运行s-function Output argument "sys" (and possibly others) not assigned a value in the execution with "ctrl>mdlOutputs" function.

function [sys,x0,str,ts,simStateCompliance] = ctrl(t,x,u,flag,pa)
switch flag,
    case 0,
        [sys,x0,str,ts,simStateCompliance]=mdlInitializeSizes;
    case 1,
        sys=mdlDerivatives(t,x,u);
    case 2,
        sys=mdlUpdate(t,x,u);
    case 3,
        sys=mdlOutputs(t,x,u,pa);
    case 4,
        sys=mdlGetTimeOfNextVarHit(t,x,u);
    case 9,
        sys=mdlTerminate(t,x,u);
    otherwise
        DAStudio.error('Simulink:blocks:unhandledFlag', num2str(flag));
end
function [sys,x0,str,ts,simStateCompliance]=mdlInitializeSizes
sizes = simsizes;
sizes.NumContStates  = 0;
sizes.NumDiscStates  = 0;
sizes.NumOutputs     = 1;
sizes.NumInputs      = 3;
sizes.DirFeedthrough = 1;
sizes.NumSampleTimes = 1;   % at least one sample time is needed
sys = simsizes(sizes);
x0  = [];
str = [];
ts  = [0 0];
simStateCompliance = 'UnknownSimState';
function sys=mdlDerivatives(t,x,u)
sys = [];
function sys=mdlUpdate(t,x,u)
sys = [];
function sys=mdlOutputs(t,x,u,pa)
%X1 hatd x2 wm x3 wmref 
r7=pa.r7;
Pn = pa.Pn;
Phi = pa.Phi;
J = pa.J;
B = pa.B;
T=pa.T;
Ts=pa.Ts;
if t<=Ts
    n =T/(T-t);
    n1=T - t;% n/diff(n)
else
    n=T*(1+a*(T-Ts))/a/(T-Ts)/(T-Ts)-T/a/(T-Ts)/(T-Ts)*exp(-a*(t-Ts));
    n1= - (exp((-a*(Ts - t)))*(exp(a*(Ts - t)) - T*a + Ts*a - 1))/a;
end
hatd=u(1);
hatwm=u(2);
wmref=u(3);
www=2*J/Phi/Pn/3*(0-hatd/Pn+B/J*hatwm+n1*(wmref-hatwm)+r7*n^(0.5)*(abs(wmref-hatwm))^0.5*sign(wmref-hatwm));
sym=www;
function sys=mdlGetTimeOfNextVarHit(t,x,u)
sampleTime = 1;    %  Example, set the next hit to be one second later.
sys = t + sampleTime;
function sys=mdlTerminate(t,x,u)
sys = [];function [sys,x0,str,ts,simStateCompliance] = ctrl(t,x,u,flag,pa)
switch flag,
    case 0,
        [sys,x0,str,ts,simStateCompliance]=mdlInitializeSizes;
    case 1,
        sys=mdlDerivatives(t,x,u);
    case 2,
        sys=mdlUpdate(t,x,u);
    case 3,
        sys=mdlOutputs(t,x,u,pa);
    case 4,
        sys=mdlGetTimeOfNextVarHit(t,x,u);
    case 9,
        sys=mdlTerminate(t,x,u);
    otherwise
        DAStudio.error('Simulink:blocks:unhandledFlag', num2str(flag));
end
function [sys,x0,str,ts,simStateCompliance]=mdlInitializeSizes
sizes = simsizes;
sizes.NumContStates  = 0;
sizes.NumDiscStates  = 0;
sizes.NumOutputs     = 1;
sizes.NumInputs      = 3;
sizes.DirFeedthrough = 1;
sizes.NumSampleTimes = 1;   % at least one sample time is needed
sys = simsizes(sizes);
x0  = [];
str = [];
ts  = [0 0];
simStateCompliance = 'UnknownSimState';
function sys=mdlDerivatives(t,x,u)
sys = [];
function sys=mdlUpdate(t,x,u)
sys = [];
function sys=mdlOutputs(t,x,u,pa)
%X1 hatd x2 wm x3 wmref 
r7=pa.r7;
Pn = pa.Pn;
Phi = pa.Phi;
J = pa.J;
B = pa.B;
T=pa.T;
Ts=pa.Ts;
if t<=Ts
    n =T/(T-t);
    n1=T - t;% n/diff(n)
else
    n=T*(1+a*(T-Ts))/a/(T-Ts)/(T-Ts)-T/a/(T-Ts)/(T-Ts)*exp(-a*(t-Ts));
    n1= - (exp((-a*(Ts - t)))*(exp(a*(Ts - t)) - T*a + Ts*a - 1))/a;
end
hatd=u(1);
hatwm=u(2);
wmref=u(3);
www=2*J/Phi/Pn/3*(0-hatd/Pn+B/J*hatwm+n1*(wmref-hatwm)+r7*n^(0.5)*(abs(wmref-hatwm))^0.5*sign(wmref-hatwm));
sym=www;
function sys=mdlGetTimeOfNextVarHit(t,x,u)
sampleTime = 1;    %  Example, set the next hit to be one second later.
sys = t + sampleTime;
function sys=mdlTerminate(t,x,u)
sys = [];

Answer 1

[Fangjun Jiang]

Probably a typo at the last line of this code below. Should be 'sys', not 'sym'. Also need to add a line 'end' to finish this function. Do the same for other functions too.

function sys=mdlOutputs(t,x,u,pa)
%X1 hatd x2 wm x3 wmref 
r7=pa.r7;
Pn = pa.Pn;
Phi = pa.Phi;
J = pa.J;
B = pa.B;
T=pa.T;
Ts=pa.Ts;
if t<=Ts
    n =T/(T-t);
    n1=T - t;% n/diff(n)
else
    n=T*(1+a*(T-Ts))/a/(T-Ts)/(T-Ts)-T/a/(T-Ts)/(T-Ts)*exp(-a*(t-Ts));
    n1= - (exp((-a*(Ts - t)))*(exp(a*(Ts - t)) - T*a + Ts*a - 1))/a;
end
hatd=u(1);
hatwm=u(2);
wmref=u(3);
www=2*J/Phi/Pn/3*(0-hatd/Pn+B/J*hatwm+n1*(wmref-hatwm)+r7*n^(0.5)*(abs(wmref-hatwm))^0.5*sign(wmref-hatwm));
sym=www;