（转载）温控器PID算法的实现(C语言)，未实验

硬件原理：加热电阻为400，电源为市电，固态继电器控制通断，市电过零信号提取，单片机采用mega48继电器最小通断时间为10ms,通断PWM周期为100个过零信号.

这个程序是绝对的PID当温差较大时，采用P算法(比例算法)，当达到设定温度时，采用算法PID算法，实用稳定性还可以，上下波动为0.5度以内.

#include

#include "PID.h"

//static PID sPID;

//static PID *sptr=&sPID;

TADD Tadd1;

TADD Tadd2;

void IncPIDInit(PID *sptr)

{

sptr->SumError=0;

sptr->LastError=0;

sptr->PrevError=0;

//sptr->Proportion = 900;

//sptr->Integral=20;

//sptr->Derivative = 2;

//sptr->SetPoint = 0;

}

typedef struct

{

int SetPoint; //设定目标值

int32_t SumError; ///累误差

//int Proportion;

//int Integral; //分常数

//int Derivative; ///微分常数

int LastError; //Error[-1]

int PrevError; //Error[-2]

}PID;

#define PID_Proportion 900 ///比例常数

#define PID_Integral 20 //分常数

#define PID_Derivative 2 ///微分常数

#define PWM_T 100

#define MAX_T 80 ///最大加热温度

typedef struct

{

PID spid; //PID控制器

unsigned char pwm_H;//输出

unsigned char EnAdd;///加热使能

int real_T; ///实际温度值

unsigned char Taddset[3]; ///加热设定温度

unsigned char set_NO; ///加热档数

unsigned char errorflg;

unsigned char addokflg;

}TADD;

void LocPIDCalc(TADD *sptr)

{

int iError,dError;

int32_t result;

iError = (sptr->spid.SetPoint*4) - (sptr->real_T/4);

//sptr->spid.LastError = iError;

if(iError>-2&&iError<4)

{

sptr->addokflg=1;

sptr->spid.SumError =iError;

dError = iError-sptr->spid.LastError;

sptr->spid.LastError = iError;

result=(PID_Proportion * iError

PID_Integral * sptr->spid.SumError

PID_Derivative * dError)/20;

}

else

{

sptr->spid.SumError =0;

sptr->spid.LastError=0;

if(iError>0)

sptr->addokflg=0;

result=(PID_Proportion * iError)/20;

}

if(result>PWM_T)

result=PWM_T;

else if(result<0)

result=0;

if((sptr->real_T>>4)>MAX_T||sptr->errorflg==0)

result=0;

sptr->pwm_H=(unsigned char) result;

//return (unsigned char) result;

}