Question 1
Consider the discrete-time control system with a proportional controller K as shown in the following figure. The sampling period T is 0.1 second.
(1) Determine the pulse transfer function of the closed-loop system. (25 marks)
(2) Determine the range of gain K for stability of the closed-loop system. (25 marks)
(3) When K=1, draw Bode diagram of the open loop system in the w-plane by using any available method. (25 marks)
(4) Design the controller gain K so that the phase margin of the digital control system is 50o . With this value of K, determine the gain margin. (25 marks)
