OpenVINOTM,给你看得见的未来!>>
电子产品世界 » 论坛首页 » 综合技术 » 电源与模拟 » msp430单片机中增量式pid算法的C实现方法

共4条 1/1 1 跳转至

msp430单片机中增量式pid算法的C实现方法

助工
2020-11-12 18:46:56    评分

#include 
  #include

  struct _pid {
   int pv; /*integer that contains the process value*/
   int sp; /*integer that contains the set point*/
   float integral;
   float pgain;
   float igain;
   float dgain;
   int deadband;
   int last_error;
  };

  struct _pid warm,*pid;
  int process_point, set_point,dead_band; 
  float p_gain, i_gain, d_gain, integral_val,new_integ;; 



  /*------------------------------------------------------------------------ 
  pid_init 

  DESCRIPTION This function initializes the pointers in the _pid structure 
  to the process variable and the setpoint. *pv and *sp are 
  integer pointers. 
  ------------------------------------------------------------------------*/ 
  void pid_init(struct _pid *warm, int process_point, int set_point)
  { 
   struct _pid *pid; 

   pid = warm; 
   pid->pv = process_point; 
   pid->sp = set_point; 
  } 


  /*------------------------------------------------------------------------ 
  pid_tune 

  DESCRIPTION Sets the proportional gain (p_gain), integral gain (i_gain), 
  derivitive gain (d_gain), and the dead band (dead_band) of 
  a pid control structure _pid. 
  ------------------------------------------------------------------------*/ 

  void pid_tune(struct _pid *pid, float p_gain, float i_gain, float d_gain, int dead_band) 
  { 
   pid->pgain = p_gain; 
   pid->igain = i_gain; 
   pid->dgain = d_gain; 
   pid->deadband = dead_band; 
   pid->integral= integral_val; 
   pid->last_error=0; 
  } 

  /*------------------------------------------------------------------------ 
  pid_setinteg 

  DESCRIPTION Set a new value for the integral term of the pid equation. 
  This is useful for setting the initial output of the 
  pid controller at start up. 
  ------------------------------------------------------------------------*/ 
  void pid_setinteg(struct _pid *pid,float new_integ)
  { 
   pid->integral = new_integ; 
   pid->last_error = 0; 
  } 

  /*------------------------------------------------------------------------ 
  pid_bumpless 

  DESCRIPTION Bumpless transfer algorithim. When suddenly changing 
  setpoints, or when restarting the PID equation after an 
  extended pause, the derivative of the equation can cause 
  a bump in the controller output. This function will help 
  smooth out that bump. The process value in *pv should 
  be the updated just before this function is used. 
  ------------------------------------------------------------------------*/ 
  void pid_bumpless(struct _pid *pid) 
  { 

   pid->last_error = (pid->sp)-(pid->pv); 

  } 

  /*------------------------------------------------------------------------ 
  pid_calc 

  DESCRIPTION Performs PID calculations for the _pid structure *a. This function uses the positional form of the pid equation, and incorporates an integral windup prevention algorithim. Rectangular integration is used, so this function must be repeated on a consistent time basis for accurate control. 

  RETURN VALUE The new output value for the pid loop. 

  USAGE #include "control.h"*/ 


  float pid_calc(struct _pid *pid)
  { 
   int err;
   float pterm, dterm, result, ferror; 

   err = (pid->sp) - (pid->pv); 
   if (abs(err) > pid->deadband) 
   { 
   ferror = (float) err; /*do integer to float conversion only once*/ 
   pterm = pid->pgain * ferror; 
   if (pterm > 100 || pterm < -100)
   {
   pid->integral = 0.0; 
   }
   else 
   { 
   pid->integral += pid->igain * ferror; 
   if (pid->integral > 100.0) 
   {
   pid->integral = 100.0; 
   }
   else if (pid->integral < 0.0) pid->integral = 0.0; 
   } 
   dterm = ((float)(err - pid->last_error)) * pid->dgain; 
   result = pterm + pid->integral + dterm; 
   } 
   else result = pid->integral; 
   pid->last_error = err; 
   return (result); 
  }


  void main(void)
  {
   float display_value;
   int count=0;

   pid = &warm;

  // printf("Enter the values of Process point, Set point, P gain, I gain, D gain \n");
  // scanf("%d%d%f%f%f", &process_point, &set_point, &p_gain, &i_gain, &d_gain);



   process_point = 30;
   set_point = 40;
   p_gain = (float)(5.2);
   i_gain = (float)(0.77);
   d_gain = (float)(0.18);



   dead_band = 2;
   integral_val =(float)(0.01);


   printf("The values of Process point, Set point, P gain, I gain, D gain \n");
   printf(" %6d %6d %4f %4f %4f\n", process_point, set_point, p_gain, i_gain, d_gain);

   printf("Enter the values of Process point\n");

   while(count<=20)
   {



   scanf("%d",&process_point);

   pid_init(&warm, process_point, set_point);
   pid_tune(&warm, p_gain,i_gain,d_gain,dead_band);
   pid_setinteg(&warm,0.0); //pid_setinteg(&warm,30.0);

   //Get input value for process point
   pid_bumpless(&warm);

   // how to display output
   display_value = pid_calc(&warm); 
   printf("%f\n", display_value); 
   //printf("\n%f%f%f%f",warm.pv,warm.sp,warm.igain,warm.dgain); 
   count++; 

   } 

  }

 msp430单片机中增量式pid算法的C实现方法.rar (1.64 KB, 下载次数: 0) 




关键词: msp430     单片     机中     增量     算法     实现     方法    

工程师
2020-11-12 22:29:31    评分
2楼

学到了


工程师
2020-11-12 22:49:32    评分
3楼

感谢分享


工程师
2020-11-13 17:24:42    评分
4楼

感谢楼主分享


共4条 1/1 1 跳转至

回复

匿名不能发帖!请先 [ 登陆 注册 ]