Create disturbance_controller.py

selfdrive/controls/lib/disturbance_controller.py

@@ -0,0 +1,39 @@
+import numpy as np
+import math
+
+from openpilot.common.realtime import DT_CTRL
+
+ALPHA_MIN = 0.004
+ALPHA_MAX = 0.4
+
+class DisturbanceController:
+  def __init__(self):
+    self.lowpass_filtered = 0.0
+    self.alpha_prev = ALPHA_MIN
+    self.desired_curvature_prev = 0.0
+
+  def compute_dynamic_alpha(self, desired_curvature, dt=DT_CTRL, A=0.02, n=2.0, beta=3.0, k=2.0):
+    d_desired = abs(desired_curvature - self.desired_curvature_prev) / dt
+    alpha_reactive = d_desired**n / (k * A) if A > 0 else 0.0
+    alpha = np.clip(self.alpha_prev * np.exp(-beta * dt) + alpha_reactive, ALPHA_MIN, ALPHA_MAX)
+    self.alpha_prev = alpha
+    self.desired_curvature_prev = desired_curvature
+    return alpha
+
+  def lowpass_filter(self, current_value, alpha):
+    alpha = min(alpha, ALPHA_MAX)
+    if alpha >= ALPHA_MAX * 0.9:
+      reset_factor = (alpha - ALPHA_MIN) / (ALPHA_MAX - ALPHA_MIN)
+      self.lowpass_filtered = (1 - reset_factor) * self.lowpass_filtered + reset_factor * current_value
+    else:
+      self.lowpass_filtered = (1 - alpha) * self.lowpass_filtered + alpha * current_value
+    return self.lowpass_filtered
+
+  def highpass_filter(self, current_value, lowpass_value):
+    return current_value - lowpass_value
+
+  def compute_disturbance(self, desired_curvature, actual_curvature):
+    alpha = self.compute_dynamic_alpha(desired_curvature)
+    reaction = self.lowpass_filter(actual_curvature, alpha)
+    disturbance = self.highpass_filter(actual_curvature, reaction)
+    return disturbance