def run(self):
try:
self.running = True
startup_str = "Activated in {:.1f} ms".format(
(timeit.default_timer() - self.thread_startup_timer) * 1000)
if self.is_paused:
startup_str += ", started Paused"
elif self.is_held:
startup_str += ", started Held"
self.logger.info(startup_str)
# Initialize PID Controller
self.PID_Controller = PIDControl(
self.period,
self.Kp,
self.Ki,
self.Kd,
integrator_min=self.integrator_min,
integrator_max=self.integrator_max)
# If activated, initialize PID Autotune
if self.autotune_activated:
self.autotune_timestamp = time.time()
self.autotune = PIDAutotune(self.setpoint,
out_step=self.autotune_outstep,
sampletime=self.period,
out_min=0,
out_max=self.period,
noiseband=self.autotune_noiseband)
self.ready.set()
while self.running:
if (self.method_start_act == 'Ended'
and self.method_type == 'Duration'):
self.stop_controller(ended_normally=False,
deactivate_pid=True)
self.logger.warning(
"Method has ended. "
"Activate the PID controller to start it again.")
elif time.time() > self.timer:
self.check_pid()
time.sleep(self.sample_rate)
except Exception as except_msg:
self.logger.exception("Run Error: {err}".format(err=except_msg))
finally:
# Turn off output used in PID when the controller is deactivated
if self.raise_output_id and self.direction in ['raise', 'both']:
self.control.output_off(self.raise_output_id,
trigger_conditionals=True)
if self.lower_output_id and self.direction in ['lower', 'both']:
self.control.output_off(self.lower_output_id,
trigger_conditionals=True)
self.running = False
self.logger.info("Deactivated in {:.1f} ms".format(
(timeit.default_timer() - self.thread_shutdown_timer) * 1000))
class PIDController(AbstractController, threading.Thread):
"""
Class to operate discrete PID controller in Mycodo
"""
def __init__(self, ready, unique_id):
threading.Thread.__init__(self)
super(PIDController, self).__init__(ready,
unique_id=unique_id,
name=__name__)
self.unique_id = unique_id
self.sample_rate = None
self.control = DaemonControl()
self.device_measurements = None
self.device_id = None
self.measurement_id = None
self.raise_output_type = None
self.lower_output_type = None
self.log_level_debug = None
self.PID_Controller = None
self.control_variable = 0.0
self.derivator = 0.0
self.integrator = 0.0
self.error = 0.0
self.P_value = None
self.I_value = None
self.D_value = None
self.lower_seconds_on = 0.0
self.raise_seconds_on = 0.0
self.lower_duty_cycle = 0.0
self.raise_duty_cycle = 0.0
self.last_time = None
self.last_measurement = None
self.last_measurement_success = False
self.is_activated = None
self.is_held = None
self.is_paused = None
self.measurement = None
self.method_id = None
self.direction = None
self.raise_output_id = None
self.raise_min_duration = None
self.raise_max_duration = None
self.raise_min_off_duration = None
self.lower_output_id = None
self.lower_min_duration = None
self.lower_max_duration = None
self.lower_min_off_duration = None
self.Kp = 0
self.Ki = 0
self.Kd = 0
self.integrator_min = None
self.integrator_max = None
self.period = 0
self.start_offset = 0
self.max_measure_age = None
self.default_setpoint = None
self.setpoint = 0
self.store_lower_as_negative = None
self.first_start = None
self.timer = None
# Hysteresis options
self.band = None
self.allow_raising = False
self.allow_lowering = False
# PID Autotune
self.autotune = None
self.autotune_activated = False
self.autotune_debug = False
self.autotune_noiseband = 0
self.autotune_outstep = 0
self.autotune_timestamp = None
# Check if a method is set for this PID
self.method_type = None
self.method_start_act = None
self.method_start_time = None
self.method_end_time = None
def loop(self):
if (self.method_start_act == 'Ended'
and self.method_type == 'Duration'):
self.stop_controller(ended_normally=False, deactivate_pid=True)
self.logger.warning(
"Method has ended. "
"Activate the PID controller to start it again.")
elif time.time() > self.timer:
while time.time() > self.timer:
self.timer = self.timer + self.period
self.attempt_execute(self.check_pid)
def run_finally(self):
# Turn off output used in PID when the controller is deactivated
if self.raise_output_id and self.direction in ['raise', 'both']:
self.control.output_off(self.raise_output_id,
trigger_conditionals=True)
if self.lower_output_id and self.direction in ['lower', 'both']:
self.control.output_off(self.lower_output_id,
trigger_conditionals=True)
def initialize_variables(self):
"""Set PID parameters"""
self.sample_rate = db_retrieve_table_daemon(
Misc, entry='first').sample_rate_controller_pid
self.device_measurements = db_retrieve_table_daemon(DeviceMeasurements)
pid = db_retrieve_table_daemon(PID, unique_id=self.unique_id)
self.device_id = pid.measurement.split(',')[0]
self.measurement_id = pid.measurement.split(',')[1]
self.is_activated = pid.is_activated
self.is_held = pid.is_held
self.is_paused = pid.is_paused
self.log_level_debug = pid.log_level_debug
self.method_id = pid.method_id
self.direction = pid.direction
self.raise_output_id = pid.raise_output_id
self.raise_min_duration = pid.raise_min_duration
self.raise_max_duration = pid.raise_max_duration
self.raise_min_off_duration = pid.raise_min_off_duration
self.lower_output_id = pid.lower_output_id
self.lower_min_duration = pid.lower_min_duration
self.lower_max_duration = pid.lower_max_duration
self.lower_min_off_duration = pid.lower_min_off_duration
self.Kp = pid.p
self.Ki = pid.i
self.Kd = pid.d
self.integrator_min = pid.integrator_min
self.integrator_max = pid.integrator_max
self.period = pid.period
self.start_offset = pid.start_offset
self.max_measure_age = pid.max_measure_age
self.default_setpoint = pid.setpoint
self.setpoint = pid.setpoint
self.band = pid.band
self.store_lower_as_negative = pid.store_lower_as_negative
self.first_start = True
self.timer = time.time() + self.start_offset
# Autotune
self.autotune_activated = pid.autotune_activated
self.autotune_noiseband = pid.autotune_noiseband
self.autotune_outstep = pid.autotune_outstep
self.set_log_level_debug(self.log_level_debug)
try:
self.raise_output_type = db_retrieve_table_daemon(
Output, unique_id=self.raise_output_id).output_type
except AttributeError:
self.raise_output_type = None
try:
self.lower_output_type = db_retrieve_table_daemon(
Output, unique_id=self.lower_output_id).output_type
except AttributeError:
self.lower_output_type = None
# Initialize PID Controller
self.PID_Controller = PIDControl(self.period,
self.Kp,
self.Ki,
self.Kd,
integrator_min=self.integrator_min,
integrator_max=self.integrator_max)
# If activated, initialize PID Autotune
if self.autotune_activated:
self.autotune_timestamp = time.time()
try:
self.autotune = PIDAutotune(self.setpoint,
out_step=self.autotune_outstep,
sampletime=self.period,
out_min=0,
out_max=self.period,
noiseband=self.autotune_noiseband)
except Exception as msg:
self.logger.error(msg)
self.stop_controller(deactivate_pid=True)
if self.method_id != '':
self.setup_method(self.method_id)
if self.is_paused:
self.logger.info("Starting Paused")
elif self.is_held:
self.logger.info("Starting Held")
self.logger.info("PID Settings: {}".format(self.pid_parameters_str()))
return "success"
def check_pid(self):
""" Get measurement and apply to PID controller """
# If PID is active, retrieve measurement and update
# the control variable.
# A PID on hold will sustain the current output and
# not update the control variable.
if self.is_activated and (not self.is_paused or not self.is_held):
self.get_last_measurement()
if self.last_measurement_success:
if self.method_id != '':
# Update setpoint using a method
this_pid = db_retrieve_table_daemon(
PID, unique_id=self.unique_id)
setpoint, ended = calculate_method_setpoint(
self.method_id, PID, this_pid, Method, MethodData,
self.logger)
if ended:
self.method_start_act = 'Ended'
if setpoint is not None:
self.setpoint = setpoint
else:
self.setpoint = self.default_setpoint
# If autotune activated, determine control variable (output) from autotune
if self.autotune_activated:
if not self.autotune.run(self.last_measurement):
self.control_variable = self.autotune.output
if self.autotune_debug:
self.logger.info('')
self.logger.info("state: {}".format(
self.autotune.state))
self.logger.info("output: {}".format(
self.autotune.output))
else:
# Autotune has finished
timestamp = time.time() - self.autotune_timestamp
self.logger.info('')
self.logger.info('time: {0} min'.format(
round(timestamp / 60)))
self.logger.info('state: {0}'.format(
self.autotune.state))
if self.autotune.state == PIDAutotune.STATE_SUCCEEDED:
for rule in self.autotune.tuning_rules:
params = self.autotune.get_pid_parameters(rule)
self.logger.info('')
self.logger.info('rule: {0}'.format(rule))
self.logger.info('Kp: {0}'.format(params.Kp))
self.logger.info('Ki: {0}'.format(params.Ki))
self.logger.info('Kd: {0}'.format(params.Kd))
self.stop_controller(deactivate_pid=True)
else:
# Calculate new control variable (output) from PID Controller
# Original PID method
self.control_variable = self.update_pid_output(
self.last_measurement)
# New PID method (untested)
# self.control_variable = self.PID_Controller.calc(
# self.last_measurement, self.setpoint)
self.write_pid_values() # Write variables to database
# Is PID in a state that allows manipulation of outputs
if self.is_activated and (not self.is_paused or self.is_held):
self.manipulate_output()
def setup_method(self, method_id):
""" Initialize method variables to start running a method """
self.method_id = ''
method = db_retrieve_table_daemon(Method, unique_id=method_id)
method_data = db_retrieve_table_daemon(MethodData)
method_data = method_data.filter(MethodData.method_id == method_id)
method_data_repeat = method_data.filter(
MethodData.duration_sec == 0).first()
pid = db_retrieve_table_daemon(PID, unique_id=self.unique_id)
self.method_type = method.method_type
self.method_start_act = pid.method_start_time
self.method_start_time = None
self.method_end_time = None
if self.method_type == 'Duration':
if self.method_start_act == 'Ended':
# Method has ended and hasn't been instructed to begin again
pass
elif (self.method_start_act == 'Ready'
or self.method_start_act is None):
# Method has been instructed to begin
now = datetime.datetime.now()
self.method_start_time = now
if method_data_repeat and method_data_repeat.duration_end:
self.method_end_time = now + datetime.timedelta(
seconds=float(method_data_repeat.duration_end))
with session_scope(MYCODO_DB_PATH) as db_session:
mod_pid = db_session.query(PID).filter(
PID.unique_id == self.unique_id).first()
mod_pid.method_start_time = self.method_start_time
mod_pid.method_end_time = self.method_end_time
db_session.commit()
else:
# Method neither instructed to begin or not to
# Likely there was a daemon restart ot power failure
# Resume method with saved start_time
self.method_start_time = datetime.datetime.strptime(
str(pid.method_start_time), '%Y-%m-%d %H:%M:%S.%f')
if method_data_repeat and method_data_repeat.duration_end:
self.method_end_time = datetime.datetime.strptime(
str(pid.method_end_time), '%Y-%m-%d %H:%M:%S.%f')
if self.method_end_time > datetime.datetime.now():
self.logger.warning(
"Resuming method {id}: started {start}, "
"ends {end}".format(id=method_id,
start=self.method_start_time,
end=self.method_end_time))
else:
self.method_start_act = 'Ended'
else:
self.method_start_act = 'Ended'
self.method_id = method_id
self.logger.debug("Method enabled: {id}".format(id=self.method_id))
def write_pid_values(self):
""" Write PID values to the measurement database """
if self.band:
setpoint_band_lower = self.setpoint - self.band
setpoint_band_upper = self.setpoint + self.band
else:
setpoint_band_lower = None
setpoint_band_upper = None
list_measurements = [
self.setpoint, setpoint_band_lower, setpoint_band_upper,
self.P_value, self.I_value, self.D_value
]
measurement_dict = {}
measurements = self.device_measurements.filter(
DeviceMeasurements.device_id == self.unique_id).all()
for each_channel, each_measurement in enumerate(measurements):
if (each_measurement.channel not in measurement_dict
and each_measurement.channel < len(list_measurements)):
# If setpoint, get unit from PID measurement
if each_measurement.measurement_type == 'setpoint':
setpoint_pid = db_retrieve_table_daemon(
PID, unique_id=each_measurement.device_id)
if setpoint_pid and ',' in setpoint_pid.measurement:
pid_measurement = setpoint_pid.measurement.split(
',')[1]
setpoint_measurement = db_retrieve_table_daemon(
DeviceMeasurements, unique_id=pid_measurement)
if setpoint_measurement:
conversion = db_retrieve_table_daemon(
Conversion,
unique_id=setpoint_measurement.conversion_id)
_, unit, _ = return_measurement_info(
setpoint_measurement, conversion)
measurement_dict[each_channel] = {
'measurement': each_measurement.measurement,
'unit': unit,
'value': list_measurements[each_channel]
}
else:
measurement_dict[each_channel] = {
'measurement': each_measurement.measurement,
'unit': each_measurement.unit,
'value': list_measurements[each_channel]
}
add_measurements_influxdb(self.unique_id, measurement_dict)
def update_pid_output(self, current_value):
"""
Calculate PID output value from reference input and feedback
:return: Manipulated, or control, variable. This is the PID output.
:rtype: float
:param current_value: The input, or process, variable (the actual
measured condition by the input)
:type current_value: float
"""
# Determine if hysteresis is enabled and if the PID should be applied
setpoint = self.check_hysteresis(current_value)
if setpoint is None:
# Prevent PID variables form being manipulated and
# restrict PID from operating.
return 0
self.error = setpoint - current_value
# Calculate P-value
self.P_value = self.Kp * self.error
# Calculate I-value
self.integrator += self.error
# First method for managing integrator
if self.integrator > self.integrator_max:
self.integrator = self.integrator_max
elif self.integrator < self.integrator_min:
self.integrator = self.integrator_min
# Second method for regulating integrator
# if self.period is not None:
# if self.integrator * self.Ki > self.period:
# self.integrator = self.period / self.Ki
# elif self.integrator * self.Ki < -self.period:
# self.integrator = -self.period / self.Ki
self.I_value = self.integrator * self.Ki
# Prevent large initial D-value
if self.first_start:
self.derivator = self.error
self.first_start = False
# Calculate D-value
self.D_value = self.Kd * (self.error - self.derivator)
self.derivator = self.error
# Produce output form P, I, and D values
pid_value = self.P_value + self.I_value + self.D_value
self.logger.debug("PID: Input: {inp},"
"Output: P: {p}, I: {i}, D: {d}, Out: {o}".format(
inp=current_value,
p=self.P_value,
i=self.I_value,
d=self.D_value,
o=pid_value))
return pid_value
def check_hysteresis(self, measure):
"""
Determine if hysteresis is enabled and if the PID should be applied
:return: float if the setpoint if the PID should be applied, None to
restrict the PID
:rtype: float or None
:param measure: The PID input (or process) variable
:type measure: float
"""
if self.band == 0:
# If band is disabled, return setpoint
return self.setpoint
band_min = self.setpoint - self.band
band_max = self.setpoint + self.band
if self.direction == 'raise':
if (measure < band_min
or (band_min < measure < band_max and self.allow_raising)):
self.allow_raising = True
setpoint = band_max # New setpoint
return setpoint # Apply the PID
elif measure > band_max:
self.allow_raising = False
return None # Restrict the PID
elif self.direction == 'lower':
if (measure > band_max or
(band_min < measure < band_max and self.allow_lowering)):
self.allow_lowering = True
setpoint = band_min # New setpoint
return setpoint # Apply the PID
elif measure < band_min:
self.allow_lowering = False
return None # Restrict the PID
elif self.direction == 'both':
if measure < band_min:
setpoint = band_min # New setpoint
if not self.allow_raising:
# Reset integrator and derivator upon direction switch
self.integrator = 0.0
self.derivator = 0.0
self.allow_raising = True
self.allow_lowering = False
elif measure > band_max:
setpoint = band_max # New setpoint
if not self.allow_lowering:
# Reset integrator and derivator upon direction switch
self.integrator = 0.0
self.derivator = 0.0
self.allow_raising = False
self.allow_lowering = True
else:
return None # Restrict the PID
return setpoint # Apply the PID
def get_last_measurement(self):
"""
Retrieve the latest input measurement from InfluxDB
:rtype: None
"""
self.last_measurement_success = False
# Get latest measurement from influxdb
try:
device_measurement = get_measurement(self.measurement_id)
if device_measurement:
conversion = db_retrieve_table_daemon(
Conversion, unique_id=device_measurement.conversion_id)
else:
conversion = None
channel, unit, measurement = return_measurement_info(
device_measurement, conversion)
self.last_measurement = read_last_influxdb(
self.device_id, unit, measurement, channel,
int(self.max_measure_age))
if self.last_measurement:
self.last_time = self.last_measurement[0]
self.last_measurement = self.last_measurement[1]
utc_dt = datetime.datetime.strptime(
self.last_time.split(".")[0], '%Y-%m-%dT%H:%M:%S')
utc_timestamp = calendar.timegm(utc_dt.timetuple())
local_timestamp = str(
datetime.datetime.fromtimestamp(utc_timestamp))
self.logger.debug(
"Latest (CH{ch}, Unit: {unit}): {last} @ {ts}".format(
ch=channel,
unit=unit,
last=self.last_measurement,
ts=local_timestamp))
if calendar.timegm(
time.gmtime()) - utc_timestamp > self.max_measure_age:
self.logger.error(
"Last measurement was {last_sec} seconds ago, however"
" the maximum measurement age is set to {max_sec}"
" seconds.".format(
last_sec=calendar.timegm(time.gmtime()) -
utc_timestamp,
max_sec=self.max_measure_age))
self.last_measurement_success = True
else:
self.logger.warning("No data returned from influxdb")
except requests.ConnectionError:
self.logger.error("Failed to read measurement from the "
"influxdb database: Could not connect.")
except Exception as except_msg:
self.logger.exception(
"Exception while reading measurement from the influxdb "
"database: {err}".format(err=except_msg))
def manipulate_output(self):
"""
Activate output based on PID control variable and whether
the manipulation directive is to raise, lower, or both.
:rtype: None
"""
# If the last measurement was able to be retrieved and was entered within the past minute
if self.last_measurement_success:
#
# PID control variable is positive, indicating a desire to raise
# the environmental condition
#
if self.direction in ['raise', 'both'] and self.raise_output_id:
if self.control_variable > 0:
# Determine if the output should be PWM or a duration
if self.raise_output_type in [
'pwm', 'command_pwm', 'python_pwm'
]:
self.raise_duty_cycle = float("{0:.1f}".format(
self.control_var_to_duty_cycle(
self.control_variable)))
# Ensure the duty cycle doesn't exceed the min/max
if (self.raise_max_duration and self.raise_duty_cycle >
self.raise_max_duration):
self.raise_duty_cycle = self.raise_max_duration
elif (self.raise_min_duration and
self.raise_duty_cycle < self.raise_min_duration):
self.raise_duty_cycle = self.raise_min_duration
self.logger.debug(
"Setpoint: {sp}, Control Variable: {cv}, Output: PWM output "
"{id} to {dc:.1f}%".format(
sp=self.setpoint,
cv=self.control_variable,
id=self.raise_output_id,
dc=self.raise_duty_cycle))
# Activate pwm with calculated duty cycle
self.control.output_on(
self.raise_output_id,
duty_cycle=self.raise_duty_cycle)
self.write_pid_output_influxdb(
'percent', 'duty_cycle', 7,
self.control_var_to_duty_cycle(
self.control_variable))
elif self.raise_output_type in [
'command', 'python', 'wired', 'wireless_rpi_rf'
]:
# Ensure the output on duration doesn't exceed the set maximum
if (self.raise_max_duration and self.control_variable >
self.raise_max_duration):
self.raise_seconds_on = self.raise_max_duration
else:
self.raise_seconds_on = float("{0:.2f}".format(
self.control_variable))
if self.raise_seconds_on > self.raise_min_duration:
# Activate raise_output for a duration
self.logger.debug(
"Setpoint: {sp} Output: {cv} to output "
"{id}".format(sp=self.setpoint,
cv=self.control_variable,
id=self.raise_output_id))
self.control.output_on(
self.raise_output_id,
duration=self.raise_seconds_on,
min_off=self.raise_min_off_duration)
self.write_pid_output_influxdb('s', 'duration_time', 6,
self.control_variable)
else:
if self.raise_output_type in [
'pwm', 'command_pwm', 'python_pwm'
]:
self.control.output_on(self.raise_output_id,
duty_cycle=0)
#
# PID control variable is negative, indicating a desire to lower
# the environmental condition
#
if self.direction in ['lower', 'both'] and self.lower_output_id:
if self.control_variable < 0:
# Determine if the output should be PWM or a duration
if self.lower_output_type in [
'pwm', 'command_pwm', 'python_pwm'
]:
self.lower_duty_cycle = float("{0:.1f}".format(
self.control_var_to_duty_cycle(
abs(self.control_variable))))
# Ensure the duty cycle doesn't exceed the min/max
if (self.lower_max_duration and self.lower_duty_cycle >
self.lower_max_duration):
self.lower_duty_cycle = self.lower_max_duration
elif (self.lower_min_duration and
self.lower_duty_cycle < self.lower_min_duration):
self.lower_duty_cycle = self.lower_min_duration
self.logger.debug(
"Setpoint: {sp}, Control Variable: {cv}, "
"Output: PWM output {id} to {dc:.1f}%".format(
sp=self.setpoint,
cv=self.control_variable,
id=self.lower_output_id,
dc=self.lower_duty_cycle))
if self.store_lower_as_negative:
stored_duty_cycle = -abs(self.lower_duty_cycle)
stored_control_variable = -self.control_var_to_duty_cycle(
abs(self.control_variable))
else:
stored_duty_cycle = abs(self.lower_duty_cycle)
stored_control_variable = self.control_var_to_duty_cycle(
abs(self.control_variable))
# Activate pwm with calculated duty cycle
self.control.output_on(self.lower_output_id,
duty_cycle=stored_duty_cycle)
self.write_pid_output_influxdb(
'percent', 'duty_cycle', 7,
stored_control_variable)
elif self.lower_output_type in [
'command', 'python', 'wired', 'wireless_rpi_rf'
]:
# Ensure the output on duration doesn't exceed the set maximum
if (self.lower_max_duration
and abs(self.control_variable) >
self.lower_max_duration):
self.lower_seconds_on = self.lower_max_duration
else:
self.lower_seconds_on = float("{0:.2f}".format(
abs(self.control_variable)))
if self.store_lower_as_negative:
stored_seconds_on = -abs(self.lower_seconds_on)
stored_control_variable = -abs(
self.control_variable)
else:
stored_seconds_on = abs(self.lower_seconds_on)
stored_control_variable = abs(
self.control_variable)
if self.lower_seconds_on > self.lower_min_duration:
# Activate lower_output for a duration
self.logger.debug("Setpoint: {sp} Output: {cv} to "
"output {id}".format(
sp=self.setpoint,
cv=self.control_variable,
id=self.lower_output_id))
self.control.output_on(
self.lower_output_id,
duration=stored_seconds_on,
min_off=self.lower_min_off_duration)
self.write_pid_output_influxdb(
's', 'duration_time', 6, stored_control_variable)
else:
if self.lower_output_type in [
'pwm', 'command_pwm', 'python_pwm'
]:
self.control.output_on(self.lower_output_id,
duty_cycle=0)
else:
self.logger.debug(
"Last measurement unsuccessful. Turning outputs off.")
if self.direction in ['raise', 'both'] and self.raise_output_id:
self.control.output_off(self.raise_output_id)
if self.direction in ['lower', 'both'] and self.lower_output_id:
self.control.output_off(self.lower_output_id)
def pid_parameters_str(self):
return "Device ID: {did}, " \
"Measurement ID: {mid}, " \
"Direction: {dir}, " \
"Period: {per}, " \
"Setpoint: {sp}, " \
"Band: {band}, " \
"Kp: {kp}, " \
"Ki: {ki}, " \
"Kd: {kd}, " \
"Integrator Min: {imn}, " \
"Integrator Max {imx}, " \
"Output Raise: {opr}, " \
"Output Raise Min On: {oprmnon}, " \
"Output Raise Max On: {oprmxon}, " \
"Output Raise Min Off: {oprmnoff}, " \
"Output Lower: {opl}, " \
"Output Lower Min On: {oplmnon}, " \
"Output Lower Max On: {oplmxon}, " \
"Output Lower Min Off: {oplmnoff}, " \
"Setpoint Tracking: {spt}".format(
did=self.device_id,
mid=self.measurement_id,
dir=self.direction,
per=self.period,
sp=self.setpoint,
band=self.band,
kp=self.Kp,
ki=self.Ki,
kd=self.Kd,
imn=self.integrator_min,
imx=self.integrator_max,
opr=self.raise_output_id,
oprmnon=self.raise_min_duration,
oprmxon=self.raise_max_duration,
oprmnoff=self.raise_min_off_duration,
opl=self.lower_output_id,
oplmnon=self.lower_min_duration,
oplmxon=self.lower_max_duration,
oplmnoff=self.lower_min_off_duration,
spt=self.method_id)
def control_var_to_duty_cycle(self, control_variable):
# Convert control variable to duty cycle
if control_variable > self.period:
return 100.0
else:
return float((control_variable / self.period) * 100)
def write_pid_output_influxdb(self, unit, measurement, channel, value):
write_pid_out_db = threading.Thread(target=write_influxdb_value,
args=(
self.unique_id,
unit,
value,
),
kwargs={
'measure': measurement,
'channel': channel
})
write_pid_out_db.start()
def pid_mod(self):
if self.initialize_variables():
return "success"
else:
return "error"
def pid_hold(self):
self.is_held = True
self.logger.info("Hold")
return "success"
def pid_pause(self):
self.is_paused = True
self.logger.info("Pause")
return "success"
def pid_resume(self):
self.is_activated = True
self.is_held = False
self.is_paused = False
self.logger.info("Resume")
return "success"
def set_setpoint(self, setpoint):
""" Set the setpoint of PID """
self.setpoint = float(setpoint)
with session_scope(MYCODO_DB_PATH) as db_session:
mod_pid = db_session.query(PID).filter(
PID.unique_id == self.unique_id).first()
mod_pid.setpoint = setpoint
db_session.commit()
return "Setpoint set to {sp}".format(sp=setpoint)
def set_method(self, method_id):
""" Set the method of PID """
with session_scope(MYCODO_DB_PATH) as db_session:
mod_pid = db_session.query(PID).filter(
PID.unique_id == self.unique_id).first()
mod_pid.method_id = method_id
if method_id == '':
self.method_id = ''
db_session.commit()
else:
mod_pid.method_start_time = 'Ready'
mod_pid.method_end_time = None
db_session.commit()
self.setup_method(method_id)
return "Method set to {me}".format(me=method_id)
def set_integrator(self, integrator):
""" Set the integrator of the controller """
self.integrator = float(integrator)
return "Integrator set to {i}".format(i=self.integrator)
def set_derivator(self, derivator):
""" Set the derivator of the controller """
self.derivator = float(derivator)
return "Derivator set to {d}".format(d=self.derivator)
def set_kp(self, p):
""" Set Kp gain of the controller """
self.Kp = float(p)
with session_scope(MYCODO_DB_PATH) as db_session:
mod_pid = db_session.query(PID).filter(
PID.unique_id == self.unique_id).first()
mod_pid.p = p
db_session.commit()
return "Kp set to {kp}".format(kp=self.Kp)
def set_ki(self, i):
""" Set Ki gain of the controller """
self.Ki = float(i)
with session_scope(MYCODO_DB_PATH) as db_session:
mod_pid = db_session.query(PID).filter(
PID.unique_id == self.unique_id).first()
mod_pid.i = i
db_session.commit()
return "Ki set to {ki}".format(ki=self.Ki)
def set_kd(self, d):
""" Set Kd gain of the controller """
self.Kd = float(d)
with session_scope(MYCODO_DB_PATH) as db_session:
mod_pid = db_session.query(PID).filter(
PID.unique_id == self.unique_id).first()
mod_pid.d = d
db_session.commit()
return "Kd set to {kd}".format(kd=self.Kd)
def get_setpoint(self):
return self.setpoint
def get_error(self):
return self.error
def get_integrator(self):
return self.integrator
def get_derivator(self):
return self.derivator
def get_kp(self):
return self.Kp
def get_ki(self):
return self.Ki
def get_kd(self):
return self.Kd
def stop_controller(self, ended_normally=True, deactivate_pid=False):
self.thread_shutdown_timer = timeit.default_timer()
self.running = False
# Unset method start time
if self.method_id != '' and ended_normally:
with session_scope(MYCODO_DB_PATH) as db_session:
mod_pid = db_session.query(PID).filter(
PID.unique_id == self.unique_id).first()
mod_pid.method_start_time = 'Ended'
mod_pid.method_end_time = None
db_session.commit()
# Deactivate PID and Autotune
if deactivate_pid:
with session_scope(MYCODO_DB_PATH) as db_session:
mod_pid = db_session.query(PID).filter(
PID.unique_id == self.unique_id).first()
mod_pid.is_activated = False
mod_pid.autotune_activated = False
db_session.commit()
def initialize_variables(self):
"""Set PID parameters"""
self.sample_rate = db_retrieve_table_daemon(
Misc, entry='first').sample_rate_controller_pid
self.device_measurements = db_retrieve_table_daemon(DeviceMeasurements)
pid = db_retrieve_table_daemon(PID, unique_id=self.unique_id)
self.device_id = pid.measurement.split(',')[0]
self.measurement_id = pid.measurement.split(',')[1]
self.is_activated = pid.is_activated
self.is_held = pid.is_held
self.is_paused = pid.is_paused
self.log_level_debug = pid.log_level_debug
self.method_id = pid.method_id
self.direction = pid.direction
self.raise_output_id = pid.raise_output_id
self.raise_min_duration = pid.raise_min_duration
self.raise_max_duration = pid.raise_max_duration
self.raise_min_off_duration = pid.raise_min_off_duration
self.lower_output_id = pid.lower_output_id
self.lower_min_duration = pid.lower_min_duration
self.lower_max_duration = pid.lower_max_duration
self.lower_min_off_duration = pid.lower_min_off_duration
self.Kp = pid.p
self.Ki = pid.i
self.Kd = pid.d
self.integrator_min = pid.integrator_min
self.integrator_max = pid.integrator_max
self.period = pid.period
self.start_offset = pid.start_offset
self.max_measure_age = pid.max_measure_age
self.default_setpoint = pid.setpoint
self.setpoint = pid.setpoint
self.band = pid.band
self.store_lower_as_negative = pid.store_lower_as_negative
self.first_start = True
self.timer = time.time() + self.start_offset
# Autotune
self.autotune_activated = pid.autotune_activated
self.autotune_noiseband = pid.autotune_noiseband
self.autotune_outstep = pid.autotune_outstep
self.set_log_level_debug(self.log_level_debug)
try:
self.raise_output_type = db_retrieve_table_daemon(
Output, unique_id=self.raise_output_id).output_type
except AttributeError:
self.raise_output_type = None
try:
self.lower_output_type = db_retrieve_table_daemon(
Output, unique_id=self.lower_output_id).output_type
except AttributeError:
self.lower_output_type = None
# Initialize PID Controller
self.PID_Controller = PIDControl(self.period,
self.Kp,
self.Ki,
self.Kd,
integrator_min=self.integrator_min,
integrator_max=self.integrator_max)
# If activated, initialize PID Autotune
if self.autotune_activated:
self.autotune_timestamp = time.time()
try:
self.autotune = PIDAutotune(self.setpoint,
out_step=self.autotune_outstep,
sampletime=self.period,
out_min=0,
out_max=self.period,
noiseband=self.autotune_noiseband)
except Exception as msg:
self.logger.error(msg)
self.stop_controller(deactivate_pid=True)
if self.method_id != '':
self.setup_method(self.method_id)
if self.is_paused:
self.logger.info("Starting Paused")
elif self.is_held:
self.logger.info("Starting Held")
self.logger.info("PID Settings: {}".format(self.pid_parameters_str()))
return "success"
class PIDController(threading.Thread):
"""
Class to operate discrete PID controller in Mycodo
"""
def __init__(self, ready, pid_id):
threading.Thread.__init__(self)
self.logger = logging.getLogger("mycodo.pid_{id}".format(
id=pid_id.split('-')[0]))
self.running = False
self.thread_startup_timer = timeit.default_timer()
self.thread_shutdown_timer = 0
self.ready = ready
self.pid_id = pid_id
self.control = DaemonControl()
self.sample_rate = db_retrieve_table_daemon(
Misc, entry='first').sample_rate_controller_pid
self.device_measurements = db_retrieve_table_daemon(DeviceMeasurements)
self.PID_Controller = None
self.control_variable = 0.0
self.derivator = 0.0
self.integrator = 0.0
self.error = 0.0
self.P_value = None
self.I_value = None
self.D_value = None
self.lower_seconds_on = 0.0
self.raise_seconds_on = 0.0
self.lower_duty_cycle = 0.0
self.raise_duty_cycle = 0.0
self.last_time = None
self.last_measurement = None
self.last_measurement_success = False
self.is_activated = None
self.is_held = None
self.is_paused = None
self.measurement = None
self.method_id = None
self.direction = None
self.raise_output_id = None
self.raise_min_duration = None
self.raise_max_duration = None
self.raise_min_off_duration = None
self.lower_output_id = None
self.lower_min_duration = None
self.lower_max_duration = None
self.lower_min_off_duration = None
self.Kp = None
self.Ki = None
self.Kd = None
self.integrator_min = None
self.integrator_max = None
self.period = None
self.start_offset = None
self.max_measure_age = None
self.default_setpoint = None
self.setpoint = None
self.store_lower_as_negative = None
# Hysteresis options
self.band = None
self.allow_raising = False
self.allow_lowering = False
# PID Autotune
self.autotune = None
self.autotune_activated = False
self.autotune_debug = False
self.autotune_noiseband = None
self.autotune_outstep = None
self.autotune_timestamp = None
self.device_id = None
self.measurement_id = None
self.input_duration = None
self.raise_output_type = None
self.lower_output_type = None
self.first_start = True
self.initialize_values()
self.timer = time.time() + self.start_offset
# Check if a method is set for this PID
self.method_type = None
self.method_start_act = None
self.method_start_time = None
self.method_end_time = None
if self.method_id != '':
self.setup_method(self.method_id)
def run(self):
try:
self.running = True
startup_str = "Activated in {time:.1f} ms".format(
time=(timeit.default_timer() - self.thread_startup_timer) * 1000)
if self.is_paused:
startup_str += ", started Paused"
elif self.is_held:
startup_str += ", started Held"
self.logger.info(startup_str)
# Initialize PID Controller
self.PID_Controller = PIDControl(
self.period,
self.Kp, self.Ki, self.Kd,
integrator_min=self.integrator_min,
integrator_max=self.integrator_max)
# If activated, initialize PID Autotune
if self.autotune_activated:
self.autotune_timestamp = time.time()
try:
self.autotune = PIDAutotune(
self.setpoint,
out_step=self.autotune_outstep,
sampletime=self.period,
out_min=0,
out_max=self.period,
noiseband=self.autotune_noiseband)
except Exception as msg:
self.logger.error(msg)
self.stop_controller(deactivate_pid=True)
self.ready.set()
while self.running:
if (self.method_start_act == 'Ended' and
self.method_type == 'Duration'):
self.stop_controller(ended_normally=False,
deactivate_pid=True)
self.logger.warning(
"Method has ended. "
"Activate the PID controller to start it again.")
elif time.time() > self.timer:
self.check_pid()
time.sleep(self.sample_rate)
except Exception as except_msg:
self.logger.exception("Run Error: {err}".format(
err=except_msg))
finally:
# Turn off output used in PID when the controller is deactivated
if self.raise_output_id and self.direction in ['raise', 'both']:
self.control.output_off(self.raise_output_id, trigger_conditionals=True)
if self.lower_output_id and self.direction in ['lower', 'both']:
self.control.output_off(self.lower_output_id, trigger_conditionals=True)
self.running = False
self.logger.info("Deactivated in {:.1f} ms".format(
(timeit.default_timer() - self.thread_shutdown_timer) * 1000))
def initialize_values(self):
"""Set PID parameters"""
pid = db_retrieve_table_daemon(PID, unique_id=self.pid_id)
self.is_activated = pid.is_activated
self.is_held = pid.is_held
self.is_paused = pid.is_paused
self.method_id = pid.method_id
self.direction = pid.direction
self.raise_output_id = pid.raise_output_id
self.raise_min_duration = pid.raise_min_duration
self.raise_max_duration = pid.raise_max_duration
self.raise_min_off_duration = pid.raise_min_off_duration
self.lower_output_id = pid.lower_output_id
self.lower_min_duration = pid.lower_min_duration
self.lower_max_duration = pid.lower_max_duration
self.lower_min_off_duration = pid.lower_min_off_duration
self.Kp = pid.p
self.Ki = pid.i
self.Kd = pid.d
self.integrator_min = pid.integrator_min
self.integrator_max = pid.integrator_max
self.period = pid.period
self.start_offset = pid.start_offset
self.max_measure_age = pid.max_measure_age
self.default_setpoint = pid.setpoint
self.setpoint = pid.setpoint
self.band = pid.band
self.store_lower_as_negative = pid.store_lower_as_negative
# Autotune
self.autotune_activated = pid.autotune_activated
self.autotune_noiseband = pid.autotune_noiseband
self.autotune_outstep = pid.autotune_outstep
self.device_id = pid.measurement.split(',')[0]
self.measurement_id = pid.measurement.split(',')[1]
input_dev = db_retrieve_table_daemon(Input, unique_id=self.device_id)
math = db_retrieve_table_daemon(Math, unique_id=self.device_id)
if input_dev:
self.input_duration = input_dev.period
elif math:
self.input_duration = math.period
try:
self.raise_output_type = db_retrieve_table_daemon(
Output, unique_id=self.raise_output_id).output_type
except AttributeError:
self.raise_output_type = None
try:
self.lower_output_type = db_retrieve_table_daemon(
Output, unique_id=self.lower_output_id).output_type
except AttributeError:
self.lower_output_type = None
self.logger.info("PID Settings: {}".format(self.pid_parameters_str()))
return "success"
def check_pid(self):
""" Get measurement and apply to PID controller """
# Ensure the timer ends in the future
while time.time() > self.timer:
self.timer = self.timer + self.period
# If PID is active, retrieve measurement and update
# the control variable.
# A PID on hold will sustain the current output and
# not update the control variable.
if self.is_activated and (not self.is_paused or not self.is_held):
self.get_last_measurement()
if self.last_measurement_success:
if self.method_id != '':
# Update setpoint using a method
this_pid = db_retrieve_table_daemon(
PID, unique_id=self.pid_id)
setpoint, ended = calculate_method_setpoint(
self.method_id,
PID,
this_pid,
Method,
MethodData,
self.logger)
if ended:
self.method_start_act = 'Ended'
if setpoint is not None:
self.setpoint = setpoint
else:
self.setpoint = self.default_setpoint
# If autotune activated, determine control variable (output) from autotune
if self.autotune_activated:
if not self.autotune.run(self.last_measurement):
self.control_variable = self.autotune.output
if self.autotune_debug:
self.logger.info('')
self.logger.info("state: {}".format(self.autotune.state))
self.logger.info("output: {}".format(self.autotune.output))
else:
# Autotune has finished
timestamp = time.time() - self.autotune_timestamp
self.logger.info('')
self.logger.info('time: {0} min'.format(round(timestamp / 60)))
self.logger.info('state: {0}'.format(self.autotune.state))
if self.autotune.state == PIDAutotune.STATE_SUCCEEDED:
for rule in self.autotune.tuning_rules:
params = self.autotune.get_pid_parameters(rule)
self.logger.info('')
self.logger.info('rule: {0}'.format(rule))
self.logger.info('Kp: {0}'.format(params.Kp))
self.logger.info('Ki: {0}'.format(params.Ki))
self.logger.info('Kd: {0}'.format(params.Kd))
self.stop_controller(deactivate_pid=True)
else:
# Calculate new control variable (output) from PID Controller
# Original PID method
self.control_variable = self.update_pid_output(
self.last_measurement)
# New PID method (untested)
# self.control_variable = self.PID_Controller.calc(
# self.last_measurement, self.setpoint)
self.write_pid_values() # Write variables to database
# Is PID in a state that allows manipulation of outputs
if self.is_activated and (not self.is_paused or self.is_held):
self.manipulate_output()
def setup_method(self, method_id):
""" Initialize method variables to start running a method """
self.method_id = ''
method = db_retrieve_table_daemon(Method, unique_id=method_id)
method_data = db_retrieve_table_daemon(MethodData)
method_data = method_data.filter(MethodData.method_id == method_id)
method_data_repeat = method_data.filter(MethodData.duration_sec == 0).first()
pid = db_retrieve_table_daemon(PID, unique_id=self.pid_id)
self.method_type = method.method_type
self.method_start_act = pid.method_start_time
self.method_start_time = None
self.method_end_time = None
if self.method_type == 'Duration':
if self.method_start_act == 'Ended':
# Method has ended and hasn't been instructed to begin again
pass
elif (self.method_start_act == 'Ready' or
self.method_start_act is None):
# Method has been instructed to begin
now = datetime.datetime.now()
self.method_start_time = now
if method_data_repeat and method_data_repeat.duration_end:
self.method_end_time = now + datetime.timedelta(
seconds=float(method_data_repeat.duration_end))
with session_scope(MYCODO_DB_PATH) as db_session:
mod_pid = db_session.query(PID).filter(
PID.unique_id == self.pid_id).first()
mod_pid.method_start_time = self.method_start_time
mod_pid.method_end_time = self.method_end_time
db_session.commit()
else:
# Method neither instructed to begin or not to
# Likely there was a daemon restart ot power failure
# Resume method with saved start_time
self.method_start_time = datetime.datetime.strptime(
str(pid.method_start_time), '%Y-%m-%d %H:%M:%S.%f')
if method_data_repeat and method_data_repeat.duration_end:
self.method_end_time = datetime.datetime.strptime(
str(pid.method_end_time), '%Y-%m-%d %H:%M:%S.%f')
if self.method_end_time > datetime.datetime.now():
self.logger.warning(
"Resuming method {id}: started {start}, "
"ends {end}".format(
id=method_id,
start=self.method_start_time,
end=self.method_end_time))
else:
self.method_start_act = 'Ended'
else:
self.method_start_act = 'Ended'
self.method_id = method_id
def write_pid_values(self):
""" Write PID values to the measurement database """
if self.band:
setpoint_band_lower = self.setpoint - self.band
setpoint_band_upper = self.setpoint + self.band
else:
setpoint_band_lower = None
setpoint_band_upper = None
list_measurements = [
self.setpoint,
setpoint_band_lower,
setpoint_band_upper,
self.P_value,
self.I_value,
self.D_value
]
measurement_dict = {}
measurements = self.device_measurements.filter(
DeviceMeasurements.device_id == self.pid_id).all()
for each_channel, each_measurement in enumerate(measurements):
if (each_measurement.channel not in measurement_dict and
each_measurement.channel < len(list_measurements)):
# If setpoint, get unit from PID measurement
if each_measurement.measurement_type == 'setpoint':
setpoint_pid = db_retrieve_table_daemon(
PID, unique_id=each_measurement.device_id)
if setpoint_pid and ',' in setpoint_pid.measurement:
pid_measurement = setpoint_pid.measurement.split(',')[1]
setpoint_measurement = db_retrieve_table_daemon(
DeviceMeasurements, unique_id=pid_measurement)
if setpoint_measurement:
conversion = db_retrieve_table_daemon(
Conversion, unique_id=setpoint_measurement.conversion_id)
_, unit, _ = return_measurement_info(
setpoint_measurement, conversion)
measurement_dict[each_channel] = {
'measurement': each_measurement.measurement,
'unit': unit,
'value': list_measurements[each_channel]
}
else:
measurement_dict[each_channel] = {
'measurement': each_measurement.measurement,
'unit': each_measurement.unit,
'value': list_measurements[each_channel]
}
add_measurements_influxdb(self.pid_id, measurement_dict)
def update_pid_output(self, current_value):
"""
Calculate PID output value from reference input and feedback
:return: Manipulated, or control, variable. This is the PID output.
:rtype: float
:param current_value: The input, or process, variable (the actual
measured condition by the input)
:type current_value: float
"""
# Determine if hysteresis is enabled and if the PID should be applied
setpoint = self.check_hysteresis(current_value)
if setpoint is None:
# Prevent PID variables form being manipulated and
# restrict PID from operating.
return 0
self.error = setpoint - current_value
# Calculate P-value
self.P_value = self.Kp * self.error
# Calculate I-value
self.integrator += self.error
# First method for managing integrator
if self.integrator > self.integrator_max:
self.integrator = self.integrator_max
elif self.integrator < self.integrator_min:
self.integrator = self.integrator_min
# Second method for regulating integrator
# if self.period is not None:
# if self.integrator * self.Ki > self.period:
# self.integrator = self.period / self.Ki
# elif self.integrator * self.Ki < -self.period:
# self.integrator = -self.period / self.Ki
self.I_value = self.integrator * self.Ki
# Prevent large initial D-value
if self.first_start:
self.derivator = self.error
self.first_start = False
# Calculate D-value
self.D_value = self.Kd * (self.error - self.derivator)
self.derivator = self.error
# Produce output form P, I, and D values
pid_value = self.P_value + self.I_value + self.D_value
return pid_value
def check_hysteresis(self, measure):
"""
Determine if hysteresis is enabled and if the PID should be applied
:return: float if the setpoint if the PID should be applied, None to
restrict the PID
:rtype: float or None
:param measure: The PID input (or process) variable
:type measure: float
"""
if self.band == 0:
# If band is disabled, return setpoint
return self.setpoint
band_min = self.setpoint - self.band
band_max = self.setpoint + self.band
if self.direction == 'raise':
if (measure < band_min or
(band_min < measure < band_max and self.allow_raising)):
self.allow_raising = True
setpoint = band_max # New setpoint
return setpoint # Apply the PID
elif measure > band_max:
self.allow_raising = False
return None # Restrict the PID
elif self.direction == 'lower':
if (measure > band_max or
(band_min < measure < band_max and self.allow_lowering)):
self.allow_lowering = True
setpoint = band_min # New setpoint
return setpoint # Apply the PID
elif measure < band_min:
self.allow_lowering = False
return None # Restrict the PID
elif self.direction == 'both':
if measure < band_min:
setpoint = band_min # New setpoint
if not self.allow_raising:
# Reset integrator and derivator upon direction switch
self.integrator = 0.0
self.derivator = 0.0
self.allow_raising = True
self.allow_lowering = False
elif measure > band_max:
setpoint = band_max # New setpoint
if not self.allow_lowering:
# Reset integrator and derivator upon direction switch
self.integrator = 0.0
self.derivator = 0.0
self.allow_raising = False
self.allow_lowering = True
else:
return None # Restrict the PID
return setpoint # Apply the PID
def get_last_measurement(self):
"""
Retrieve the latest input measurement from InfluxDB
:rtype: None
"""
self.last_measurement_success = False
# Get latest measurement from influxdb
try:
device_measurement = get_measurement(self.measurement_id)
if device_measurement:
conversion = db_retrieve_table_daemon(
Conversion, unique_id=device_measurement.conversion_id)
else:
conversion = None
channel, unit, measurement = return_measurement_info(
device_measurement, conversion)
self.last_measurement = read_last_influxdb(
self.device_id,
unit,
measurement,
channel,
int(self.max_measure_age))
if self.last_measurement:
self.last_time = self.last_measurement[0]
self.last_measurement = self.last_measurement[1]
utc_dt = datetime.datetime.strptime(
self.last_time.split(".")[0],
'%Y-%m-%dT%H:%M:%S')
utc_timestamp = calendar.timegm(utc_dt.timetuple())
local_timestamp = str(datetime.datetime.fromtimestamp(utc_timestamp))
self.logger.debug("Latest (CH{ch}, Unit: {unit}): {last} @ {ts}".format(
ch=channel,
unit=unit,
last=self.last_measurement,
ts=local_timestamp))
if calendar.timegm(time.gmtime()) - utc_timestamp > self.max_measure_age:
self.logger.error(
"Last measurement was {last_sec} seconds ago, however"
" the maximum measurement age is set to {max_sec}"
" seconds.".format(
last_sec=calendar.timegm(time.gmtime()) - utc_timestamp,
max_sec=self.max_measure_age
))
self.last_measurement_success = True
else:
self.logger.warning("No data returned from influxdb")
except requests.ConnectionError:
self.logger.error("Failed to read measurement from the "
"influxdb database: Could not connect.")
except Exception as except_msg:
self.logger.exception(
"Exception while reading measurement from the influxdb "
"database: {err}".format(err=except_msg))
def manipulate_output(self):
"""
Activate output based on PID control variable and whether
the manipulation directive is to raise, lower, or both.
:rtype: None
"""
# If the last measurement was able to be retrieved and was entered within the past minute
if self.last_measurement_success:
#
# PID control variable is positive, indicating a desire to raise
# the environmental condition
#
if self.direction in ['raise', 'both'] and self.raise_output_id:
if self.control_variable > 0:
# Determine if the output should be PWM or a duration
if self.raise_output_type in ['pwm',
'command_pwm',
'python_pwm']:
self.raise_duty_cycle = float("{0:.1f}".format(
self.control_var_to_duty_cycle(self.control_variable)))
# Ensure the duty cycle doesn't exceed the min/max
if (self.raise_max_duration and
self.raise_duty_cycle > self.raise_max_duration):
self.raise_duty_cycle = self.raise_max_duration
elif (self.raise_min_duration and
self.raise_duty_cycle < self.raise_min_duration):
self.raise_duty_cycle = self.raise_min_duration
self.logger.debug(
"Setpoint: {sp}, Control Variable: {cv}, Output: PWM output "
"{id} to {dc:.1f}%".format(
sp=self.setpoint,
cv=self.control_variable,
id=self.raise_output_id,
dc=self.raise_duty_cycle))
# Activate pwm with calculated duty cycle
self.control.output_on(self.raise_output_id,
duty_cycle=self.raise_duty_cycle)
self.write_pid_output_influxdb(
'percent', 'duty_cycle', 7,
self.control_var_to_duty_cycle(self.control_variable))
elif self.raise_output_type in ['command',
'python',
'wired',
'wireless_rpi_rf']:
# Ensure the output on duration doesn't exceed the set maximum
if (self.raise_max_duration and
self.control_variable > self.raise_max_duration):
self.raise_seconds_on = self.raise_max_duration
else:
self.raise_seconds_on = float("{0:.2f}".format(
self.control_variable))
if self.raise_seconds_on > self.raise_min_duration:
# Activate raise_output for a duration
self.logger.debug(
"Setpoint: {sp} Output: {cv} to output "
"{id}".format(
sp=self.setpoint,
cv=self.control_variable,
id=self.raise_output_id))
self.control.output_on(
self.raise_output_id,
duration=self.raise_seconds_on,
min_off=self.raise_min_off_duration)
self.write_pid_output_influxdb(
's', 'duration_time', 6,
self.control_variable)
else:
if self.raise_output_type in ['pwm',
'command_pwm',
'python_pwm']:
self.control.output_on(self.raise_output_id,
duty_cycle=0)
#
# PID control variable is negative, indicating a desire to lower
# the environmental condition
#
if self.direction in ['lower', 'both'] and self.lower_output_id:
if self.control_variable < 0:
# Determine if the output should be PWM or a duration
if self.lower_output_type in ['pwm',
'command_pwm',
'python_pwm']:
self.lower_duty_cycle = float("{0:.1f}".format(
self.control_var_to_duty_cycle(abs(self.control_variable))))
# Ensure the duty cycle doesn't exceed the min/max
if (self.lower_max_duration and
self.lower_duty_cycle > self.lower_max_duration):
self.lower_duty_cycle = self.lower_max_duration
elif (self.lower_min_duration and
self.lower_duty_cycle < self.lower_min_duration):
self.lower_duty_cycle = self.lower_min_duration
self.logger.debug(
"Setpoint: {sp}, Control Variable: {cv}, "
"Output: PWM output {id} to {dc:.1f}%".format(
sp=self.setpoint,
cv=self.control_variable,
id=self.lower_output_id,
dc=self.lower_duty_cycle))
if self.store_lower_as_negative:
stored_duty_cycle = -abs(self.lower_duty_cycle)
stored_control_variable = -self.control_var_to_duty_cycle(abs(self.control_variable))
else:
stored_duty_cycle = abs(self.lower_duty_cycle)
stored_control_variable = self.control_var_to_duty_cycle(abs(self.control_variable))
# Activate pwm with calculated duty cycle
self.control.output_on(
self.lower_output_id,
duty_cycle=stored_duty_cycle)
self.write_pid_output_influxdb(
'percent', 'duty_cycle', 7,
stored_control_variable)
elif self.lower_output_type in ['command',
'python',
'wired',
'wireless_rpi_rf']:
# Ensure the output on duration doesn't exceed the set maximum
if (self.lower_max_duration and
abs(self.control_variable) > self.lower_max_duration):
self.lower_seconds_on = self.lower_max_duration
else:
self.lower_seconds_on = float("{0:.2f}".format(
abs(self.control_variable)))
if self.store_lower_as_negative:
stored_seconds_on = -abs(self.lower_seconds_on)
stored_control_variable = -abs(self.control_variable)
else:
stored_seconds_on = abs(self.lower_seconds_on)
stored_control_variable = abs(self.control_variable)
if self.lower_seconds_on > self.lower_min_duration:
# Activate lower_output for a duration
self.logger.debug("Setpoint: {sp} Output: {cv} to "
"output {id}".format(
sp=self.setpoint,
cv=self.control_variable,
id=self.lower_output_id))
self.control.output_on(
self.lower_output_id,
duration=stored_seconds_on,
min_off=self.lower_min_off_duration)
self.write_pid_output_influxdb(
's', 'duration_time', 6,
stored_control_variable)
else:
if self.lower_output_type in ['pwm',
'command_pwm',
'python_pwm']:
self.control.output_on(self.lower_output_id,
duty_cycle=0)
else:
if self.direction in ['raise', 'both'] and self.raise_output_id:
self.control.output_off(self.raise_output_id)
if self.direction in ['lower', 'both'] and self.lower_output_id:
self.control.output_off(self.lower_output_id)
def pid_parameters_str(self):
return "Device ID: {did}, " \
"Measurement ID: {mid}, " \
"Direction: {dir}, " \
"Period: {per}, " \
"Setpoint: {sp}, " \
"Band: {band}, " \
"Kp: {kp}, " \
"Ki: {ki}, " \
"Kd: {kd}, " \
"Integrator Min: {imn}, " \
"Integrator Max {imx}, " \
"Output Raise: {opr}, " \
"Output Raise Min On: {oprmnon}, " \
"Output Raise Max On: {oprmxon}, " \
"Output Raise Min Off: {oprmnoff}, " \
"Output Lower: {opl}, " \
"Output Lower Min On: {oplmnon}, " \
"Output Lower Max On: {oplmxon}, " \
"Output Lower Min Off: {oplmnoff}, " \
"Setpoint Tracking: {spt}".format(
did=self.device_id,
mid=self.measurement_id,
dir=self.direction,
per=self.period,
sp=self.setpoint,
band=self.band,
kp=self.Kp,
ki=self.Ki,
kd=self.Kd,
imn=self.integrator_min,
imx=self.integrator_max,
opr=self.raise_output_id,
oprmnon=self.raise_min_duration,
oprmxon=self.raise_max_duration,
oprmnoff=self.raise_min_off_duration,
opl=self.lower_output_id,
oplmnon=self.lower_min_duration,
oplmxon=self.lower_max_duration,
oplmnoff=self.lower_min_off_duration,
spt=self.method_id)
def control_var_to_duty_cycle(self, control_variable):
# Convert control variable to duty cycle
if control_variable > self.period:
return 100.0
else:
return float((control_variable / self.period) * 100)
def write_pid_output_influxdb(self, unit, measurement, channel, value):
write_pid_out_db = threading.Thread(
target=write_influxdb_value,
args=(self.pid_id,
unit,
value,),
kwargs={'measure': measurement,
'channel': channel})
write_pid_out_db.start()
def pid_mod(self):
if self.initialize_values():
return "success"
else:
return "error"
def pid_hold(self):
self.is_held = True
self.logger.info("Hold")
return "success"
def pid_pause(self):
self.is_paused = True
self.logger.info("Pause")
return "success"
def pid_resume(self):
self.is_activated = True
self.is_held = False
self.is_paused = False
self.logger.info("Resume")
return "success"
def set_setpoint(self, setpoint):
""" Set the setpoint of PID """
self.setpoint = float(setpoint)
with session_scope(MYCODO_DB_PATH) as db_session:
mod_pid = db_session.query(PID).filter(
PID.unique_id == self.pid_id).first()
mod_pid.setpoint = setpoint
db_session.commit()
return "Setpoint set to {sp}".format(sp=setpoint)
def set_method(self, method_id):
""" Set the method of PID """
with session_scope(MYCODO_DB_PATH) as db_session:
mod_pid = db_session.query(PID).filter(
PID.unique_id == self.pid_id).first()
mod_pid.method_id = method_id
if method_id == '':
self.method_id = ''
db_session.commit()
else:
mod_pid.method_start_time = 'Ready'
mod_pid.method_end_time = None
db_session.commit()
self.setup_method(method_id)
return "Method set to {me}".format(me=method_id)
def set_integrator(self, integrator):
""" Set the integrator of the controller """
self.integrator = float(integrator)
return "Integrator set to {i}".format(i=self.integrator)
def set_derivator(self, derivator):
""" Set the derivator of the controller """
self.derivator = float(derivator)
return "Derivator set to {d}".format(d=self.derivator)
def set_kp(self, p):
""" Set Kp gain of the controller """
self.Kp = float(p)
with session_scope(MYCODO_DB_PATH) as db_session:
mod_pid = db_session.query(PID).filter(
PID.unique_id == self.pid_id).first()
mod_pid.p = p
db_session.commit()
return "Kp set to {kp}".format(kp=self.Kp)
def set_ki(self, i):
""" Set Ki gain of the controller """
self.Ki = float(i)
with session_scope(MYCODO_DB_PATH) as db_session:
mod_pid = db_session.query(PID).filter(
PID.unique_id == self.pid_id).first()
mod_pid.i = i
db_session.commit()
return "Ki set to {ki}".format(ki=self.Ki)
def set_kd(self, d):
""" Set Kd gain of the controller """
self.Kd = float(d)
with session_scope(MYCODO_DB_PATH) as db_session:
mod_pid = db_session.query(PID).filter(
PID.unique_id == self.pid_id).first()
mod_pid.d = d
db_session.commit()
return "Kd set to {kd}".format(kd=self.Kd)
def get_setpoint(self):
return self.setpoint
def get_error(self):
return self.error
def get_integrator(self):
return self.integrator
def get_derivator(self):
return self.derivator
def get_kp(self):
return self.Kp
def get_ki(self):
return self.Ki
def get_kd(self):
return self.Kd
def is_running(self):
return self.running
def stop_controller(self, ended_normally=True, deactivate_pid=False):
self.thread_shutdown_timer = timeit.default_timer()
self.running = False
# Unset method start time
if self.method_id != '' and ended_normally:
with session_scope(MYCODO_DB_PATH) as db_session:
mod_pid = db_session.query(PID).filter(
PID.unique_id == self.pid_id).first()
mod_pid.method_start_time = 'Ended'
mod_pid.method_end_time = None
db_session.commit()
# Deactivate PID and Autotune
if deactivate_pid:
with session_scope(MYCODO_DB_PATH) as db_session:
mod_pid = db_session.query(PID).filter(
PID.unique_id == self.pid_id).first()
mod_pid.is_activated = False
mod_pid.autotune_activated = False
db_session.commit()
def run(self):
try:
self.running = True
startup_str = "Activated in {time:.1f} ms".format(
time=(timeit.default_timer() - self.thread_startup_timer) * 1000)
if self.is_paused:
startup_str += ", started Paused"
elif self.is_held:
startup_str += ", started Held"
self.logger.info(startup_str)
# Initialize PID Controller
self.PID_Controller = PIDControl(
self.period,
self.Kp, self.Ki, self.Kd,
integrator_min=self.integrator_min,
integrator_max=self.integrator_max)
# If activated, initialize PID Autotune
if self.autotune_activated:
self.autotune_timestamp = time.time()
try:
self.autotune = PIDAutotune(
self.setpoint,
out_step=self.autotune_outstep,
sampletime=self.period,
out_min=0,
out_max=self.period,
noiseband=self.autotune_noiseband)
except Exception as msg:
self.logger.error(msg)
self.stop_controller(deactivate_pid=True)
self.ready.set()
while self.running:
if (self.method_start_act == 'Ended' and
self.method_type == 'Duration'):
self.stop_controller(ended_normally=False,
deactivate_pid=True)
self.logger.warning(
"Method has ended. "
"Activate the PID controller to start it again.")
elif time.time() > self.timer:
self.check_pid()
time.sleep(self.sample_rate)
except Exception as except_msg:
self.logger.exception("Run Error: {err}".format(
err=except_msg))
finally:
# Turn off output used in PID when the controller is deactivated
if self.raise_output_id and self.direction in ['raise', 'both']:
self.control.output_off(self.raise_output_id, trigger_conditionals=True)
if self.lower_output_id and self.direction in ['lower', 'both']:
self.control.output_off(self.lower_output_id, trigger_conditionals=True)
self.running = False
self.logger.info("Deactivated in {:.1f} ms".format(
(timeit.default_timer() - self.thread_shutdown_timer) * 1000))