PolyCraft/kiln-controller
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- big change to PID class. It was not properly handling the integral.

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Essentially it was never large enough to impact the loop. The integral
has been inverted so if you want more integral, define it as a smaller
number.
- added a comment to the config about changing the temp scale
This commit is contained in:
Jason Bruce 2021-03-24 08:32:06 -04:00
parent 2831c3094a
commit a3243097c7
2 changed files with 23 additions and 12 deletions
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17
config.py
View File

@ -52,20 +52,20 @@ sensor_time_wait = 2
########################################################################
#
# PID parameters
pid_kp = 25 # Proportional
pid_ki = 1088 # Integration
pid_kd = 217 # Derivative was 217
pid_kp = 25 # Proportional 25
pid_ki = 100 # Integration 100
pid_kd = 100 # Derivative was 25
########################################################################
#
# Simulation parameters
simulate = True
sim_t_env = 25.0 # deg C
sim_t_env = 60.0 # deg C
sim_c_heat = 100.0 # J/K heat capacity of heat element
sim_c_oven = 5000.0 # J/K heat capacity of oven
sim_p_heat = 5450.0 # W heating power of oven
sim_R_o_nocool = 1.0 # K/W thermal resistance oven -> environment
sim_R_o_nocool = 0.1 # K/W thermal resistance oven -> environment
sim_R_o_cool = 0.05 # K/W " with cooling
sim_R_ho_noair = 0.1 # K/W thermal resistance heat element -> oven
sim_R_ho_air = 0.05 # K/W " with internal air circulation
@ -74,6 +74,9 @@ sim_R_ho_air = 0.05 # K/W " with internal air circulation
########################################################################
#
# Time and Temperature parameters
#
# If you change the temp_scale, all settings in this file are assumed to
# be in that scale.
temp_scale = "f" # c = Celsius | f = Fahrenheit - Unit to display
time_scale_slope = "h" # s = Seconds | m = Minutes | h = Hours - Slope displayed in temp_scale per time_scale_slope
@ -83,9 +86,9 @@ time_scale_profile = "m" # s = Seconds | m = Minutes | h = Hours - Enter and vi
# when solid state relays fail, they usually fail closed. this means your
# kiln receives full power until your house burns down.
# this should not replace you watching your kiln or use of a kiln-sitter
emergency_shutoff_temp = 2264 #cone 7
emergency_shutoff_temp = 2264 #cone 7
# If the kiln cannot heat fast enough and is off by more than
# If the kiln cannot heat or cool fast enough and is off by more than
# kiln_must_catch_up_max_error the entire schedule is shifted until
# the desired temperature is reached. If your kiln cannot attain the
# wanted temperature, the schedule will run forever.

18
lib/oven.py
View File

@ -401,15 +401,19 @@ class PID():
now = datetime.datetime.now()
timeDelta = (now - self.lastNow).total_seconds()
window_size = 50
window_size = 100
error = float(setpoint - ispoint)
self.iterm += (error * timeDelta * self.ki)
self.iterm = sorted([-1, self.iterm, 1])[1]
dErr = (error - self.lastErr) / timeDelta
if self.ki > 0:
self.iterm += (error * timeDelta * (1/self.ki))
#self.iterm = sorted([-1, self.iterm, 1])[1]
#self.iterm = sorted([-1 * window_size, self.iterm, window_size])[1]
#self.iterm = float(self.iterm / window_size)
dErr = (error - self.lastErr) / timeDelta
output = self.kp * error + self.iterm + self.kd * dErr
log.info("pid raw = %f" % (output))
output = sorted([-1 * window_size, output, window_size])[1]
self.lastErr = error
self.lastNow = now
@ -418,6 +422,10 @@ class PID():
if output < 0:
output = 0
#if output > 1:
# output = 1
output = float(output / window_size)
log.info("pid=%f p=%f i=%f d=%f" % (output,self.kp * error, self.iterm,self.kd * dErr))
return output