Distance from center of gravity to center of geometry, or how to initialize the occupancy of an ego vehicle?

[lukaskoehrer]

I am trying to correctly initialize the occupancy of an ego vehicle for collision checking.

In commonroad-vehicle-models v3.0.2 I cannot find any parameter that explains how much the center of gravity of a given vehicle differs from its center of geometry. Since all the reference points of the car-like vehicle models are either center of rear axle or center of mass, I don't know how to initialize the center of the rectangle (defined by vehicle width and length) relative to the center of mass or center of rear axle.

If I take a look at the tutorial 00 of commonroad-drivability-checker section "Create ego vehicle trajectory"

# create Ego Vehicle trajectory from state list
ego_vehicle_trajectory = Trajectory(initial_time_step=1, state_list=state_list[1:])
ego_vehicle_shape = Rectangle(length=4.569, width=1.844)
ego_vehicle_prediction = TrajectoryPrediction(trajectory=ego_vehicle_trajectory, shape=ego_vehicle_shape)

# create Ego Vehicle obstacle from trajectory
ego_vehicle = DynamicObstacle(obstacle_id=100, obstacle_type=ObstacleType.CAR, obstacle_shape=ego_vehicle_shape,
                              initial_state=initial_state, prediction=ego_vehicle_prediction)

the position in the vehicle state - which as per commonroad-vehicle-models depends on a specific vehicle model type - is just used as the center of geometry for the resulting rectangle.

In the underlying functions that calculate the occupancy like occupancy_shape_from_state, the position of the vehicle state is directly used as the center of the shape, regardless of the vehicle model type.

The resulting questions for me are:

1. Is there any information on the distance of the center of gravity to the center of geometry for the car-like vehicle models?
2. When initializing the occupancy of an ego vehicle, do I have to account for different reference points and possibly not coinciding centers of gravity and centers of geometry myself?