Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

docs(behavior_path_planner): add documentation for avoidance by lane change module #4087

Merged
merged 1 commit into from
Jun 27, 2023
+394 −10
Merged

docs(behavior_path_planner): add documentation for avoidance by lane change module #4087

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
20 changes: 10 additions & 10 deletions planning/behavior_path_planner/README.md
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -16,16 +16,16 @@ The `behavior_path_planner` module is responsible to generate

Behavior path planner has following scene modules.

| Name | Description | Details |
| :------------------- | :------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | :----------------------------------------------------------- |
| Lane Following | this module generates reference path from lanelet centerline. | LINK |
| Avoidance | this module generates avoidance path when there is objects that should be avoid. | [LINK](./docs/behavior_path_planner_avoidance_design.md) |
| Avoidance By LC | this module generates lane change path when there is objects that should be avoid. | LINK |
| Lane Change | this module is performed when it is necessary and a collision check with other vehicles is cleared. | [LINK](./docs/behavior_path_planner_lane_change_design.md) |
| External Lane Change | WIP | LINK |
| Goal Planner | this module is performed when ego-vehicle is in the road lane and goal is in the shoulder lane. ego-vehicle will stop at the goal. | [LINK](./docs/behavior_path_planner_goal_planner_design.md) |
| Pull Out | this module is performed when ego-vehicle is stationary and footprint of ego-vehicle is included in shoulder lane. This module ends when ego-vehicle merges into the road. | [LINK](./docs/behavior_path_planner_start_planner_design.md) |
| Side Shift | (for remote control) shift the path to left or right according to an external instruction. | [LINK](./docs/behavior_path_planner_side_shift_design.md) |
| Name | Description | Details |
| :------------------- | :------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | :---------------------------------------------------------------------- |
| Lane Following | this module generates reference path from lanelet centerline. | LINK |
| Avoidance | this module generates avoidance path when there is objects that should be avoid. | [LINK](./docs/behavior_path_planner_avoidance_design.md) |
| Avoidance By LC | this module generates lane change path when there is objects that should be avoid. | [LINK](./docs/behavior_path_planner_avoidance_by_lane_change_design.md) |
| Lane Change | this module is performed when it is necessary and a collision check with other vehicles is cleared. | [LINK](./docs/behavior_path_planner_lane_change_design.md) |
| External Lane Change | WIP | LINK |
| Goal Planner | this module is performed when ego-vehicle is in the road lane and goal is in the shoulder lane. ego-vehicle will stop at the goal. | [LINK](./docs/behavior_path_planner_goal_planner_design.md) |
| Pull Out | this module is performed when ego-vehicle is stationary and footprint of ego-vehicle is included in shoulder lane. This module ends when ego-vehicle merges into the road. | [LINK](./docs/behavior_path_planner_start_planner_design.md) |
| Side Shift | (for remote control) shift the path to left or right according to an external instruction. | [LINK](./docs/behavior_path_planner_side_shift_design.md) |

![behavior_modules](./image/behavior_modules.png)

Expand Down
40 changes: 40 additions & 0 deletions ...vior_path_planner/docs/behavior_path_planner_avoidance_by_lane_change_design.md
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -0,0 +1,40 @@
# Avoidance by lane change design

This is a sub-module to avoid obstacles by lane change maneuver.

## Purpose / Role

This module is designed as one of the obstacle avoidance features and generates a lane change path if the following conditions are satisfied.

- Exist lane changeable lanelet.
- Exist avoidance target objects on ego driving lane.

![avoidance_by_lane_change](../image/avoidance_by_lane_change/avoidance_by_lane_change.svg)

## Inner-workings / Algorithms

Basically, this module is implemented by reusing the avoidance target filtering logic of the existing [Normal Avoidance Module](./behavior_path_planner_avoidance_design.md) and the path generation logic of the [Normal Lane Change Module](./behavior_path_planner_lane_change_design.md). On the other hand, the conditions under which the module is activated differ from those of a normal avoidance module.

Check that the following conditions are satisfied after the filtering process for the avoidance target.

### Number of the avoidance target objects

This module is launched when the number of avoidance target objects on **EGO DRIVING LANE** is greater than `execute_object_num`. If there are no avoidance targets in the ego driving lane or their number is less than the parameter, the obstacle is avoided by normal avoidance behavior (if the normal avoidance module is registered).

![trigger_1](../image/avoidance_by_lane_change/avoidance_by_lc_trigger_1.svg)

### Lane change end point condition

Unlike the normal avoidance module, which specifies the shift line end point, this module does not specify its end point when generating a lane change path. On the other hand, setting `execute_only_when_lane_change_finish_before_object` to `true` will activate this module only if the lane change can be completed before the avoidance target object.

Although setting the parameter to `false` would increase the scene of avoidance by lane change, it is assumed that sufficient lateral margin may not be ensured in some cases because the vehicle passes by the side of obstacles during the lane change.

![trigger_2](../image/avoidance_by_lane_change/avoidance_by_lc_trigger_2.svg)

## Parameters

| Name | Unit | Type | Description | Default value |
| :------------------------------------------------- | ---- | ------ | ---------------------------------------------------------------------------------------------------------------------------------------- | ------------- |
| execute_object_num | [-] | int | Number of avoidance target objects on ego driving lane is greater than this value, this module will be launched. | 1 |
| execute_object_longitudinal_margin | [m] | double | [maybe unused] Only when distance between the ego and avoidance target object is longer than this value, this module will be launched. | 0.0 |
Copy link
Contributor

@tkimura4 tkimura4 Jun 27, 2023 •
edited
Loading

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

[maybe unused] <- Is this intentional?

Copy link
Contributor Author

@satoshi-ota satoshi-ota Jun 27, 2023 •
edited
Loading

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Is this intentional?

Yes. But I'll remove this parameter.

| execute_only_when_lane_change_finish_before_object | [-] | bool | If this flag set `true`, this module will be launched only when the lane change end point is **NOT** behind the avoidance target object. | true |
Loading