基于AT89S52单片机的直流电机闭环PID算法控制系统

/*********课程设计********* 课题：小型直流电机PID控制 ****************************** 自动化1304 *******************************/ #include<reg52.h> extern void HD7279A_SEND(unsigned char comm); extern char KEY_SCAN(); sbit PWM=P1^7; sbit key1=P1^0; sbit key2=P1^2; int Key_flag=0; int flag=0; int pidtimer0=0,pwmtimer0=0,num=0; int setspeed=0,speed=0,allspeed=0; typedef struct PID { int SetPoint;//设定目标Desired Value long SumError;//误差累计 double Proportion;//比例常数Proportional Const double Integral;//积分常数Integral const double Derivative;//微分常数Derivative Const int LastError;//Error[-1] int PrevError;//Error[-2] }PID; static PID sPID; static PID *sptr = &sPID; void display() //数码显示 { unsigned char datas[8]; unsigned char b; datas[0]=num/1000; datas[1]=num%1000/100; datas[2]=num%100/10; datas[3]=num%10; datas[4]=setspeed/1000; datas[5]=setspeed%1000/100; datas[6]=setspeed%100/10; datas[7]=setspeed%10; for(b=0;b<8;b++) { HD7279A_SEND(0x80|(7-b));//WEI HD7279A_SEND(datas[b]); } } void delay(unsigned int a) { unsigned int i,j; for(i=0;i<a;i++) for(j=0;j<200;j++); } void Scankey(void) { if(key1==0) { delay(30); //消抖 if(key1==0) { setspeed=setspeed+10; } while(!key1) ; //松手检查 } if(key2==0) { delay(30); if(key2==0) { setspeed=setspeed-10; } while(!key2) ; } if(setspeed>=215) setspeed=215; } /* Initialize PID Structrue PID参数初始化 */ void IncPIDInit(void) { sptr->SumError = 0; sptr->LastError = 0;//Error[-1] sptr->PrevError = 0;//Error[-2] sptr->Proportion =0.7;//比例常数Proportional Const sptr->Integral = 0.5;//积分常数Integral Const sptr->Derivative = 0;//微分常数Derivative Const sptr->SetPoint = 0; } /* 增量式PID计算部分 */ int IncPIDCalc(int NextPoint) { int iError,iIncpid;//当前误差 sptr->SetPoint =setspeed; iError = sptr->SetPoint-NextPoint;//增量计算 iIncpid=sptr->Proportion*(iError-sptr->LastError)+ sptr->Integral*iError+ sptr->Derivative*(iError-2*sptr->LastError+sptr->PrevError);//增量计算 //存储误差，用于下次计算 sptr->PrevError = sptr->LastError; sptr->LastError = iError; //返回增量值 return(iIncpid); } /**********计数器0初始化**********/ void timer0_init(void) { TMOD=0x01; TH0=0X0FC; TL0=0X66 ;//定时器0定时1ms IT0=1; EX0=1; TR0=1; ET0=1; EA=1;//EA=0 总中断 } void main(void) { IncPIDInit(); timer0_init(); setspeed=150; //0~215 while(1) { Scankey(); } } void Getspeed(void) interrupt 0 { num++; } void Timer0(void) interrupt 1//1ms { pwmtimer0++; pidtimer0++; if(pwmtimer0<=speed) PWM=1; else PWM=0; if(pwmtimer0>=255) pwmtimer0=0; //PWM T=255MS if(pidtimer0==400) //PID T=400MS { display(); sptr->SumError=sptr->SumError+IncPIDCalc(num); speed=sptr->SumError*1; pidtimer0=0; num=0; } TH0=0X0FC; TL0=0X66 ;//定时器0定时1ms }