How to debug a lane change module when candidate_path is displayed on RViz but ego car never change the lane?

[felixf4xu]

Hi,

I'm debugging a lane change module, ( autoware_behavior_path_avoidance_by_lane_change_module), now I can see the lane change candidate on rviz, but the ego car never change the lane, where (which variable) should I debug into?

These concepts are killing me, very difficult to understand what they real means:

IsWaitingApprovel?
RTC?

[Somdit]

Hi @felixf4xu,

I am also trying to understand the avoidance by the lane change module, and wanted to have Autoware to avoid the obstacle through taking another lane. May I know how you can trigger the candidate path to show up, and under what scenarios? When I placed an obstacle in front of the ego vehicle, the /planning/path_candidate/avoidance_by_lane_change topic is always empty. And I tried many different scenarios, but the avoidance by lane change was never triggered.

[felixf4xu]

you can debug into the result of getLaneChangeTargetLane()

[felixf4xu]

IsWaitingApprovel() is the key to make candidate path approved.

[0xd1ma]

@felixf4xu, at the moment, I’m also working on getting the external lane-changing(lc) planner and obstacle lc avoidance modules to function properly.

I managed to modify the external lane changes by moving away from the preferred lane approach and introducing additional conditions and methods.

Attached is a screenshot showing functional external lane changes after fixing

However, I couldn’t fully grasp the logic behind how obstacle lc avoidance work. After seeing your messages, I tried simply commenting out the condition—and it worked.

Is this a proper fix, or just a temporary solution?
I’d really appreciate it if you could explain in more detail the modifications that need to be made.