wcp_mds.m

关于Mass-Damper-Spring System 的鲁棒控制源代码

% Worst case performance of the mass/damper/spring system
% 
sim_mds
clp_ic = lft(sim_ic,K,1,1);
%
% determine worst case uncertainty
T = clp_ic(1,1);
[maxgain,maxgainunc] = wcgain(T);
Twc = usubs(T,maxgainunc);
T20 = usample(T,20);
%
% worst case frequency response
omega = logspace(-1,3,400);
figure(1)
bodemag(Twc,'r-',T20,'b-.',omega), grid
title('Worst case closed-loop system Bode plot')
legend('Worst case','Random samples',3)
%
% worst case transient response
clp = usubs(clp_ic,maxgainunc);
%
% response to the reference
r = 1.0;    
ti = 0.01;    % time increment
tfin1 = 20.0; 
time1 = 0:ti:tfin1;
nstep1 = size(time1,2);
ref1(1:nstep1) = r;
tfin2 = 40.0; 
time2 = tfin1+ti:ti:tfin2;
nstep2 = size(time2,2);
ref2(1:nstep2) = 0.0;
tfin3 = 60.0;  % final time value
time3 = tfin2+ti:ti:tfin3;
nstep3 = size(time3,2);
ref3(1:nstep3) = r;
time = [time1,time2,time3];
ref = [ref1,ref2,ref3];
nstep = size(time,2);
dist(1:nstep) = 0.0;
[y,t] = lsim(clp_ic.Nominal,[ref',dist'],time);
%
figure(2)
plot(t,ref,'r--',t,y(:,1),'b-'), grid
title('Worst case closed-loop transient response')
xlabel('Time (secs)')
ylabel('y (m)')
clear ref1, clear ref2, clear ref3
clear dist
%
% response to the disturbance
ti = 0.01;     % time increment
tfin1 = 20.0; 
time1 = 0:ti:tfin1;
nstep1 = size(time1,2);
dist1(1:nstep1) = 1.0;
tfin2 = 40.0; 
time2 = tfin1+ti:ti:tfin2;
nstep2 = size(time2,2);
dist2(1:nstep2) = 0.0;
tfin3 = 60.0;  % final time value
time3 = tfin2+ti:ti:tfin3;
nstep3 = size(time3,2);
dist3(1:nstep3) = 1.0;
time = [time1,time2,time3];
dist = [dist1,dist2,dist3];
nstep = size(time,2);
ref(1:nstep) = 0.0;
[y,t] = lsim(clp_ic.Nominal,[ref',dist'],time);
figure(3)
plot(t,dist,'r--',t,y(:,1),'b-'), grid
title('Worst case transient response to the disturbance')
xlabel('Time (secs)')
ylabel('y (m)')
clear dist1, clear dist2, clear dist3
clear ref