A closed-loop system is distinguished from open loop system by which of the following?
Right Answer is:
- A closed-loop control system utilizes a measure of the actual output to compare the actual output with the desired output response.
- A Closed-loop Control System is also called the feedback control system which uses the concept of an open-loop system as its forward path but has one or more feedback loops.
- The measure of the output is called the feedback signal. The elements of a general closed-loop feedback control system are shown in Figure.
- A closed-loop control system compares the measurement of the output with the desired output (reference or command input).
- The difference between the two quantities (the error signal) is then used to drive the output closer to the reference input through the controller and actuator.
- Often the difference between the output of the process under control and the reference input is amplified and used to control the process so that the difference is continually reduced.
Feedback:- Feedback is that property of a closed-loop system that permits the output (or some other controlled variable) to be compared with the input to the system (or input to some other internally situated component or subsystem) so that the appropriate controł action may be formed as some function of the output and input.
Note:- Essentially, the advantages of closed-loop systems are the disadvantages of open-loop systems, and the disadvantages of closed-loop systems are the advantages of open-loop systems. The introduction of feedback enables the engineer to control the desired output and improve accuracy, but it requires attention to the issue of stability of response. Feedback is used for the purpose of reducing the error between the reference input and the system output. However, the significance of the effects of feedback in control systems is more complex.