www.pudn.com > chap1.rar > chap1_7f.m

function [u]=pidsimf(u1,u2) 
persistent pidmat errori error_1 
 
if u1==0 
   errori=0 
   error_1=0 
end    
 
ts=0.001; 
kp=1.5; 
ki=2.0; 
kd=0.05; 
 
error=u2; 
errord=(error-error_1)/ts; 
errori=errori+error*ts; 
 
u=kp*error+kd*errord+ki*errori; 
error_1=error;