Question

PROBLEMS: (10%) (a) Do zeros in the transfer function affect the stability of the system? What do they affect? (4%) (Medium) (b) A DC motor has constant voltage supply. Suppose the motor has no mechanical friction. Can the velocity of the motor accelerate all the way to infinity? Why? (3%) (Hard) (c) In PID control, which term will be dominant during the transient period and which term will be dominant at steady state? (3%) (Easy)

Answer 1

1st (A) Answer3rd (C) Answer

1.1 Steady state response:-

It is that part of response that remains after the transient have died out or it remains even after infinity time

1.2Transient response:-

Transient response is that Part of response which vanishes as time approaches to ∞.Such type of change is called as transient response .the nature of transient response of a linear control system is revealed by any of standard test signals that is Impulse, step ramp and parabolic. The nature of a transient response depends upon system poles only and not on the type of input.

Some people find the transient overshoot levels of the classic Z-N rule excessive and will accept a slightly longer transient interval in exchange for smoother settling.