The block diagram representation of a tachometer feedback speed control system is shown in Figure 4. R(s) 15.5 C(s) K, s+1 Tachometer Ko Figure 4 (1). Develop the closed loop transfer function. (ii). Evaluate the value of DC gain K and the time constant T with the assumption of tachometer feedback variable Ko. (i). The system step response is represented by y = K(1 – e¬), sketch the step response curve for the system when the tachometer feedback variable Ko. (iv). Write a general MATLAB codes to reduce the block diagram into a single feedback control system, to calculate transfer function and to obtain unit step response and impulse response. (v). Comment on the step response curve which is obtained in (i) and (iv) with respect to K and time constant T. ko=2 k1=2.2 Note: Refer the Table for Ko and K, values.

5.Consider the feedback system shown in figure. Determine system parameters (a, K, z, p, Ko) to guarantee closed-loop system stability. K. (s+z) K (s +p) e RO E O Y (s² – a²)

Question 6 Calculate the gain margin in linear scale of a feedback control loop, when its open loop transfer function has no unstable poles and has associated the Nyquist plot si below, where a=0.71. Give your answer to 2 decimal places. Nyquist Diagram 0.6 0.4 0.2 -0.2 -0.4 -0.6 -2a/5 Real Axis -a/5 -a -4a/5 -3a/5 a/5 Calculate your answer to 2 decimal places.