ex3_3.m

我们上课的资料

% 关闭所有图形窗口并清除内存变量
close all;
clear all;
% 系统开环传递函数描述
numo=[0 0 0 0 0.86];
den1=[1 0];
den2=[0.36,1];
den3=[0.3906 0.75 1];
deno=conv(den1,conv(den2,den3)); % Convolution and polynomial multiplication.
% 系统闭环传递函数描述
numc=numo;
denc=deno+numo;
% 系统仿真时间及频率初始化
t=0:0.1:20;
% 系统增益裕量及相角裕量 
[Gm,Pm,Wcg,Wcm]=margin(numo, deno);
% 显示结果
disp('System Gain Mardn and its associated frequency are:');
    Gm
    Wcg
disp('System Phase Margin and its associated frequencyare:');
    Pm
    Wcm
% 系统的闭环阶跃响应
figure(1);
step(numc,denc,t);
title('System Time Response');
xlabel('Time—sect');
ylabel('Response—valuet');
grid;
% 对数幅频特性函数
figure(2);
bode(numo,deno);
grid;