OPGM - QOL tweaks - lower Volt enable speed - EV gas/brake lookup tables

Co-Authored-By: Eric Brown <13560103+nworb-cire@users.noreply.github.com>

selfdrive/car/gm/carcontroller.py

@@ -6,7 +6,7 @@ from openpilot.common.realtime import DT_CTRL
 from opendbc.can.packer import CANPacker
 from openpilot.selfdrive.car import apply_driver_steer_torque_limits, create_gas_interceptor_command
 from openpilot.selfdrive.car.gm import gmcan
-from openpilot.selfdrive.car.gm.values import DBC, CanBus, CarControllerParams, CruiseButtons, GMFlags, CC_ONLY_CAR, SDGM_CAR
+from openpilot.selfdrive.car.gm.values import DBC, CanBus, CarControllerParams, CruiseButtons, GMFlags, CC_ONLY_CAR, SDGM_CAR, EV_CAR
 from openpilot.selfdrive.car.interfaces import CarControllerBase
 
 VisualAlert = car.CarControl.HUDControl.VisualAlert
@@ -122,6 +122,11 @@ class CarController(CarControllerBase):
           self.apply_brake = int(min(-100 * self.CP.stopAccel, self.params.MAX_BRAKE))
         else:
           # Normal operation
+          if self.CP.carFingerprint in EV_CAR:
+            self.params.update_ev_gas_brake_threshold(CS.out.vEgo)
+            self.apply_gas = int(round(interp(actuators.accel, self.params.EV_GAS_LOOKUP_BP, self.params.GAS_LOOKUP_V)))
+            self.apply_brake = int(round(interp(actuators.accel, self.params.EV_BRAKE_LOOKUP_BP, self.params.BRAKE_LOOKUP_V)))
+          else:
             self.apply_gas = int(round(interp(actuators.accel, self.params.GAS_LOOKUP_BP, self.params.GAS_LOOKUP_V)))
             self.apply_brake = int(round(interp(actuators.accel, self.params.BRAKE_LOOKUP_BP, self.params.BRAKE_LOOKUP_V)))
           # Don't allow any gas above inactive regen while stopping

selfdrive/car/gm/interface.py

@@ -171,6 +171,7 @@ class CarInterface(CarInterfaceBase):
       ret.lateralTuning.pid.kiV = [0.]
       ret.lateralTuning.pid.kf = 1.  # get_steer_feedforward_volt()
       ret.steerActuatorDelay = 0.2
+      ret.minEnableSpeed = -1.
 
     elif candidate == CAR.ACADIA:
       ret.minEnableSpeed = -1.  # engage speed is decided by pcm

selfdrive/car/gm/values.py

@@ -2,6 +2,7 @@ from dataclasses import dataclass, field
 from enum import Enum, IntFlag
 
 from cereal import car
+from openpilot.common.numpy_fast import interp
 from openpilot.selfdrive.car import dbc_dict, PlatformConfig, DbcDict, Platforms, CarSpecs
 from openpilot.selfdrive.car.docs_definitions import CarFootnote, CarHarness, CarDocs, CarParts, Column
 from openpilot.selfdrive.car.fw_query_definitions import FwQueryConfig, Request, StdQueries
@@ -67,6 +68,17 @@ class CarControllerParams:
     self.BRAKE_LOOKUP_BP = [self.ACCEL_MIN, max_regen_acceleration]
     self.BRAKE_LOOKUP_V = [self.MAX_BRAKE, 0.]
 
+  # determined by letting Volt regen to a stop in L gear from 89mph,
+  # and by letting off gas and allowing car to creep, for determining
+  # the positive threshold values at very low speed
+  EV_GAS_BRAKE_THRESHOLD_BP = [1.29, 1.52, 1.55, 1.6, 1.7, 1.8, 2.0, 2.2, 2.5, 5.52, 9.6, 20.5, 23.5, 35.0] # [m/s]
+  EV_GAS_BRAKE_THRESHOLD_V = [0.0, -0.14, -0.16, -0.18, -0.215, -0.255, -0.32, -0.41, -0.5, -0.72, -0.895, -1.125, -1.145, -1.16] # [m/s^s]
+
+  def update_ev_gas_brake_threshold(self, v_ego):
+    gas_brake_threshold = interp(v_ego, self.EV_GAS_BRAKE_THRESHOLD_BP, self.EV_GAS_BRAKE_THRESHOLD_V)
+    self.EV_GAS_LOOKUP_BP = [gas_brake_threshold, max(0., gas_brake_threshold), self.ACCEL_MAX]
+    self.EV_BRAKE_LOOKUP_BP = [self.ACCEL_MIN, gas_brake_threshold]
+
 
 class Footnote(Enum):
   OBD_II = CarFootnote(