utils for PID control

utils/heater_model_finder.py

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+#!/usr/bin/env python
+
+import os
+import sys
+import time
+
+cnc_dir = os.path.dirname(os.path.dirname(os.path.realpath(__file__)))
+sys.path.append(cnc_dir)
+from cnc.hal_raspberry import hal
+
+
+"""
+This executable module is looking for heating and cooling transfer coefficients.
+Can be ran only on real hardware.
+"""
+
+# change settings below for your hardware/environment
+EXTRUDER_MAX_TEMPERATURE = 200
+EXTRUDER_DELTA_TEMPERATURE = 50
+BED_MAX_TEMPERATURE = 70
+BED_DELTA_TEMPERATURE = 10
+ENVIRONMENT_TEMPERATURE = 25
+
+
+# finder itself
+def finder(max_temperature, delta_temperature, get_temperature, control):
+    ca = 0
+    cn = 0
+    ha = 0
+    hn = 0
+    print("Heating...")
+    control(100)
+    last_t = get_temperature()
+    last_time = time.time()
+    heated = False
+    while True:
+        t = get_temperature()
+        if t >= max_temperature:
+            if not heated:
+                control(0)
+                heated = True
+        if heated and t <= max_temperature:
+            break
+        if abs(last_t - t) >= 1:
+            print("Temperature is " + str(t))
+            last_time = time.time()
+            last_t = t
+        time.sleep(0.1)
+    print("Heated, measure cooling transfer coefficient.")
+    while True:
+        t = get_temperature()
+        if abs(last_t - t) >= 1:
+            current_time = time.time()
+            if t <= max_temperature - delta_temperature:
+                break
+            v = abs(last_t - t) \
+                / abs((last_t + t) / 2.0 - ENVIRONMENT_TEMPERATURE) \
+                / (current_time - last_time)
+            print("Temperature is {}, coefficient is {}".format(t, v))
+            ca += v
+            cn += 1
+            last_time = current_time
+            last_t = t
+        time.sleep(0.001)
+    c = ca / float(cn)
+    print("Cooled off, waiting...")
+    time.sleep(60)
+    print("Heating, measure heating transfer coefficient.")
+    control(100)
+    heat_start = 0
+    while True:
+        t = get_temperature()
+        if abs(last_t - t) >= 1:
+            current_time = time.time()
+            if t > max_temperature:
+                heat_end = current_time
+                break
+            if t >= max_temperature - delta_temperature:
+                ct = last_t \
+                     - c * (current_time - last_time) \
+                     * abs((last_t + t) / 2.0 - ENVIRONMENT_TEMPERATURE)
+                v = abs(t - ct) / (current_time - last_time)
+                print("Temperature is {}, coefficient is {}".format(t, v))
+                if hn == 0:
+                    heat_start = current_time
+                ha += v
+                hn += 1
+            else:
+                print("Temperature is " + str(t))
+            last_time = current_time
+            last_t = t
+        time.sleep(0.001)
+    h = ha / float(hn)
+    control(0)
+    print("Testing results...")
+    # quick test
+    heat_time = heat_end - heat_start
+    t = max_temperature - delta_temperature
+    for i in range(0, int(heat_time + 0.5)):
+        t -= abs((t - ENVIRONMENT_TEMPERATURE)) * c
+        t += h
+    model_status = abs(max_temperature - t) < max_temperature * 0.1
+    print("Model quick test result is {}/{} - {}"
+          .format(t, max_temperature, model_status))
+    print("Cooling transfer coefficient is " + str(c))
+    print("Heating transfer coefficient is " + str(h))
+    return c, h
+
+
+# finder itself
+def main():
+    hal.init()
+    try:
+        hal.fan_control(True)
+        print("Running for extruder...")
+        try:
+            ec, eh = finder(EXTRUDER_MAX_TEMPERATURE,
+                            EXTRUDER_DELTA_TEMPERATURE,
+                            hal.get_extruder_temperature,
+                            hal.extruder_heater_control)
+        except (IOError, OSError):
+            ec, eh = None, None
+            print("Extruder malfunction")
+        hal.extruder_heater_control(0)
+        print("Running for bed...")
+        try:
+            bc, bh = finder(BED_MAX_TEMPERATURE,
+                            BED_DELTA_TEMPERATURE,
+                            hal.get_bed_temperature,
+                            hal.bed_heater_control)
+        except (IOError, OSError):
+            bc, bh = None, None
+            print("Bed malfunction")
+        hal.bed_heater_control(0)
+        print("Done")
+        print("Extruder transfer coefficients, cooling {}, heating {}"
+              .format(ec, eh))
+        print("Bed transfer coefficients, cooling {}, heating {}"
+              .format(bc, bh))
+        hal.fan_control(False)
+    except KeyboardInterrupt:
+        pass
+    hal.deinit()
+
+
+if __name__ == '__main__':
+    main()

utils/pid_finder.py

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+#!/usr/bin/env python
+import os
+import sys
+import time
+
+cnc_dir = os.path.dirname(os.path.dirname(os.path.realpath(__file__)))
+sys.path.append(cnc_dir)
+from cnc.hal_raspberry import hal
+
+"""
+This executable module is looking for PID coefficients.
+Can be ran only on real hardware.
+"""
+
+# change settings below for your hardware/environment
+EXTRUDER_TARGET_TEMPERATURE = 200
+BED_TARGET_TEMPERATURE = 70
+DUMMY_CYCLES = 2
+TOTAL_CYCLES = 7
+
+
+# finder itself
+def finder(target_temperature, get_temperature, control):
+    print("Heating...")
+    on = True
+    control(100)
+    last_t = get_temperature()
+    last_time = time.time()
+    max_t = 0
+    min_t = 10000
+    cycle_number = 0
+    cycle_accumulator = 0
+    cycle_counter = 0
+    cycle_time = 0
+    while True:
+        current_time = time.time()
+        t = get_temperature()
+        time_filter = (current_time - last_time) > 0.1
+        if t >= target_temperature and on and time_filter:
+            on = False
+            control(0)
+            last_time = current_time
+            cycle_number += 1
+            if cycle_number > DUMMY_CYCLES:
+                print("Cycle took {} s".format(current_time - cycle_time))
+                cycle_accumulator += current_time - cycle_time
+                cycle_counter += 1
+            cycle_time = current_time
+        if t < target_temperature and not on and time_filter:
+            if cycle_number > TOTAL_CYCLES:
+                break
+            on = True
+            control(100)
+            last_time = current_time
+        if abs(last_t - t) >= 1:
+            print("Temperature is {}, cycle #{}".format(t, cycle_number))
+            last_t = t
+        if cycle_number > DUMMY_CYCLES:
+            if t > max_t:
+                max_t = t
+            if t < min_t:
+                min_t = t
+        time.sleep(0.001)
+    d_temperature = max_t - min_t
+    d_time = cycle_accumulator / cycle_counter
+    print("dT={}, dt={}".format(d_temperature, d_time))
+    p = 1.0 / (1.2 * d_temperature)
+    i = 1.0 / (15.0 * d_time)
+    d = 1.0 / (0.15 * d_time)
+    print("Finder result P={}, I={}, D={}".format(p, i, d))
+    return p, i, d
+
+
+# finder itself
+def main():
+    hal.init()
+    try:
+        hal.fan_control(True)
+        print("Running for extruder...")
+        try:
+            ep, ei, ed = finder(EXTRUDER_TARGET_TEMPERATURE,
+                                hal.get_extruder_temperature,
+                                hal.extruder_heater_control)
+        except (IOError, OSError):
+            ep, ei, ed = None, None, None
+            print("Extruder malfunction")
+        hal.extruder_heater_control(0)
+        print("Running for bed...")
+        try:
+            bp, bi, bd = finder(BED_TARGET_TEMPERATURE,
+                                hal.get_bed_temperature,
+                                hal.bed_heater_control)
+        except (IOError, OSError):
+            bp, bi, bd = None, None, None
+            print("Bed malfunction")
+        print("Done")
+        print("Extruder P={}, I={}, D={}".format(ep, ei, ed))
+        print("Bed P={}, I={}, D={}".format(bp, bi, bd))
+        hal.bed_heater_control(0)
+        hal.fan_control(False)
+    except KeyboardInterrupt:
+        pass
+    hal.deinit()
+
+
+if __name__ == '__main__':
+    main()