void PID_autotune(float temp, int extruder, int ncycles)
{
float input = 0.0;
int cycles = 0;
bool heating = true;
millis_t temp_ms = millis(), t1 = temp_ms, t2 = temp_ms;
long t_high = 0, t_low = 0;
long bias, d;
float Ku, Tu;
float Kp, Ki, Kd;
float max = 0, min = 10000;
#if HAS_AUTO_FAN
millis_t next_auto_fan_check_ms = temp_ms + 2500;
#endif
if (extruder >= EXTRUDERS
#if !HAS_TEMP_BED
|| extruder < 0
#endif
) {
SERIAL_ECHOLN(MSG_PID_BAD_EXTRUDER_NUM);
return;
}
SERIAL_ECHOLN(MSG_PID_AUTOTUNE_START);
disable_heater(); // switch off all heaters.
if (extruder < 0)
soft_pwm_bed = bias = d = MAX_BED_POWER / 2;
else
soft_pwm[extruder] = bias = d = PID_MAX / 2;
// PID Tuning loop
for (;;) {
millis_t ms = millis();
if (temp_meas_ready) { // temp sample ready
updateTemperaturesFromRawValues();
input = (extruder<0)?current_temperature_bed:current_temperature[extruder];
max = max(max, input);
min = min(min, input);
#if HAS_AUTO_FAN
if (ms > next_auto_fan_check_ms) {
checkExtruderAutoFans();
next_auto_fan_check_ms = ms + 2500;
}
#endif
if (heating == true && input > temp) {
if (ms - t2 > 5000) {
heating = false;
if (extruder < 0)
soft_pwm_bed = (bias - d) >> 1;
else
soft_pwm[extruder] = (bias - d) >> 1;
t1 = ms;
t_high = t1 - t2;
max = temp;
}
}
if (heating == false && input < temp) {
if (ms - t1 > 5000) {
heating = true;
t2 = ms;
t_low = t2 - t1;
if (cycles > 0) {
long max_pow = extruder < 0 ? MAX_BED_POWER : PID_MAX;
bias += (d*(t_high - t_low))/(t_low + t_high);
bias = constrain(bias, 20, max_pow - 20);
d = (bias > max_pow / 2) ? max_pow - 1 - bias : bias;
SERIAL_PROTOCOLPGM(MSG_BIAS); SERIAL_PROTOCOL(bias);
SERIAL_PROTOCOLPGM(MSG_D); SERIAL_PROTOCOL(d);
SERIAL_PROTOCOLPGM(MSG_T_MIN); SERIAL_PROTOCOL(min);
SERIAL_PROTOCOLPGM(MSG_T_MAX); SERIAL_PROTOCOLLN(max);
if (cycles > 2) {
Ku = (4.0 * d) / (3.14159265 * (max - min) / 2.0);
Tu = ((float)(t_low + t_high) / 1000.0);
SERIAL_PROTOCOLPGM(MSG_KU); SERIAL_PROTOCOL(Ku);
SERIAL_PROTOCOLPGM(MSG_TU); SERIAL_PROTOCOLLN(Tu);
Kp = 0.6 * Ku;
Ki = 2 * Kp / Tu;
Kd = Kp * Tu / 8;
SERIAL_PROTOCOLLNPGM(MSG_CLASSIC_PID);
SERIAL_PROTOCOLPGM(MSG_KP); SERIAL_PROTOCOLLN(Kp);
SERIAL_PROTOCOLPGM(MSG_KI); SERIAL_PROTOCOLLN(Ki);
SERIAL_PROTOCOLPGM(MSG_KD); SERIAL_PROTOCOLLN(Kd);
/*
Kp = 0.33*Ku;
Ki = Kp/Tu;
Kd = Kp*Tu/3;
SERIAL_PROTOCOLLNPGM(" Some overshoot ");
SERIAL_PROTOCOLPGM(" Kp: "); SERIAL_PROTOCOLLN(Kp);
SERIAL_PROTOCOLPGM(" Ki: "); SERIAL_PROTOCOLLN(Ki);
SERIAL_PROTOCOLPGM(" Kd: "); SERIAL_PROTOCOLLN(Kd);
Kp = 0.2*Ku;
Ki = 2*Kp/Tu;
Kd = Kp*Tu/3;
SERIAL_PROTOCOLLNPGM(" No overshoot ");
SERIAL_PROTOCOLPGM(" Kp: "); SERIAL_PROTOCOLLN(Kp);
SERIAL_PROTOCOLPGM(" Ki: "); SERIAL_PROTOCOLLN(Ki);
SERIAL_PROTOCOLPGM(" Kd: "); SERIAL_PROTOCOLLN(Kd);
*/
}
}
if (extruder < 0)
soft_pwm_bed = (bias + d) >> 1;
else
soft_pwm[extruder] = (bias + d) >> 1;
cycles++;
min = temp;
}
void PID_autotune(float temp, int hotend, int ncycles) {
float input = 0.0;
int cycles = 0;
bool heating = true;
millis_t temp_ms = millis(), t1 = temp_ms, t2 = temp_ms;
long t_high = 0, t_low = 0;
long bias, d;
float Ku, Tu;
float Kp_temp, Ki_temp, Kd_temp;
float max = 0, min = 10000;
#if HAS_AUTO_FAN
millis_t next_auto_fan_check_ms = temp_ms + 2500;
#endif
if (hotend >= HOTENDS
#if !HAS_TEMP_BED
|| hotend < 0
#endif
) {
ECHO_LM(ER, MSG_PID_BAD_EXTRUDER_NUM);
return;
}
ECHO_LM(DB, MSG_PID_AUTOTUNE_START);
if (hotend < 0) {
ECHO_SM(DB, "BED");
}
else {
ECHO_SMV(DB, "Hotend: ", hotend);
}
ECHO_MV(" Temp: ", temp);
ECHO_EMV(" Cycles: ", ncycles);
disable_all_heaters(); // switch off all heaters.
if (hotend < 0)
soft_pwm_bed = bias = d = MAX_BED_POWER / 2;
else
soft_pwm[hotend] = bias = d = PID_MAX / 2;
// PID Tuning loop
for (;;) {
millis_t ms = millis();
if (temp_meas_ready) { // temp sample ready
updateTemperaturesFromRawValues();
input = (hotend<0)?current_temperature_bed:current_temperature[hotend];
max = max(max, input);
min = min(min, input);
#if HAS_AUTO_FAN
if (ms > next_auto_fan_check_ms) {
checkExtruderAutoFans();
next_auto_fan_check_ms = ms + 2500;
}
#endif
if (heating && input > temp) {
if (ms > t2 + 5000) {
heating = false;
if (hotend < 0)
soft_pwm_bed = (bias - d) >> 1;
else
soft_pwm[hotend] = (bias - d) >> 1;
t1 = ms;
t_high = t1 - t2;
max = temp;
}
}
if (!heating && input < temp) {
if (ms > t1 + 5000) {
heating = true;
t2 = ms;
t_low = t2 - t1;
if (cycles > 0) {
long max_pow = hotend < 0 ? MAX_BED_POWER : PID_MAX;
bias += (d*(t_high - t_low))/(t_low + t_high);
bias = constrain(bias, 20, max_pow - 20);
d = (bias > max_pow / 2) ? max_pow - 1 - bias : bias;
ECHO_MV(MSG_BIAS, bias);
ECHO_MV(MSG_D, d);
ECHO_MV(MSG_T_MIN, min);
ECHO_MV(MSG_T_MAX, max);
if (cycles > 2) {
Ku = (4.0 * d) / (3.14159265 * (max - min) / 2.0);
Tu = ((float)(t_low + t_high) / 1000.0);
ECHO_MV(MSG_KU, Ku);
ECHO_EMV(MSG_TU, Tu);
Kp_temp = 0.6 * Ku;
Ki_temp = 2 * Kp_temp / Tu;
Kd_temp = Kp_temp * Tu / 8;
ECHO_EM(MSG_CLASSIC_PID);
ECHO_MV(MSG_KP, Kp_temp);
ECHO_MV(MSG_KI, Ki_temp);
ECHO_EMV(MSG_KD, Kd_temp);
}
else {
ECHO_E;
}
}
if (hotend < 0)
soft_pwm_bed = (bias + d) >> 1;
else
soft_pwm[hotend] = (bias + d) >> 1;
cycles++;
min = temp;
}