pid控制c源程序.txt

单片机c51写的PID控制程序

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++;  
　　  
　　 }  
　　 
　　}