Anna University Coimbatore 2009 B.E Electrical and Electronics Engineering Control system - Question Paper

R(t) = A u(t)
Where, u(t) = 1, t > 0
u(t) = 0,t<0
13. describe Ramp signal:
A ramp signal is a signal whose value increases linearly with time from an initial value of zero at t = 0. It is mathematically represented as
r(t) = A t, t > 0= 0, t < 0

14. describe parabolic signal:
It is a signal in which the instantaneous value varies as square of the time from an initial value impulse signal. Ideal impulse signal is a unit impulse signal
which is described as a signal having zero values at all time other than at t = 0. At t = 0 the magnitude becomes infinite. It is ted by _(t)of zero at t = 0. It is mathematically represented as r(t) = A t2, t>02= 0, t<0
15. What is the order of a system?
The order of the system is provided by the order of the differential formula governing the system. It is also provided by the maximum power of s in the denominator polynomial of transfer function. The maximum power of s also provide the number of poles of the system and so the order of the system is also provided by number of poles of the transfer function.
16. describe Damping ratio:
The damping ratio is described as the ratio of the true damping to critical damping.
17. provide the expression for damping ratio of mechanical and electrical system:
The damping ratio of 2nd order mechanical translational system, _ = B / two _(MK)
The damping ratio of 2nd order mechanical rotational system, _ = B / two _(JK)
The damping ratio of 2nd order electrical system, _ = R / two _(L/C)
18. How the system is classified depending on the value of damping?
Depending on the value of damping, the system can be classified into the subsequent 4 cases
Case one : Undamped system, _ = 0
Case two : Underdamped system, 0 < _ < 1
Case three : Critically damped system, _ = 1
Case four : Over damped system, _ > 1.
19. What will be the nature of response of a 2nd order system with various kinds of damping?
??For undamped system the response is oscillatory.
??For underdamped system the response is damped oscillatory.
??For critically damped system the response is exponentially rising.
??For overdamped system the response is exponentially rising but the rise time will be very large.
20. List the time domain specifications:
The time domain specifications are :
(i) Delay time
(ii) Rise time
(iii) Peak time
(iv) Maximum overshoot

Earning:   Approval pending.