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Added PID autotune. (experimental)

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M303 Starts autotune. Wait till the Kp Ki and Kd constants are printed.
Put these values in Configuration.h
This commit is contained in:
Erik van der Zalm
2012-03-08 21:43:21 +01:00
parent 116dc86b8a
commit c077316b2b
5 changed files with 274 additions and 169 deletions
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89
Marlin/temperature.cpp
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@ -62,7 +62,7 @@ int current_raw_bed = 0;
//===========================================================================
//=============================private variables============================
//===========================================================================
static bool temp_meas_ready = false;
static volatile bool temp_meas_ready = false;
static unsigned long previous_millis_bed_heater;
//static unsigned long previous_millis_heater;
@ -132,7 +132,94 @@ static unsigned long previous_millis_bed_heater;
//===========================================================================
//============================= functions ============================
//===========================================================================
void PID_autotune(float temp)
{
float input;
int cycles=0;
bool heating = true;
soft_pwm[0] = 255>>1;
unsigned long temp_millis = millis();
unsigned long t1=temp_millis;
unsigned long t2=temp_millis;
long t_high;
long t_low;
long bias=127;
long d = 127;
float Ku, Tu;
float Kp, Ki, Kd;
float max, min;
SERIAL_ECHOLN("PID Autotune start");
for(;;) {
if(temp_meas_ready == true) { // temp sample ready
CRITICAL_SECTION_START;
temp_meas_ready = false;
CRITICAL_SECTION_END;
input = analog2temp(current_raw[0], 0);
max=max(max,input);
min=min(min,input);
if(heating == true && input > temp) {
if(millis() - t2 > 5000) {
heating=false;
soft_pwm[0] = (bias - d) >> 1;
t1=millis();
t_high=t1 - t2;
max=temp;
}
}
if(heating == false && input < temp) {
if(millis() - t1 > 5000) {
heating=true;
t2=millis();
t_low=t2 - t1;
if(cycles > 0) {
bias += (d*(t_high - t_low))/(t_low + t_high);
bias = constrain(bias, 20 ,235);
if(bias > 127) d = 254 - bias;
else d = bias;
SERIAL_PROTOCOLPGM(" bias: "); SERIAL_PROTOCOL(bias);
SERIAL_PROTOCOLPGM(" d: "); SERIAL_PROTOCOL(d);
SERIAL_PROTOCOLPGM(" min: "); SERIAL_PROTOCOL(min);
SERIAL_PROTOCOLPGM(" max: "); SERIAL_PROTOCOLLN(max);
if(cycles > 2) {
Ku = (4.0*d)/(3.14159*(max-min)/2.0);
Tu = ((float)(t_low + t_high)/1000.0);
Kp = 0.6*Ku;
Ki = 2*Kp/Tu;
Kd = Kp*Tu/8;
SERIAL_PROTOCOLPGM(" Kp: "); SERIAL_PROTOCOLLN(Kp);
SERIAL_PROTOCOLPGM(" Ki: "); SERIAL_PROTOCOLLN(Ki);
SERIAL_PROTOCOLPGM(" Kd: "); SERIAL_PROTOCOLLN(Kd);
}
}
soft_pwm[0] = (bias + d) >> 1;
cycles++;
min=temp;
}
}
}
if(input > (temp + 20)) {
SERIAL_PROTOCOLLNPGM("PID Autotune failed !!!, Temperature to high");
return;
}
if(millis() - temp_millis > 2000) {
temp_millis = millis();
SERIAL_PROTOCOLPGM("ok T:");
SERIAL_PROTOCOL(degHotend(0));
SERIAL_PROTOCOLPGM(" @:");
SERIAL_PROTOCOLLN(getHeaterPower(0));
}
LCD_STATUS;
}
}
void updatePID()
{
#ifdef PIDTEMP