PID控制C源程序？ BC31 TC30 编译过，可运行。 ＃i nclude <stdio.h> ＃i nclude<math.h> struct _pid { int pv; /*integer that contains the process value*/ int sp; /*integer that contains the set point*/ float integral; float pgain; float igain; float dgain; int deadband; int last_error; }; struct _pid warm,*pid; int process_point, set_point,dead_band; float p_gain, i_gain, d_gain, integral_val,new_integ;; /*------------------------------------------------------------------------ pid_init DESCRIPTION This function initializes the pointers in the _pid structure to the process variable and the setpoint. *pv and *sp are integer pointers. ------------------------------------------------------------------------*/ void pid_init(struct _pid *warm, int process_point, int set_point) { struct _pid *pid; pid = warm; pid->pv = process_point; pid->sp = set_point; } /*------------------------------------------------------------------------ pid_tune DESCRIPTION Sets the proportional gain (p_gain), integral gain (i_gain), derivitive gain (d_gain), and the DEAD band (dead_band) of a pid control structure _pid. ------------------------------------------------------------------------*/ void pid_tune(struct _pid *pid, float p_gain, float i_gain, float d_gain, int dead_band) { pid->pgain = p_gain; pid->igain = i_gain; pid->dgain = d_gain; pid->deadband = dead_band; pid->integral= integral_val; pid->last_error=0; } /*------------------------------------------------------------------------ pid_setinteg DESCRIPTION Set a new value for the integral term of the pid equation. This is useful for setting the initial output of the pid controller at start up. ------------------------------------------------------------------------*/ void pid_setinteg(struct _pid *pid,float new_integ) { pid->integral = new_integ; pid->last_error = 0; } /*------------------------------------------------------------------------ pid_bumpless DESCRIPTION Bumpless transfer algorithim. When suddenly changing setpoints, or when restarting the PID equation after an extended pause, the derivative of the equation can cause a bump in the controller output. This function will help smooth out that bump. The process value in *pv should be the updated just before this function is used. ------------------------------------------------------------------------*/ void pid_bumpless(struct _pid *pid) { pid->last_error = (pid->sp)-(pid->pv); } /*------------------------------------------------------------------------ pid_calc DESCRIPTION Performs PID calculations for the _pid structure *a. This function uses the positional form of the pid equation, and incorporates an integral windup prevention algorithim. Rectangular integration is used, so this function must be repeated on a consistent time basis for accurate control. RETURN VALUE The new output value for the pid loop. USAGE ＃i nclude "control.h"*/ float pid_calc(struct _pid *pid) { int err; float pterm, dterm, result, ferror; err = (pid->sp) - (pid->pv); if (abs(err) > pid->deadband) { ferror = (float) err; /*do integer to float conversion only once*/ pterm = pid->pgain * ferror; if (pterm > 100 || pterm < -100) { pid->integral = 0.0; } else { pid->integral += pid->igain * ferror; if (pid->integral > 100.0) { pid->integral = 100.0; } else if (pid->integral < 0.0) pid->integral = 0.0; } dterm = ((float)(err - pid->last_error)) * pid->dgain; result = pterm + pid->integral + dterm; } else result = pid->integral; pid->last_error = err; return (result); } void main(void) { float display_value; int count=0; pid = &warm; // printf("Enter the values of Process point, Set point, P gain, I gain, D gain \n"); // scanf("%d%d%f%f%f", &process_point, &set_point, &p_gain, &i_gain, &d_gain); process_point = 30; set_point = 40; p_gain = (float)(5.2); i_gain = (float)(0.77); d_gain = (float)(0.18); dead_band = 2; integral_val =(float)(0.01); printf("The values of Process point, Set point, P gain, I gain, D gain \n"); printf(" %6d %6d %4f %4f %4f\n", process_point, set_point, p_gain, i_gain, d_gain); printf("Enter the values of Process point\n"); while(count<=20) { scanf("%d",&process_point); pid_init(&warm, process_point, set_point); pid_tune(&warm, p_gain,i_gain,d_gain,dead_band); pid_setinteg(&warm,0.0); //pid_setinteg(&warm,30.0); //Get input value for process point pid_bumpless(&warm); // how to display output display_value = pid_calc(&warm); printf("%f\n", display_value); //printf("\n%f%f%f%f",warm.pv,warm.sp,warm.igain,warm.dgain); count++; } } PID常用口诀 参数整定找最佳，从小到大顺序查 先是比例后积分，最后再把微分加 曲线振荡很频繁，比例度盘要放大 曲线漂浮绕大湾，比例度盘往小扳 曲线偏离回复慢，积分时间往下降 曲线波动周期长，积分时间再加长 曲线振荡频率快，先把微分降下来 动差大来波动慢。微分时间应加长 理想曲线两个波，前高后低4比1 一看二调多分析，调节质量不会低查看更多0个回答 . 2人已关注
帮忙看看这个句子咋理解? the first pumping cell exerts an oxygen pumping action against the first measurement chamber to adjust the oxygen concentration in the gas under measurement within the first measurement chamber to a given level. 关于NOx sensor 的。 pumping cell 指的什么？抽气单元？ 这个句子我实在不晓得怎么断句了都。大家帮帮忙啊。查看更多4个回答 . 5人已关注
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