P13.7 A closed-loop system is shown in Figure E13.10. 

This system represents the pitch control of an aircraft. The process transfer function is G s p( ) =

K s[ ] ( ) 0.5s + 1 . Select a gain K and sampling period

T so that the percent overshoot is limited to 0.3 for a unit step input and the steady-state error for a unit ramp input is less than 1.0.

E(z) U(a) R(2) D(z) G(z) [{z) FIGURE P13.10 Feedback control system with a digital controller.