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1. The act of measuring or the process of being mea, sured., 2. A system of measuring: measurement in miles., 3. The dimension, quantity, or capacity determined b, y measuring: the measurements of a room., , 6.3 MEASUREMENT APPLICATION
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MEASUREMENT APPLICATION, • Measurement applications, application using sensors and, other electronic hardware (such as microprocessor), are many and varied., • This types of application involves sensors constantly taking measurement, data (such as temperature, rate of rotation or light intensity)., , • Data recorded in sensor are often in an analogue form, thus they have to, be sent to an Analogue to Digital converter (ADC) to turn the data into a, digital format., • This is needed because microprocessor and computers only, understand digital data.
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MEASUREMENT, APPLICATION, • When controlling devices such as pumps, valves, heaters, etc, data/signals (a, series of 1s and 0s) from the computer often need to be converted back into, an analogue form (e.g. electric signals) using a Digital to Analogue Converter, (DAC)., • After conversion, the data is sent to a microprocessor where it is processed., , • However, in measurement applications, the microprocessor simply reviews, the data from the sensors (by sometimes comparing it to data stored in, memory) and updates its files and sometimes gives a warning signal if the, values are outside given parameters., • The microprocessor will take no action to change any of the conditions, during the measurement process.
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MEASUREMENT APPLICATIONS, • Weather stations, , • Scientific experiments (e.g. taking temperature measurements), • Measuring a patient’s vital signs on a hospital, , • Pollution monitoring, • Burglar alarm systems
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6.3.1 WEATHER STATIONS, • Weather stations are set up to automatically gather data from the, environment., • They usually unmanned ad use a variety of sensors to measure:, , ❖Rainfall (rain gauge,udometer, pluviometer, or an ombrometer), ❖Temperature (temperature, heat), ❖Wind speed ( anemometer), ❖Wind direction (Wind vanes), ❖Pressure (air pressure), , ❖Humidity (humidity)
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HOW IT WORKS, • Sensor collect data from the environment and send to, Analogue to digital converter (ADC) to turn data into digital, format., • Data is then send to microprocessor and compare with the, preset values., , • Data is send to output devices (monitor/ printer) to display, result.
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6.3.2 MEASURING A PATIENT’S VITAL SIGNS IN, HOSPITAL, • Sensors used in hospital to measure patient’s vital signs:, , • Temperature sensor (temperature), • Oxygen sensor (respiration), • optical heart rate sensor (heart rate), • Sphygmomanometers (blood pressure)
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HOW IT WORK?, • Sensor read key vital signs ( such as pulse rate, heart rate, temperature,, blood pressure, respiration etc.), • Data from the sensor is converted into digital using an ADC, • Data is stored in the computer’s memory, • The computer compares the data from the sensors with the values stored, in its memory (these will be input by the nurse or doctor for a particular, patient), , • The results are output on the screen in the form of graphs and/ or, numerical readouts, • An alarm is activated if any of the data is outside acceptable input values
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Pulse Oximetry, , Blood pressure sensor, , Temperature sensor, , Heart rate sensor
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6.3.3 MEASURING POLLUTION IN A RIVER, • The sensors are placed in at least two different positions so that a pollution, comparison can be made., • The data from the sensors is converted into digital using an ADC and sent to a, computer., , • The computer stores the received data., • The oxygen levels and acidity levels are also compared to pre-set levels stored in, memory., , • The oxygen and acidity levels from the different positions in the river are also, compared to see if they are similar – this is used to see if the source of the pollution, can be found.
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6.3.3 MEASURING POLLUTION IN A RIVER, • Either the data is transferred to a CD / DVD or to a memory stick and, taken away for analysis, , • Or a computer is connected to a mobile phone network and transmits the, data back automatically to the monitoring station., , • ** Other sensor: light, temperature, oxygen, ……
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6.3.3 MEASURING POLLUTION IN A RIVER, Advantages:, • The computer wouldn’t forget to take readings, • The computer's response time is much faster (very important in the, hospital monitoring application)., • Doctors, nurses, scientist, etc. can all get on with other tasks whilst the, measurements are taken automatically., • Computer give 24-hour cover every day, • The readings will tend to be more accurate.
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6.3.3 MEASURING POLLUTION IN A RIVER, Advantages:, • Reading can be taken more frequently if done by a computer and, sensors., • It could also be safer since whatever is being measured may have, potential hazards (falling into river whilst attempting to take readings or, nurse looking after a patient who has a contagious disease)., • Computers can produce graphs automatically for analysis of results, • Potential cost saving as fever staff are needed since the measurements, are now done by a computer
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6.3.3 MEASURING POLLUTION IN A RIVER, Disadvantages:, • The computer are unable to respond to unusual circumstances, , • Computer equipment and measuring software can be expensive to, purchase and set up in the first place, • Students will rely on the computer doing the measurement and analysis, (loss analysis skill), • If the computer malfunctions or if there is a power cut, then the, computer cannot be used, and there must be a good backup procedure, in place to cover this eventually, •
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Analogue:, Data is constantly varying and has no discrete values., (e.g. the height of mercury in a thermometer to represent, temperature.), Digital:, Refer to discrete data which is made up from the binary, values 0 and 1.
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6.4 MICROPROCESSORS IN CONTROL, APPLICATIONS, • In control applications, sensors and a microprocessor or computer are again used., • Sensors send data to the microprocessor or computer which then compares the, incoming data to stored values or data entered earlier on. As with measuring, applications, an ADC may be needed before the microprocessor / computer can, process the data., , • The microprocessor / computer will check whether the incoming data is outside the, given parameters and will take any necessary action. For example, a temperature, sensor sends data to a computer which will then check whether the temperature is, greater than the preset or stored value., • If the temperature is greater than preset value, the computer will send a signal to, switch off a heater.
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EXAMPLE OF CONTROL APPLICATIONS, • Automatic washing machines, , • Automatic ovens/ cookers, • Central heating systems, • Chemical plants, • Glasshouse environment control (green house control)
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HOW CAN COMPUTERS CONTROL THINGS?, • A computer control system, like any system, is made up of three parts., , 1.Input devices called sensors, feed data into the computer, 2.The computer then processes the, input data (by following a set, of instructions), 3.As a result of the processing, the, computer, can, turn, on, or, off output devices called actuators.
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Actuators, A normal PC has no way of affecting what is happening around it., It can’t turn on the lights, or make the room hotter. How do we, change what is happening around us? We use our muscles to, move things, press things, lift things, etc. (and we can also, make sound using our voice)., A normal PC has no muscles, but we can give it some. In fact we, can give it the ability to do lots of things by connecting a range, of actuators to it…, , An actuator is a device, controlled by a computer, that can affect, the real-world.
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Examples of actuators, and what they can do are...
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AUTOMATIC OVEN/COOKER, • An automatic cooker /oven has temperature sensors and a number of controls to set, the cooking time (i.e when to switch the cooker / oven on and off)., , • First of all. The start time and end time (or the actual cooking time) are entered., • Finally, the cooking temperature is selected., , • The microprocessor checks the set time against the current time and when they are, equal, the cooker/ oven heating elements are switched on., • Once the cooker / oven starts the cooking process, the microprocessor then constantly, checks the end time against current time (the end time may be a pre-set value entered, by the user or it may be a value calculated by the microprocessor, based on the, cooking time entered); when they are equal, the cooking process is stopped.
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AUTOMATIC OVEN/COOKER, • The microprocessor checks the temperature data sent from a sensor and turns the, heating elements on if the value less than the preset value chosen by user. If the, temperature is great than or equal to preset value, then the heating element is, switched off by the microprocessor., , • Once the cooking process is finished, the microprocessor sends a signal to a beeper, to making a beeping sound to indicate that the cooking cycle is completed.
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CENTRAL HEATING SYSTEM, , • Picture below shows a gas supply is used to heat water in a boiler. A valve on the gas, supply is controlled by a microprocessor and is opened if the heating levels need to, be increased., • A water pump is used to pump hot water around the central heating system, whenever the temperature drops below a preset value.
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AN AUTOMATED GREENHOUSE, • A computer-controlled greenhouse might have a number of sensors and, actuators:, A light sensor to detect how much light the plants are getting, • A temperature sensor to see how cold/hot the greenhouse is, • A moisture sensor to se how wet/dry the soil is, • Lights to illuminate the plants if it gets too dark, • A heater to warm up the greenhouse if it gets too cold, • A water pump for the watering system, • A motor to open the window if it gets too warm inside
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WHY USE COMPUTERS TO CONTROL, THING (COMPUTER MODELLING)?, It is often far better to have a system that is managed and controlled by a computer, rather a human because:, • Computers never need breaks - they can control a system without stopping, all, day, every day, • Computers don’t need to be paid. To buy and install a computerised control, system can be very expensive, but, in the long-term, money is saved by not, having to employee staff to do the work, • Computers can operate in conditions that would be very hazardous to human, health, e.g. nuclear power stations, chemical factories, paint-spraying areas, • Computers can control systems far more accurately, and respond to changes, far more quickly than a human could
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WHAT IS A COMPUTER MODEL?, • A computer model is a computer program that attempts, to simulate a real-life system. In other words, it is a ‘virtual’ version of, something in the real-world., • The computer model is designed to behave just like the real-life, system. The more accurate the model, the closer it matches real-life.
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MODELLING APPLICATIONS, • A computer model is the creation of a model of a real system in order to, study the behaviour of the system., • The model is computer generated and is based on mathematical, presentations., • The whole idea is to try to find out what mechanisms control how a, system behaves., , • This them makes it possible to predict the behaviours of the system in the, future and also see if it is possible to influence this future behaviours., • The are many examples of computer models which range from simple, spreadsheet representations through to complex flight simulators.
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• The following is an example of using a spreadsheet to do the modelling of a tuck, shop in school:, , • Thus by varying the values in column C or in column E it would be possible to model the shop’s, profit or loss. This is a very simple model but it shows the principal of using spreadsheet to, carry out any types of modelling that can be represented in a mathematical form.
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TRAFFIC LIGHT SIMULATION, , • A set of traffic lights are to be modelled at a Y-junction:, • In this computer model it is necessary to consider:, , • How and what data needs to be collected, • How the computer model is carried out, • How the system would work in real life
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TRAFFIC LIGHT SIMULATION, • How and what data needs to be collected?, • Manual data collection is possible but is prone to errors and is difficult to do over an 18hour period per day (for example)., • The sort of data that would need to be collected or considered for collection is as follows:, • A count of the number of vehicles passing the junction in all directions at all different, times of the day, • The day of the week (weekends, bank holidays, etc. can alter how the data need to be, interpreted), , • How long it takes a vehicle to clear junction, • How long it takes the slowest vehicle to pas through the junction, • Whether there are any pedestrian crossings etc. nearby, , • Whether there are other factors which might affect the junction (left turn, right turns)
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HOW IS THE COMPUTER MODEL CARRIED, OUT?
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HOW WOULD THE SYSTEM WORK IN REAL, LIFE?
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WHY ARE COMPUTER MODELS, USED?, There are several reasons that computer models are used:, • To test a system without having to create the system for real (Building, real-life systems can be expensive, and take a long time), • To predict what might happen to a system in the future (An accurate, model allows us to go forward in virtual time to see what the system will, be doing in the future), • To train people to use a system without putting them at risk (Learning, to fly an airplane is very difficult and mistake will be made. In a real, plane mistakes could be fatal!), • To investigate a system in great detail (A model of a system can be, zoomed in/out or rotated. Time can be stopped, rewound, etc.)
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WHY ARE COMPUTER MODELS, USED?, • There are less expensive than having to build the real thing, • On many occasions, it is safer to run a computer model (chemical, processes), • With computer models, it is much easier to try out various scenarios in, advance, , • Nearly impossible to try out some tasks in real life because of high risk, involved or the remoteness (e.g. outer space, under the sea, nuclear, reactors, crash testing cars), • Time scales are reduced by doing a computer model rather than the real, thing (population growth)
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EXAMPLES OF COMPUTER, MODELLING, • Designing Safer Cars, • A computer model of a car can be used to test how safe the design of, the car is in a crash., • The virtual car can be crashed over and over again, the effects, investigated and the design easily changed until it is as safe as, possible., • This is much quicker and cheaper than building and crashing real, cars!, , https://www.youtube.com/watch?v=7RAWDI4rIuY, , https://www.youtube.com/watch?v=TikJC0x65X0
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WEATHER FORECASTING, • A computer model of a weather system can be used to predict storms., The wind patterns, temperatures, etc. for the whole planet, are simulated using very powerful computers. If the computer model, is accurate (it is very difficult to make an accurate model since our planet is, rather big) then weather forecasters can use it to ‘fast-forward’ into, the future to see a prediction of what the weather will be tomorrow, next, week, next month., •, (Since weather is so complex, and the models, accurate enough, often the weather forecast is wrong!), , are, , not, , (yet)
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BUILDING BETTER BRIDGES, • A computer model of a bridge can be used to test the design., • Bridges have to be able to survive extreme weather conditions. It is, obvious not practical to build a real bridge and then wait to see if, it falls down in a storm. Instead, a computer model of the bridge is, created and tested in virtual storms., • If the model breaks, it can be quickly and cheaply redesigned and re-tested. If it doesn’t break, the real bridge can be, built, confident that it will survive real storms., • Bridges can also be tested to see if they can cope with heavy, traffic. The virtual bridge can be loaded with a traffic jam of virtual, trucks to check that it won’t collapse., • A similar system is used by building designers, especially for very, large or tall buildings, such as skyscrapers.
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RUNNING A BUSINESS, • A computer model of a business can be used to help predict future profits., , • If the workings of a business can be modelled accurately, in particular the, financial systems, then these models can be used to make predictions. The, models are used to help answer ‘what if …?’ type questions, e.g. “What if we, decrease the workforce by 15%? Will our profits increase or decrease?”, • Based on the answers that the model gives, the managers of the business, can make decisions., , Spreadsheets are often used to model the financial, systems of a business.
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Pilots can make, mistakes without, putting anyone’s life, at risk., , FLIGHT SIMULATOR, • Trainee pilots have many hours of lessons in flight, simulators before being allowed to fly a real airplane., • Flight simulators behave almost exactly like real airplanes, since they are controlled by a computer with a very accurate, and realistic model of the airplane. The main difference is, that the simulator can’t actually crash!, , https://www.youtube.com/watch?v=5Miei8UHiYg, https://www.youtube.com/watch?v=DQqY3gz_O8E&t=227s
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FLIGHT SIMULATOR, • Flight simulators can provide a pilot with any number of highly realistic, flying situations: storms, engine failures, low cloud hiding the, runway, etc., The experience that pilots gain whilst using the simulator means that, when they eventually start flying real airplanes, they already have many, of the required skills.
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WHAT IS AN INDUSTRIAL ROBOT?, • When you think of the word 'robot', you might picture a, human-shaped robot with arms, legs and a head - the, sort you see in sci-fi films. However this is not how the, sort of robots used in factories look., • Robots used in factories are called industrial robots,, and they come in a wide variety of shapes and sizes., • The most common type of industrial robot looks a little, bit like a human arm. The robot has joints (like, our shoulder, elbow, and wrist) and some sort of, manipulator / device on the end of the arm (where our, hand would be)., , The robot's joints are powered by very, strong electric motors. These motors, are controlled by a computer.
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A scene from an old, factory - no robots in, sight! This type of, manual labour, is repetitive and bori, ng., , In a new factory,, the same tasks, are performed, by robots, , •The robot's manipulator / device, depends upon the job that the, robot has to do. It could be:, •a gripper (like a hand, for picking, things up), •suction pads (for lifting sheet, metal or glass), •a paint spray gun (for painting, things), •a welding gun (for joining metal, together)
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HOW ARE ROBOTS USED IN A, FACTORY?, Robots in factories are used to:, • lift heavy items into from place to place, • assemble parts together to create things, • join parts together using glue, or by welding (melting metal), • paint things, Spray painting things (a, hazardous job for a human - most, paint is toxic), Stacking boxes for shipping, (tedious and hard for a human to do, all day), , Welding metals parts, together (needs skill and, accurac
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HERE ARE SOME VIDEOS OF, ROBOTS AT WORK:, •, , Industrial robots: how they're made and what they do, , •, , Examples of industrial robots at work, , •, , Two robot arms picking objects off a conveyor, , •, , Huge robot arm handling sheets of glass, , •, , Line of robots welding Toyota car bodies, , •, , Demo of a huge robot arm lifting car bodies, , •, , Mini Cooper cars built by robots, , •, , Robots building computer power supplies, , •, , Robots stacking trays of food, , •, , Robots packing and stacking games
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CONTROL OF ROBOTICS, • Control of robots is either through embedded (built-in) microprocessors or, linked to a computer system., • Programming of the robot to do a series of tasks is generally done in two, ways:, 1. The robots is programmed with a sequence of instruction which allow it, to carry out the series of tasks (e.g. spraying a car body with paint)
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ROBOTICS, 2. alternatively, a human operator manually carries out the series of, tasks; this can be done in two ways. In our example, we will assume, an object is being painted using a robot arm., (i) The robot arm is guided by a worker when spraying the objects;, each movement of the arm is stored as an instruction in the, computer
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ROBOTICS, Or, (ii) The worker straps sensors to his own arm and sprays the object;, each movement is stored as a set of instructions in a computer; the, sensors send back information such as position, relative to the object, arm rotation,, and so on – this information forms, part of the instructions stored in the, computer.
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ROBOTICS, • Whichever method is used, once the instructions have been saved,, each series of tasks can then be carried out by a robot arm, automatically., • Each instruction will be carried out identically every time (e.g, assembling parts in a television) giving a consistent product., • Robots are often equipped with sensors so they can gather, important information about their surroundings and also, preventing them from doing ‘stupid things’ e.g. stopping a robot, spraying a car if no car is present, or stop the spraying operation if
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ADVANTAGES OF USING ROBOTS, • They can work in environments harmful to human operators, • They can work non-stop (24/7), • They are less expensive in long term (although expensive to buy initially,, they don’t need wages), • Higher productivity (don’t need holidays, etc), , • Greater consistency (e.g. every car coming off a production line is, identical), • They can do boring, repetitive tasks leaving humans free to do other more, skilled work (e.g. quality control)
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DISADVANTAGES OF USING ROBOTS, • They find it difficult to do ‘unusual’ tasks like a human can (e.g. if an item on, the line is not in the correct place, a human worker would notice and correct, it)., • They can cause higher employment (replacing skilled worker), • There is a real risk of certain skills (such as welding) being lost, • Robots are independent of the skills base, factories can be moved anywhere, in the world, , • The initial set up and maintenance cost of robots can be expensive
