- Compensate for max heat rate to reduce overshoot

components/pid/pid.py

@@ -3,6 +3,7 @@
 class Pid:
     def __init__(self, params):
         self.params = params
+        self.k = 1.0
 
         # Integrator
         self.yi = 0
@@ -18,6 +19,9 @@ class Pid:
         # Output
         self.y = 0
 
+    def scale(self, k):
+        self.k = k
+
     @staticmethod
     def params(kp, ki, kd, kt):
         p = dict(kp=kp, ki=ki, kd=kd, kt=kt)
@@ -30,10 +34,10 @@ class Pid:
 
     def process(self, err):
         dt = self.params['dt']
-        kp = self.params['kp']
-        ki = self.params['ki']
-        kd = self.params['kd']
-        kt = self.params['kt']
+        kp = self.params['kp'] * self.k
+        ki = self.params['ki'] * self.k
+        kd = self.params['kd'] * self.k
+        kt = self.params['kt'] * self.k
 
         self.yi = self.yi + ki*dt * err + kt*dt * self.awu
         yd = kd/dt*(err - self.err)

components/pid/temp_controller.py

@@ -55,6 +55,10 @@ class TempController(AttributeChange):
 			self.theta_ist = self.theta_ist_set
 			self.heatrate_ist = self.heatrate_ist_set
 
+		# Compensate for max heat rate to reduce overshoot
+		if self.heatrate_soll_set > 0:
+			self.pid_hold.scale(1.0/self.heatrate_soll_set)
+
 		self.heatrate_soll = self.heatrate_soll_set * self.pid_hold.get_y()
 		theta_err = self.theta_soll_set - self.theta_ist
 		heatrate_err = self.heatrate_soll - self.heatrate_ist