TrafficSimulation

Abstract

Traffic Simulation simulates traffic situation follow traffic rules.
Spawn points (Spawnable Lanes) and spawnable vehicles can be configured using components and Traffic Simulation simulates traffic situation following configuration.

Overview

Traffic Simulation consists of the following components:

Component	Description
TrafficSimulator	Collecting all traffic simulators and managing the spawning and simulating process.
NpcVehicleSpawner	Get Npc vehicle states and updating simulation steps.
NpcVehicleSimulator	Spawning random Npc vehicle in spawning lanes.
RandomTrafficSimulator	Managing lifecycle of NPCs and simulating NPC behaviours.
TrafficLane TrafficLight TrafficIntersection StopLine	Traffic entities.
NpcVehicle	Vehicle models (NPCs) controlled by RandomTrafficSimulator.

Configuration

Traffic Simulation can be configured from TrafficSimulator component.

The configurable elements are listed in the following table:

General Settings

Parameter	Description
Ego Vehicle	Ego vehicle handler. If not set, the manager creates a dummy ego. This reference is also set automatically when the Ego spawns via the traffic simulator.
Seed	Seed value for random generator.
Traffic Intersections	The field that is set TrafficIntersection objects. TrafficIntersection to be set is controlled by Traffic Simulation.

NPC Vehicle Settings

Parameter	Description
Vehicle Config	Parameters for NPC vehicle control. Sudden Deceleration is a deceleration related to emergency braking.
Obstacle Layer Mask	The obstacle layer for raytracing the collision distances.
Ground Layer Mask	The Ground layer for raytracing the collision distances.
Max Vehicle Count	The maximum number of vehicles that can simultaneously live in the scene. Lowering this value results in less dense traffic but improves the simulator's performance.
Spawn Distance To Ego	The minimal distance between the EGO and the NPC to spawn.

Debug

Parameter	Description
Show Gizmos	Enable the checkbox to show all visualization using editor gizmos.
Show Yielding Phase	Enable the checkbox to show editor gizmos that visualize Yielding Phase of NPCs.
Show Obstacle Checking	Enable the checkbox to show editor gizmos that visualize Obstacle Checking phase of NPCs.
Show Spawn Points	Enable the checkbox to show editor gizmos that visualize Spawn Points where NPCs is generated.

Random Traffic Sims

Parameter	Description
Enable Simulation	Enable the checkbox to Random Traffic Sims which spawn NPC vehicles randomly.
TrafficSim Npc Vehicle Prefabs	Prefabs representing controlled vehicles. They must have NPCVehicle component attached.
Spawnable TrafficLanes	TrafficLane components where NPC vehicles can be spawned during traffic simulation.
Enable Spawn Count Limit	Enable the checkbox to limit of vehicle spawning.
Spawn Count Limit	The number of limit of vehicles spawning.

Gizmos

Gizmos are useful for checking current behavior of NPCs and its causes.
Gizmos have a high computational load so please disable them if the simulation is laggy.

The visualizable elements are listed in the following table:

Shape	Description
Rectangle	Yielding Phase of each NPCs to avoid colliding with the other NPCs.
Arrow	Obstacle Checking of each NPCs to stop in front of the obstacle.
Diamond	Spawn Points where NPCs is generated by Random Traffic Sims.

Instruction

To use Traffic Simulation, please follow the steps below.

For the preparation, the following must be prepared:

• 3D map (.fbx)
• lanelet map (.osm)

1. Place Traffic Simulator

Create empty GameObject (should be named TrafficSimulator).
Attach this object to TrafficSimulator component.

(optional) To place objects which is generated later, you may creat empty objects named TrafficIntersections and NPCPedestrians.

2. TrafficIntersection and LaneletTrafficLight settings

Please place intersection objects and attach LaneletTrafficLight script.
Then, please you set traffic lights to intersection.

Please configure TrafficIntersection and LaneletTrafficLight components as the following:

1. Add a empty GameObject as a child object of TrafficIntersections hierarchy
   1. The GameObject should be named TrafficIntersection.x
   2. The Transform of GameObject should be set on the target intersection
2. Attach a TrafficIntersection component to the intersection game object
3. Attach LaneletTrafficLight to traffic light objects placed on the target intersection
4. Modify Bulb Material Config as follow images
   vehicle raffic light
   
   pedestrian traffic light
   
   1. If there are wrong order of bulb, modify each Bulb Material Config
5. Set traffic light objects attached LaneletTrafficLight in step. 3 to TrafficLightGroups in TrafficIntersection
   1. Traffic lights which should light same sequences should be set on same TrafficLightGroups

Warning

Do not attach LaneletTrafficLight to traffic lights which are not set to TrafficIntersection.
It causes errors.

Info

For detailed settings of Bulb Material Config, see here.

Modify Lighting Sequences

If you need to set an arbitrary signal control pattern, you can modify it in Lighting Sequences field.

Create any number of of lements of Lighting Sequences and set parameters for each one.
When the scene plays, the Lighting Sequences will execute sequentially from Element 0.
In addition, when the last element completes, the sequence will loop back to Element 0.

The Waypoint settings parameters are listed in the following table:

Lighting Sequences

Parameter	Description
Interval Sec	Duration for which this sequence continues.
Group Lighting Orders	Settings for lighting each TrafficLightGroups.

Group Lighting Orders

Parameter	Description
Group	Target TrafficLightGroups.
Bulb Data	Setting for lighting each bulb in traffic lights within TrafficLightGroups.

Bulb Data

Parameter	Description
Type	Target bulb.
Color	Color of lighting on target bulb.
Status	Type of lighting. (Solid On, Solid Off and Flashing)

Set right of ways on uncontrolled intersections

On intersections without traffic lights, it is needed to set the right of way of TrafficLane manually for the vehicles to operate properly.

Please configure TrafficLane components as the following:

1. Select a straight lane that should be right of way in the intersection
   1. The selected lane should be highlighted
2. Click the Set RightOfWays button to give the lane priority over other lanes

Please check if all lanes that intersect with the selected lane are highlighted yellow.
This means that the right of way was applied correctly.

3. Load lanelet

LaneletLoader can load a lanelet map and create TrafficLane and StopLine. In addition, LaneletLoader set parameter of traffic rules to TrafficLane, StopLine and traffic lights.
LaneletLoader can be performed by opening AWSIM -> Common -> Load Lanelet at the toolbar of Unity Editor.

Please use LaneletLoader as the following: 1. Fill in Osm field with a lanelet map (.osm) you prepared, Root Object field with a TrafficSimulator object.
2. Adjust Waypoint settings parameters for the loading process if needed.
3. To load the lanelet map, please click Load button.

The Waypoint settings parameters are listed in the following table:

Parameter	Description
Resolution	Resolution of resampling. Lower values provide better accuracy at the cost of processing time.
Min Delta Length	Minimum length(m) between adjacent points.
Min Delta Angle	Minimum angle(deg) between adjacent edges. Lowering this value produces a smoother curve.

TrafficLane, StopLine and TrafficLight will be generated and placed as child objects of the Root Object.
You can check their visual representation by clicking consecutive elements in the scene hierarchy.

4. TrafficSimulator setting

Please configure TrafficSimulator component as the following:

1. Fill in Ego Vehicle field with EGO vehicle
   1. Example: EgoVehicle/Lexus RX450h 2015
2. Change Obstacle Layer Mask and Ground Layer Mask field to Everything
3. Fill in Traffic Intersections field with TrafficIntersection objects
4. Fill in Random Traffic Sims field
   1. Fill in Traffic Sim Npc Vehicle Prefab field with vehicle prefabs what you want to spawn
      1. Prefabs is in Assets/Awsim/Prefabs/Usecase/TrafficSimulation/
   2. Fill in Spawnable Traffic Lanes field with TrafficLane where you want to spawn vehicles

Info

For detailed settings of TrafficSimulator, see here.

5. Place Pedestrian (optional)

You can place pedestrian NPCs if needed.
Pedestrians can animated and walk around where they are placed.
Direction which pedestrian start to walking can be set in Transform of it.

Please configure pedestrian NPCs as the following:

1. Place pedestrian prefabs on a scene
   1. Prefabs is in Assets/Awsim/Prefabs/Entity/Npc/Pedestrian/
   2. Pedestrians should be child object of NPCPedestrians hierarchy
2. Attach SimplePedestrianWalkerController component to pedestrians
3. (optional) Configure parameters of SimplePedestrianWalkerController

The parameters of SimplePedestrianWalkerController are listed in the following table:

Parameter	Description
Duration	Duration at which the pedestrian walk.
Speed	Speed at which the pedestian walk.

6. Call methods of TrafficSimulator

To enable Traffic Simulation, some methods of TrafficSimulator should be called from callback of MonoBehaviour.

Please create or open class which is inherit MonoBehaviour and make field of TrafficSimulator.
Then, add description of calling method of TrafficSimulator.

The method should be called are listed in the following table:

Method	Description
Initialize()	Should be called Start() callback.
OnUpdate()	Should be called Update() callback.
OnFixedUpdate()	Should be called FixedUpdate() callback.

Info

AWSIM includes AutowareSimulationDemo scene.
Please refer to:
* Assets/Awsim/Scenes/AutowareSimulationDemo/AutowareSimulationDemo.cs
* Assets/Awsim/Scenes/AutowareSimulationDemo.unity scene

Call methods of Pedestrian (optional)

To move Pedestrian, some methods of SimplePedestrianWalkerController should be called same as TrafficSimulator.

Please create or open class which is inherit MonoBehaviour and make field of SimplePedestrianWalkerController[].
Then, add description of calling method of each element of SimplePedestrianWalkerController[] using for loop.

The method should be called are listed in the following table:

Method	Description
Initialize()	Should be called Start() callback.
OnUpdate()	Should be called Update() callback.
OnFixedUpdate()	Should be called FixedUpdate() callback.