(Design, develop and demonstrate a simple open loop and closed loop feedback control system like temperature control system, liquid level control system, steam pressure control system, positional control system, speed control system, etc. Finally compare and discuss the results obtained by open loop and closed loop system.)hmm i hav this question in my assigment...n i don hav any idea wat 2 do n from wher 2 start.....??? plzzz reply me as soon as possible
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Open loop system: eating as much as you want.. no advice from doctor.
Closed loop system: Eat regulated food.. Doctor is constantly monitoring parameters and controls your food intake.
In essence that is what it is. Open loop temperature control is. You increase the voltage applied to a resistor, and its temperature increases. In closed loop control, we also note what the temperature is of the resistor and apply only as much voltage as is required to get the required temperature.
open loop voltage control: uses a variac or an autotransformer to increase or decrease voltage. Closed loop "servo stabiliser" monitors the output Regulated voltage, and any correction required is made by readjusting the auto transformer or variac.
Speed control. Increase of voltage in shunt motor yields higher speed with field held constant. In closed loop control we also monitor speed and feed just as much voltage as required, so that speed is desired value.
Closed loop control can be done using ON OFF, or PID. Typical control of refrigerator is ON OFF control. Stand near the refrigerator for half an hour and note the time at which you hear the compressor running. It runs till a temp sensor inside tells that adequate cooling has been done. Then compressor switches off. But temperature slowly increases, and once again the temperature sensor will automatically turn the compressor On after say 3 or 4 mins, for say 1 minute. It is AUTOMATIC control. You do not have to be doing anything .. just as in cruise control of speed in cars. the fuel gets automatically fed to maintain a desired speed. If speed is too high, fuel is automatically reduced and vice versa. This is closed loop, where parameter under control is "monitored" and corrective action taken to keep the parameter close to desired value.
temperature controlled soldering iron is an example of , yes you guessed it, closed loop control. The temperature of the tip is monitored and controls the heater duty cycle: how long it is On and Off. An LED typically shows what is happening.. The LED is ON when the heater is ON. Get to see one, and study it.
Closed loop system: Eat regulated food.. Doctor is constantly monitoring parameters and controls your food intake.
In essence that is what it is. Open loop temperature control is. You increase the voltage applied to a resistor, and its temperature increases. In closed loop control, we also note what the temperature is of the resistor and apply only as much voltage as is required to get the required temperature.
open loop voltage control: uses a variac or an autotransformer to increase or decrease voltage. Closed loop "servo stabiliser" monitors the output Regulated voltage, and any correction required is made by readjusting the auto transformer or variac.
Speed control. Increase of voltage in shunt motor yields higher speed with field held constant. In closed loop control we also monitor speed and feed just as much voltage as required, so that speed is desired value.
Closed loop control can be done using ON OFF, or PID. Typical control of refrigerator is ON OFF control. Stand near the refrigerator for half an hour and note the time at which you hear the compressor running. It runs till a temp sensor inside tells that adequate cooling has been done. Then compressor switches off. But temperature slowly increases, and once again the temperature sensor will automatically turn the compressor On after say 3 or 4 mins, for say 1 minute. It is AUTOMATIC control. You do not have to be doing anything .. just as in cruise control of speed in cars. the fuel gets automatically fed to maintain a desired speed. If speed is too high, fuel is automatically reduced and vice versa. This is closed loop, where parameter under control is "monitored" and corrective action taken to keep the parameter close to desired value.
temperature controlled soldering iron is an example of , yes you guessed it, closed loop control. The temperature of the tip is monitored and controls the heater duty cycle: how long it is On and Off. An LED typically shows what is happening.. The LED is ON when the heater is ON. Get to see one, and study it.