Manual Lane Change Handler

Purpose

Manual Lane Change Handler helps shift the preferred-primitives of a route to the left or right. A manual lane-change handler rviz plugin is also available for use for the user.

Example for using the Manual Lane Change Handler

Service call to shift the preferred-lanes to the left

ros2 service call /planning/mission_planning/manual_lane_change_handler/set_preferred_lane tier4_external_api_msgs/srv/SetPreferredLane lane_change_direction:\ 0\

Services

Subscriptions

Publications

Service client

Registered Servers

Setting Preferred Lane

This service allows for shifting the current preferred lane to the left or right, or reverting to the default preferred lane received from the route planner. As the vehicle moves, the shifting is done relative to the current preferred lane.

Based on certain criteria, shifting may be rejected, as in the following cases:

1. Left or Right shift is not available due to no lane being present to shift to
2. The next segment is a turn or the very last lane - this is to ensure that we can navigate the enter path and end up at the goal

@startuml
title process_lane_change_request

start
:Compute override_direction from request;

if (override_direction == AUTO) then (yes)
  if (currently in lane-change override) then (yes)
    :revert to original route;
    stop
  else (no)
    :do nothing;
    stop
  endif
else (no)
  if (has a route been set?) then (yes)
    :find initial segment;
    while (not penultimate segment) is (yes)
      if (shift unavailable\nor next segment is turn?) then (yes)
        --> while (not penultimate segment)   ' continue
      else (no)
        if (left-shift requested and possible) then (yes)
          :shift left;
        elseif (right-shift requested and possible) then (yes)
          :shift right;
        endif
        --> while (not penultimate segment)   ' jump back instead of implicit join
      endif
    endwhile (no)
    stop

  else (no)
    :do nothing;
    stop
  endif
endif
@enduml