S-function error: sizes vector

Question

liang 2020-4-19

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/518991-s-function-error-sizes-vector

回答： liang 2020-4-19

There exists error:

Sizes vector returned by MATLAB S-function 'vehicle_model_verification_Sfunction' in 'vehicle_model_verification/S-Function' must be a real vector consisting of integer value of length 7

when I run the S-function code:

function [sys,x0,str,ts,simStateCompliance] = vehicle_model_verification_Sfunction(t,x,u,flag)
switch flag,
  %%%%%%%%%%%%%%%%%%
  % Initialization %
  %%%%%%%%%%%%%%%%%%
  case 0,
    [sys,x0,str,ts,simStateCompliance]=mdlInitializeSizes;
  %%%%%%%%%%%%%%%
  % Derivatives %
  %%%%%%%%%%%%%%%
  case 1,
    sys=mdlDerivatives(t,x,u);
  %%%%%%%%%%
  % Update %
  %%%%%%%%%%
  case 2,
    sys=mdlUpdate(t,x,u);
  %%%%%%%%%%%
  % Outputs %
  %%%%%%%%%%%
  case 3,
    sys=mdlOutputs(t,x,u);
  %%%%%%%%%%%%%%%%%%%%%%%
  % GetTimeOfNextVarHit %
  %%%%%%%%%%%%%%%%%%%%%%%
  case 4,
    sys=mdlGetTimeOfNextVarHit(t,x,u);
  %%%%%%%%%%%%%
  % Terminate %
  %%%%%%%%%%%%%
  case 9,
    sys=mdlTerminate(t,x,u);
  %%%%%%%%%%%%%%%%%%%%
  % Unexpected flags %
  %%%%%%%%%%%%%%%%%%%%
  otherwise
    DAStudio.error('Simulink:blocks:unhandledFlag', num2str(flag));
end
% end sfuntmpl
%
%=============================================================================
% mdlInitializeSizes
% Return the sizes, initial conditions, and sample times for the S-function.
%=============================================================================
%
function [sys,x0,str,ts,simStateCompliance]=mdlInitializeSizes
%
% call simsizes for a sizes structure, fill it in and convert it to a
% sizes array.
%
% Note that in this example, the values are hard coded.  This is not a
% recommended practice as the characteristics of the block are typically
% defined by the S-function parameters.
%
sizes = simsizes;
sizes.NumContStates  = 0;
sizes.NumDiscStates  = 6;
sizes.NumOutputs     = 6;
sizes.NumInputs      = 2;
sizes.DirFeedthrough = 0;
sizes.NumSampleTimes = 1;   % at least one sample time is needed
sys = simsizes(sizes);
%
% initialize the initial conditions
%
x0  = zeros(6,1);
Cf = -2*62610;
Cr = -2*74076;
Bs = 0.8;
Js = 0.1;
u = 10;
m = 1673;
a = 1.413;
b = 1.53;
Izz = 2750;
i0 = 16;
Kalpha = 2*39;
Ac = [0    1   0   0   0    0
      -Kalpha/i0/Js     -Bs/Js         Kalpha/u/Js     Kalpha/u/Js*a      0    0
      -Cf/m/i0     0     (Cf+Cr)/u/m    (a*Cf-b*Cr)/u/m-u      0     0
      -a*Cr/Izz/i0   0    (a*Cf-b*Cr)/u/Izz    (a^2*Cf+b^2*Cr)/u/Izz    0    0
      0    0   1   0   0   u
      0    0   0   1   0   0];
B1c = [0           0
       1/Js        0
       0           -Cr/m
       0           b*Cr/Izz
       0           0
       0           0];
Cc = eye(6);
Dc = zeros(6, 2);
sys = ss(Ac, B1c, Cc, Dc);
sysd = c2d( sys, 0.01 );
global Ad; Ad = sysd.a;
global Bd; Bd = sysd.b;
%
% str is always an empty matrix
%
str = [];
%
% initialize the array of sample times
%
ts  = [0.01 0];
% Specify the block simStateCompliance. The allowed values are:
%    'UnknownSimState', < The default setting; warn and assume DefaultSimState
%    'DefaultSimState', < Same sim state as a built-in block
%    'HasNoSimState',   < No sim state
%    'DisallowSimState' < Error out when saving or restoring the model sim state
simStateCompliance = 'UnknownSimState';
% end mdlInitializeSizes
%
%=============================================================================
% mdlDerivatives
% Return the derivatives for the continuous states.
%=============================================================================
%
function sys=mdlDerivatives(t,x,u)
sys = [];
% end mdlDerivatives
%
%=============================================================================
% mdlUpdate
% Handle discrete state updates, sample time hits, and major time step
% requirements.
%=============================================================================
%
function sys=mdlUpdate(t,x,u)
global Ad;
global Bd;
sys = Ad*x+Bd*u;
% end mdlUpdate
%
%=============================================================================
% mdlOutputs
% Return the block outputs.
%=============================================================================
%
function sys=mdlOutputs(t,x,u)
sys = eye(6) * x;
% end mdlOutputs
%
%=============================================================================
% mdlGetTimeOfNextVarHit
% Return the time of the next hit for this block.  Note that the result is
% absolute time.  Note that this function is only used when you specify a
% variable discrete-time sample time [-2 0] in the sample time array in
% mdlInitializeSizes.
%=============================================================================
%
function sys=mdlGetTimeOfNextVarHit(t,x,u)
sampleTime = 0.01;    %  Example, set the next hit to be one second later.
sys = t + sampleTime;
% end mdlGetTimeOfNextVarHit
%
%=============================================================================
% mdlTerminate
% Perform any end of simulation tasks.
%=============================================================================
%
function sys=mdlTerminate(t,x,u)
sys = [];
% end mdlTerminate