dfr_rock.m

导弹控制系统的鲁棒控制设计实例

% Frequency responses of the discrete-time rocket
% stabilization system
%
% flight time
t = input ('Enter time t = ');
% closed-loop interconnection
sim_rock
% discrete model
dsim_ic = samhld(sim_ic,Ts);
dclp = starp(dsim_ic,KD);
%
% closed-loop frequency response
ref_loop = sel(dclp,10,8);
[A,B,C,D] = unpck(ref_loop);
[magp,phasep,w] = dbode(A,B,C,D,Ts,1);
mag = 20*log10(magp);
figure(1)
semilogx(w,mag,'r'), grid
xlabel('Frequency (rad/s)'), ylabel('Magnitude (dB)')
title('Closed-loop magnitude plot')
figure(2)
semilogx(w,phasep,'b'), grid
xlabel('Frequency (Hz)'), ylabel('Phase')
title('Closed-loop phase plot')
%
% sensitivity to accelerometer and rate giro noise
noise_loop = sel(dclp,10,9:10);
[A,B,C,D] = unpck(noise_loop);
[magp1,phasep1,w1] = dbode(A,B,C,D,Ts,1);
mag1 = 20*log10(magp1);
[magp2,phasep2,w2] = dbode(A,B,C,D,Ts,2);
mag2 = 20*log10(magp2);
figure(3)
semilogx(w1,mag1,'r-',w2,mag2,'r--'), grid
axis([10^(-1) 10^3 -160 -40])
xlabel('Frequency (rad/s)'), ylabel('Magnitude (dB)')
title('Sensitivity to accelerometer and rate giro noises')
legend('Sensitivity to accelerometer noise','Sensitivity to rate giro noise',3)
%
% controller frequency responses
[A,B,C,D] = unpck(KD);
[magp1,phasep1,w1] = dbode(A,B,C,D,Ts,1);
mag1 = 20*log10(magp1);
[magp2,phasep2,w2] = dbode(A,B,C,D,Ts,2);
mag2 = 20*log10(magp2);
figure(4)
semilogx(w1,mag1,'r-',w2,mag2,'r--'), grid
axis([10^(-1) 10^4 -80 60])
xlabel('Frequency (rad/s)'), ylabel('Magnitude (dB)')
title('Controller magnitude plots')
legend('K_{\delta^o n_{y1}}','K_{\delta^o d\vartheta/dt}',3)
figure(5)
semilogx(w1,phasep1,'b-',w2,phasep2,'b--'), grid
axis([10^(-1) 10^4 -200 200])
xlabel('Frequency (rad/s)'), ylabel('Phase')
title('Controller phase plots')
legend('K_{\delta^o n_{y1}}','K_{\delta^o d\vartheta/dt}',3)