openpilot v0.9.6 release

date: 2024-02-21T23:02:42
master commit: 0b4d08fab8e35a264bc7383e878538f8083c33e5

selfdrive/controls/lib/pid.py

@@ -0,0 +1,75 @@
+import numpy as np
+from numbers import Number
+
+from openpilot.common.numpy_fast import clip, interp
+
+
+class PIDController():
+  def __init__(self, k_p, k_i, k_f=0., k_d=0., pos_limit=1e308, neg_limit=-1e308, rate=100):
+    self._k_p = k_p
+    self._k_i = k_i
+    self._k_d = k_d
+    self.k_f = k_f   # feedforward gain
+    if isinstance(self._k_p, Number):
+      self._k_p = [[0], [self._k_p]]
+    if isinstance(self._k_i, Number):
+      self._k_i = [[0], [self._k_i]]
+    if isinstance(self._k_d, Number):
+      self._k_d = [[0], [self._k_d]]
+
+    self.pos_limit = pos_limit
+    self.neg_limit = neg_limit
+
+    self.i_unwind_rate = 0.3 / rate
+    self.i_rate = 1.0 / rate
+    self.speed = 0.0
+
+    self.reset()
+
+  @property
+  def k_p(self):
+    return interp(self.speed, self._k_p[0], self._k_p[1])
+
+  @property
+  def k_i(self):
+    return interp(self.speed, self._k_i[0], self._k_i[1])
+
+  @property
+  def k_d(self):
+    return interp(self.speed, self._k_d[0], self._k_d[1])
+
+  @property
+  def error_integral(self):
+    return self.i/self.k_i
+
+  def reset(self):
+    self.p = 0.0
+    self.i = 0.0
+    self.d = 0.0
+    self.f = 0.0
+    self.control = 0
+
+  def update(self, error, error_rate=0.0, speed=0.0, override=False, feedforward=0., freeze_integrator=False):
+    self.speed = speed
+
+    self.p = float(error) * self.k_p
+    self.f = feedforward * self.k_f
+    self.d = error_rate * self.k_d
+
+    if override:
+      self.i -= self.i_unwind_rate * float(np.sign(self.i))
+    else:
+      i = self.i + error * self.k_i * self.i_rate
+      control = self.p + i + self.d + self.f
+
+      # Update when changing i will move the control away from the limits
+      # or when i will move towards the sign of the error
+      if ((error >= 0 and (control <= self.pos_limit or i < 0.0)) or
+          (error <= 0 and (control >= self.neg_limit or i > 0.0))) and \
+         not freeze_integrator:
+        self.i = i
+
+    control = self.p + self.i + self.d + self.f
+
+    self.control = clip(control, self.neg_limit, self.pos_limit)
+    return self.control