PID算法實(shí)現(xiàn)（c 語言)

ID:198331 · 發(fā)表于 2017-5-9 16:46

#include <stdio.h>
#include<math.h>
//定義PID 的結(jié)構(gòu)體
struct _pid
{
int pv; //integer that contains the process value 過程量
int sp; //＊integer that contains the set point 設(shè)定值
float integral; // 積分值－－偏差累計(jì)值
float pgain;
float igain;
float dgain;
int deadband; //死區(qū)
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.
設(shè)定PID參數(shù) －－－－ P,I,D,死區(qū)
－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－ */
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.
設(shè)定輸出初始值
－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－ */
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.
pid_bumpless 實(shí)現(xiàn)無擾切換
當(dāng)突然改變設(shè)定值時(shí)，或重新啟動(dòng)后，將引起擾動(dòng)輸出。這
個(gè)函數(shù)將能實(shí)現(xiàn)平順擾動(dòng)，在調(diào)用該函數(shù)之前需要先更新 PV值
－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－*/
void pid_bumpless(struct _pid *pid)
{
pid->last_error = (pid->sp)-(pid->pv); //設(shè)定值與反饋值偏差
}
/*－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－
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"
本函數(shù)使用位置式PID計(jì)算方式，并且采取了積分飽和限制運(yùn)算
PID計(jì)算
－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－*/
float pid_calc(struct _pid *pid)
{
int err;
float pterm, dterm, result, ferror;
// 計(jì)算偏差
err = (pid->sp) - (pid->pv);
// 判斷是否大于死區(qū)
if (abs(err) > pid->deadband)
{
ferror = (float) err; //do integer to float conversion only once 數(shù)據(jù)類型轉(zhuǎn)換
// 比例項(xiàng)
pterm = pid->pgain * ferror;
if (pterm > 100 || pterm < -100)
{
pid->integral = 0.0;
}
else
{
// 積分項(xiàng)
pid->integral += pid->igain * ferror;
// 輸出為0－－100%
// 如果計(jì)算結(jié)果大于100，則等于100
if (pid->integral > 100.0)
{
pid->integral = 100.0;
}
// 如果計(jì)算結(jié)果小于0.0，則等于0
else if (pid->integral < 0.0)
{
pid->integral = 0.0;
}
}
// 微分項(xiàng)
dterm = ((float)(err - pid->last_error)) * pid->dgain;
result = pterm + pid->integral + dterm;
}
else
{
result = pid->integral; // 在死區(qū)范圍內(nèi)，保持現(xiàn)有輸出
}
// 保存上次偏差
pid->last_error = err;
// 輸出PID值(0-100)
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);
// 初始化參數(shù)
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);
// 設(shè)定PV,SP 值
pid_init(&warm, process_point, set_point);
// 初始化PID 參數(shù)值
pid_tune(&warm, p_gain,i_gain,d_gain,dead_band);
// 初始化PID 輸出值
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,wa
rm.dgain);
count++;
}
}

復(fù)制代碼

ID:200117 · 發(fā)表于 2017-5-13 10:34

一定用的到！謝謝

ID:200607 · 發(fā)表于 2017-5-14 15:00

收下了，感謝

ID:221442 · 發(fā)表于 2017-11-17 15:32

好厲害

ID:43600 · 發(fā)表于 2017-12-11 00:26

收下了，研究中，謝分享。

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PID算法實(shí)現(xiàn)（c 語言)

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