ex7_35.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

% ex7_35
% 非线性系统线性化
figure('pos',[50,50,200,150],'color','w');
syms x1 x2 u
a11=jacobian('x2',[x1]);
a12=jacobian('x2',[x2]);
a21=jacobian('-2*x1^3-1.5*x1*x2+u',[x1]);
a22=jacobian('-2*x1^3-1.5*x1*x2+u',[x2]);
b1=jacobian('x2',[u]);
b2=jacobian('-2*x1^3-1.5*x1*x2+u',[u]);
A=[a11 a12;a21 a22];
B=[b1;b2];
c=[1 0];
d=0;
aa=subs(A,{x1,x2,u},{0.7937,0,1});
a=sym2poly(aa);
b=subs(B,{x1,x2,u},{0.7937,0,1});
G=ss(a,b,c,d);
G1=augstate(G);
[y,t,x]=step(G1);
plotyy(t,-0.1*x(:,1)+0.7937,t,-0.1*x(:,2)+0)