incpid.c

matlab的c语言s函数

/*
 * sfuntmpl_basic.c: Basic 'C' template for a level 2 S-function.
 *
 *  -------------------------------------------------------------------------
 *  | See matlabroot/simulink/src/sfuntmpl_doc.c for a more detailed template |
 *  -------------------------------------------------------------------------
 *
 * Copyright 1990-2002 The MathWorks, Inc.
 * $Revision: 1.27 $
 */


/*
 * You must specify the S_FUNCTION_NAME as the name of your S-function
 * (i.e. replace sfuntmpl_basic with the name of your S-function).
 */

#define S_FUNCTION_NAME  IncPID
#define S_FUNCTION_LEVEL 2
#include "simstruc.h"
#include "math.h"                                                                          

#define Ref_macro *mxGetPr(ssGetSFcnParam(S,0))
#define Kp_macro  *mxGetPr(ssGetSFcnParam(S,1))              /*define the macros,Kp,Ti,Td,DR,CP,ST are the parameters of this S Function*/
#define Ti_macro  *mxGetPr(ssGetSFcnParam(S,2))
#define Td_macro  *mxGetPr(ssGetSFcnParam(S,3))
#define DR_macro  *mxGetPr(ssGetSFcnParam(S,4))
#define CP_macro  *mxGetPr(ssGetSFcnParam(S,5))
#define ST_macro  *mxGetPr(ssGetSFcnParam(S,6))

/*====================*
 * 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)
{   
    ssSetNumContStates(S, 0);
    
    /* 4 discrete states,respectively for e(k),e(k-1),e(k-2) and counter for control period */
    ssSetNumDiscStates(S, 4);                                    
    
    /* 2 inputs, respectively for feedback and last control signal */
    if (!ssSetNumInputPorts(S, 2)) return;                     
    ssSetInputPortWidth(S, 0, 1);
    ssSetInputPortWidth(S, 1, 1);
      
    ssSetInputPortRequiredContiguous(S, 0, true); 
    ssSetInputPortRequiredContiguous(S, 1, true);
             
    ssSetInputPortDirectFeedThrough(S, 0, 1);
    ssSetInputPortDirectFeedThrough(S, 1, 1);
       
    if (!ssSetNumOutputPorts(S, 1)) return;                 
    ssSetOutputPortWidth(S, 0, 1);
  
    ssSetNumSampleTimes(S, 1);
   
    /* 7 sfunction parameters, respectively for reference,Kp,Ti,Td,DR,CP and ST */
    ssSetNumSFcnParams(S, 7); 
    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)
{ 
    real_T ST;
    
    ST = ST_macro;
    
    ssSetSampleTime(S, 0, ST);
    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)
  {       
        real_T *x = ssGetRealDiscStates(S);          
                 
        int_T lp;                                   
        
        /*mdlinitialize all the disc states*/
        for (lp=0;lp<3;lp++)
        {
            *x++=0; 
        }              
        
        /*initialize the control period*/
        x[3] = CP_macro;                                   
         
  }
#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)
  {
  	real_T       *y = ssGetOutputPortSignal(S,0);    /*initialize the output y*/                  
  	
  	*y=0;
}
#endif /*  MDL_START */



/* Function: mdlOutputs =======================================================
 * Abstract:
 *    In this function, you compute the outputs of your S-function
 *    block. Generally outputs are placed in the output vector, ssGetY(S).
 */
static void mdlOutputs(SimStruct *S, int_T tid)
{                                                               
    real_T   *y = ssGetOutputPortRealSignal(S,0);     /*get the output port real signal */                
    real_T   *x = ssGetRealDiscStates(S);             /*get real disc states */             
    
    const real_T *feedback = ssGetInputPortRealSignal(S,0); /*get feedback */                  
    const real_T *lastcontrol = ssGetInputPortRealSignal(S,1); /*get last control signal */
    
    real_T Ref,Kp, Ti, Td, DR, ST,deltau;           
    int_T CP;
    
    /*get the parameters' value of this model*/
    Ref = Ref_macro;
    Kp = Kp_macro;                               
    Ti = Ti_macro;
    Td = Td_macro;
    DR = DR_macro;
    CP = CP_macro;
    ST = ST_macro;
    
    /*if the control period is up ,then compute the output */
    if (x[3]<=0)                                   
    {
        if (fabs(x[0])>(DR))                                              
        {
            /* deltau(k) = Kp[(e(k)-e(k-1)) + T*e(k)/Ti + Td(e(k)-2*e(k-1)+e(k-2))/T] */
            deltau=(Kp)*((x[0]-x[1])+CP*ST*x[0]/Ti+Td*(x[0]-2*x[1]+x[2])/(CP*ST));  
            
            /*compute the pid control output,*u(k)=u(k-1)+deltau*/
            *y=(*lastcontrol)+deltau;                          
        }
        else  /*if feedback is close enough to setvalue ,there is no need to compute pid*/
        {
            /*the output of block keeps its value*/
            *y = *y;                               
        } 
   }    
   else   /*if control time is not up,keep the output value u(k) unchanged*/
   {
        *y=*y;
        
   }
}    
    
#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)
 {  
    real_T       *x  = ssGetRealDiscStates(S);         /*get real disc states x*/
                  
   const real_T *feedback = ssGetInputPortRealSignal(S,0);                 
   const real_T *lastcontrol = ssGetInputPortRealSignal(S,1);   
    
   real_T Ref;
   int_T CP;                                          
   
   Ref = Ref_macro;
   CP = CP_macro;     
   
   x[2]=x[1];       /*e(k-2)=e(k-1)*/
   x[1]=x[0];       /*e(k-1)=e(k)*/
   x[0]=Ref-(*feedback);     /*e(k)=setvalue-feedback */
     
   /*refresh the counter's value, x[3]*/
   if(x[3]<=0)
   {
        x[3] = CP-1;
   }
   else
   {
        x[3]=x[3]-1;
   }
          
}  
        
#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