Modern Control Engineering

(Chris Devlin) #1
Example Problems and Solutions 839

MATLAB Program 10–27


% Response to initial condition


A = [0 0 1 0;0 0 0 1;-36 36 -0.6 0.6;18 -18 0.3 -0.3];


B = [0;0;1;0];


K = [130.4444 -41.5556 23.1000 15.4185];


Ke = [14.4 0.6;0.3 15.7];


F = [0 0;0 0;1 0;0 1];


Aab = [1 0;0 1];


Abb = [-0.6 0.6;0.3 -0.3];


AA = [A-BK BKF; zeros(2,4) Abb-KeAab];


sys = ss(AA,eye(6),eye(6),eye(6));


t = 0:0.01:4;


y = initial(sys,[0.1;0;0;0;0.1;0.05],t);


x1 = [1 0 0 0 0 0]*y';


x2 = [0 1 0 0 0 0]*y';


x3 = [0 0 1 0 0 0]*y';


x4 = [0 0 0 1 0 0]*y';


e1 = [0 0 0 0 1 0]*y';


e2 = [0 0 0 0 0 1]*y';


subplot(3,2,1); plot(t,x1); grid; title('Response to initial condition'),


xlabel('t (sec)'); ylabel('x1')


subplot(3,2,2); plot(t,x2); grid; title('Response to initial condition'),


xlabel('t (sec)'); ylabel('x2')


subplot(3,2,3); plot(t,x3); grid; xlabel('t (sec)'); ylabel('x3')


subplot(3,2,4); plot(t,x4); grid; xlabel('t (sec)'); ylabel('x4')


subplot(3,2,5); plot(t,e1); grid; xlabel('t (sec)');ylabel('e1')


subplot(3,2,6); plot(t,e2); grid; xlabel('t (sec)'); ylabel('e2')


r=0 y–y Observer u
+– controller
4
s(s+ 2)

Figure 10–51 Plant
Regulator system.


A–10–14. Consider the system shown in Figure 10–51. Design both the full-order and minimum-order observers
for the plant. Assume that the desired closed-loop poles for the pole-placement part are located at

Assume also that the desired observer poles are located at
(a)s=–8, s=–8for the full-order observer
(b)s=–8for the minimum-order observer
Compare the responses to the initial conditions specified below:
(a) for the full-order observer:
x 1 (0)=1, x 2 (0)=0, e 1 (0)=1, e 2 (0)= 0

s=- 2 +j2 13 , s=- 2 - j2 13

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