Control System (EX-405) - Important Questions

Explain and distinguish between open-loop and closed-loop control systems with suitable examples.

Use Mason's gain formula to determine the overall transfer function C(s)/R(s) from the given signal flow graph shown in Figure 1.

Obtain the force-voltage analogous electrical network for the given mechanical system shown in Figure 2.

Explain the construction and working of AC and DC servomotors along with their advantages, disadvantages and applications.

Explain the state-space description of dynamic systems. Obtain the state model for open-loop and closed-loop systems.

Find the static error coefficients Kp, Kv, Ka and the steady-state error for a unity feedback system subjected to a composite step plus ramp plus parabolic input.

Derive the time response of a second-order system to unit step input and explain the effect of damping ratio.

For the unity feedback system with G(s) = 10/[(s+2)(s+5)], determine the damping factor and time-domain specifications such as rise time, peak time, maximum overshoot and settling time for unit step input.

Using Routh array, determine stability and number/location of roots with positive, zero and negative real parts for the characteristic equation s^6+2s^5+8s^4+12s^3+20s^2+16s+16 = 0.

Sketch the complete root locus for G(s)H(s) = K/[s(s+6)(s^2+4s+13)] as K varies from 0 to infinity and comment on stability.

Sketch the Bode plot for the transfer function G(s)H(s) = 10/[s(s+1)(s+2)] and determine gain margin, phase margin, gain crossover frequency and phase crossover frequency, and comment on stability.

Draw the polar plot for the unity feedback system with open-loop transfer function G(s) = 1/[(1+s)(1+2s)] and determine the gain margin and phase margin.

Sketch the Nyquist plot for G(s)H(s) = K/[s(s+2)(s+10)] and determine the range of K for closed-loop stability.

Explain eigenvalues and eigenvectors and compute them (and modal/eigen matrix) for the system matrix A = [[0, 1], [-2, -3]].

What is a lag-lead compensator and under what conditions is it employed? Explain its effect on frequency response.

State the properties of State Transition Matrix. Compute the State Transition Matrix for A = [[-1, 1], [0, 2]].