Automated Systems

Automated Systems • What are automated systems? • In today’s modern industrial society companies must be competitive in the market place in order to survive. • Whoever can complete a contract within the required time and to the necessary quality and price, will usually get the job. • Companies are continually trying to improve their productivity in order to be more competitive. • Automating many industrial processes and tasks can be an effective way of improving productivity. • Many industrial tasks and processes consist of operations that are repeated over and over again. • These type of tasks can usually be carried out very effectively by automatic machines. • Computers are ideal for controlling these automatic machines.

Anautomated systemis a system where a user provides theinput, the machine or computer carries out theprocessand provides you withoutput. • Example: washing machine • Input - water, powder, dirty clothes. • Process – select a pre-programmed routine • Output – clean clothes., dirty water • Can you name two examples in your house?

Numerous examples of Automated systems occur in industry. In the manufacture of cars, an assembly line is fully automated and is controlled by a mainframe computer that is linked to individual robots and machines that assemble the components.

Why do we use automated systems? • We use automated systems to both assist humans and replace them. • Reasons for automating • Speed • Tasks are carried out more quickly. (e.g. more items can be manufactured each day, repairs can be carried out more quickly) • Hazardous (Dangerous) environment • Automated system can be designed to perform tasks in places where it is extremely dangerous for people to work. (e.g. nuclear reactors, in chemical factories, on North Sea oil platforms) • Repetitive tasks • Humans get bored when carrying out the same task time after time. Automated systems are able to carry out the same task over and over again without making mistakes or slowing down.

Accuracy • Automated systems can produce exactly the same high quality product in a factory time after time. • They follow precisely the instructions in the programs which control them. This guarantees 100% accuracy. • E.g. An automated system designed to cut metal parts for an aeroplane will produce the parts with absolute precision. It is capable of error only if the programmer has made a mistake when entering the instructions or if a mechanical fault develops. • Efficiency • Automated systems are very efficient because they are very accurate, they do not make mistakes and they waste no time or materials. • E.g. Every part produced by an automated system for an aeroplane will be the exact size and shape, there will be no parts thrown away because there are mistakes, there will be no time lost mending errors or replacing parts.

Adaptability • Automated systems can be designed to be flexible and handle a range of different tasks. • A robot arm can be programmed to spray a car one week, the following week it could be programmed to lift equipment onto a conveyor belt. • Other automated systems are adaptable because they are equipped with a range of sensors to help them detect the need to change their output. An automated system regulating pressures in a petrochemical plant has sensors which feed it data about gas escapes and rises and drops in pressure.

Summary: • Faster than humans • Can do boring or repetitious tasks • Used where it is dangerous • More efficient • Flexible • Accuracy

Robots Many automated systems make use of Robots to carry out the necessary processes. A robotis a machine that is controlled by a computer and is flexible enough to be able to do a variety of tasks. Robots don't have to look like humans. Some robots have parts that resemble human limbs and so these parts are called after the human parts they resemble. A jointed arm robot has a waist, shoulder, elbow and wrist. The ‘hand’ of the robot can be changed or modified to suit the task the robot is programmed to do. These different ‘hands’ are called end effectors and they could be a gripper, suction cup, paint spray or a collar.

A robot arm has a number of joints like a human's: • - waist, • - shoulder, • - elbow, • - wrist, • - end-effector.

The end-effector is the device at the end of the robot arm. There are several different types of end-effector to suit the different possible tasks: • grippes • suction pad • drill • screwdriver • paint gun • etc

Stationary Robots • Many robots are simply fixed in one position in a factory. (e.g.fixed point on an assembly line) These are called stationary robots. One type of stationary robot is the robot arm, which attempts to copy the movements of a human arm. • Mobile robots • A robot that moves (on wheels or tracks with a motor) is a mobile robot e.g. a robot buggy (vehicle) carrying parts around a warehouse, a bomb disposal robot.

Mobile robots follow: • Magnetic guides:a track formed by wire buried in the floor. Sensors on the robot detect magnetic field form electricity in the wire so follow the path of the wire. • Light guides: The robot shines a light onto a white line on the floor and detects reflected light with 2 light sensors. If the robot is centred over the line then both sensors give an equal signal. • Remote control: used in places where it is not safe for people to go e.g. bomb disposal

*Intelligent robot • A robot that has sensors on board and can make decisions/ adapt behaviour based on environment using artificial intelligence. • Only expert systems allows a robot to adapt to new situations. • Intelligent robots have a range of sensors attached to them as well as powerful onboard processors, and significant memory capacity. All of these enables them to mimic the capacities of the 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, etc • http://www.cooldictionary.com/splotchy.mpl • http://www.iwantoneofthose.com/robot-guinea-pig/index.html

Controlling Robotic Devices Robots are controlled by programs which are running on the controlling computer. In order to change the task that a robot does it is necessary to change the controlling program. *Control languages are very specialised languages for programming robots using commands like GRASP, WAIT, MOVE, TURN, and SPEED. These are specific to robot devices. • *Automated systems often stores the controlling software on ROM chips. The advantages of this are: • the instructions in the software are immediately available to the processor without having to be loaded from backing storage • The software can not be deleted or infected with viruses

When the control software and an operating system are stored on an electronic chip as part of an automated system, the combination is called EMBEDDED SYSTEM. • Embedded systems is the use of a computer system built into a machine of some sort, e.g.: in washing machines, microwaves, dishwasher, mobile phones, etc.

ARTIFICIAL INTELIGENCE • AI is the study of how to make computers do things that – at the present time – people can do better. • Research in the field of artificial intelligence can be divided into four categories: • EXPERT SYSTEMS – programs that mimic the decision-making and problem-solving thought processes of human experts. These AI systems present the computer as an expert on some particular topic. • ROBOTICS – machines that can move and relate to objects as humans can.

Early Mishaps “ The spirit is willing, but the flesh is weak” “ The vodka is good, but the meat is spoiled” How Computers Learn? Key elements: • knowledge base is a set of facts and rules about those facts. • inference engine accesses, selects, and interprets a set of rules

The inference engine applies the rules to the facts to make up new facts – therefore the computer has learned something new. • Ex: FACT: Amy is Ken’s wife • RULE: If X is Y’s wife, then Y is X’s husband • The computer – the inference engine – can apply the rule to the fact and come up with a new fact: FACT: Ken is Amy’s husband.

EXPERT SYSTEMS An EXPERT SYSTEM is a software package used with an extensive set of organised data that presents the computer as an expert on a particular topic. There are three areas which all work together to make up an expert system and all have specialist titles. These are: • The knowledge base • a set of facts and rules about those facts • The inference engine • the reasoning part of the system -accesses, selects, and interprets a set of rules • The explanatory interface (the user interface)- the part which communicates with the user

Why not just stick with human experts? • they are typically expensive, subject to biases and emotions, and they may be inconsistent • there have been occasions when experts have resigned or retired, leaving the company in a state of crises. • If there is just one expert, or even just a few experts, there may not be enough to satisfy the needs of the system The computer, however, is ever present and just as available as the telephone Advantages: -An ES can reach in a few seconds a conclusion based on complex calculations that would take a human days or weeks to perform. - they are usually faster more accurate and provide up-to –date information

LIMITATIONS OF EXPERT SYSTEMS: • ES are unable to deal with unexpected input and cannot make a what we consider a common-sense decision in exceptional circumstances. • Data contained in the knowledge base is only as good as long as it is accurate. Errors can be made by domain experts or by some sort of misunderstanding between the domain experts and the knowledge engineerduring the construction of the system • The task of knowledge acquisition is so enormous for the engineer that is inevitable that omissions are made

Computer Control Applications *1) CAD ( Computer Aided Design) are computer systems used for commercial design work - The workstations are composed of a high resolution monitor, a mouse or graphics pad (tablet) and a powerful processor with large capacity backing storage, usually hard disk. Designers can create objects, plans or designs in two or three dimensions and store them on backing store. They can be easily altered, added to, deleted from, rotated and viewed from different angles before being stored back on disk or multiple copies can be printed out.

*2) CAM - Computer Aided Manufacture uses machines controlled by the computer to manufacture things. • - the machines can be either a range of robots or Computer Numeric Controlled (CNC) machines used for cutting shapes from metal. • once instructions are fed to them they will accurately cut the required shape over and over again until instructed to stop. • 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.

Computer Controlled Simulations • Computers can be used to create models of the real world in many different ways. Simulator programs range from programs which contain no graphics but carry out only calculations (e.g. spreadsheets - used by business and government for budget forecasting) to simulators such as aircraft simulators which are mock-ups of the cockpits of real aircraft and allow the pilot to "fly" the aircraft and experience exactly what it is like. Virtual Realityis a form of simulation where the movements of the user are translated into screen changes by computer. VR systems use stereo vision screens and surround sound to make the user feel as if they are actually inside the computer’s world. Real-time operation uses the computer to process events as they happen.

Using Real-time Processing In Real-time processing the system reacts instantly to data fed back to the processor from sensors. e.g: an automated system that controls the flight path of a plane has to react instantly , for safety reasons.

Advantages of using simulations rather than the 'real thing' include : • - Simulations allow you to alter the time that the real life event takes - either faster (simulating a battle scene) or slower (launching a rocket) or (slowing up a chemical reaction). • - they often cost less than the real event - war games • - they can create a fantasy or unreal event • - they may allow dangerous events to take place in safety - learning to fly • they are safer because there is no injury or death in the event of failure • they are not expensive e.g.: the opportunity to experience normal and rare conditions without destroying equipment.

Automated systems - The Hardware I. INPUTandOUTPUTdevices are connected to the processor. INPUT PROCESS OUTPUT INPUTcomes from sensors that give information about the surroundings. (e.g. sensors that detect heat, light and movement) OUTPUTgoes to control motors and machines SENSOR: a device which detects something and provides input to a computer. A sensor gathers data and feeds it back to the processor. Types of sensors: pressure sensor, infra-red sensor, magnetic sensors, electromagnetic sensor, light sensor, radiation sensors, etc. E.g. A pressure pad at a traffic light - a signal is produced if a car goes over it.

II.FEEDBACK • A computer sends signals to output devices. • The computer does not know if its commands have been carried out if no information comes back from the output devices. • Information can be sent back to the computer if sensors are fitted to the output device. • The return of information from the sensors to the computer is described as feedback. • Feedback – is information that is passed from sensors to a control system • With feedback, a robot can be made to follow a magnetic guide line using a sensor that detects magnetism or a white guide line using a light sensor.

Interfaces The input and output devices have to communicate with the processor. (the processor is faster than I/O devices) • An interface is used to allow for the differences in speed of operation and codes used by these different devices. An interfaceis circuitry between the computer and its peripherals, which makes possible the comunnication between the computer and the peripheral devices attached to it. An interface compensate for thedifferences insignals and other characteristics between the CPU and the peripheral devices. The interface may be built into the computer system or it may be part of the device; it may also be a separate box between the two.

Computers are only capable of processing digital data, but many of the inputs from sensors are analogue. • *These inputs are converted by analogue-to-digital converters (A to D) so that the computer can process the signals accordingly. • *If the output from the computer has to be converted into some analogue form, this would be done by a digital-to-analogue converter (D to A).

Analogue & Digital Signals • Analogue: • An Analoguesignal is a continuous signal which can have any value.The handson a watch or the needle on a car speedometer both give an analogue signal as they can point at any value on the face of the watch or speedometer. • Digital: • ADigitalsignal is a signal which can only take on specific values. • Computers are said to be digital devices as they operate using only two values, 0 and 1. • A digital watch shows hours, minutes and perhaps seconds but not the values in between each second. • The digitalsignal used by a computer is binary code (0's and 1's) and no other values.

Signals • Most electrical signals are analoguesignals. Analogue signals can vary continuously between two limits. • Computers only work with digitalsignals which have only two values - on or off. An ‘on’ signal is represented by a 1 and an ‘off’ by a 0.

Implications of Automated Systems 1. Social– people may lose their jobs, computers can replace them. Computers are quicker and cheaper. It incurs that there is a re-training of jobs for the people who have lost their jobs. Fewer workers are required, the people who have lost their job may have more leisure time, however for some people, new technologies have made more work. Some people now work from home. People now suffer from R.s.i. working at computers. 2. Technical – moving parts of machines must be covered, workers must take care, robot vehicles must be fitted with sensors to avoid collisions. 3.Quality – automated systems allow the quality of a product to be kept consistent. They will produce a printout of the results and they can be used to monitor the efficiency of the production process. This continuous checking improves quality.

4. Economic – automated systems are very expensive to initially install, but their expense balances out as they do not require payment, holidays or sickness. However, they do require maintenance and can break down. One machine can replace many people and this can lead to increased productivity, which means that more goods can be produced in the same time for the same cost.

Advantages and Disadvantages:- There are many long term savings because - - fewer workers are required (labour is expensive) - less lighting and heating required if fewer humans. - machines run for long periodsof time and still produce the same high quality and accuracy, so contracts can be completed quickly making the company more competitive. - - machines, unlike people, do not ask for wage rises and do not get sick or go on strike. (non-automated factories are capital and labour intensive. Start-up costs of machinery and buildings is high and running costs which include wages are also high.) - special facilities (canteens, toilets, personnel departments, etc.) must be provided for employees but not for machines. - automated factories make for higher productivity (more goods produced for money invested) than traditional manual systems.

Automated Systems