fig6_69.m

包含了控制理论的各种仿真程序

%  Figure 6.69      Feedback Control of Dynamic Systems, 4e
%                   Franklin, Powell, Emami
% 

clear all
close all;

num=0.9*2;
den=[1 2 0 0];
w=logspace(-4,3,100);
Nw=size(w);
[m,p]=bode(num,den,w);
n1=conv([10 1],[1 0.005]);
num=conv(num,n1);
den=conv(den,[1 0]);
[mc,pc]=bode(num,den,w);
subplot(2,1,1)
loglog(w,m,w,mc,w,ones(Nw));
axis([.0001 100 .01 1000])
grid;
%xlabel('\omega (rad/sec)');
ylabel('magnitude');
title('Fig. 6.69: Compensation for PID design example: (a) magnitude.');
subplot(2,1,2)
if p>0, p=p-360; end      % Matlab quadrant control varies in different versions
if pc>0, pc=pc-360; end
semilogx(w,p,w,pc,w,-179*ones(Nw));
axis([.0001 100 -270 -90])
grid;
xlabel('\omega (rad/sec)');
ylabel('phase (deg)');
title('Fig. 6.69: Compensation design for PID example:phase.');