DP8. 5 Consider the control system depicted in Figure
DP8.5(a) where the plant is a "black box" for which
little is known in the way of mathematical models. The
only information available on the plant is the frequen-
cy response shown in Figure DP8.5(b). Design a con-
troller G_(c)(s) to meet the following specifications:
(i) The crossover frequency is between 10ra(d)/(sec) and
50ra(d)/(sec); (ii) The magnitude of G_(c)(s)G(s) is
greater than 20dB for omega <0.1ra(d)/(sec).
Bode Diagram
FIGURE DP8.5
(a) Feedback
system with "black
box" plant.
(b) Frequency
response plot
of the "black box"
represented
by G(s).
(b)
Consider the control system depicted in Figure DP8.5a where the plant is a black boxfor which little is known in the way of mathematical models.The only information available on the plant is the frequen cy response shown in Figure DP8.5(b.Design a con- troller G.s to meet the following specifications: iThe crossover frequency is between l0 rad/sec and 50 rad/seciiThe magnitudeof GsGsis greater than 20 dB for<0.1 rad/sec.
Controller
Black box
R(s
G.(s)
G(s)
(a)
Bode Diagram
0
-20 Magnitude(dB 60 -80
-45 FIGURE DP8.5 Phase(deg) (a)Feedback system with "black 135 box"plant. -180 (b)Frequency 10-1 response plot of the"black box" represented by G(s.
100 101 Frequency (rad/sec
(b)