基于STM32定时器的PID温度控制程序

admin 2017-6-25 4525

 

PWM控制N沟道MOSFET驱动半导体制冷片电路

PWM采用STM32单片机TIM3产生,2KHZ,实际测量负载两端波形良好,但MOSFET有发热现象。MOSFET采用NTP125NO2R

制冷片电流8A左右。

最终方案还是将软件PID部分进行了修改,使用定时器开启8S周期的PWM波,最低每2S一个开关

周期。

该方案可满足±1.5度的精度要求。如果将PID参数进一步调整,应该效果会更好。

PID_Parameters.P_gain_Cold= (float)(1.0f);
  PID_Parameters.I_gain_Cold= (float)(0.1f);
  PID_Parameters.D_gain_Cold= (float)(0.1f);
  PID_Parameters.Deadband_Cold= 0.2f;
  PID_Parameters.Integral_Cold= 5.0f;
void Temperature_Pwm_Configuration(void)
{
        TIM_TimeBaseInitTypeDef  TIM_TimeBaseStructure;
        TIM_OCInitTypeDef  TIM_OCInitStructure;
        GPIO_InitTypeDef GPIO_InitStructure;
        RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOB, ENABLE);
        RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM4, ENABLE);
        
    
        GPIO_InitStructure.GPIO_Pin =  GPIO_Pin_8|GPIO_Pin_9;
        GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
        GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
        GPIO_Init(GPIOB, &GPIO_InitStructure);
        
        GPIO_InitStructure.GPIO_Pin =  GPIO_Pin_6|GPIO_Pin_7;
        GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_PP;
        GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
        GPIO_Init(GPIOB, &GPIO_InitStructure);
        /* -----------------------------------------------------------------------
          TIM4 Configuration: generate 4 PWM signals with 4 different duty cycles:
          TIM4CLK = 72 MHz, Prescaler = 35999, TIM3 counter clock = 2 KHz
          TIM4 ARR Register = 15999 => TIM4 Frequency = TIM4 counter clock/(ARR + 1)
          TIM4 Frequency = 0.125Hz. 
          4000为基本单位保证开关频率大于2秒
          
        ----------------------------------------------------------------------- */
        
        /* Time base configuration */
        TIM_TimeBaseStructure.TIM_Period = Tim4_Arr;
        TIM_TimeBaseStructure.TIM_Prescaler = 35999;
        TIM_TimeBaseStructure.TIM_ClockDivision = 0;
        TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
        TIM_TimeBaseInit(TIM4, &TIM_TimeBaseStructure);
        
        /* PWM4 Mode configuration: Channel1 
        TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1;
        TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
        TIM_OCInitStructure.TIM_Pulse = Tim4_Arr;
        TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High;
        TIM_OC1Init(TIM4, &TIM_OCInitStructure);
        TIM_OC1PreloadConfig(TIM4, TIM_OCPreload_Enable);*/
        
        /* PWM4 Mode configuration: Channel2 
        TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1;
        TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
        TIM_OCInitStructure.TIM_Pulse = Tim4_Arr;
        TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High;
        TIM_OC2Init(TIM4, &TIM_OCInitStructure);
        TIM_OC2PreloadConfig(TIM4, TIM_OCPreload_Enable);*/
        
        /* PWM4 Mode configuration: Channel3 */
        TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1;
        TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
        TIM_OCInitStructure.TIM_Pulse = Tim4_Arr;
        TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High;
        TIM_OC3Init(TIM4, &TIM_OCInitStructure);
        TIM_OC3PreloadConfig(TIM4, TIM_OCPreload_Enable);
        
        /* PWM4 Mode configuration: Channel4 */
        TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1;
        TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
        TIM_OCInitStructure.TIM_Pulse = Tim4_Arr;
        TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High;
        TIM_OC4Init(TIM4, &TIM_OCInitStructure);
        TIM_OC4PreloadConfig(TIM4, TIM_OCPreload_Enable);
        
        TIM_ARRPreloadConfig(TIM4, ENABLE);
        
    TIM_ClearFlag(TIM4, TIM_FLAG_Update);
    TIM_ITConfig(TIM4,TIM_IT_Update, ENABLE);
        
        /* TIM4 enable counter */
        TIM_Cmd(TIM4, ENABLE);
        TIM_CtrlPWMOutputs(TIM4,ENABLE);
        Fans_Stop;
}
float PID_Cold(void)
{
        static float err=0,ferror=0;
        static float Temprature_Setting_Old=0.0f,Temprature_Setting=0.0f;
    static u8 Setting_Refresh_Flag=0;
        
        Temprature_Setting = PID_Parameters.Control_Temprature_Set;
        if(Temprature_Setting_Old!=Temprature_Setting)
                {
                  Temprature_Setting_Old = Temprature_Setting;
                  Setting_Refresh_Flag =1 ;
            }
        //计算偏差
        err=(PID_Parameters.Control_Temprature_Set)-(PID_Parameters.Control_Temprature_Measure);
                        
        if(abs(err)>PID_Parameters.Deadband_Heat)
          {
                        ferror=(float)err; //数据类型转换
                        //计算比例项
                        PID_Parameters.proportion_Cold = PID_Parameters.P_gain_Cold* ferror;
                        //计算积分项
                        if(PID_Parameters.proportion_Cold<-5.0f || PID_Parameters.proportion_Cold>5.0f)
                                {
                                        PID_Parameters.Integral_Cold= 5.0f;
                            }
                        else
                                {
                                        if(Setting_Refresh_Flag)
                                                {
                                                 Setting_Refresh_Flag = 0 ;
                                                 PID_Parameters.Integral_Cold = 5.0f;
                                            }
                                        else
                                                {
                                                 PID_Parameters.Integral_Cold += PID_Parameters.I_gain_Cold* ferror;
                                            }
                                        
                                        if(PID_Parameters.Integral_Cold>5.0f)
                                          {
                                                PID_Parameters.Integral_Cold= 5.0f;
                                                Hot_Cold_Flag = 0 ;
                                          }
                                        else if(PID_Parameters.Integral_Cold<0.0f)
                                          {
                                                PID_Parameters.Integral_Cold=0.0f;
                                          }
                                }
                        //输出结果
                        PID_Parameters.Result_Cold = PID_Parameters.proportion_Cold + PID_Parameters.Integral_Cold;
          }
        else
          {
                         PID_Parameters.Result_Cold = PID_Parameters.Integral_Cold;
          }
                
                if(PID_Parameters.Result_Cold>5.0f)
                  {
                        PID_Parameters.Result_Cold= 5.0f;
                        Hot_Cold_Flag = 0 ;
                  }
                else if(PID_Parameters.Result_Cold<0.0)
                  {
                        PID_Parameters.Result_Cold=0.0;
                  }
                if(PID_Parameters.Result_Cold <=1.0f)
                        PID_Parameters.Result_Cold_PWM= 0.0f;
                else if(PID_Parameters.Result_Cold <=2.0f)
                        PID_Parameters.Result_Cold_PWM = 4000.0f;
                else if(PID_Parameters.Result_Cold <=3.0f)
                        PID_Parameters.Result_Cold_PWM = 8000.0f;
                else if(PID_Parameters.Result_Cold <=4.0f)
                        PID_Parameters.Result_Cold_PWM = 12000.0f;
                else
                        PID_Parameters.Result_Cold_PWM = 15999.0f;
           return  PID_Parameters.Result_Cold_PWM;
}


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