Reconsider the unity feedback system discussed in E4.14. This time select K = 120 and K1 = 10.

The closed-loop system is depicted in Figure E4.15.

(a) Calculate the steady-state error of the closedloop system due to a unit step input, R(s) = 1/s, with Td (s) = 0. Recall that the tracking error is defined as E(s) = R(s)−Y(s).

(b) Calculate the steady-state response, y yt t

ss = lim (

y yt t

ss = lim ( ),

when Td (s) = 1/s and R(s) = 0.

FIGURE E4.15 Closed-loop feedback system with K K = 10. 120 and + R(s) Controller K = 120 Ta(s) + Process 1 s(s + 10) Y(s)