m6_12.m

設計一個比例控制器去對閉迴路轉移函數做控制。

%m6_12.m
clc
clf
clear

num=[2];                       
den=poly([0 -3.5 -10.34]);            
sys=tf(num,den)                 
pos=input('Please type POS  ');            
z=(-log(pos/100))/(sqrt(pi^2+log(pos/100)^2));                                   
Pm=atan(2*z/(sqrt(-2*z^2+sqrt(1+4*z^4))))*(180/pi);
w=0.01:0.5:1000;                
[mag,phase]=bode(sys,w);                   
Ph=-180+Pm;
for k=1:1:length(phase)
if phase(k)-Ph<=0                                                         
M=mag(k);                            
disp('Request Gain ')                       
K=1/M                              
break                              
end
end                             
sysc=feedback(K*sys,1);                 
[y,t,x]=step(sysc);
plot(t,y)
grid
title(['Closed-Loop Response for K= ',num2str(K)])
xlabel('Time(sec)')
ylabel('Amptuilde')