BTWorkshop_ROSCON_ES25

BT4.x, Groot2, BTROS2: orquestación avanzada en ROS2

This repository contains BT.CPP assets to set up the simulation environment and tools stack for the workshop on advanced orchestration in ROS2, integrating BT.CPP 4.x, Groot2, BT.ROS2 for robotics behavior modular and composable orchestration.

Overview

The stack combines:

• BehaviorTree.CPP 4.x: Core BT engine for ROS2
• Groot2: Visual editor and monitor for BTs
• BT.ROS2: ROS2 integration for BT prototipation and execution

Build Setup

Prerequisites

• Docker with Compose support
• Git
• X11 for GUI applications (Groot2, etc.)

Building the Container

Use the provided build script to create the development environment:

cd Docker
./build_container.sh [OPTIONS]

Build Options

• [Option A] No arguments: Pull image from dockerhub (suggested!!!)
• [Option B] --clean-rebuild: Force a complete rebuild of the container, removing cached layers

With [Option B] The build process will:

1. Base Image: Use the latest pyrobosim_ros:${ROS_DISTRO} as the foundation
2. Dependency Management: Import and update dependencies in deps/ using VCS
3. ROS2 Setup: Install dependencies via rosdep and build the workspace
4. Environment: Prepare a full ROS2 workspace with all integrated BT components

Development Environment

Using Docker Compose

Launch the development container:

cd Docker
docker compose -f dev-docker-compose.yaml  up [--force-recreate]

This starts the main container with:

• Network: Host mode for ROS2 communication
• Display: X11 forwarding for GUI applications (Groot2)
• Volumes: Workspace and world files persistence

Access the Container

Option(A): Use VSCode with devcontainer extension

Open the project in VSCode with the Dev Container extension installed:

1. ctrl+shift+p -> "Dev Containers -> Open Folder in Container..."
2. Select folder Docker/DevContainer

Option(B): Use your custom editor and access the container through CLI

Connect to the running container:

docker exec --user btdev -it <container-name> bash

Inspect container-name with docker ps -a

The workspace is pre-built and sourced automatically.

Quick Start

0. Health check of the environment

Once inside the development environment, quickly test the following cmds:

# Check your user 
whoami 
# btdev

# Check ros distro and ros_domain_id
env | grep ROS_D 
# ROS_DOMAIN_ID=12
# ROS_DISTRO=jazzy

# Check you are in the correct workspace
echo $PWD
# /roscon25_ws

# Compile and source
colcon build --symlink-install && source install/setup.bash
# Summary: 9 packages finished [...s]

#Check presence of this pkg
ros2 pkg list | grep behaviortree_pyrobosim
# behaviortree_pyrobosim

1. Launch simulator and Groot2

Before launching any graphical application, on a terminal on your host machine (not in your container!!!) give once the following command

xhost +local:docker

Let's go back to the container now....

To start the simulator:

ros2 launch simple_pyrobosim_ros demo.launch.py world_file:=/roscon25_ws/worlds/world12.yaml

world_file can have the following values:

• /roscon25_ws/worlds/world12.yaml for Exercise 1 and Exercise 2
• /roscon25_ws/worlds/world3.yaml for Exercise 3
• /roscon25_ws/worlds/world4.yaml for Exercise 4

To install Groot2 (it is a simple GUI installation):

cd /roscon25_ws
chmod +x Groot2-v1.6.1-linux-installer.run && ./Groot2-v1.6.1-linux-installer.run

Follow gui installation and then create an alias (suggested, not mandatory). You can put the alias directly in the .bashrc to easily start it from a new terminal.

# default <groot2-bin-exec-path> might be "/home/btdev/Groot2/bin/groot2"
alias groot2=<groot2-bin-exec-path> 
groot2 #should start groot2

# to "save" the alias in the user bash session
echo "alias groot2=/home/btdev/Groot2/bin/groot2" >> /home/btdev/.bashrc 
source /home/btdev/.bashrc
groot2 #should start groot2

2. Launch BTROS2 Executor and trigger a tree execution

Having launched already the simulator (step 1)...

Start BTROS2 Executor through:

ros2 launch behaviortree_pyrobosim executor.launch.xml

In another terminal, now you should be able to call:

ros2 action send_goal /pyrobosim_bt_action_server btcpp_ros2_interfaces/action/ExecuteTree "{target_tree: '<your-tree-name>'}"

You can replace <your-tree-name> with Exercise0 to test it out. Please note that the simulator must be started, otherwise the tree will take more time to load (ros2 srv and action will not be found and clients in the tree will timed out).

If you start:

• Simulator
• BTExecutor
• (optional) groot

and you launch the sample tree execution (with Exercise0 tree for instance), the result should look as in the image below.

Pro tip: You can open groot2 in monitor and check out the tree execution real-time by clicking on "Connect".

Acknowledgements

We thank Sebastian Castro for the amazing work on pyrobosim that we extensively have taken leverage of to prepare the material for this workshop.