Question

Write down a transfer function of a stable system for which pure proportional feedback could drive the system unstable.

Answer 1

`Gs = 1 / (s + 1)^3`

Step-by-step explanation:

A system is known to be a stable system if the poles of the system lie on the negative real axis of the s plane.

A system that could be driven unstable by a P-controller would be:

`Gs = 1 / (s + 1)^3`

As the value of K increases, the closed loop poles move into the right half s plane