comparepid.m

该程序用PID系统实现差动转向车辆控制

%% Author: epokh
%% Website: www.epokh.org/drupy
%% This software is under GPL

clf;
close all;
K=[2,0.05,2];
decayInt=8;
scale=200;
time=[0 60];
[errInt1,errDiff1,Ct1,position_pts1]=simPID(K,time,0);
[errInt2,errDiff2,Ct2,position_pts2]=simPIDWindup(K,decayInt,scale,time,0);

maxCt1=max(Ct1);
minCt1=min(Ct1);
maxCt2=max(Ct2);
minCt2=min(Ct2);
Ct1norm=Ct1*(maxCt2-minCt2)/(maxCt1-minCt1);

subplot(2,1,1);
title('Control error comparison');
hold on;
grid on;
%%plot(Ct1-Ct2,'b--');
plot(Ct1norm,'r');
plot(Ct2,'g');
legend('Cerr normalized windup','Cerr no windup');
minCt2=minCt2+minCt2*0.001;
maxCt2=maxCt2+maxCt2*0.001;
axis([1 length(Ct2) min(Ct1norm) max(Ct1norm)]);
xlabel('sample time');
ylabel('normalized control error');
subplot(2,1,2);
%%now do a spectral analysis
CtFFT=fft(Ct2,512);
Pct=CtFFT.*conj(CtFFT)/512;
freq=1000*(0:256)/512;
plot(freq,Pct(1:257));
title('Frequency analysis of Ct no wind');
xlabel('frequency (Hz)');