状态反馈matlab仿真程序，注释详细，包括pid控制_状态反馈PID_matlab

clf, num=1,den=[1 3 2],tao=1, w=logspace(-2,2,200)', pause; % plot Nyquist graph clf; [r,i]=nyquist(num,den,w), rd=real((r+j*i).*exp(-j*w*tao)), id=imag((r+j*i).*exp(-j*w*tao)), plot(rd,id,'--'), pause; % slove the magnitude and phase %[mag,phase]=nichols(num,den,w), %mag,phase, %pause; %magdb=20*log10(mag), %[gm,pm,wpc,wgc]=margin(magdb,phase,w),grid, %gm,pm,wpc,wgc, %pause; % System Identification A=abs((rd(109,1)+rd(110,1))/2), w0=(w(109)+w(110))/2, t=[0:0.1:10], [y,x]=step(num,den,t); K=y(100,1), T=(sqrt(K*K/A/A-1))/w0,ti=(pi-atan(w0*T))/w0, num1=K, den1=[T 1], printsys(num1,den1), [r1,i1]=nyquist(num1,den1,w); %step(num1,den1), rd1=real((r1+j*i1).*exp(-j*w*ti)), id1=imag((r1+j*i1).*exp(-j*w*ti)), hold on, plot(rd1,id1,':'), pause; %Simulition by SIMULINK %k2=(1.41*0.6174*T-T-ti)/(K*ti), %k1=(0.6174^2*T/ti-1)/K-k2, %Kp=(2.15*T*ti-K*k1-K*k2-1)/K, %Td=(1.75*T*ti-T-ti-K*k2*ti)/(K*Kp), %Kd=Kp*Td, %Ti=(K*Kp*ti^2)/(T*0.6174^3), %Ki=Kp/Ti, num2=0.3099*0.6174^2, den2=[1 1.41*0.6174 0.6174^2], [r2,d2]=nyquist(num2,den2,w), plot(r2,d2),grid,