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Add temperature controlled fans

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Signed-off-by Douglas Hammond  <wizhippo@gmail.com>
This commit is contained in:
Douglas Hammond 2018-05-13 23:02:01 -04:00 • committed by KevinOConnor
parent 6d376017bc
commit 5712283e91
2 changed files with 123 additions and 26 deletions
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118
klippy/extras/temperature_fan.py
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@ -5,8 +5,10 @@
# This file may be distributed under the terms of the GNU GPLv3 license.
import fan
PIN_MIN_TIME = 0.100
KELVIN_TO_CELCIUS = -273.15
MAX_FAN_TIME = 5.0
AMBIENT_TEMP = 25.
PID_PARAM_BASE = 255.
class TemperatureFan:
def __init__(self, config):
@ -14,31 +16,105 @@ class TemperatureFan:
self.printer = config.get_printer()
self.fan = fan.PrinterFan(config)
self.mcu = self.fan.mcu_fan.get_mcu()
self.fan_speed = config.getfloat('fan_speed', 1., minval=0., maxval=1.)
min_temp = config.getfloat('min_temp', minval=KELVIN_TO_CELCIUS)
max_temp = config.getfloat('max_temp', above=min_temp)
self.temp = config.getfloat('temp', 40. if max_temp > 40. else max_temp,
minval=min_temp, maxval=max_temp)
self.fan.set_shutdown_speed(1.)
self.last_temp = KELVIN_TO_CELCIUS
self.min_temp = config.getfloat('min_temp', minval=KELVIN_TO_CELCIUS)
self.max_temp = config.getfloat('max_temp', above=self.min_temp)
self.sensor = self.printer.lookup_object('heater').setup_sensor(config)
self.sensor.setup_minmax(min_temp, max_temp)
self.sensor.setup_minmax(self.min_temp, self.max_temp)
self.sensor.setup_callback(self.temperature_callback)
def printer_state(self, state):
if state == 'ready':
reactor = self.printer.get_reactor()
reactor.register_timer(self.callback, reactor.NOW)
def callback(self, eventtime):
power = 0.
if self.last_temp > self.temp:
power = self.fan_speed
print_time = self.mcu.estimated_print_time(eventtime) + PIN_MIN_TIME
self.fan.set_speed(print_time, power)
return eventtime + 1.
self.speed_delay = self.sensor.get_report_time_delta()
self.fan.set_shutdown_speed(1.)
self.max_speed = config.getfloat('max_speed', 1., above=0., maxval=1.)
self.min_speed = config.getfloat('min_speed', 0.3, above=0., maxval=1.)
self.last_temp = 0.
self.last_temp_time = 0.
self.target_temp = config.getfloat('target_temp', 40. if self.max_temp > 40. else self.max_temp,
minval=self.min_temp, maxval=self.max_temp)
algos = {'watermark': ControlBangBang, 'pid': ControlPID}
algo = config.getchoice('control', algos)
self.control = algo(self, config)
self.next_speed_time = 0.
self.last_speed_value = 0.
def set_speed(self, read_time, value):
if value < self.min_speed:
value = 0.
if self.target_temp <= 0.:
value = 0.
if ((read_time < self.next_speed_time or not self.last_speed_value)
and abs(value - self.last_speed_value) < 0.05):
# No significant change in value - can suppress update
return
speed_time = read_time + self.speed_delay
self.next_speed_time = speed_time + 0.75 * MAX_FAN_TIME
self.last_speed_value = value
self.fan.set_speed(speed_time, value)
def temperature_callback(self, read_time, temp):
self.last_temp = temp
self.control.temperature_callback(read_time, temp)
def stats(self, eventtime):
return True, '%s: temp=%.1f' % (self.name, self.last_temp)
return True, '%s: temp=%.1f fan_speed=%.3f' % (self.name, self.last_temp, self.last_speed_value)
######################################################################
# Bang-bang control algo
######################################################################
class ControlBangBang:
def __init__(self, temperature_fan, config):
self.temperature_fan = temperature_fan
self.max_delta = config.getfloat('max_delta', 2.0, above=0.)
self.heating = False
def temperature_callback(self, read_time, temp):
if self.heating and temp >= self.temperature_fan.target_temp+self.max_delta:
self.heating = False
elif not self.heating and temp <= self.temperature_fan.target_temp-self.max_delta:
self.heating = True
if self.heating:
self.temperature_fan.set_speed(read_time, 0.)
else:
self.temperature_fan.set_speed(read_time, self.temperature_fan.max_power)
######################################################################
# Proportional Integral Derivative (PID) control algo
######################################################################
PID_SETTLE_DELTA = 1.
PID_SETTLE_SLOPE = .1
class ControlPID:
def __init__(self, temperature_fan, config):
self.temperature_fan = temperature_fan
self.Kp = config.getfloat('pid_Kp') / PID_PARAM_BASE
self.Ki = config.getfloat('pid_Ki') / PID_PARAM_BASE
self.Kd = config.getfloat('pid_Kd') / PID_PARAM_BASE
self.min_deriv_time = config.getfloat('pid_deriv_time', 2., above=0.)
imax = config.getfloat('pid_integral_max', temperature_fan.max_speed, minval=0.)
self.temp_integ_max = imax / self.Ki
self.prev_temp = AMBIENT_TEMP
self.prev_temp_time = 0.
self.prev_temp_deriv = 0.
self.prev_temp_integ = 0.
def temperature_callback(self, read_time, temp):
time_diff = read_time - self.prev_temp_time
# Calculate change of temperature
temp_diff = temp - self.prev_temp
if time_diff >= self.min_deriv_time:
temp_deriv = temp_diff / time_diff
else:
temp_deriv = (self.prev_temp_deriv * (self.min_deriv_time-time_diff)
+ temp_diff) / self.min_deriv_time
# Calculate accumulated temperature "error"
temp_err = self.temperature_fan.target_temp - temp
temp_integ = self.prev_temp_integ + temp_err * time_diff
temp_integ = max(0., min(self.temp_integ_max, temp_integ))
# Calculate output
co = self.Kp*temp_err + self.Ki*temp_integ - self.Kd*temp_deriv
bounded_co = max(0., min(self.temperature_fan.max_speed, co))
self.temperature_fan.set_speed(read_time, self.temperature_fan.max_speed - bounded_co)
# Store state for next measurement
self.prev_temp = temp
self.prev_temp_time = read_time
self.prev_temp_deriv = temp_deriv
if co == bounded_co:
self.prev_temp_integ = temp_integ
def load_config_prefix(config):
return TemperatureFan(config)