function [sys,x0,str,ts]=mySfunction4_PID3(t,x,u,flag,Kp,Ki,Kd,L_upper,L_lower,T_samp)
%說明：此PID對積分項做了限幅，并沒有對輸出作限幅
switch flag
    case 0
        [sys,x0,str,ts]=mdlInitializeSizes(T_samp);
    case 1
        sys=mdlDerivatives(t,x,u);
    case 2
        sys=mdlUpdate(t,x,u);
    case 3
        sys=mdlOutputs(t,x,u,Kp,Ki,Kd,L_upper,L_lower);
    case 4
        sys=mdlGetTimeOfNextVarHit(t,x,u);
    case 9
        sys=mdlTerminate(t,x,u);
    otherwise
        error(['Unhandle flag =',num2str(flag)]);
end
%-------------------------------------------------------------------------------------------%
function [sys,x0,str,ts]=mdlInitializeSizes(T_samp)
sizes=simsizes;
sizes.NumContStates=0;
sizes.NumDiscStates=0;
sizes.NumOutputs   =1;
sizes.NumInputs    =1;
sizes.DirFeedthrough=1;
sizes.NumSampleTimes=1;
sys=simsizes(sizes);
x0=[];
str=[];
ts=[T_samp 0];
mydata.pre_out=0;
mydata.pre1_in=0;
mydata.pre2_in=0;
set_param(gcb,'UserData',mydata);
%-------------------------------------------------------------------------------------------%
function sys=mdlDerivatives(t,x,u)
sys=[];
%-------------------------------------------------------------------------------------------%
%說明：此處只對積分項做了限幅，并沒有對輸出作限幅
function sys=mdlUpdate(t,x,u)
sys=[];
%-------------------------------------------------------------------------------------------%
function sys=mdlOutputs(t,x,u,Kp,Ki,Kd,L_upper,L_lower)
mydata=get_param(gcb,'UserData');
pre_out=mydata.pre_out;
pre1_in=mydata.pre1_in;
pre2_in=mydata.pre2_in;
%set_param(gcb,'UserData',u(1));
out=Kp*(u(1)-pre1_in)+Ki*u(1)*0.0033+Kd*(u(1)-2*pre1_in+pre2_in)/0.0033+pre_out;
if out>=L_upper
    out=L_upper;
elseif out<=L_lower
    out=L_lower;
end
mydata.pre_out=out;
mydata.pre2_in=mydata.pre1_in;
mydata.pre1_in=u(1);
set_param(gcb,'UserData',mydata);
sys=out;
%-------------------------------------------------------------------------------------------%
function sys=mdlGetTimeOfNextVarHit(t,x,u)
sys=[];
%-------------------------------------------------------------------------------------------%
function sys=mdlTerminate(t,x,u)
sys=[];