openpilot v0.9.6 release

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

selfdrive/controls/lib/latcontrol_torque.py

@@ -0,0 +1,92 @@
+import math
+
+from cereal import log
+from openpilot.common.numpy_fast import interp
+from openpilot.selfdrive.car.interfaces import LatControlInputs
+from openpilot.selfdrive.controls.lib.latcontrol import LatControl
+from openpilot.selfdrive.controls.lib.pid import PIDController
+from openpilot.selfdrive.controls.lib.vehicle_model import ACCELERATION_DUE_TO_GRAVITY
+
+# At higher speeds (25+mph) we can assume:
+# Lateral acceleration achieved by a specific car correlates to
+# torque applied to the steering rack. It does not correlate to
+# wheel slip, or to speed.
+
+# This controller applies torque to achieve desired lateral
+# accelerations. To compensate for the low speed effects we
+# use a LOW_SPEED_FACTOR in the error. Additionally, there is
+# friction in the steering wheel that needs to be overcome to
+# move it at all, this is compensated for too.
+
+LOW_SPEED_X = [0, 10, 20, 30]
+LOW_SPEED_Y = [15, 13, 10, 5]
+
+
+class LatControlTorque(LatControl):
+  def __init__(self, CP, CI):
+    super().__init__(CP, CI)
+    self.torque_params = CP.lateralTuning.torque
+    self.pid = PIDController(self.torque_params.kp, self.torque_params.ki,
+                             k_f=self.torque_params.kf, pos_limit=self.steer_max, neg_limit=-self.steer_max)
+    self.torque_from_lateral_accel = CI.torque_from_lateral_accel()
+    self.use_steering_angle = self.torque_params.useSteeringAngle
+    self.steering_angle_deadzone_deg = self.torque_params.steeringAngleDeadzoneDeg
+
+  def update_live_torque_params(self, latAccelFactor, latAccelOffset, friction):
+    self.torque_params.latAccelFactor = latAccelFactor
+    self.torque_params.latAccelOffset = latAccelOffset
+    self.torque_params.friction = friction
+
+  def update(self, active, CS, VM, params, steer_limited, desired_curvature, llk):
+    pid_log = log.ControlsState.LateralTorqueState.new_message()
+    if not active:
+      output_torque = 0.0
+      pid_log.active = False
+    else:
+      actual_curvature_vm = -VM.calc_curvature(math.radians(CS.steeringAngleDeg - params.angleOffsetDeg), CS.vEgo, params.roll)
+      roll_compensation = params.roll * ACCELERATION_DUE_TO_GRAVITY
+      if self.use_steering_angle:
+        actual_curvature = actual_curvature_vm
+        curvature_deadzone = abs(VM.calc_curvature(math.radians(self.steering_angle_deadzone_deg), CS.vEgo, 0.0))
+      else:
+        actual_curvature_llk = llk.angularVelocityCalibrated.value[2] / CS.vEgo
+        actual_curvature = interp(CS.vEgo, [2.0, 5.0], [actual_curvature_vm, actual_curvature_llk])
+        curvature_deadzone = 0.0
+      desired_lateral_accel = desired_curvature * CS.vEgo ** 2
+
+      # desired rate is the desired rate of change in the setpoint, not the absolute desired curvature
+      # desired_lateral_jerk = desired_curvature_rate * CS.vEgo ** 2
+      actual_lateral_accel = actual_curvature * CS.vEgo ** 2
+      lateral_accel_deadzone = curvature_deadzone * CS.vEgo ** 2
+
+      low_speed_factor = interp(CS.vEgo, LOW_SPEED_X, LOW_SPEED_Y)**2
+      setpoint = desired_lateral_accel + low_speed_factor * desired_curvature
+      measurement = actual_lateral_accel + low_speed_factor * actual_curvature
+      gravity_adjusted_lateral_accel = desired_lateral_accel - roll_compensation
+      torque_from_setpoint = self.torque_from_lateral_accel(LatControlInputs(setpoint, roll_compensation, CS.vEgo, CS.aEgo), self.torque_params,
+                                                            setpoint, lateral_accel_deadzone, friction_compensation=False, gravity_adjusted=False)
+      torque_from_measurement = self.torque_from_lateral_accel(LatControlInputs(measurement, roll_compensation, CS.vEgo, CS.aEgo), self.torque_params,
+                                                               measurement, lateral_accel_deadzone, friction_compensation=False, gravity_adjusted=False)
+      pid_log.error = torque_from_setpoint - torque_from_measurement
+      ff = self.torque_from_lateral_accel(LatControlInputs(gravity_adjusted_lateral_accel, roll_compensation, CS.vEgo, CS.aEgo), self.torque_params,
+                                          desired_lateral_accel - actual_lateral_accel, lateral_accel_deadzone, friction_compensation=True,
+                                          gravity_adjusted=True)
+
+      freeze_integrator = steer_limited or CS.steeringPressed or CS.vEgo < 5
+      output_torque = self.pid.update(pid_log.error,
+                                      feedforward=ff,
+                                      speed=CS.vEgo,
+                                      freeze_integrator=freeze_integrator)
+
+      pid_log.active = True
+      pid_log.p = self.pid.p
+      pid_log.i = self.pid.i
+      pid_log.d = self.pid.d
+      pid_log.f = self.pid.f
+      pid_log.output = -output_torque
+      pid_log.actualLateralAccel = actual_lateral_accel
+      pid_log.desiredLateralAccel = desired_lateral_accel
+      pid_log.saturated = self._check_saturation(self.steer_max - abs(output_torque) < 1e-3, CS, steer_limited)
+
+    # TODO left is positive in this convention
+    return -output_torque, 0.0, pid_log