Open and closed loop control system Essay Example for Free

Open and closed loop mesh establishment EssayIn this assignment I shall be looking at the differences surrounded by open loop control bodys, closes loop control systems and also looking at and identifying the foreplay, output and feedback gained. Open eyehole lock System The open loop control system is the cheapest homunculus of control system you earth-closet have, this is due to its simplicity. The open loop control system has absolutely no artificial intelligence or whatever form of sensor what so ever. This then means there is nonhing controlling the inputs going in to the system, this then means that accuracy may be deficient and the system will not be working to its true efficiency. An pillow slip of this kind of system would be that for a zap. When we turn a microwave on we select the power we want and the time limit we want and away it goes. The thing is, when it is powering itself up, how does it no if its hitting the true temperature we wanted successfull y? The answer to this is that is doesnt. Open-loop control is useful for well-defined systems where the relationship between input and the resultant state can be modeled by a mathematical formula.For congressman determining the voltage to be fed to an electric motor that drives a constant load, in rank to achieve a desired speed would be a good application of open-loop control. If the load were not predictable, on the other hand, the motors speed might vary as a function of the load as well as of the voltage, and an open-loop ascendence would therefore not be sufficient to ensure repeatable control of the velocity. Closed Loop Control System The closed loop control system is rather to a greater extent expensive to implement than that of its counterpart.This is down to the complexity of the functions that it can complete. The closed loop does have some form of monitoring capabilities and can in fact use sensors ad artificial intelligence well. An example of a closed loop control s ystem would be that of the sprinkler system, where the user sets the desired time for the sprinkler to come on, and instead of juts doing this when set it could read the grass moisture in the first place and then compensate a split decision in whether it deficiencyed to be implemented or not. Control Loop Operations Normally an open loop control system comprises of the make outing three things, 1. Sensor This is apply to measure a value before being passed in to the process 2.Decision Decisions usually follow culture from the sensor being collected and analysed. This allows the system to remain up to date and make each appropriate changes accordingly 3. Action This is the action of the computer or comparator altering settings There are devil differing types of systems that can be used for control and they are Analogue or digital. The two shall be explained in greater detail below. Digital and Analogue Control Systems.The digital control system is used in the form of a mic ro controller to control a computer system. A digital controller is usually cascaded with the plant in a feedback system. The rest of the system can either be digital or analog. Some examples of analog systems with a digital feedback controller are Aircraft HVAC Electric motors PID controllers microwave radar Robotics Typically, a digital controller requires For mixed control types such as digital and analogue systems we sine qua non a process of conversion, for example digital to analogue converters (these are called DACS).The opposite can take place, by using an analogue to digital conversion process called ADC. All of these analogue control systems are engraft with micro controllers. These micro controllers have the power to run the systems and comprise of fairly common hardware properties. The characteristic hardware properties that can be found in the control systems micro controller can be seen below CPU This is the central processing unit EPROM Non volatile memory sourc e that doesnt prosperous its data when the power is switched off RAM This is the random access memory.I/O These are the input output devises A micro processor will control the control system and process the information in order for it to function correctly. For example, if we have a sprinkler system in the garden as antecedently described, the inputs and outputs would need to be managed by the micro controller. If the ground was wet, it could check its EPROM (erasable program read save memory) to see what the body of water density was, and then the process could make a decision and process it appropriately.on a lower floor is a contestation of the inputs that could be put in to this system. Time for eater to be sprinkled Required water density in the ground Temperature of the ground Duration timer Transducers (analogue systems) Usually the forms of input found in the analogue systems are called transducers. There is a specific purpose to doing this and its main reason is down to conversion. If for example we have an galvanic input and we want to display it as a picture on the scallywag we must use a television. The transducer in this will be the Cathode ray tube (CRT) which is electromagnetic.When using sensors or transducers the signal must be converted in to an electrical measurement (volts). Below is a list of the possible input devises we can have within a system or a circuit. Geophone Converts solid ground tremors in to electrical voltage Geiger-Muller tube used for measuring radioactivity Cathode ray tube (CRT) converts electrical signals into visual form When the electrical charge is received it then needs to be converted in to the correct signal type using one of the transducers above, however for these signals to be used correctly we need to obtain the appropriate components.Lamp The input for a lamp is electrical energy and this is then output as a get off source after being converted. This type of power source is used for many things Sp eaker Gathers electricity from the data source and then is output as a volume so people can hear it. This also has a large application/usage basis Heat The input once more is electricity, this is then converted and output as heat. This is normally found on things like electric fires and cable car cigarette lighters Motor This is input of electricity and then is output as movement energy. This type of system is used within moving doors.