Home » Control Systems » Control systems miscellaneous » Question
  1. The condition of a stability for a unity feedback control system whose open loop transfer function is given by
    G(s) =
    e–sT
    s(s + 2)

    1. T < 2
    2. T = 2
    3. T > 2
    4. 0
Correct Option: A

Given

G(s) =
e-sT
. H(s) = 1
s(s + 2)

We know that,
C(s)
=
G(s)
R(s)1 + G(s)H(S)

or
C(s)
=
e-sT
R(s)s22s - e-sT

The C.E. s2 + 2s + e–sT = 0
or
s2 + 2s + (1 – st + st2/2! – ……) = 0
or
s2 + 2s + 1 – st = 0
or
s2 + s (2 – t) + 1 = 0
for stability 2 – T > 0
or
T < 2



Your comments will be displayed only after manual approval.