Failure in initial user-supplied objective function evaluation. FMINCON cannot continue.

Hi,

by executing the following code, I get the error message:

An error occurred while running the simulation and the simulation was terminated

Error evaluating registered method 'Outputs' of MATLAB S-Function 'potential_field' in 'model_4WID/Level-2 MATLAB S-Function'. The following is the MATLAB call stack (file names and line numbers) that produced this error: 
 ['C:\Program Files\MATLAB\MATLAB Production Server\R2015a\toolbox\shared\optimlib\optimfcnchk.p'] [317]
 ['C:\Program Files\MATLAB\MATLAB Production Server\R2015a\toolbox\shared\optimlib\fmincon.p'] [534]
 ['C:\Users\Valéry EBOGO\Documents\MATLAB\potential_field.m'] [113]

User function '@(X)(a0*(u(6)-X(1))^2+av*(X(1)*tan(X(2))-u(10))^2+Urep_1+Urep_2+c*(X(2)-u(3))^2)' returned NaN when evaluated;
 FMINCON cannot continue.

Failure in initial user-supplied objective function evaluation. FMINCON cannot continue.

when I evaluate the objective function in X0, J=0*(0-0) ~=NAN.

moreover, by changing the algorithm(sqp or inerior-point) the result is the same. And when i set "Funvalcheck" to 'off', this message appears: "Objective function is undefined at initial point. Fmincon cannot continue."

all my attempts to solve this problem have so far been unsuccessful.

i really need your help!!!!

Thank you in advance.

function potential_field(block)

  setup(block);
end
  
function setup(block)


  % Register number of ports
  block.NumInputPorts  = 1;
  block.NumOutputPorts = 1;
  
  % Setup port properties to be inherited or dynamic
  block.SetPreCompInpPortInfoToDynamic;
  block.SetPreCompOutPortInfoToDynamic;

  %% Override input port properties----------------------------------------
  block.InputPort(1).DatatypeID  = 0;  % double
  block.InputPort(1).Complexity  = 'Real';
  block.InputPort(1).Dimensions        = 10;
  block.InputPort(1).DirectFeedthrough = false;
  
  
  %% Override output port properties--------------------------------------- 
  block.OutputPort(1).DatatypeID  = 0; % double
  block.OutputPort(1).Complexity  = 'Real';
  block.OutputPort(1).Dimensions       = 6;
 

  % Register the parameters.
  block.NumDialogPrms     = 0;
  
  % Set up the continuous states.
  block.NumContStates = 0;

  block.SampleTimes = [0 0];
  
  block.SetAccelRunOnTLC(false);
  
  block.SimStateCompliance = 'DefaultSimState';
  
 
 

  % sample-based mode=mode échatillon----- frame-based mode=mode base de donnée

  block.RegBlockMethod('Outputs', @Outputs);
 
end


function Outputs(block)

%%% Paramètres de contrôle :

a0=0;
av=1;
c=80000;           
b1=0;
b2=0;
u=zeros(1,10);

for i=1:10  
    if isfinite(block.InputPort(1).Data(i))
    u(i)=block.InputPort(1).data(i);  % création d'un vecteur de taille 6 contenant les entrées i
    end
end

                  %%% Calcul des limites de la route et des potentiels de répulsion Urep %%%%
                  %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

                  
yub=u(7);   %upper boundary: limite sup de la route
ylb=u(8);   %lower boundary: limite inf de la route
y_center_line= u(9);   %center line: centre de la route

%% calcul des potentiels de répulsion Urep_1 et Urep_2, respectivement des limites sup et inf de la route
%   Urep_1=zeros(1,1); 
%   Urep_2=zeros(1,1);
  
  if (ylb<=u(5) && yub>=u(5))
      
      Urep_1=b1/(u(5)-yub)^2;
      Urep_2=b2/(u(5)-ylb)^2;
  
  
  
  %% Fonction objective dont les  variables d'entrées X(1) et X(2) sont
  % respectivements la vitesse et l'angle de lacet désiré calculés par la fonction "fmincon",
  % qui résout le problème d'optimisation avec contraintes posé:
  % ici, le dernier terme de notre fonction objective ie c*(phi(k+1)-phi(k))^2
  % qui représente le potentiel d'attraction, qui va attirer la cible jusqu'a sa destination final(goal!!)
  % ici, phi(k) est la valeur initialle donnée par les équations du mouvement du véhicule            
  % notre ojectif est de trouver phi(k+1)! 

  vxd=u(6); % vitesse désirée ie vitesse longitudinale de la trajectoire
  
J=@(X)(a0*(u(6)-X(1))^2 + av*(X(1)*tan(X(2))-u(10))^2 + Urep_1 + Urep_2 + c*(X(2)-u(3))^2); 
  end

X0=[0,0];          %Initial point for X
A = [];
b = [];
Aeq=[];            %Matrix for linear equality constraints	 
beq=[];            %Vector for linear equality constraints	 
lb=[0,-pi/2];	   %Vector of lower bounds	 
ub=[90,pi/2];      %Vector of upper bounds

 opts = optimoptions(@fmincon,'Display','iter-detailed','Algorithm','sqp',...
                  'MaxFunEval',inf,'MaxIter',inf,'funvalcheck','on');


Q = fmincon(J,X0,A,b,Aeq,beq,lb,ub,[],opts); %% les valeurs réelles retournées sont la vitesse désirée et l'angle de lacet désiré

  
%% calcul des sorties :

block.OutputPort(1).Data(1) = vxd;
block.OutputPort(1).Data(2) = Q(2); % angle de lacet désiré
block.OutputPort(1).Data(3) = yub;
block.OutputPort(1).Data(4) = ylb;
block.OutputPort(1).Data(5) = y_center_line;
block.OutputPort(1).Data(6) = Q(1);
  
end