P7.3 Consider a unity feedback system with open-loop transfer function $\frac{K}{(s+a)(s+b)}$.
When the closed-loop system is subjected to a step input, the output has an overshoot of $16.3 \%$ but ultimately attains the final value of 1 . The response to a ramp input has a steady-state error of 0.0625 .
(a) Find the value of $K, a$ and $b$.
(b) Mark the closed-loop poles.
(c) If the gain is doubled, find the closed-loop poles and mark it on the s-plane.
(d) Find percentage overshoot corresponding to the gain obtained in (c).