Virtual Traffic Light

Role

Autonomous vehicles have to cooperate with the infrastructures such as:

• Warehouse shutters
• Traffic lights with V2X support
• Communication devices at intersections
• Fleet Management Systems (FMS)

The following items are example cases:

1. Traffic control by traffic lights with V2X support

2. Intersection coordination of multiple vehicles by FMS.

It’s possible to make each function individually, however, the use cases can be generalized with these three elements.

1. start: Start a cooperation procedure after the vehicle enters a certain zone.
2. stop: Stop at a defined stop line according to the status received from infrastructures.
3. end: Finalize the cooperation procedure after the vehicle reaches the exit zone. This should be done within the range of stable communication.

This module sends/receives status from infrastructures and plans the velocity of the cooperation result.

System Configuration Diagram

@startuml
!theme cerulean-outline

' Component
node "Autoware ECU" as autoware_ecu {
  component "Behavior Planner" as behavior_planner
  component "Autoware API" as autoware_api
  database "Vector Map" as vector_map
  note bottom of vector_map
    Communication metadata is stored.
  end note
}

package "Infrastructures" as infrastructures {
  node "FMS" as fms
  node "Automatic Shutter" as automatic_shutter
  node "Manual Shutter" as manual_shutter
  node "Remove Controllable Traffic Light" as remote_controllable_traffic_light
  node "Warning Light" as warning_light
}

' Relationship
'' Behavior Planner <-> Autoware API
behavior_planner -up-> autoware_api : infrastructure\n command
autoware_api -down-> behavior_planner : infrastructure\n state

'' Vector Map
vector_map -left-> behavior_planner : vector map

'' Autoware API <-> Infrastructure
autoware_api -up-> fms : <color:blue>lock\n <color:blue>request
fms -down-> autoware_api : <color:blue>right-of-way\n <color:blue>state

autoware_api -up-> automatic_shutter : <color:green>approach\n <color:green>notification
automatic_shutter -down-> autoware_api : <color:green>shutter\n <color:green>state

autoware_api -up-> manual_shutter : <color:blue>open/close\n <color:blue>command
manual_shutter -down-> autoware_api : <color:blue>shutter\n <color:blue>state

autoware_api -up-> remote_controllable_traffic_light : <color:green>light change\n <color:green>command
remote_controllable_traffic_light -down-> autoware_api : <color:green>light\n <color:green>state

autoware_api -up-> warning_light : <color:blue>activation\n <color:blue>command
warning_light -down-> autoware_api : <color:blue>warning light\n <color:blue>state

' Layout
'' Infrastructure
fms -[hidden]right-> automatic_shutter
automatic_shutter -[hidden]right-> manual_shutter
manual_shutter -[hidden]right-> remote_controllable_traffic_light
remote_controllable_traffic_light -[hidden]right-> warning_light

@enduml

Planner and each infrastructure communicate with each other using common abstracted messages.

• Special handling for each infrastructure is not scalable. The interface is defined as an Autoware API.
• The requirements for each infrastructure are slightly different, but will be handled flexibly.

FMS: Intersection coordination when multiple vehicles are in operation and the relevant lane is occupied

• Automatic shutter: Open the shutter when approaching/close it when leaving
• Manual shutter: Have the driver open and close the shutter.
• Remote control signal: Have the driver change the signal status to match the direction of travel.
• Warning light: Activate the warning light

Support different communication methods for different infrastructures

• HTTP
• Bluetooth
• ZigBee

Have different meta-information for each geographic location

• Associated lane ID
• Hardware ID
• Communication method

FMS: Fleet Management System

@startuml
!theme cerulean-outline

' Component
node "Autoware ECU" as autoware_ecu {
component "Behavior Planner" as behavior_planner
component "Autoware API" as autoware_api
component "Web.Auto Agent" as web_auto_agent
note right of web_auto_agent : (fms_bridge)
database "Vector Map" as vector_map

package "Infrastructure Bridges" as infrastructure_bridges {
  component "Automatic Shutter Bridge" as automatic_shutter_bridge
  component "Manual Shutter Bridge" as manual_shutter_bridge
  component "Remove Controllable Traffic Light Bridge" as remote_controllable_traffic_light_bridge
  component "Warning Light Bridge" as warning_light_bridge
}
}

cloud "FMS" as fms {
  component "FMS Gateway" as fms_gateway

  component "Intersection Arbitrator" as intersection_arbitrator
  database "Intersection Lock Table" as intersection_lock_table

  component "Vector Map Builder" as vector_map_builder
  database "Vector Map Database" as vector_map_database
}

package "Infrastructures" as infrastructures {
  node "Automatic Shutter" as automatic_shutter
  node "Manual Shutter" as manual_shutter
  node "Remote Controllable Traffic Light" as remote_controllable_traffic_light
  node "Warning Light" as warning_light
}

' Relationship
'' Behavior Planner <-> Autoware API
behavior_planner -up-> autoware_api : infrastructure\n command
autoware_api -down-> behavior_planner : infrastructure state\n as virtual traffic light

'' Autoware API <-> Web.Auto
autoware_api -up-> web_auto_agent : infrastructure\n command
web_auto_agent -down-> autoware_api : infrastructure state\n as virtual traffic light

'' Autoware API <-> Infrastructure Bridge
autoware_api -right-> infrastructure_bridges : infrastructure\n command
infrastructure_bridges -left-> autoware_api : infrastructure state\n as virtual traffic light

'' Infrastructure Bridge <-> Infrastructure
automatic_shutter_bridge -right-> automatic_shutter : approach notification
automatic_shutter -left-> automatic_shutter_bridge : shutter state

manual_shutter_bridge -right-> manual_shutter : open/close command
manual_shutter -left-> manual_shutter_bridge : shutter state

remote_controllable_traffic_light_bridge -right-> remote_controllable_traffic_light : light change command
remote_controllable_traffic_light -left-> remote_controllable_traffic_light_bridge : light state

warning_light_bridge -right-> warning_light : activation command
warning_light -left-> warning_light_bridge : warning light state

'' Web.Auto
web_auto_agent -up-> fms_gateway : infrastructure\n command
fms_gateway -down-> web_auto_agent : infrastructure state\n as virtual traffic light

fms_gateway -up-> intersection_arbitrator : lock request
intersection_arbitrator -down-> fms_gateway : right-of-way state

intersection_arbitrator -up-> intersection_lock_table : lock request
intersection_lock_table -down-> intersection_arbitrator : lock result

vector_map_builder -down-> vector_map_database : create vector map
vector_map_database -left-> intersection_arbitrator : vector map

'' Vector Map
vector_map_database .down.> web_auto_agent : vector map
web_auto_agent -left-> vector_map : vector map
vector_map -down-> behavior_planner : vector map

' Layout
'' Infrastructure Bridge
automatic_shutter_bridge -[hidden]down-> manual_shutter_bridge
manual_shutter_bridge -[hidden]down-> remote_controllable_traffic_light_bridge
remote_controllable_traffic_light_bridge -[hidden]down-> warning_light_bridge

'' Infrastructure
automatic_shutter -[hidden]down-> manual_shutter
manual_shutter -[hidden]down-> remote_controllable_traffic_light
remote_controllable_traffic_light -[hidden]down-> warning_light

@enduml

Module Parameters

Parameter	Type	Description
max_delay_sec	double	[s] maximum allowed delay for command
near_line_distance	double	[m] threshold distance to stop line to check ego stop.
dead_line_margin	double	[m] threshold distance that this module continue to insert stop line.
hold_stop_margin_distance	double	[m] parameter for restart prevention (See following section)
check_timeout_after_stop_line	bool	[-] check timeout to stop when linkage is disconnected

Restart prevention

If it needs X meters (e.g. 0.5 meters) to stop once the vehicle starts moving due to the poor vehicle control performance, the vehicle goes over the stopping position that should be strictly observed when the vehicle starts to moving in order to approach the near stop point (e.g. 0.3 meters away).

This module has parameter hold_stop_margin_distance in order to prevent from these redundant restart. If the vehicle is stopped within hold_stop_margin_distance meters from stop point of the module (_front_to_stop_line < hold_stop_margin_distance), the module judges that the vehicle has already stopped for the module’s stop point and plans to keep stopping current position even if the vehicle is stopped due to other factors.

{width=1000}

{width=1000}

{width=1000}

Flowchart

@startuml
!theme cerulean-outline
start

if (before start line?) then (yes)
  stop
else (no)
endif

if (after end line?) then (yes)
  stop
else (no)
endif

:send command to infrastructure;

if (no stop line?) then (yes)
  stop
else (no)
endif

:check infrastructure state;

if (timeout or not received?) then (yes)
  :stop at stop line;
  stop
else (no)
endif

if (no right of way?) then (yes)
  :stop at stop line;
else (no)
endif

if (finalization is requested?) then (yes)
  if (not finalized?) then (yes)
    :stop at end line;
  else (no)
  endif
else (no)
endif

stop
@enduml

Map Format

• To avoid sudden braking, the length between the start line and stop line of a virtual traffic light must be longer than $l_{\mathrm{min}}$ calculated as follows, assuming that $v_0$ is the velocity when passing the start line and $a_{\mathrm{min}}$ is minimum acceleration defined in Autoware.

\[\begin{align} l_{\mathrm{min}} = -\frac{v_0^2}{2 a_{\mathrm{min}}} \end{align}\]

Known Limits

• tbd.

Changelog for package autoware_behavior_velocity_virtual_traffic_light_module

0.44.0 (2025-04-18)

0.43.0 (2025-03-21)

• Merge remote-tracking branch 'origin/main' into chore/bump-version-0.43
• chore: rename from [autoware.universe]{.title-ref} to [autoware_universe]{.title-ref} (#10306)
• fix(behavior_velocity_planner): planning factor integration (#10292)
  • fix: blind_spot
  • fix: crosswalk
  • fix: detection_area
  • fix: intersection
  • fix: no_drivable_lane
  • fix: no_stopping_area
  • fix: run_out
  • fix: stop_line
  • fix: traffic_light
  • fix: virtual_traffic_light

  * fix: walk_way ---------

• feat(Autoware_planning_factor_interface): replace tier4_msgs with autoware_internal_msgs (#10204)
• Contributors: Hayato Mizushima, Satoshi OTA, Yutaka Kondo, 心刚

0.42.0 (2025-03-03)

• Merge remote-tracking branch 'origin/main' into tmp/bot/bump_version_base
• feat(autoware_utils): replace autoware_universe_utils with autoware_utils (#10191)
• feat!: replace tier4_planning_msgs/PathWithLaneId with autoware_internal_planning_msgs/PathWithLaneId (#10023)
• feat(planning_test_manager): abstract message-specific functions (#9882)
  • abstract message-specific functions
  • include necessary header
  • adapt velocity_smoother to new test manager
  • adapt behavior_velocity_planner to new test manager
  • adapt path_optimizer to new test manager
  • fix output subscription
  • adapt behavior_path_planner to new test manager
  • adapt scenario_selector to new test manager
  • adapt freespace_planner to new test manager
  • adapt planning_validator to new test manager
  • adapt obstacle_stop_planner to new test manager
  • adapt obstacle_cruise_planner to new test manager
  • disable test for freespace_planner
  • adapt behavior_velocity_crosswalk_module to new test manager
  • adapt behavior_path_lane_change_module to new test manager
  • adapt behavior_path_avoidance_by_lane_change_module to new test manager
  • adapt behavior_path_dynamic_obstacle_avoidance_module to new test manager
  • adapt behavior_path_external_request_lane_change_module to new test manager
  • adapt behavior_path_side_shift_module to new test manager
  • adapt behavior_path_static_obstacle_avoidance_module to new test manager
  • adapt path_smoother to new test manager
  • adapt behavior_velocity_blind_spot_module to new test manager
  • adapt behavior_velocity_detection_area_module to new test manager
  • adapt behavior_velocity_intersection_module to new test manager
  • adapt behavior_velocity_no_stopping_area_module to new test manager
  • adapt behavior_velocity_run_out_module to new test manager
  • adapt behavior_velocity_stop_line_module to new test manager
  • adapt behavior_velocity_traffic_light_module to new test manager
  • adapt behavior_velocity_virtual_traffic_light_module to new test manager
  • adapt behavior_velocity_walkway_module to new test manager
  • adapt motion_velocity_planner_node_universe to new test manager
  • include necessary headers

  * Odometries -> Odometry ---------Co-authored-by: Takayuki Murooka <<takayuki5168@gmail.com>>

• Contributors: Fumiya Watanabe, Mitsuhiro Sakamoto, Ryohsuke Mitsudome, 心刚

0.41.2 (2025-02-19)

• chore: bump version to 0.41.1 (#10088)
• Contributors: Ryohsuke Mitsudome

0.41.1 (2025-02-10)

0.41.0 (2025-01-29)

• Merge remote-tracking branch 'origin/main' into tmp/bot/bump_version_base
• feat(autoware_planning_test_manager): remove dependency of VirtualTrafficLightState and ExpandStopRange (#9953)
  • feat(autoware_planning_test_manager): remove dependency of virtual traffic light

  * modify obstacle_stop test code ---------

• chore(planning): move package directory for planning factor interface (#9948)
  • chore: add new package for planning factor interface
  • chore(surround_obstacle_checker): update include file
  • chore(obstacle_stop_planner): update include file
  • chore(obstacle_cruise_planner): update include file
  • chore(motion_velocity_planner): update include file
  • chore(bpp): update include file
  • chore(bvp-common): update include file
  • chore(blind_spot): update include file
  • chore(crosswalk): update include file
  • chore(detection_area): update include file
  • chore(intersection): update include file
  • chore(no_drivable_area): update include file
  • chore(no_stopping_area): update include file
  • chore(occlusion_spot): update include file
  • chore(run_out): update include file
  • chore(speed_bump): update include file
  • chore(stop_line): update include file
  • chore(template_module): update include file
  • chore(traffic_light): update include file
  • chore(vtl): update include file
  • chore(walkway): update include file

  * chore(motion_utils): remove factor interface ---------

• feat(behavior_velocity_planner)!: remove velocity_factor completely (#9943)
  • feat(behavior_velocity_planner)!: remove velocity_factor completely

  * minimize diff ---------

• feat(planning_factor)!: remove velocity_factor, steering_factor and introduce planning_factor (#9927) Co-authored-by: Satoshi OTA <<44889564+satoshi-ota@users.noreply.github.com>> Co-authored-by: Ryohsuke Mitsudome <<43976834+mitsudome-r@users.noreply.github.com>> Co-authored-by: satoshi-ota <<satoshi.ota928@gmail.com>>
• feat(behavior_velocity_planner): remove virtual traffic light dependency from behavior_velocity_planner and behavior_velocity_planner_common (#9746)
  • feat: remove-virtual-traffic-light-dependency-from-plugin-manager
  • build passed
  • fix test
  • fix test
  • fix

  * fix typo ---------

• feat(behavior_velocity_modules): add node test (#9790)
  • feat(behavior_velocity_crosswalk): add node test
  • fix
  • feat(behavior_velocity_xxx_module): add node test
  • fix
  • fix
  • fix
  • fix

  * change directory tests -> test ---------

• refactor(behavior_velocity_planner_common): add behavior_velocity_rtc_interface and move RTC-related implementation (#9799)
  • split into planer_common and rtc_interface

  * Update planning/behavior_velocity_planner/autoware_behavior_velocity_planner_common/include/autoware/behavior_velocity_planner_common/scene_module_interface.hpp Co-authored-by: Mamoru Sobue <<mamoru.sobue@tier4.jp>> * Update planning/behavior_velocity_planner/autoware_behavior_velocity_rtc_interface/include/autoware/behavior_velocity_rtc_interface/scene_module_interface_with_rtc.hpp Co-authored-by: Mamoru Sobue <<mamoru.sobue@tier4.jp>> * fix ——

  Co-authored-by: Mamoru Sobue <<mamoru.sobue@tier4.jp>>

• Contributors: Fumiya Watanabe, Mamoru Sobue, Satoshi OTA, Takayuki Murooka

0.40.0 (2024-12-12)

• Merge branch 'main' into release-0.40.0
• Revert "chore(package.xml): bump version to 0.39.0 (#9587)" This reverts commit c9f0f2688c57b0f657f5c1f28f036a970682e7f5.
• fix: fix ticket links in CHANGELOG.rst (#9588)
• chore(package.xml): bump version to 0.39.0 (#9587)
  • chore(package.xml): bump version to 0.39.0
  • fix: fix ticket links in CHANGELOG.rst

  * fix: remove unnecessary diff ---------Co-authored-by: Yutaka Kondo <<yutaka.kondo@youtalk.jp>>

• fix: fix ticket links in CHANGELOG.rst (#9588)
• fix(cpplint): include what you use - planning (#9570)
• feat(behavior_velocity_planner)!: remove stop_reason (#9452)
• 0.39.0
• update changelog
• fix: fix ticket links to point to https://github.com/autowarefoundation/autoware_universe (#9304)
• fix: fix ticket links to point to https://github.com/autowarefoundation/autoware_universe (#9304)
• chore(package.xml): bump version to 0.38.0 (#9266) (#9284)
  • unify package.xml version to 0.37.0
  • remove system_monitor/CHANGELOG.rst
  • add changelog

  * 0.38.0

• Contributors: Esteve Fernandez, Fumiya Watanabe, M. Fatih Cırıt, Mamoru Sobue, Ryohsuke Mitsudome, Yutaka Kondo

0.39.0 (2024-11-25)

• fix: fix ticket links to point to https://github.com/autowarefoundation/autoware_universe (#9304)
• fix: fix ticket links to point to https://github.com/autowarefoundation/autoware_universe (#9304)
• chore(package.xml): bump version to 0.38.0 (#9266) (#9284)
  • unify package.xml version to 0.37.0
  • remove system_monitor/CHANGELOG.rst
  • add changelog

  * 0.38.0

• Contributors: Esteve Fernandez, Yutaka Kondo

0.38.0 (2024-11-08)

• unify package.xml version to 0.37.0
• test(virtual_traffic_light): add unit tests for utils (#9107)
• chore(virtual_traffic_light): add soblin to maintainer (#9147)
• refactor(virtual_traffic_light): move to utils for unit test (#9106)
• fix(autoware_behavior_velocity_virtual_traffic_light_module): fix unusedFunction (#8670) fix:unusedFunction
• fix(behavior_velocity_planner): fix cppcheck warnings of virtualCallInConstructor (#8376) Co-authored-by: Ryuta Kambe <<ryuta.kambe@tier4.jp>>
• fix(autoware_behavior_velocity_virtual_traffic_light_module): fix unusedStructMember (#8394) fix:unusedStructMember
• fix(behavior_path_planner, behavior_velocity_planner): fix redefinition errors (#7688)
• feat: add [autoware_]{.title-ref} prefix to [lanelet2_extension]{.title-ref} (#7640)
• fix(autoware_behavior_velocity_planner_common): remove lane_id check from arc_lane_util (#7710)
  • fix(arc_lane_util): remove lane_id check from arc_lane_util

  * modify test_arc_lane_util.cpp ---------

• refactor(universe_utils/motion_utils)!: add autoware namespace (#7594)
• refactor(motion_utils)!: add autoware prefix and include dir (#7539) refactor(motion_utils): add autoware prefix and include dir
• feat(autoware_universe_utils)!: rename from tier4_autoware_utils (#7538) Co-authored-by: kosuke55 <<kosuke.tnp@gmail.com>>
• chore(behavior_velocity_planner): move packages (#7526)
• Contributors: Fumiya Watanabe, Kosuke Takeuchi, Ryuta Kambe, Takayuki Murooka, Yukinari Hisaki, Yutaka Kondo, kobayu858, taisa1

0.26.0 (2024-04-03)