PID-C.rar_The Process

PID控制C源程序 作者：未知 文章来源：未知 点击数：3409 更新时间：2006-4-24 关键词 PID pid算法 pid控制算法 pid程序 pid调节 BC31 TC30 编译过，可运行。 　　 　　 　　#include <stdio.h> 　　#include<math.h> 　　 　　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++; 　　 　　 } 　　 　　}