ex5_1.m

华东理工大学自动化系《控制系统分析、设计和应用》教材配套程序实例,有关说明： 1. 安装MATLAB软件。安装时

% ex5_1
% 根轨迹和等增益轨迹
G=tf([1 2],[1 2 3]);
H=1;
GH=G*H;
figure('pos',[50,50,220,210],'color','w');
syms alpha beta
for k=[1,2,5,10]; 
    y=subs(poly2sym(GH.num{1}),alpha+j* beta)/subs(poly2sym(GH.den{1}), alpha +j* beta);
    ezplot(abs(y)*k-1);
    hold on;
end;
[r,K]=rlocus(GH);
plot(real(r(1,:)),imag(r(1,:)),real(r(2,:)),imag(r(2,:)));
set(get(gca,'title'),'string','');