Lane Departure Checker#

The Lane Departure Checker checks if vehicle follows a trajectory. If it does not follow the trajectory, it reports its status via diagnostic_updater.

Features#

This package includes the following features:

Lane Departure: Check if ego vehicle is going to be out of lane boundaries based on output from control module (predicted trajectory).
Trajectory Deviation: Check if ego vehicle's pose does not deviate from the trajectory. Checking lateral, longitudinal and yaw deviation.

Inner-workings / Algorithms#

How to extend footprint by covariance#

Calculate the standard deviation of error ellipse(covariance) in vehicle coordinate.

1.Transform covariance into vehicle coordinate.

$\begin{align} \left( \begin{array}{cc} x_{vehicle}\\ y_{vehicle}\\ \end{array} \right) = R_{map2vehicle} \left( \begin{array}{cc} x_{map}\\ y_{map}\\ \end{array} \right) \end{align}$

Calculate covariance in vehicle coordinate.

$\begin{align} Cov_{vehicle} &= E \left[ \left( \begin{array}{cc} x_{vehicle}\\ y_{vehicle}\\ \end{array} \right) (x_{vehicle}, y_{vehicle}) \right] \\ &= E \left[ R\left( \begin{array}{cc} x_{map}\\ y_{map}\\ \end{array} \right) (x_{map}, y_{map})R^t \right] \\ &= R E\left[ \left( \begin{array}{cc} x_{map}\\ y_{map}\\ \end{array} \right) (x_{map}, y_{map}) \right] R^t \\ &= R Cov_{map} R^t \end{align}$

2.The longitudinal length we want to expand is correspond to marginal distribution of $x_{vehicle}$ , which is represented in $Cov_{vehicle}(0,0)$ . In the same way, the lateral length is represented in $Cov_{vehicle}(1,1)$ . Wikipedia reference here.
Expand footprint based on the standard deviation multiplied with footprint_margin_scale.

Interface#

Input#

/localization/kinematic_state [nav_msgs::msg::Odometry]
/map/vector_map [autoware_auto_mapping_msgs::msg::HADMapBin]
/planning/mission_planning/route [autoware_auto_planning_msgs::msg::HADMapRoute]
/planning/scenario_planning/trajectory [autoware_auto_planning_msgs::msg::Trajectory]
/control/trajectory_follower/predicted_trajectory [autoware_auto_planning_msgs::msg::Trajectory]

Output#

[diagnostic_updater] lane_departure : Update diagnostic level when ego vehicle is out of lane.
[diagnostic_updater] trajectory_deviation : Update diagnostic level when ego vehicle deviates from trajectory.

Parameters#

Node Parameters#

Name	Type	Description	Default value
update_rate	double	Frequency for publishing [Hz]	10.0
visualize_lanelet	bool	Flag for visualizing lanelet	False

Core Parameters#

Name	Type	Description	Default value
footprint_margin_scale	double	Coefficient for expanding footprint margin. Multiplied by 1 standard deviation.	1.0
resample_interval	double	Minimum Euclidean distance between points when resample trajectory.[m]	0.3
max_deceleration	double	Maximum deceleration when calculating braking distance.	2.8
delay_time	double	Delay time which took to actuate brake when calculating braking distance. [second]	1.3
max_lateral_deviation	double	Maximum lateral deviation in vehicle coordinate. [m]	2.0
max_longitudinal_deviation	double	Maximum longitudinal deviation in vehicle coordinate. [m]	2.0
max_yaw_deviation_deg	double	Maximum ego yaw deviation from trajectory. [deg]	60.0