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Blind spot design

Blind Spot#

Role#

Blind spot check while turning right/left by a dynamic object information and planning a velocity of the start/stop.

brief

Activation Timing#

This function is activated when the lane id of the target path has an intersection label (i.e. the turn_direction attribute is left or right).

Inner-workings / Algorithms#

Sets a stop line, a pass judge line, a detection area and conflict area based on a map information and a self position.

  • Stop line : Automatically created based on crossing lane information.
  • Pass judge line : A position to judge if stop or not to avoid a rapid brake.
  • Detection area : Right/left side area of the self position.
  • Conflict area : Right/left side area from the self position to the stop line.

Stop/Go state: When both conditions are met for any of each object, this module state is transited to the "stop" state and insert zero velocity to stop the vehicle.

  • Object is on the detection area
  • Object’s predicted path is on the conflict area

In order to avoid a rapid stop, the “stop” judgement is not executed after the judgment line is passed.

Once a "stop" is judged, it will not transit to the "go" state until the "go" judgment continues for a certain period in order to prevent chattering of the state (e.g. 2 seconds).

Module Parameters#

Parameter Type Description
stop_line_margin double [m] a margin that the vehicle tries to stop before stop_line
backward_length double [m] distance from closest path point to the edge of beginning point.
ignore_width_from_center_line double [m] ignore threshold that vehicle behind is collide with ego vehicle or not
max_future_movement_time double [s] maximum time for considering future movement of object

Flowchart#

uml diagram