Automsystems tcm4 121509

450 views

Published on

Published in: Technology
  • Be the first to comment

Automsystems tcm4 121509

  1. 1. Standard Grade Computing Studies Automated Systems Frank Frame
  2. 2. AUTOMATED SYSTEMSAcknowledgementThanks to Dorothy Tedman for her contribution to the review of the content.First published 2004© Learning and Teaching Scotland 2004This publication may be reproduced in whole or in part for educational purposes by schools andcolleges in Scotland provided that no profit accrues at any stage.ISBN 1 84399 039 3 ii STANDARD GR ADE COMPUTING STUDIES © Learning and Teaching Scotland
  3. 3. AUTOMATED SYSTEMSContents 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 16 STANDARD GR ADE COMPUTING STUDIES iii © Learning and Teaching Scotland
  4. 4. AUTOMATED SYSTEMSIntroductionThis publication is part of a series of publications to support Standard GradeArrangements 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 andNetworks, provide complete coverage of the content as specified in the updatedarrangements for Standard Grade Computing Studies.The other three packs, Computer Systems, Automated Systems, and CommercialData Processing have been produced to support the three programmes featuredon the DVD. The content of these materials has been written to relate directlyto the programmes on the DVD and may not cover all the content as specifiedin the course arrangements.Automated SystemsThe materials contained in this pack support the programme on the DVDentitled Dreaming in Digital. The materials cover automated systems at avariety of different companies and organisations such as Aberdeen TrafficControl Systems, Department of Informatics at Edinburgh University, GlasgowScience Centre, Linn Systems and Torness Nuclear Power Station. Thematerials cover the following content as specified in the course arrangements. Note: Credit level is marked in this document with shading. iv STANDARD GR ADE COMPUTING STUDIES © Learning and Teaching Scotland
  5. 5. AUTOMATED SYSTEMSAutomated Systems –Content covered in support materialsMain Aspect F/G/C G/C CNeed • speed • efficiency • adaptability • hazardous environment • accuracy • repetitive tasksHardware • sensors • analogue I/O • A to D and Dand Software • feedback • interface guides to A converters • robots: – magnetic and light • control language – anatomy • simulation • ROM software – motor • virtual reality • embedded systems – programmable • real-time processing • intelligent robots – stationary/mobile – tools • CAD/CAMImplications– Social • retraining • employment: – changes in nature of job– Technical • industrial automation • design of workplace • safety precautions • modern factory • high initial cost– Economic • long term savings • replacement costs STANDARD GR ADE COMPUTING STUDIES v © Learning and Teaching Scotland
  6. 6. AUTOMATED SYSTEMSvi STANDARD GR ADE COMPUTING STUDIES © Learning and Teaching Scotland
  7. 7. AUTOMATED SYSTEMSThe Reasons forUsing Automated SystemsAs this table shows, the programme makes clear the reasons why automatedsystems are needed.Reason for using automated system Example from the programmeThey operate at high speed. Linn Systems uses automated systems to produce circuit boards at very high speeds.They can handle repetitive tasks Aberdeen Traffic Control centrewithout making mistakes. 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 areasit 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 re- programmed 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. STANDARD GR ADE COMPUTING STUDIES 1 © Learning and Teaching Scotland
  8. 8. AUTOMATED SYSTEMSAutomated 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 programmePressure sensor Front of the mobile robotInfra-red sensor Aberdeen Traffic Control points at traffic lights Edinburgh University robotsMagnetic sensor Linn Systems Mobile robotsInduction loop: electromagnetic sensor Aberdeen Traffic Control points at traffic lightsLight sensor Edinburgh University robotsRadiation sensor Torness Nuclear Power plantSensors detecting the levels of acidity in Torness Nuclear Power planta water purification plantThere are two main types of robot you need to know about: stationary robotsand mobile robots. There are examples of both in the programme. 2 STANDARD GR ADE COMPUTING STUDIES © Learning and Teaching Scotland
  9. 9. AUTOMATED SYSTEMSStationary robotsThese are robot arms that are fixed inposition. The diagram below shows alarge-scale stationary robot arm. It hasmobile joints called ‘the wrist’, ‘theelbow’, ‘the waist’ and ‘the shoulder’.Changing the tools on arobot armA whole range of tools can be fitted tothe end of a robot arm, for example aspray gun, a welding gun, a gripper, etc.In the Linn Systems factory the robot arms were relatively small, were fitted tothe production line and had a tool fitted to enable them to place parts on thecircuit boards. This tool could be changed to enable the arm to place a rangeof different electronic parts on the circuit board.Mobile robotsMobile robots move around using wheels or tracks and are usually poweredby electric motors.Guiding mobile robotsTwo ways of guiding a mobile robotare magnetic guides and light guides.Magnetic guidesMagnetic guides work as follows.1. A cable buried in the floor gives off a magnetic field.2. Sensors suspended underneath the robot detect the magnetic field and feed the data back to the processor controlling the robot.3. 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 carrymaterials around the factory floor, used magnetic guides to follow the cablesburied in the factory floor. STANDARD GR ADE COMPUTING STUDIES 3 © Learning and Teaching Scotland
  10. 10. AUTOMATED SYSTEMSLight guidesUsing this method the robot follows a path marked out by a white line paintedon the floor as follows:1. The robot shines a light on to the floor.2. This light is reflected back off the white line and is picked up by light sensors that are positioned underneath the robot.3. 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 frombuildings to aeroplanes, from conservatories to mobile phones.Why use CAD systems?Reasons Example from the programmeIt is much easier to produce complex Linn Systems used CAD to designdrawings using a CAD system than it their circuit boards.is to do it by hand.Altering a drawing is a simple processof making the change and saving thenew version to disk. By hand the wholedrawing would have to be done again.Producing multiple copies of a design isstraightforward: it is simply a matter ofprinting out as many copies as areneeded 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• PlotterYou can find out more about hardware in the Computer Systems programmeand support notes. 4 STANDARD GR ADE COMPUTING STUDIES © Learning and Teaching Scotland
  11. 11. AUTOMATED SYSTEMSComputer-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 forthe circuit boards are completed using the CAD system, they are transferred directlyto the computer systems that control the robot arms. The robot arms then assemblethe circuit boards.SimulationA computer simulation is the use of the computer system to mimic acomplicated 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 ajoystick to control a simulation of a plane flight. The signals are then processedby the system, which reacts to the signals by changing the display on thescreen, 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. STANDARD GR ADE COMPUTING STUDIES 5 © Learning and Teaching Scotland
  12. 12. AUTOMATED SYSTEMSVirtual RealityVirtual reality systems use stereo vision screens and surround sound to makethe user feel as if they are actually inside the computer’s world.Virtual reality systems even let the user move around the virtual world andmanipulate it by touching and movingobjects. This is done by buildingsensors into the gloves, helmet andeven suits that the user wears while inthe virtual world.Glasgow Science Centre has a virtualreality theatre that can be used bydesigners to inspect their virtualCAD models.Using SoftwareAutomated systems are controlled using software.This controlling software contains instructions about what an automatedsystem has to do. Take the example of the robots being developed atEdinburgh University: the actions of the robots and the way they react to thedata being fed to them by their sensors are controlled by the instructions in thecontrolling software.These instructions are written using a control language that has features suchas special commands for controlling robot movements, for specifying thedegrees of rotation of robots arms, and special input/output facilities.Control language has instructions that the programmer can use to tell a robotwhich way to turn, how high to lift up the gripper, how far to travel or even tocontrol the speed of the motor.Using embedded systemsEmbedded systems are found in machines. An embedded system is a singleprocessor that has a few simple functions to carry out. Modern car engineshave embedded systems as have mobile phones and other electronicequipment such as digital cameras and games consoles. 6 STANDARD GR ADE COMPUTING STUDIES © Learning and Teaching Scotland
  13. 13. AUTOMATED SYSTEMSAn embedded system gives the user a simple control interface such as a touchscreen with a simple menu and/or a couple of control buttons. Embeddedsystems 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 robotsIntelligent robots have a range of sensors attached to them as well as their ownpowerful onboard processors, and significant memory capacity. All of whichenables 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 largememory capacity means that robots of this type are very flexible and can reactto the environment they are working in. This in turn means that they can beused 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 beingdeveloped at Edinburgh University. STANDARD GR ADE COMPUTING STUDIES 7 © Learning and Teaching Scotland
  14. 14. AUTOMATED SYSTEMSRobot IllustratingThe robot that followed a person The ability to mimicaround a room the human ability to ‘see’.The robot that moved towards The ability toa sound. mimic the human ability to ‘hear’.The robot that used infra-red The ability tosensors to avoid objects. mimic the human abillity to ‘see’ and detect obstacles.Analogue to DigitalTo understand how sensors feed data back to a processor, let us look at theexample of the magnetic sensor attached to the mobile robots in LinnSystems.As a robot moves along the factory floor, the sensor detects the magnetic fieldand, 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. Becauseit 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 theprocessor can deal with it. 8 STANDARD GR ADE COMPUTING STUDIES © Learning and Teaching Scotland
  15. 15. AUTOMATED SYSTEMSAn A to D converter is an interface that changes analogue signals into digitalform. It does this by sampling the incoming analogue signal thousands oftimes per second and changing the samples into digital numbers. A to Dconverters are used to change the analogue signals coming from the magneticsensors attached to the mobile robots in the programme into the digital formthat the controlling processor can accept and understand.A D to A converter is an interface that changes digital information toanalogue form, reversing the process of an A to D converter. The D to Aconverter is used when the processor is sending signals out, for example, tocontrol the speed of a mobile robot or to change the direction of its wheels. STANDARD GR ADE COMPUTING STUDIES 9 © Learning and Teaching Scotland
  16. 16. AUTOMATED SYSTEMSUsing ROM ChipsAutomated systems often store the controlling software and the software thatcarries out the A to D–D to A conversion on ROM chips. The advantage ofthis is that the instructions in the software are immediately available to theprocessor without having to be loaded from backing storage.Using Real-time ProcessingIn real-time processing the system reacts instantly to data fed back to theprocessor from sensors. Take the example of how the Aberdeen traffic controlsystem operates.1. The incoming analogue signals from the infra-red traffic sensors are converted into digital form.2. 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 tocontrol the lights and regulate the flow of traffic.The Glasgow Science Centre TowerGlasgow Science Centre Tower is a spectacularexample of an automated system. The giant towerhas a viewing platform that you can reach by a lift.From there you can see a panoramic view of thecity 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. 10 STANDARD GR ADE COMPUTING STUDIES © Learning and Teaching Scotland
  17. 17. AUTOMATED SYSTEMSHow 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 themotors to adjust the position of the tower.The Costs of Automated SystemsInitial costsIt takes a lot of money to set up an automated system. The following list givesyou 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 stationhave all invested millions of pounds in their automated systems.Why do businesses and organisations invest somuch on automated systems?One reason is because automated systems make businesses run efficiently and, inthe long term, save money.Linn Systems depend on their automatedsystems to maintain a high rate ofproduction and to produce electronicgoods of the highest quality. Theautomated assembly line guaranteesprecision and produces high-quality circuitboards much faster than any manualsystem could. STANDARD GR ADE COMPUTING STUDIES 11 © Learning and Teaching Scotland
  18. 18. AUTOMATED SYSTEMSAberdeen traffic control system uses the automated system because it is themost efficient way of controlling traffic flows around the city.And, of course, using automated systems means a reduction in the number ofpeople 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 dangerousto humans: Torness power station relies on automated systems to ensure thatpower is produced efficiently and, above all, safely.RetrainingWhen automated systems are introduced into a workplace people need to betrained to work with the new system. Staff members in Linn Systems have hadto 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 WorkplaceWhen a factory introduces an automated system the entire layout has to beredesigned.The entire layout of the Linn Systems factory has been designed specificallyto accommodate both the automated production lines with their stationaryrobot arms and the mobile robots. The following are key features of thedesign 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 12 STANDARD GR ADE COMPUTING STUDIES © Learning and Teaching Scotland
  19. 19. AUTOMATED SYSTEMSSafety SystemsSafety is important, especially when robots are being used. They can bedangerous 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 fittedwith flashing lights and sirensSensors can be fitted to mobilerobots to detect when theycome into contact with objects.All of these safety precautionsare in place in the LinnSystems factory. STANDARD GR ADE COMPUTING STUDIES 13 © Learning and Teaching Scotland
  20. 20. AUTOMATED SYSTEMSAutomated 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. What kind of tool was fitted to the robot arms making the circuit boards? 3. Describe the job being done by the mobile robots in the Linn Systems factory. 4. What kind of guidance system did the Linn robots have? 5. How did this type of guidance system operate? 6. List the sensors attached to the Linn Systems mobile robots. 7. List the sensors used by: (a) Aberdeen Traffic Control System (b) Torness Nuclear Power Plant. 8. What was the job of the sensors in (a) Aberdeen Traffic Control System (b) Torness Nuclear Power Plant? 9. What are the reasons for using CAD?10. What did Linn Systems use CAD for?11. Describe how CAD linked up with CAM in the Linn Systems factory.12. What was the CAM system used for in the Linn Systems factory?13. How do virtual reality systems make the user feel as if they are actually inside the computer’s world?14. Describe an example of a virtual reality system you saw in the programme. 14 STANDARD GR ADE COMPUTING STUDIES © Learning and Teaching Scotland
  21. 21. AUTOMATED SYSTEMS15. (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 senses19. 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? STANDARD GR ADE COMPUTING STUDIES 15 © Learning and Teaching Scotland
  22. 22. AUTOMATED SYSTEMSAutomated Systems Answers1. 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 Example from the programme automated system 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. They are accurate. The automated systems in Torness power station use sensors to accurately monitor and control radiation. They work in dangerous The automated systems work in areas places where it is unsafe for of Torness nuclear power plant where it people to work. would be very dangerous for people.2. It was a specialised tool for fitting the electronic parts on to the circuit boards.3. They were being used to carry materials around the factory floor.4. Magnetic guidance.5. 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.6. Magnetic sensor, infra-red sensor, pressure/bump sensor.7. (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.8. (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. 16 STANDARD GR ADE COMPUTING STUDIES © Learning and Teaching Scotland
  23. 23. AUTOMATED SYSTEMS9. 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.10. To design their circuit boards.11. 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.12. Controlling the robot arms that place the electronic parts on to the circuit boards.13. 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.14. 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.15. 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.16. 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.17. Because they had a range of sensors linked to processors that enabled them to mimic human senses.18. 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 Seeing19. To change the analogue signals that come from the sensors into the digital form that the controlling processors can understand. STANDARD GR ADE COMPUTING STUDIES 17 © Learning and Teaching Scotland
  24. 24. AUTOMATED SYSTEMS20. 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.18 STANDARD GR ADE COMPUTING STUDIES © Learning and Teaching Scotland

×