chap7.zip_PID CONTROL_nonlinear observer_pid controller_robust_鲁

%Closed system approaching and zero phase error controller design clear all; close all; load freq.mat; ts=0.001; f=FF; for i=1:length(ph) if ph(i)>0 ph(i)=ph(i)-360; end end %Transfer function approaching %(1)Freq parameters w=2*pi*f; %From Hz to rad/sec mag1=10.^(mag/20); %From dB to degree ph1=ph*pi/180; %From degree to radian h=mag1.*cos(ph1)+j*mag1.*sin(ph1); %(2)Continous function na=3; %Three ranks approaching nb=1; %bb and aa are real numerator and denominator of transfer function [bb,aa]=invfreqs(h,w,nb,na); %w contains the frequency values in radians/s display('Transfer function approaching is:'); sysx=tf(bb,aa) [zs,ps,ks]=zpkdata(sysx,'v'); %(3)Discrete function Gc=c2d(sysx,ts,'zoh'); zpksys=zpk(Gc); [z,p,k]=zpkdata(zpksys,'v'); %Getting zero-pole-gain: z,p,k display('Zeros and Poles of the Transfer function is:'); z p %In z-1 format zGc=tf(Gc); [nGc,dGc]=tfdata(zGc,'v'); zGc=filt(nGc,dGc,ts); %(4)Magnitude and Phase to draw Bode %Frequency response:create the complex frequency response vector: h=a+bi h=freqs(bb,aa,w); %Magnitude and phase sysmag=abs(h); %Degree sysmag1=20*log10(sysmag); %From degree to dB sysph=angle(h); %Get radian sysph1=sysph*180/pi; %From radian to degree %(5)Drawing practical plant and its approach function Bode to compare figure(1); subplot(2,1,1); semilogx(w,sysmag1,'r',w,mag,'b');grid on; xlabel('Frequency(rad/sec)');ylabel('magnitude approach(dB)'); subplot(2,1,2); semilogx(w,sysph1,'r',w,ph,'b');grid on; xlabel('Frequency(rad/sec)');ylabel('phase approach(deg)'); figure(2); magError=sysmag1-mag; phError=sysph1-ph; plot(w,phError,'r',w,magError,'b'); xlabel('Frequency(rad/sec)');ylabel('error of phase(deg) and magnitude(dB)'); %(6)Plant in zero-pole-gain format zu=z(1); %Unstable zero point z1=z(2); p1=p; p1(4)=1/zu; k1=1; Gctemp=zpk(z1,p1,k1,ts); dc=dcgain(Gctemp); %Getting DC gain k1=1/dc; %G(1)=1; Gcn=zpk(z1,p1,k1,ts); %(7)Design controller Fdz=1/Gcn; %Fdz=zpk(p1,z1,1/k1,ts); display('ZPE Controller is:'); tfdz=tf(Fdz) %z^(-3):three rank delay [nn1,dd1]=tfdata(tfdz,'v'); nF=nn1; dF(1)=dd1(4); %z^(-3):three rank delay dF(2)=dd1(5); dF(3)=dd1(1); dF(4)=dd1(2); dF(5)=dd1(3); format long; display('ZPE Controller coefficient is:'); nF dF save zpecoeff.mat nF dF; %Controller F=filt(nF,dF,ts); %Equal conversion:from z to z-1 dcgain(F); %(8)Verify the controller Gn=series(F,Gc); %Gn(z)=F(z)*Gc(z) figure(3); bode(Gn); yk=minreal(Gn,ts); %Simpling Gn(z)