeen Traffic Control System and Torness Power station
have all invested millions of pounds in their automated systems.
Why do businesses and organisations invest so
much on automated systems?
One reason is because automated systems make businesses run efficiently and, in
the long term, save money.
Linn Systems depend on their automated
systems to maintain a high rate of
production and to produce electronic
goods of the highest quality. The
automated assembly line guarantees
precision and produces high-quality circuit
boards much faster than any manual
system could.
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Aberdeen traffic control system uses the automated system because it is the
most efficient way of controlling traffic flows around the city.
And, of course, using automated systems means a reduction in the number of
people required to do the work, cutting down on the wage bill.
Another reason is safety.
Automated systems can operate in environments that would be very dangerous
to humans: Torness power station relies on automated systems to ensure that
power is produced efficiently and, above all, safely.
Retraining
When automated systems are introduced into a workplace people need to be
trained to work with the new system. Staff members in Linn Systems have had
to be trained to carry out a range of tasks such as:
•
•
•
•
using the controlling software
maintaining the robots and the robot arms
supplying the robot arms with parts
working safely alongside the mobile robots.
Designing a Modern Workplace
When a factory introduces an automated system the entire layout has to be
redesigned.
The entire layout of the Linn Systems factory has been designed specifically
to accommodate both the automated production lines with their stationary
robot arms and the mobile robots. The following are key features of the
design of the factory.
•
•
•
•
•
The location of the stationary robots
The paths for the mobile robots
The installation of the cabling
Safety zones
The number, type and location of the computer systems
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Safety Systems
Safety is important, especially when robots are being used. They can be
dangerous and precautions have to be taken.
What safety measures can be taken?
Mark out the areas where automated systems are operating by:
•
painting hatched areas on the floor in bright yellow
•
hanging up signs.
Mobile robots can be fitted
with flashing lights and sirens
Sensors can be fitted to mobile
robots to detect when they
come into contact with objects.
All of these safety precautions
are in place in the Linn
Systems factory.
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AUTOMATED SYSTEMS
Automated Systems Questions
1.
Complete the following table using examples from the programme
Reason for using automated system Example from the programme
They operate at high speed.
Linn Systems use automated
systems to produce circuit boards
at very high speeds.
They can handle repetitive tasks
without making mistakes.
They are accurate.
They work in dangerous places
where it is unsafe for people to work.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
What kind of tool was fitted to the robot arms making the circuit boards?
Describe the job being done by the mobile robots in the Linn Systems factory.
What kind of guidance system did the Linn robots have?
How did this type of guidance system operate?
List the sensors attached to the Linn Systems mobile robots.
List the sensors used by: (a) Aberdeen Traffic Control System (b) Torness
Nuclear Power Plant.
What was the job of the sensors in (a) Aberdeen Traffic Control System
(b) Torness Nuclear Power Plant?
What are the reasons for using CAD?
What did Linn Systems use CAD for?
Describe how CAD linked up with CAM in the Linn Systems factory.
What was the CAM system used for in the Linn Systems factory?
How do virtual reality systems make the user feel as if they are actually
inside the computer’s world?
Describe an example of a virtual reality system you saw in the programme.
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15. (a) What are embedded systems? (b) What are they used for?
16. What is an intelligent robot?
17. Why could the robots being developed at Edinburgh University be
described as intelligent?
18. Complete this table setting out the sensors that the Edinburgh
University intelligent robots used and the human senses they mimicked.
Sensor
Human senses
19. Why does the Aberdeen Traffic Control System need interfaces?
20. What is the job of a D to A converter on the automated system
controlling the robot arms in the Linn Systems factory?
21. What is the job of a D to A converter on the mobile robots?
22. The Linn Systems factory has been designed specifically for working with
automated systems. List the key features of the design of the factory.
23. Which sensors does the Glasgow Science Centre Tower use?
24. Why is an automated system used to control the position of the tower?
25. A salesman is trying to sell a mobile robot to a factory owner. The
factory owner hesitates because the robots are very expensive to buy.
What could the salesman say to convince him that the investment would
be worthwhile?
26. What training would people require to work alongside the mobile
robots and robot arms in the Linn factory?
27. What safety measures would you put in place (a) around a stationary
robot? (b) on and around a mobile robot?
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Automated Systems Answers
1.
The table below shows examples for each reason for using automated
systems. You might want to use other examples from the programme.
Reason for using
automated system
Example from the programme
They operate at high speed.
Linn Systems uses automated systems to
produce circuit boards at very high speeds.
They can handle repetitive
Aberdeen Traffic Control Centre uses
tasks without making mistakes. automated systems to monitor traffic
flow by repeatedly counting vehicles as
they pass through road junctions.
2.
3.
4.
5.
6.
7.
8.
They are accurate.
The automated systems in Torness
power station use sensors to accurately
monitor and control radiation.
They work in dangerous
places where it is unsafe for
people to work.
The automated systems work in areas
of Torness nuclear power plant where it
would be very dangerous for people.
It was a specialised tool for fitting the electronic parts on to the circuit
boards.
They were being used to carry materials around the factory floor.
Magnetic guidance.
Cables were buried in the floor to mark the robots’ path. The cables
produce a magnetic field that is detected by the sensors attached to the
robot. The sensors pass this data to the controlling processor that uses it
to control the direction in which the robot moves.
Magnetic sensor, infra-red sensor, pressure/bump sensor.
(a) infra-red sensors on the traffic lights, induction loop electro-magnetic
sensors buried in the roads (b) Sensors measuring temperatures,
voltages, radiation and sensors monitoring the other sensors.
(a) To gather information about the number and frequency of vehicles
on the roads and at junctions (b) To gather data about the processes
involved in producing power including: temperatures, voltages and
radiation to enable the operators to control the production process.
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9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
19.
The reasons for using CAD are as follows.
• It is much easier to produce complex drawings using a CAD system
than it is to do it by hand.
• Altering a drawing is a simple process of making the change and
saving the new version to disk. By hand the whole drawing would
have to be done again.
• Producing multiple copies of a design is straightforward: it is simply a
matter of printing out as many copies as are needed by sending them
to the printer.
To design their circuit boards.
Once a design was completed it was sent, in digital form, through a
network to the computer systems that controlled the robot arms on the
assembly line.
Controlling the robot arms that place the electronic parts on to the
circuit boards.
Virtual reality systems use stereo vision screens and surround sound to
make the users feel as if they are actually inside the computer’s world.
The virtual reality theatre in the Glasgow Science Centre was used by
designers to test stress points in a new car, by scientists to analyse
molecular structures and by town planners to design a new town.
An embedded system is a single processor that has a few simple
functions to carry out. Modern car engines have embedded systems as
have mobile phones and other electronic equipment such as digital
cameras and games consoles.
An intelligent robot is a robot that has a range of sensors attached to it as
well as its own powerful onboard processors, and significant memory
capacity. These sensors enable it to mimic the capabilities of human
senses.
Because they had a range of sensors linked to processors that enabled
them to mimic human senses.
Complete this table setting out (a) the sensors that the Edinburgh
University intelligent robots used (b) the human senses they mimicked.
Sensor
Human senses
Microphones
Hearing
Infra-red sensor
Seeing
To change the analogue signals that come from the sensors into the
digital form that the controlling processors can understand.
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AUTOMATED SYSTEMS
20. It changes the digital instructions from the processor into analogue
signals. These analogue signals are used to control the electric motors
that move the robot arms.
21. It changes the digital instructions from the processor into analogue
signals that control the electric motors that turn and move the wheels,
and apply and release the brakes.
22. The key features of the design of the factory are:
• the location of the stationary robots
• the paths for the mobile robots paths
• the installation of the cabling
• safety zones
• the number, type and location of the computer systems.
23. It uses sensors to detect wind speed and direction.
24. Because it can react accurately and quickly to changes in wind direction
and adjust the position of the tower accordingly.
25. He could say that the investment would, in the long term, actually make
the business money because it would increase efficiency and reduce the
wages bill.
26. People would have to be trained in:
• using the controlling software
• maintaining the mobile robots and the robot arms
• supplying the robot arms with parts
• safety procedures.
27. (a) Brightly painted ‘robot only’ areas on the floor, warning signs
hanging near the robots (b) Flashing lights, sirens, collision sensors.
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