--- a/thermferm/thermferm.c Sun Feb 15 23:09:00 2015 +0100
+++ b/thermferm/thermferm.c Mon Feb 16 19:52:42 2015 +0100
@@ -834,9 +834,9 @@
units_list *unit;
profiles_list *profile;
prof_step *step;
- int rc, run = 1, seconds = 0, minutes = 0, piddelay = 0, temp, deviation;
+ int rc, run = 1, seconds = 0, minutes = 0, temp, deviation;
int run_seconds, run_minutes, run_hours, tot_minutes;
- float sp, pv, P_err = 0.0, D_err, Out;
+ float sp, pv, P_err = 0.0, Out;
#ifdef HAVE_WIRINGPI_H
struct tm *tm;
int row, key;
@@ -1302,62 +1302,65 @@
#endif
}
- piddelay++;
- if (piddelay == 5) {
- piddelay = 0;
+ /*
+ * PID controller per unit, each second
+ */
+ for (unit = Config.units; unit; unit = unit->next) {
+ if ((unit->mode == UNITMODE_FRIDGE) || (unit->mode == UNITMODE_BEER) || (unit->mode == UNITMODE_PROFILE)) {
+ double pTerm, dTerm, iTerm;
+
+ sp = unit->beer_set;
+ pv = unit->beer_temperature / 1000.0;
+ if (unit->mode == UNITMODE_FRIDGE) {
+ sp = unit->fridge_set;
+ pv = unit->air_temperature / 1000.0;
+ } else if (unit->mode == UNITMODE_PROFILE) {
+ sp = unit->prof_target;
+ }
+
+ /*
+ * PID controller compute
+ */
+ P_err = sp - pv;
+// if (P_err < unit->idle_rangeH && P_err > unit->idle_rangeL) {
+// P_err = 0.0;
+// }
+ pTerm = unit->PID_Kp * P_err;
- for (unit = Config.units; unit; unit = unit->next) {
- if ((unit->mode == UNITMODE_FRIDGE) || (unit->mode == UNITMODE_BEER) || (unit->mode == UNITMODE_PROFILE)) {
- /*
- * PID controller
- */
- sp = unit->beer_set;
- pv = unit->beer_temperature / 1000.0;
- if (unit->mode == UNITMODE_FRIDGE) {
- sp = unit->fridge_set;
- pv = unit->air_temperature / 1000.0;
- } else if (unit->mode == UNITMODE_PROFILE) {
- sp = unit->prof_target;
- }
+ /*
+ * Calculate the intergral state with appropriate limiting
+ */
+ unit->PID_I_err += P_err;
+ /* Limit integral error */
+ if (unit->PID_I_err < -100.0)
+ unit->PID_I_err = -100.0;
+ if (unit->PID_I_err > 100.0)
+ unit->PID_I_err = 100.0;
+ iTerm = unit->PID_I_err * unit->PID_Ki;
+ dTerm = unit->PID_err_old * unit->PID_Kd;
- P_err = sp - pv;
- if (P_err < unit->idle_rangeH && P_err > unit->idle_rangeL) {
- P_err = 0.0;
- }
- unit->PID_I_err += (unit->PID_Ki * P_err);
-// unit->PID_I_err -= unit->PID_err_old;
-// } else {
-// unit->PID_I_err += unit->PID_err_old;
+ /*
+ * A postive value means heating, a negative value cooling.
+ * Start with Kp, Kd and Ki set to 0.
+ * Increase Kp until small oscillation.
+ * Increase Kd until a little damping.
+ * Increase Ki after Kp and Kd are set until longterm convergence.
+ */
+ Out = pTerm + dTerm + iTerm;
+ if (Out > 100.0)
+ Out = 100.0;
+ if (Out < -100.0)
+ Out = -100.0;
+// if /* (P_err != 0.0) */ (i == 1) {
+ if (debug)
+ fprintf(stdout, "sp=%.2f pv=%.2f err_old=%.2f P_err=%.2f I_err=%.2f Out=%.2f\n",
+ sp, pv, unit->PID_err_old, P_err, unit->PID_I_err, Out);
+ syslog(LOG_NOTICE, "sp=%.2f pv=%.2f err_old=%.2f P_err=%.2f I_err=%.2f Out=%.2f pTerm=%.2f iTerm=%.2f dTerm=%.2f, N=%.2f",
+ sp, pv, unit->PID_err_old, P_err, unit->PID_I_err, Out, pTerm, iTerm, dTerm, pTerm + dTerm + iTerm);
// }
- /* Limit integral error */
- if (unit->PID_I_err < -100.0)
- unit->PID_I_err = -100.0;
- if (unit->PID_I_err > 100.0)
- unit->PID_I_err = 100.0;
- D_err = P_err - unit->PID_err_old;
+ unit->PID_err_old = P_err;
- /*
- * A postive value means heating, a negative value cooling.
- * Start with Kp, Kd and Ki set to 0.
- * Increase Kp until small oscillation.
- * Increase Kd until a little damping.
- * Increase Ki after Kp and Kd are set until longterm convergence.
- */
- Out = (unit->PID_Kp * P_err) + unit->PID_I_err - (unit->PID_Kd * D_err);
- if (Out > 100.0)
- Out = 100.0;
- if (Out < -100.0)
- Out = -100.0;
-// if (P_err != 0.0) {
- if (debug)
- fprintf(stdout, "sp=%.2f pv=%.2f err_old=%.2f P_err=%.2f I_err=%.2f D_err=%.2f Out=%.2f\n",
- sp, pv, unit->PID_err_old, P_err, unit->PID_I_err, D_err, Out);
- syslog(LOG_NOTICE, "sp=%.2f pv=%.2f err_old=%.2f P_err=%.2f I_err=%.2f D_err=%.2f Out=%.2f",
- sp, pv, unit->PID_err_old, P_err, unit->PID_I_err, D_err, Out);
-// }
- unit->PID_err_old = P_err;
-
- if (unit->heater_address) {
+ if (unit->heater_address) {
if (Out >= 1) {
if (unit->heater_wait < unit->heater_delay) {
unit->heater_wait++;
@@ -1380,8 +1383,8 @@
}
}
device_out(unit->heater_address, unit->heater_state);
- }
- if (unit->cooler_address) {
+ }
+ if (unit->cooler_address) {
if (Out <= -1) {
if (unit->cooler_wait < unit->cooler_delay) {
unit->cooler_wait++;
@@ -1404,8 +1407,8 @@
}
}
device_out(unit->cooler_address, unit->cooler_state);
- }
- if (unit->heater_address && unit->cooler_address && unit->fan_address) {
+ }
+ if (unit->heater_address && unit->cooler_address && unit->fan_address) {
/*
* If the temperature difference between air and beer is more then
* xxx degrees, turn the fan on to make an airflow.
@@ -1424,12 +1427,11 @@
unit->fan_state = 0;
}
device_out(unit->fan_address, unit->fan_state);
- }
- } else {
+ }
+ } else {
P_err = 0.0;
unit->PID_I_err = 0.0;
unit->PID_err_old = 0.0;
- }
}
}
