MPC_Validator.c

/*
 * MPC_Validator.c: an oversight s-function to check the status code
 * returned from the MPC calculation process to make sure that the
 * steering command received was calculated properly.
 *
 */

#define S_FUNCTION_NAME  MPC_Validator
#define S_FUNCTION_LEVEL 2

/*
 * Need to include simstruc.h for the definition of the SimStruct and
 * its associated macro definitions.
 */
#include "simstruc.h"



/* Error handling
 * --------------
 *
 * You should use the following technique to report errors encountered within
 * an S-function:
 *
 *       ssSetErrorStatus(S,"Error encountered due to ...");
 *       return;
 *
 * Note that the 2nd argument to ssSetErrorStatus must be persistent memory.
 * It cannot be a local variable. For example the following will cause
 * unpredictable errors:
 *
 *      mdlOutputs()
 *      {
 *         char msg[256];         {ILLEGAL: to fix use "static char msg[256];"}
 *         sprintf(msg,"Error due to %s", string);
 *         ssSetErrorStatus(S,msg);
 *         return;
 *      }
 *
 * See matlabroot/simulink/src/sfuntmpl_doc.c for more details.
 */

/*====================*
 * S-function methods *
 *====================*/

/* Function: mdlInitializeSizes ===============================================
 * Abstract:
 *    The sizes information is used by Simulink to determine the S-function
 *    block's characteristics (number of inputs, outputs, states, etc.).
 */
static void mdlInitializeSizes(SimStruct *S)
{
    ssSetNumSFcnParams(S, 0);  /* Number of expected parameters */
    if (ssGetNumSFcnParams(S) != ssGetSFcnParamsCount(S)) {
        /* Return if number of expected != number of actual parameters */
        return;
    }

    // Not using any states since this s-function just processes current data
    ssSetNumContStates(S, 0);
    ssSetNumDiscStates(S, 0);

    if (!ssSetNumInputPorts(S, 3)) return;
    ssSetInputPortWidth(S, 0, 1);
    ssSetInputPortWidth(S, 1, 1);
    ssSetInputPortWidth(S, 2, 1);
    ssSetInputPortDataType(S, 0, DYNAMICALLY_TYPED);
    ssSetInputPortDataType(S, 1, DYNAMICALLY_TYPED);
    ssSetInputPortDataType(S, 2, DYNAMICALLY_TYPED);
    ssSetInputPortRequiredContiguous(S, 0, true); /*direct input signal access*/
    ssSetInputPortRequiredContiguous(S, 1, true); /*direct input signal access*/
    ssSetInputPortRequiredContiguous(S, 2, true); /*direct input signal access*/
    /*
     * Set direct feedthrough flag (1=yes, 0=no).
     * A port has direct feedthrough if the input is used in either
     * the mdlOutputs or mdlGetTimeOfNextVarHit functions.
     * See matlabroot/simulink/src/sfuntmpl_directfeed.txt.
     */
    ssSetInputPortDirectFeedThrough(S, 0, 1);
    ssSetInputPortDirectFeedThrough(S, 1, 1);

    if (!ssSetNumOutputPorts(S, 1)) return;
    ssSetOutputPortWidth(S, 0, 1);

    ssSetNumSampleTimes(S, 1);
    ssSetNumRWork(S, 0);
    ssSetNumIWork(S, 0);
    ssSetNumPWork(S, 0);
    ssSetNumModes(S, 0);
    ssSetNumNonsampledZCs(S, 0);

    ssSetOptions(S, 0);
}



/* Function: mdlInitializeSampleTimes =========================================
 * Abstract:
 *    This function is used to specify the sample time(s) for your
 *    S-function. You must register the same number of sample times as
 *    specified in ssSetNumSampleTimes.
 */
static void mdlInitializeSampleTimes(SimStruct *S)
{
    ssSetSampleTime(S, 0, INHERITED_SAMPLE_TIME);
    ssSetOffsetTime(S, 0, 0.0);

}



#define MDL_INITIALIZE_CONDITIONS   /* Change to #undef to remove function */
#if defined(MDL_INITIALIZE_CONDITIONS)
  /* Function: mdlInitializeConditions ========================================
   * Abstract:
   *    In this function, you should initialize the continuous and discrete
   *    states for your S-function block.  The initial states are placed
   *    in the state vector, ssGetContStates(S) or ssGetRealDiscStates(S).
   *    You can also perform any other initialization activities that your
   *    S-function may require. Note, this routine will be called at the
   *    start of simulation and if it is present in an enabled subsystem
   *    configured to reset states, it will be call when the enabled subsystem
   *    restarts execution to reset the states.
   */
  static void mdlInitializeConditions(SimStruct *S)
  {
  }
#endif /* MDL_INITIALIZE_CONDITIONS */



#define MDL_START  /* Change to #undef to remove function */
#if defined(MDL_START) 
  /* Function: mdlStart =======================================================
   * Abstract:
   *    This function is called once at start of model execution. If you
   *    have states that should be initialized once, this is the place
   *    to do it.
   */
  static void mdlStart(SimStruct *S)
  {
  }
#endif /*  MDL_START */



/* Function: mdlOutputs =======================================================
 * Abstract:
 *    In this function, you compute the outputs of your S-function
 *    block.
 */
static void mdlOutputs(SimStruct *S, int_T tid)
{
    const uint32_T *delta = (const uint32_T*) ssGetInputPortSignal(S,0);
    const int8_T *status = (const int8_T*) ssGetInputPortSignal(S,1);
    const uint16_T *cycle = (const uint16_T*) ssGetInputPortSignal(S,2);
    real_T       *y = ssGetOutputPortSignal(S,0);
    float deltaWork;
    
    /* Here is where the meat of this s-function gets done. First we check
     * the status flag, then we convert the steering command, then finally
     * we check the command and output it to the vehicle. */
    if(*status != -1)
    {
        /* We got to here, so the solver at least thinks that it produced
         * a reasonable solution. Now we need to convert the steering
         * command back to a double, and we'll check it out too. */
        
        /* We'll use memcpy to do a straight transfer of bits from the
         * uint32 type to a single precision variable. Later we'll turn
         * it into a double so that Simulink can be happy with it */
        memcpy(&deltaWork,delta,sizeof(double));
   
        y[0] = (double)deltaWork;
        y[1] = y[0];
    }
    else
    {
        /* The "we're screwed" case where the solver didn't find a
         * feasible solution to the problem.  Need to figure out what the
         * backup plan is. */
    }
}



#define MDL_UPDATE  /* Change to #undef to remove function */
#if defined(MDL_UPDATE)
  /* Function: mdlUpdate ======================================================
   * Abstract:
   *    This function is called once for every major integration time step.
   *    Discrete states are typically updated here, but this function is useful
   *    for performing any tasks that should only take place once per
   *    integration step.
   */
  static void mdlUpdate(SimStruct *S, int_T tid)
  {
  }
#endif /* MDL_UPDATE */



#define MDL_DERIVATIVES  /* Change to #undef to remove function */
#if defined(MDL_DERIVATIVES)
  /* Function: mdlDerivatives =================================================
   * Abstract:
   *    In this function, you compute the S-function block's derivatives.
   *    The derivatives are placed in the derivative vector, ssGetdX(S).
   */
  static void mdlDerivatives(SimStruct *S)
  {
  }
#endif /* MDL_DERIVATIVES */



/* Function: mdlTerminate =====================================================
 * Abstract:
 *    In this function, you should perform any actions that are necessary
 *    at the termination of a simulation.  For example, if memory was
 *    allocated in mdlStart, this is the place to free it.
 */
static void mdlTerminate(SimStruct *S)
{
}


/*======================================================*
 * See sfuntmpl_doc.c for the optional S-function methods *
 *======================================================*/

/*=============================*
 * Required S-function trailer *
 *=============================*/

#ifdef  MATLAB_MEX_FILE    /* Is this file being compiled as a MEX-file? */
#include "simulink.c"      /* MEX-file interface mechanism */
#else
#include "cg_sfun.h"       /* Code generation registration function */
#endif