Question

Jim and Jill each designed a controller for a system and simulated the response to an
input. The controllers are different as are the responses. Both claim their controller
performs better than the others and both claim to have numerical data measuring the
quality of control to prove their case. Can they both be right? Why or why not?

Answer 1

Yes it is possible.

There are mainly three typess of controller ; P, PI and PID. P controller has only one adjustible parameter namely k_c , PI has two adjsutible parameter, K_c and _I while PID controller has thee adjustible parameter K_c , _I and _D. The best response is recorded by an effective trade off among the various parameters. Increasing the integral action in PI controller help in faster eliminating the offset but at the cost of higher oscillation. Whereas in PID controller, derivative action is used to reduce the slugishness of the response but for a radiply changing error, derivative action is not advisable. Hence for a system having rapidly changing error, one can say that PI controller should be preferred while if reducing oscillations is the primary concern, one can say that PID should be preferred.