gusucode.com > MATLAB与控制系统仿真实践 源代码 > MATLAB与控制系统仿真实践 源代码/第十四章/eg14_12.m
delta=6; s=tf('s'); G=1500/s/(s+10)/(s+5); figure(1) margin(G) figure(2) step(feedback(G,1)) ex_pm=40; phi=-180+ex_pm+delta; [mag,phase,w]=bode(G); wc=spline(phase,w,phi); mag1=spline(w,mag,wc); magdB=20*log10(mag1); beta=10^(-magdB/20); t=1/(beta*(wc/10)); Gc=(1+beta*t*s)/(1+t*s); figure(3) margin(Gc*G) figure(4) step(feedback(Gc*G,1)) G2=feedback(G*Gc,1); [num2,den2]=tfdata(G2,'v'); t=0:0.01:10; y2=step(num2,[den2,0],t); plot(t,t,t,y2,':');grid title('斜坡输入和滞后校正后系统的斜坡响应') legend('斜坡输入','滞后校正后系统的斜坡响应');