Describe and compare the characteristics of Proportional control, Integral and Derivative Control
Answers
Proportional Controllers
All controllers have a specific use case to which they are best suited. We cannot just insert any type of controller at any system and expect a good result – there are certain conditions that must be fulfilled. For a proportional controller, there are two conditions and these are written below:
1) The deviation should not be large; i.e. there should not be a large deviation between the input and output.
2) The deviation should not be sudden.
Derivative Controllers
We never use derivative controllers alone. It should be used in combinations with other modes of controllers because of its few disadvantages which are written below:
1) It never improves the steady-state error.
2) It produces saturation effects and also amplifies the noise signals produced in the system.
Integral Controllers
As the name suggests in integral controllers the output (also called the actuating signal) is directly proportional to the integral of the error signal.