Question

Which one of the following is an advantage of a PD controller in terms of damping and natural frequency?

(a) G remains fixed but natural frequency increases

(b) G remains fixed but natural frequency decreases

(c) Natural frequency fixed but G increases

(d) Natural frequency fixed but G decreases

The question was asked in unit test.

I need to ask this question from Design Considerations for Higher-Order Systems in portion Time Response Analysis, Design Specifications and Performance Indices of Control Systems

Answer 1

Right choice is (c) Natural frequency fixed but G increases

To explain: Comparing with the characteristic equation natural frequency remains fixed but the value of G that increases hence the transient response is improved.