www.pudn.com > slidingmode3.rar > chap4_6plant.m

%S-function for continuous state equation 
function [sys,x0,str,ts]=s_function(t,x,u,flag) 
 
switch flag, 
%Initialization 
  case 0, 
    [sys,x0,str,ts]=mdlInitializeSizes; 
case 1, 
    sys=mdlDerivatives(t,x,u); 
%Outputs 
  case 3, 
    sys=mdlOutputs(t,x,u); 
%Unhandled flags 
  case {2, 4, 9 } 
    sys = []; 
%Unexpected flags 
  otherwise 
    error(['Unhandled flag = ',num2str(flag)]); 
end 
 
%mdlInitializeSizes 
function [sys,x0,str,ts]=mdlInitializeSizes 
sizes = simsizes; 
sizes.NumContStates  = 2; 
sizes.NumDiscStates  = 0; 
sizes.NumOutputs     = 3; 
sizes.NumInputs      = 1; 
sizes.DirFeedthrough = 0; 
sizes.NumSampleTimes = 0; 
 
sys=simsizes(sizes); 
x0=[pi/60 0]; 
str=[]; 
ts=[]; 
 
function sys=mdlDerivatives(t,x,u) 
 
g=9.8; 
mc=1.0; 
m=0.1; 
l=0.5; 
 
S=l*(4/3-m*(cos(x(1)))^2/(mc+m)); 
fx=g*sin(x(1))-m*l*x(2)^2*cos(x(1))*sin(x(1))/(mc+m); 
fx=fx/S; 
gx=cos(x(1))/(mc+m); 
gx=gx/S; 
 
sys(1)=x(2); 
sys(2)=fx+gx*u+3*sin(pi*t)*1; 
 
function sys=mdlOutputs(t,x,u) 
 
g=9.8; 
mc=1.0; 
m=0.1; 
l=0.5; 
 
S=l*(4/3-m*(cos(x(1)))^2/(mc+m)); 
fx=g*sin(x(1))-m*l*x(2)^2*cos(x(1))*sin(x(1))/(mc+m); 
fx=fx/S; 
gx=cos(x(1))/(mc+m); 
gx=gx/S; 
 
sys(1)=x(1); 
sys(2)=fx; 
sys(3)=gx;