Scenario Manager

The scenario_manager package is a ROS2 package designed to manage and execute various robot scenarios involving teleportation, speed setting, and collision simulations. It provides action servers to control robot behavior and a tool for calculating Time to Collision (TTC).

Launching the Scenario Manager

To start the scenario_manager, launch it using the following command:

ros2 launch scenario_manager scenario_manager.launch.py

This initializes three action servers: - teleport_action_server: Handles teleportation of robots. - set_speed_action_server: Controls robot speed. - collision_action_server: Configures scenarios where robots collide (only applicable to jackal and pallet_truck).

Collision Action Server

The collision_action_server configures collisions by setting speeds and initial positions for two robots to ensure a collision occurs. It requires: - Angle: The approach angle. - Speed of pallet_truck: The movement speed of the pallet truck. - Collision Type: An enum from the simlan_custom_msg package specifying the type of collision.

Collision Types

There are three predefined collision types:

Collision Type	Enum Value	Description
HEAD_ON	0	Robots collide head-on.
PALLET_TRUCK_SIDE	1	Pallet truck collides into the side of Jackal.
JACKAL_SIDE	2	Jackal collides into the side of the pallet truck.

Below are images illustrating the different collision types:

Head-On Collision	Pallet Truck Side Collision	Jackal Side Collision

Running a Scenario

To execute a scenario, use the following command:

ros2 launch scenario_execution_ros scenario_launch.py scenario:=<scenario_file>

Replace <scenario_file> with a specific scenario file, such as:

ros2 launch scenario_execution_ros scenario_launch.py scenario:=simulation/scenario_manager/scenarios/case1.osc

or scenario 6 can be run from the scenarios.sh file like so:

./scenarios.sh 6

This runs a collision action client, executing multiple collision simulations with varying angles and speeds.

Note: If the robots are not moving or something feels like it is not working, there can be ghost processes from an earlier run. Stop the program and run ./control.sh kill and try running again.

Time to Collision (TTC) Calculation

The package includes a TTC node that logs the Time to Collision (TTC) and Closest Point of Arrival (CPA) for two robots using the Minkowski-Difference, assuming constant speed and direction.

Running the TTC Node

ros2 run scenario_manager ttc

This node calculates and logs: - ⏱️ TTC: The time at which the closest approach occurs. - 📍 CPA: The closest distance between the two robots, assuming constant speed and trajectory.