planning mode doesn't change if lane change path can't be executed in behavior path planner

[alanmengg]

Checklist

• I've read the contribution guidelines.
• I've searched other issues and no duplicate issues were found.
• I'm convinced that this is not my fault but a bug.

Description

In lane driving, if vehicle in lane change mode and lane change can't successfully executed such as obstacle blocks the lane change path, it would stuck with it.

Expected behavior

if lane change can't be executed because of the obstacle, it should change to obstacle avoidance mode to plan a new path.
if planning mode change to obstacle avoidance, it can plan a new path to execute like below.

Actual behavior

it stuck with lane change path and doesn't plan new path.

Steps to reproduce

like the picture uploaded above, put some obstacle around road, make vehicle start and goal in different lane.

Versions

1.OS: Ubuntun 20.04
2.ROS2: Galactic
3.Autoware: Autoware.universe:main

Possible causes

No response

Additional context

No response

[raminterpl]

@alanmengg : Can you please provide a map that used for testing

[xmfcx]

@alanmengg could you provide the map please?

[zulfaqar-azmi-t4]

Hi, there is another lane change PR that you might be interested that indirectly related #1139 (with visualization #1140).
It is ready, but we haven't merge them yet as they are still in review phases.

Also currently the updated parameters allows lane change to be aborted.

With the new PR, I think in this situation, lane change shouldn't happened in the first place, since it might be unsafe.

[alanmengg]

@alanmengg could you provide the map please?
sorry, I just saw your request. here is the map
map.zip

[raminterpl]

Hi @alanmengg : I confirm above issue.
Planning mode is not changing if there is an obstacle in the path of behavior path planner.

[zulfaqar-azmi-t4]

Hi @alanmengg and @raminterpl
Suppose I understand correctly, as lane change is approved while an obstacle is blocking the lane changing path. In that case, you will not be able to continue.

Since the behavior path planning uses the behavior tree, only one scene module will be executed at a time. For example, suppose we are currently executing a lane change maneuver. In that case, until the lane-changing process is completed, we will not be able to run other modules. Performing lane change while also avoiding obstacles is currently a limitation that is constantly under discussion internally. And modifying the behavior tree's behavior will take a bit of time for now.

Now about the reported scenario, one thing we can do is abort the lane change and only perform the lane changing maneuver as soon as the path is safe. The current universe is able to do so, as shown in the video below.

2022-08-30-19-18-09.mp4

2022-08-30-19-19-19.mp4

However, there are limitations, for example this scenario over here. In the following scenario, ego vehicle reaches to the point where the remaining distance is equal to minimum_lane_change_distance (see here for its explanation)

Basically lane change requires a certain amount of distance, and for this case, the path is totally blocked. If such situation happen, then yes, we might not be able to perform lane change, until the vehicle is removed.

But it is possible to relax the condition, for example, when the object is barely blocking the path.

The latest universe's documentation provide some explanation of the lane changing process. Please let me know you thoughts and I am very happy for any comments and point of improvement.

[alanmengg]

thank u for your explanation.
my first thought was to change to another planning mode but it would cause other problems. but perform the lane changing maneuver in this case is a better thing to do.