[求助] 【求助】simulink程序滑模控制老是报错，已附上程序，谢谢

function [sys,x0,str,ts]=zmwctrl2(t,x,u,Ps,PL,flag)
switch flag,
case 0,
    [sys,x0,str,ts]=mdlInitializeSizes;
case 1,
    sys=mdlDerivatives(t,x,u,Ps,PL);
case 3,
    sys=mdlOutputs(t,x,u,Ps,PL);
case {2, 4, 9 }
    sys = [];
otherwise
    error(['Unhandled flag = ',num2str(flag)]);
end
function [sys,x0,str,ts]=mdlInitializeSizes(t,x,u)
sizes = simsizes;
sizes.NumContStates  = 0;
sizes.NumDiscStates  = 0;
sizes.NumOutputs     = 1;
sizes.NumInputs      = 5;
sizes.DirFeedthrough = 1;
sizes.NumSampleTimes = 0;
sys=simsizes(sizes);
x0=[];
str=[];
ts=[];
function sys=mdlOutputs(t,x,u,Ps,PL)
xd=u(1);
dxd=0.02*2*pi*cos(2*pi*t);
ddxd=-0.02*(2*pi)^2*sin(2*pi*t);
dddxd=-0.02*(2*pi)^3*cos(2*pi*t);
x=u(2);dx=u(3);ddx=u(4);dddx=u(5);
e=xd-x;
de=dxd-dx;
dde=ddxd-ddx;
ddde=dddxd-dddx;
c1=25;c2=25;Ee=1400e6; Kce=1.1615e-12;
A=pi*(0.048^2-0.032^2)/4; M=200;B=63.7;Vt0=A*0.1;
Vt0=A*0.1;K=120e3;Cdpi=0.62*pi*5e-3*sqrt(2/880);
s=c1*e+c2*de+dde;

f=-4*Ee*K*Kce*x/(M*Vt0)-(4*Ee*A^2+4*Ee*B*Kce+K*Vt0)*dx/(M*Vt0)-(4*Ee*M*Kce+BVt0)*ddx/(M*Vt0);
b=4*Ee*(A*6e-3)*Cdpi*sqrt(Ps-PL)/(M*Vt0);

ueq=1/b*(c1*de+c2*dde+ddde-f);
D=50;
xite=0.10;
H=D+xite;
usw=1/b*H*sign(s);

ut=ueq+usw;

sys(1)=ut;

function [sys,x0,str,ts]=zmwplant2(t,x,u,flag)
switch flag,
case 0,
    [sys,x0,str,ts]=mdlInitializeSizes;
case 1,
    sys=mdlDerivatives(t,x,u);
case 3,
    sys=mdlOutputs(t,x,u);
case {2, 4, 9 }
    sys = [];
otherwise
    error(['Unhandled flag = ',num2str(flag)]);
end
function [sys,x0,str,ts]=mdlInitializeSizes
sizes = simsizes;
sizes.NumContStates  = 4;   
sizes.NumDiscStates  = 0;
sizes.NumOutputs     = 1;
sizes.NumInputs      = 1;
sizes.DirFeedthrough = 0;
sizes.NumSampleTimes = 0;
sys=simsizes(sizes);
x0=[0,0,0,0];
str=[];
ts=[];
function sys=mdlDerivatives(t,x,u)
dt=9;
Ee=1400e6; Kce=1.1615e-12;
A=pi*(0.048^2-0.032^2)/4; M=200;B=63.7;Vt0=A*0.1;
Vt0=A*0.1;K=120e3;Cdpi=0.62*pi*5e-3*sqrt(2/880);
f=-4*Ee*K*Kce*x(1)/(M*Vt0)-(4*Ee*A^2+4*Ee*B*Kce+K*Vt0)*x(2)/(M*Vt0)-(4*Ee*M*Kce+BVt0)*x(3)/(M*Vt0);
b=4*Ee*A*(A*6e-3)*Cdpi*sqrt(Ps-PL)/(M*Vt0);
sys(1)=x(3);
sys(2)=f+b*u+dt;
sys(2)=x(4);
sys(1)=x(1);
sys(2)=x(2);
sys(3)=x(3);
sys(4)=x(4);

function sys=mdlOutputs(t,x,u)
sys(1)=x(1);
sys(2)=x(2);
sys(3)=x(3);
sys(4)=x(4)