Consider the following block diagram Let Hs dss a and let

Consider the following block diagram: Let H(s) = d/s(s + a) and let C(s) be a proportional-derivative controller. Assuming that the closed-loop is stable, find the steady-state error when R(s) is a unit step input.

Solution

Correct answer is zero

It is a proportional derivative controller so at this controller the unit input always gives her zero output with respect to the input.