STM32L476应用开发之七：流量的PID控制

  1 /* PID初始化操作,需在对vPID对象的值进行修改前完成                             */
  2 /* CLASSICPID vPID，通用PID对象变量，实现数据交换与保存                       */
  3 /* float vMax,float vMin，过程变量的最大最小值（量程范围）                    */
  4 void PIDParaInitialization(CLASSICPID vPID,float vMax,float vMin)
  5 {
  6   vPID->maximum=vMax;                /*输出值上限*/
  7   vPID->minimum=vMin;                /*输出值下限*/
  8 
  9   vPID->setpoint=vMin;               /*设定值*/
 10   vPID->kp=0.6;                      /*比例系数*/
 11   vPID->ki=0.03;                     /*积分系数*/
 12   vPID->kd=0.01;                     /*微分系数*/
 13 
 14   vPID->lasterror=0.0;              /*前一拍偏差*/
 15   vPID->preerror=0.0;               /*前两拍偏差*/
 16   vPID->result=vMin;                /*PID控制器结果*/
 17   vPID->output=0.0;                 /*输出值*/
 18 
 19   vPID->errorabsmax=(vMax-vMin)*0.8;
 20   vPID->errorabsmin=(vMax-vMin)*0.2;
 21 
 22   vPID->deadband=(vMax-vMin)*0.005;               /*死区*/
 23   vPID->alpha=0.2;                  /*不完全微分系数*/
 24   vPID->deltadiff=0.0;
 25 
 26   vPID->integralValue=0.0;
 27 }
 28 
 29 /* 通用PID控制器,采用增量型算法，具有变积分，梯形积分和抗积分饱和功能         */
 30 /* 微分项采用不完全微分，一阶滤波，alpha值越大滤波作用越强                    */
 31 /* CLASSICPID vPID，PID对象变量，实现数据交换与保存                           */
 32 /* float pv，过程测量值，对象响应的测量数据，用于控制反馈                     */
 33 void PIDRegulator(CLASSICPID vPID,float pv)
 34 {
 35   float thisError;
 36   float result;
 37   float factor;
 38   float increment;
 39   float pError,dError,iError;
 40 
 41   thisError=vPID->setpoint-processValue; //得到偏差值
 42   result=vPID->result;
 43   if (ABS(thisError)>vPID->deadband)
 44   {
 45     pError=thisError-vPID->lasterror;
 46     iError=(thisError+vPID->lasterror)/2.0;
 47     dError=thisError-2*(vPID->lasterror)+vPID->preerror;
 48 
 49     //变积分系数获取
 50     factor=VariableIntegralCoefficient(thisError,vPID->errorabsmax,vPID->errorabsmin);
 51 
 52     //计算微分项增量带不完全微分
 53     vPID->deltadiff=kd*(1-vPID->alpha)*dError+vPID->alpha*vPID->deltadiff;
 54 
 55     increment=vPID->kp*pError+vPID->ki*factor*iError+vPID->deltadiff;   //增量计算
 56   }
 57   else
 58   {
 59     if((abs(vPID->setpoint-vPID->minimum)<vPID->deadband)&&(abs(pv-vPID->minimum)<vPID->deadband))
 60     {
 61       result=vPID->minimum;
 62     }
 63     increment=0.0;
 64   }
 65 
 66   result=result+increment;
 67 
 68   /*对输出限值，避免超调和积分饱和问题*/
 69   if(result>=vPID->maximum)
 70   {
 71     result=vPID->maximum;
 72   }
 73   if(result<=vPID->minimum)
 74   {
 75     result=vPID->minimum;
 76   } 
 77 
 78   vPID->preerror=vPID->lasterror;  //存放偏差用于下次运算
 79   vPID->lasterror=thisError;
 80   vPID->result=result;
 81   vPID->output=((result-vPID->minimum)/(vPID->maximum-vPID->minimum))*100.0;
 82 }
 83 
 84 /*变积分系数处理函数，实现一个输出0和1之间的分段线性函数                    */
 85 /* 当偏差的绝对值小于最小值时，输出为1；当偏差的绝对值大于最大值时，输出为0   */
 86 /* 当偏差的绝对值介于最大值和最小值之间时，输出在0和1之间现行变化             */
 87 /* float error，当前输入的偏差值                                              */
 88 /* float absmax，偏差绝对值的最大值                                           */
 89 /* float absmin，偏差绝对值的最小值                                           */
 90 static float VariableIntegralCoefficient(float error,float absmax,float absmin)
 91 {
 92   float factor=0.0;
 93 
 94   if(abs(error)<=absmin)
 95   {
 96     factor=1.0;
 97   }
 98   else if(abs(error)>absmax)
 99   {
100     factor=0.0;
101   }
102   else
103   {
104     factor=(absmax-abs(error))/(absmax-absmin);
105   }
106 
107   return factor;
108 }

 1 *阀门控制调节*/
 2 void ControlProcess(void)
 3 {
 4   uint16_t TimerPeriod = 0;
 5   uint16_t PWMPulse = 0;
 6   float dutyfactor=0.0;//定义占空比
 7 
 8   vPID.setpoint=aPara.phyPara.flowSetPoint;
 9   PIDRegulation(&vPID, aPara.phyPara.flowMeasuredValue);
10   dutyfactor=vPID.result/ADC1HighRange;
11 
12   /*计算频率和占空比*/
13   TimerPeriod = PWMTimePeriod;//计算用于设置ARR寄存器的值使产生信号的频率为17.57 Khz
14   PWMPulse = (uint16_t) ((TimerPeriod - 1)*dutyfactor);//计算CCR1寄存器的值在通道1和1N产生50%占空比，用于TIM1
15 
16   HAL_TIM_PWM_Stop(&htim3, TIM_CHANNEL_1);//停止PWM
17   PWM_TIM_Configuration(TimerPeriod,PWMPulse);
18   HAL_TIM_PWM_Start(&htim3,TIM_CHANNEL_1);//启动PWM
19 }