From c6a228d62ed7f42eb2a019801d9fa4316b45bdb7 Mon Sep 17 00:00:00 2001 From: Keegi Date: Tue, 9 Aug 2011 10:56:34 +0300 Subject: PID fixes --- Sprinter/Configuration.h | 12 ++++++++---- Sprinter/Sprinter.pde | 45 ++++++++++++++++++++++++++++++--------------- 2 files changed, 38 insertions(+), 19 deletions(-) diff --git a/Sprinter/Configuration.h b/Sprinter/Configuration.h index bc00ce1..df55c7d 100644 --- a/Sprinter/Configuration.h +++ b/Sprinter/Configuration.h @@ -120,10 +120,14 @@ char uuid[] = "00000000-0000-0000-0000-000000000000"; // Uncomment the following line to enable PID support. This is untested and could be disastrous. Be careful. //#define PIDTEMP #ifdef PIDTEMP -#define PID_INTEGRAL_DRIVE_MAX 220 -#define PID_PGAIN 180 //100 is 1.0 -#define PID_IGAIN 2 //100 is 1.0 -#define PID_DGAIN 100 //100 is 1.0 +#define PID_INTEGRAL_DRIVE_MAX 80 // too big, and heater will lag after changing temperature, too small and it might not compensate enough for long-term errors +#define PID_PGAIN 1280 //256 is 1.0 // value of 5.0 means that error of 20C is changing it almost halfway of the PWM range +#define PID_IGAIN 64 //256 is 1.0 // value of 0.25 means that each degree error over 1 sec (2 measurements) changes duty cycle by 0.5 units (verify?) +#define PID_DGAIN 2048 //256 is 1.0 // value of 8.0 means that each degree change over one measurement (half second) adjusts PWM by 8 units to compensate +// magic formula 1, to get approximate "zero error" PWM duty. It is most likely linear formula +#define HEATER_DUTY_FOR_SETPOINT(setpoint) (22+1*setpoint) +// magic formula 2, to make led brightness approximately linear +#define LED_PWM_FOR_BRIGTHNESS(brightness) ((64*brightness-1384)/(300-brightness)) #endif // Change this value (range 1-255) to limit the current to the nozzle diff --git a/Sprinter/Sprinter.pde b/Sprinter/Sprinter.pde index d385285..2f8cac9 100644 --- a/Sprinter/Sprinter.pde +++ b/Sprinter/Sprinter.pde @@ -1,4 +1,4 @@ -// Tonokip RepRap firmware rewrite based off of Hydra-mmm firmware. + // Tonokip RepRap firmware rewrite based off of Hydra-mmm firmware. // Licence: GPL #include "fastio.h" @@ -112,20 +112,22 @@ char *strchr_pointer; // just a pointer to find chars in the cmd string like X, // degree increments (i.e. 100=25 deg). int target_raw = 0; +int target_temp = 0; int current_raw = 0; int target_bed_raw = 0; int current_bed_raw = 0; int tt = 0, bt = 0; #ifdef PIDTEMP int temp_iState = 0; - int temp_dState = 0; + int prev_temp = 0; int pTerm; int iTerm; int dTerm; //int output; int error; - int temp_iState_min = 100 * -PID_INTEGRAL_DRIVE_MAX / PID_IGAIN; - int temp_iState_max = 100 * PID_INTEGRAL_DRIVE_MAX / PID_IGAIN; + int heater_duty = 0; + const int temp_iState_min = 256L * -PID_INTEGRAL_DRIVE_MAX / PID_IGAIN; + const int temp_iState_max = 256L * PID_INTEGRAL_DRIVE_MAX / PID_IGAIN; #endif #ifndef HEATER_CURRENT #define HEATER_CURRENT 255 @@ -766,7 +768,7 @@ inline void process_commands() } break; case 104: // M104 - if (code_seen('S')) target_raw = temp2analogh(code_value()); + if (code_seen('S')) target_raw = temp2analogh(target_temp = code_value()); #ifdef WATCHPERIOD if(target_raw > current_raw){ watchmillis = max(1,millis()); @@ -791,6 +793,12 @@ inline void process_commands() #if (TEMP_0_PIN > -1) || defined (HEATER_USES_MAX6675) || defined HEATER_USES_AD595 Serial.print("ok T:"); Serial.print(tt); + #ifdef PIDTEMP + Serial.print(" @:"); + Serial.print(heater_duty); + Serial.print(","); + Serial.print(iTerm); + #endif #if TEMP_1_PIN > -1 || defined BED_USES_AD595 Serial.print(" B:"); Serial.println(bt); @@ -803,7 +811,7 @@ inline void process_commands() return; //break; case 109: { // M109 - Wait for extruder heater to reach target. - if (code_seen('S')) target_raw = temp2analogh(code_value()); + if (code_seen('S')) target_raw = temp2analogh(target_temp = code_value()); #ifdef WATCHPERIOD if(target_raw>current_raw){ watchmillis = max(1,millis()); @@ -1461,7 +1469,7 @@ void manage_heater() #ifdef WATCHPERIOD if(watchmillis && millis() - watchmillis > WATCHPERIOD){ if(watch_raw + 1 >= current_raw){ - target_raw = 0; + target_temp = target_raw = 0; WRITE(HEATER_0_PIN,LOW); analogWrite(HEATER_0_PIN, 0); #if LED_PIN>-1 @@ -1474,11 +1482,11 @@ void manage_heater() #endif #ifdef MINTEMP if(current_raw <= minttemp) - target_raw = 0; + target_temp = target_raw = 0; #endif #ifdef MAXTEMP if(current_raw >= maxttemp) { - target_raw = 0; + target_temp = target_raw = 0; #if (ALARM_PIN > -1) WRITE(ALARM_PIN,HIGH); #endif @@ -1486,14 +1494,21 @@ void manage_heater() #endif #if (TEMP_0_PIN > -1) || defined (HEATER_USES_MAX6675) || defined (HEATER_USES_AD595) #ifdef PIDTEMP - error = target_raw - current_raw; - pTerm = (PID_PGAIN * error) / 100; + int current_temp = analog2temp(current_raw); + error = target_temp - current_temp; + int delta_temp = current_temp - prev_temp; + prev_temp = current_temp; + pTerm = ((long)PID_PGAIN * error) / 256; temp_iState += error; temp_iState = constrain(temp_iState, temp_iState_min, temp_iState_max); - iTerm = (PID_IGAIN * temp_iState) / 100; - dTerm = (PID_DGAIN * (current_raw - temp_dState)) / 100; - temp_dState = current_raw; - analogWrite(HEATER_0_PIN, constrain(pTerm + iTerm - dTerm, 0, HEATER_CURRENT)); + iTerm = ((long)PID_IGAIN * temp_iState) / 256; + dTerm = ((long)PID_DGAIN * delta_temp) / 256; + const int H0 = min(HEATER_DUTY_FOR_SETPOINT(target_temp),HEATER_CURRENT); + heater_duty = H0 + constrain(pTerm + iTerm - dTerm, -H0, HEATER_CURRENT-H0); + analogWrite(HEATER_0_PIN, heater_duty); + #if LED_PIN>-1 + analogWrite(LED_PIN, constrain(LED_PWM_FOR_BRIGHTNESS(heater_duty),0,255)); + #endif #else if(current_raw >= target_raw) { -- cgit v1.2.1