单片机PID算法实现
// 比例项
pterm = pid->pgain * ferror;
if (pterm > 100 || pterm < -100)
{
pid->integral = 0.0;
}
else
{
// 积分项
pid->integral += pid->igain * ferror;
if (pid->integral > 100.0)
{
pid->integral = 100.0;
}
else if (pid->integral < 0.0)
pid->integral = 0.0;
}
// 微分项
dterm = ((float)(err - pid->last_error)) * pid->dgain;
result = pterm + pid->integral + dterm;
}
else
result = pid->integral; // 在死区范围内,保持现有输出
// 保存上次偏差
pid->last_error = err;
return (result);
}
//----------------------------------------------
参数说明:
p_gain = (float)(5.2);//比例系数
i_gain = (float)(0.77);//积分系数
d_gain = (float)(0.18);//微分系数
process_point为设定的稳定值
display_value为系统输出值
process_point为传感器传入当前值
函数调用示例:
float display_value;
int count=0;
pid = &warm;
process_point = 30;
set_point = 40;
dead_band = 2;
integral_val =(float)(0.01);
scanf("%d",&process_point);
// 设定PV,SP值
pid_init(&warm, process_point, set_point);
// 初始化PID参数值
pid_tune(&warm, p_gain,i_gain,d_gain,dead_band);
// 初始化PID输出值
pid_setinteg(&warm,0.0);
//pid_setinteg(&warm,30.0);
pid_bumpless(&warm);
display_value = pid_calc(&warm);
printf("%f", display_value);
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