obstacle_collision_checker

Purpose

obstacle_collision_checker is a module to check obstacle collision for predicted trajectory and publish diagnostic errors if collision is found.

Inner-workings / Algorithms

Flow chart

@startuml
skinparam monochrome true

title obstacle collision checker : update
start

:calculate braking distance;

:resampling trajectory;
note right
to reduce calculation cost
end note
:filter point cloud by trajectory;

:create vehicle foot prints;

:create vehicle passing area;

partition will_collide {

while (has next ego vehicle foot print) is (yes)
  :found collision with obstacle foot print;
  if (has collision with obstacle) then (yes)
      :set diag to ERROR;
      stop
  endif
end while (no)
:set diag to OK;
stop
}

@enduml

Algorithms

Check data

Check that obstacle_collision_checker receives no ground pointcloud, predicted_trajectory, reference trajectory, and current velocity data.

Diagnostic update

If any collision is found on predicted path, this module sets ERROR level as diagnostic status else sets OK.

Inputs / Outputs

Input

Name	Type	Description
~/input/trajectory	autoware_auto_planning_msgs::msg::Trajectory	Reference trajectory
~/input/trajectory	autoware_auto_planning_msgs::msg::Trajectory	Predicted trajectory
/perception/obstacle_segmentation/pointcloud	sensor_msgs::msg::PointCloud2	Pointcloud of obstacles which the ego-vehicle should stop or avoid
/tf	tf2_msgs::msg::TFMessage	TF
/tf_static	tf2_msgs::msg::TFMessage	TF static

Output

Name	Type	Description
~/debug/marker	visualization_msgs::msg::MarkerArray	Marker for visualization

Parameters

Name	Type	Description	Default value
delay_time	double	Delay time of vehicle [s]	0.3
footprint_margin	double	Foot print margin [m]	0.0
max_deceleration	double	Max deceleration for ego vehicle to stop [m/s^2]	2.0
resample_interval	double	Interval for resampling trajectory [m]	0.3
search_radius	double	Search distance from trajectory to point cloud [m]	5.0

Assumptions / Known limits

To perform proper collision check, it is necessary to get probably predicted trajectory and obstacle pointclouds without noise.