Tutorial 5: PID Control Q.1 In the following typical control system block diagram, which block would represent the controller unit? -.. - R(s) + E(s) U (s) G. Go U (s ) Y(s) GA Q.2 In a typical control loop, the aim is to control: . .. R(s) E(s) Uls K G(s) Y(s) Q.3 For what values of K is the time constant of the closed-loop system less than 0.2s? R(s) + E(s ) U(s) K 3 12s + Q.4 A proportional controller, Kp is used wih a first-order system given by G(s)=K/(ts+1). What is the closed-loop transfer function? Q.5 The figure shows a typical closed-loop transfer function with the system transfer function G(s) and the controller transfer function K(s). R(S) E(s) U(s) Y(s K(s) G(s) What are the closed-loop transfer function GCL(s) for the following cases. (a) K(s)=Kp+Kas, G(s)=32/(s2+2.4s+16) (b) K(s)=Kp+K/s, G(s)=12/(s+10) Instrumentation & Control p. 1 of 2Q.6 For a step input of magnitude 3, determine the steady state error for the controller K(s) being: a) a proportional controller; b) a P + D controller; c) PHI controller. R(s) + E(s) U(s) Y(s) K(s) 6 s+ 1 Q.7 Let the reference be a unit ramp and determine the steady state error for the controller K(s) being a) a P + D controller; b) a P + I controller R(s) + E(s) U(s) Y(s) K(s 3 s(s2 +2s+1) Q.8 Increasing a proportional gain will: a) increase the overshoot, decrease the steady state error b) decrease the overshoot, increase the steady state error c) increase the overshoot, increase the steady state error d) decrease the overshoot, decrease the steady state error Q.9 Integral control has the advantage of: a) reducing steady state offsets b) reducing overshoot c) increasing stability d) all of the above Instrumentation & Control p. 2 of 2