pid.i

用MEGA16控制发电机输出恒定的电压

// CodeVisionAVR C Compiler
// (C) 1998-2004 Pavel Haiduc, HP InfoTech S.R.L.

// I/O registers definitions for the ATmega128


#pragma used+
sfrb PINF=0;
sfrb PINE=1;
sfrb DDRE=2;
sfrb PORTE=3;
sfrb ADCL=4;
sfrb ADCH=5;
sfrw ADCW=4;      // 16 bit access
sfrb ADCSRA=6;
sfrb ADMUX=7;
sfrb ACSR=8;
sfrb UBRR0L=9;
sfrb UCSR0B=0xa;
sfrb UCSR0A=0xb;
sfrb UDR0=0xc;
sfrb SPCR=0xd;
sfrb SPSR=0xe;
sfrb SPDR=0xf;
sfrb PIND=0x10;
sfrb DDRD=0x11;
sfrb PORTD=0x12;
sfrb PINC=0x13;
sfrb DDRC=0x14;
sfrb PORTC=0x15;
sfrb PINB=0x16;
sfrb DDRB=0x17;
sfrb PORTB=0x18;
sfrb PINA=0x19;
sfrb DDRA=0x1a;
sfrb PORTA=0x1b;
sfrb EECR=0x1c;
sfrb EEDR=0x1d;
sfrb EEARL=0x1e;
sfrb EEARH=0x1f;
sfrw EEAR=0x1e;   // 16 bit access
sfrb SFIOR=0x20;
sfrb WDTCR=0x21;
sfrb OCDR=0x22;
sfrb OCR2=0x23;
sfrb TCNT2=0x24;
sfrb TCCR2=0x25;
sfrb ICR1L=0x26;
sfrb ICR1H=0x27;
sfrw ICR1=0x26;   // 16 bit access
sfrb OCR1BL=0x28;
sfrb OCR1BH=0x29;
sfrw OCR1B=0x28;  // 16 bit access
sfrb OCR1AL=0x2a;
sfrb OCR1AH=0x2b;
sfrw OCR1A=0x2a;  // 16 bit access
sfrb TCNT1L=0x2c;
sfrb TCNT1H=0x2d;
sfrw TCNT1=0x2c;  // 16 bit access
sfrb TCCR1B=0x2e;
sfrb TCCR1A=0x2f;
sfrb ASSR=0x30;
sfrb OCR0=0x31;
sfrb TCNT0=0x32;
sfrb TCCR0=0x33;
sfrb MCUCSR=0x34;
sfrb MCUCR=0x35;
sfrb TIFR=0x36;
sfrb TIMSK=0x37;
sfrb EIFR=0x38;
sfrb EIMSK=0x39;
sfrb EICRB=0x3a;
sfrb RAMPZ=0x3b;
sfrb XDIV=0x3c;
sfrb SPL=0x3d;
sfrb SPH=0x3e;
sfrb SREG=0x3f;
#pragma used-


// Interrupt vectors definitions


// CodeVisionAVR C Compiler
// (C) 1998-2000 Pavel Haiduc, HP InfoTech S.R.L.


#pragma used+

void delay_us(unsigned int n);
void delay_ms(unsigned int n);

#pragma used-


unsigned char CurSpeed;          

//========================================================================
       //Ki=Kp*T/Ti
       //Kd=Kp*Td/T
       //T为采样周期，Ti为积分时间常数，Td为微分时间常数

//======================定义PID结构=======================================
static struct PID{
 float Ki;                //定义积分常数
 float Kp;                //定义比例常数
 float Kd;                //定义微分常数
 float E_2;               //存储前前次误差
 float E_1;               //存诸前次误差
 float E;                 //存储本次误差
 float OutPut;            //本次输出量
 int ValueSet;            //速度值设定   
} Car_Speed;                          
  

//==========================初始化速度=====================================
void Speed_Init() {
  Car_Speed.Kp=-10;       
  Car_Speed.Ki=-3;        
  Car_Speed.Kd=-5;         
  Car_Speed.E=0;
  Car_Speed.E_2=0;
  Car_Speed.E_1=0;
  Car_Speed.ValueSet=0;
  Car_Speed.OutPut=0;
}   
/*************************** AD 初始化*************************/
 void AD_init(void)
{
   ADMUX |=0x40;  //4.96V 的基准电压源,转换结果右对齐,ADC0(PF0口)单端输入 
   ADCSRA |=0x8b; // AD使能,单次转换模式, AD 中断使能, AD 8分频
   #asm("sei");   //开总中断
} 

void PWM_init()
{
    /********************* PWM  ***********************/
     TCCR0 =0x76; //相位修正P W M，比较匹配发生时 OC0 置位，计数到 TOP时 OC0清零
                  //clk /256 (来自预分频器 )
     TCNT0 =0x00; //记时初值
     OCR0 =Car_Speed.ValueSet; //占空比为:    频率为122Hz
   /*******************************************************/ 
}
//===========================速度PID处理函数==============================
void SpeedWork() {
  float Up,Ud,Ui; 
  Car_Speed.E=CurSpeed-Car_Speed.ValueSet;                         //得到本次误差
  Up=Car_Speed.Kp*(Car_Speed.E-Car_Speed.E_1);                     //得到比例项
  Ud=Car_Speed.Kd*(Car_Speed.E-2*Car_Speed.E_1+Car_Speed.E_2);     //得到微分项
  Ui=Car_Speed.Ki*Car_Speed.E;                                     //得到积分项
  Car_Speed.E_2=Car_Speed.E_1;                                     //历史存储
  Car_Speed.E_1=Car_Speed.E;
  Car_Speed.OutPut+=Up+Ud+Ui;                                      //计算增量和
  if(Car_Speed.OutPut<0)Car_Speed.OutPut=0;                        //值域限制
   OCR0=Car_Speed.ValueSet-(int)Car_Speed.OutPut;                                      //值输出   

} 



/**************************************************************/
 void AD_start(void)      //启动一次AD转换
{
    ADCSRA.6=1;   //启动一次AD转换
    ADCSRA.6=0;
    ADCSRA.3=1;   //开AD中断
}

interrupt [22]void Ad_data()
{
 CurSpeed=ADCW;
 SpeedWork();
}

main()
{ 
 DDRB.4=1;
 Speed_Init();
 AD_init();
 Car_Speed.ValueSet=80;
 PWM_init();
 
while(1)
   {
     AD_start();
     delay_us(2);
    } 
}