feat(lane_change): implement terminal lane change feature

[mkquda]

Description

Currently when LC module fails to find a safe lane change path, ego will continue up to the end of current lanes (terminal point) and stop in the middle of the lane. And lane change cannot be performed except by manual override.

To increase the rate of successful LC maneuvers, even in difficult situations, and reduce the need of manual override, it is better to always have a fallback terminal lane change path connecting the end of current lanes to target lanes, in case no valid & safe candidate path is found, the fallback terminal path can be force approved to complete the LC maneuver.

Changes

• Implement function compute_terminal_lane_change_path
• Terminal lane change path is computed only once, and is updated and reused.
• At every cycle, if no valid candidate path is found, terminal path will pushed to candidate path list
• Refactored functions insert_stop_point_on_current_lanes & calc_dist_to_last_fit_width
• When status is "waiting for approval" and terminal lane change path is available, stop point will be inserted along the path at the point where is path footprint exits current lane.
• Added parameter enable_terminal_path to enable/disable the feature

The videos below demonstrate the difference in the behavior:

no_terminal_lc_path.mp4

terminal_lc_path.mp4

Related links

• None.

How was this PR tested?

• PSIM
• Internal TIER IV Evaluation

Notes for reviewers

None.

Interface changes

ROS Parameter Changes

Additions and removals

Change type	Parameter Name	Type	Default Value	Description
Added	terminal_path.enable	bool	true	flag to enable/disable terminal lane change path feature
Added	terminal_path.disable_near_terminal	bool	true	flag to disable terminal lane change path feature near goal
Added	terminal_path.stop_at_boundary	bool	true	flag to configure stop point placement, if true ego will stop at current lane boundary

Effects on system behavior

In case of failure to find a valid candidate path until terminal point, if terminal path is computed, it can be force approved to complete LC maneuver successfully.

If using terminal path feature and terminal path is computed, instead of placing stop point in the middle of current lane, stop point will be inserted at the last point along the path where Ego foot print is within current lane boundary. This would result in Ego stopping to the side of the lane, which can help incite other vehicles to give way for Ego.

[github-actions]

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[github-actions]

Documentation URL: https://autowarefoundation.github.io/autoware.universe/pr-9592/
Modified URLs:

• https://autowarefoundation.github.io/autoware.universe/pr-9592/planning/behavior_path_planner/autoware_behavior_path_lane_change_module/

[zulfaqar-azmi-t4]

LGTM