BT on ROS 2

BT_ros2 is a demo of how to use Behavior Tree to control AMR. All the examples are tested on our NeuronBot simulation. If you are interested in NeuronBot simulation, please go to see the tutorials: https://github.com/Adlink-ROS/neuronbot2#bring-up-in-simulation

Build

1. git clone the repo.

mkdir -p ~/bt_ros2_ws/src
cd ~/bt_ros2_ws/src
git clone https://github.com/Adlink-ROS/BT_ros2.git

2. Install dependencies

source /opt/ros/<ROS2_DISTRO>/setup.bash
cd ~/bt_ros2_ws
rosdep install --from-paths src --ignore-src -r -y

3. Build

colcon build --symlink-install
# If you want to build with OpenVINO support, add the define
# Remember to source OpenVINO before build
colcon build --symlink-install --cmake-args -DBUILD_OPENVINO=ON

Usage

We will run Gazebo with NeuronBot2 and show simple BT examples.

Basic Example

This example makes NeuronBot2 continuously moving between the pre-defined three goals in bt_nav_mememan.xml.

• Open 1st terminal and run mememan world.

source /opt/ros/<ROS2_DISTRO>/local_setup.bash
source ~/neuronbot2_ros2_ws/install/local_setup.bash
ros2 launch neuronbot2_gazebo neuronbot2_world.launch.py world_model:=mememan_world.model

• Open 2nd terminal and run navigation.

source /opt/ros/<ROS2_DISTRO>/local_setup.bash
source ~/neuronbot2_ros2_ws/install/local_setup.bash
ros2 launch neuronbot2_nav bringup_launch.py map:=$HOME/neuronbot2_ros2_ws/src/neuronbot2/neuronbot2_nav/map/mememan.yaml open_rviz:=true use_sim_time:=true

• Open 3rd termainal and run BT.

source /opt/ros/<ROS2_DISTRO>/local_setup.bash
source ~/bt_ros2_ws/install/local_setup.bash
ros2 launch bt_ros2 bt_ros2.launch.py

Advanced Example - Interrupt

In this example (refer to bt_nav_mememan_interrupt.xml), when BT receives /interrupt_event, which is gohome, then NeuronBot2 will move to Goal_c.

• Open 1st terminal and run mememan world.

source /opt/ros/<ROS2_DISTRO>/local_setup.bash
source ~/neuronbot2_ros2_ws/install/local_setup.bash
ros2 launch neuronbot2_gazebo neuronbot2_world.launch.py world_model:=mememan_world.model

• Open 2nd terminal and run navigation.

source /opt/ros/<ROS2_DISTRO>/local_setup.bash
source ~/neuronbot2_ros2_ws/install/local_setup.bash
ros2 launch neuronbot2_nav bringup_launch.py map:=$HOME/neuronbot2_ros2_ws/src/neuronbot2/neuronbot2_nav/map/mememan.yaml open_rviz:=true use_sim_time:=true

• Open 3rd termainal and run BT.

source /opt/ros/<ROS2_DISTRO>/local_setup.bash
source ~/bt_ros2_ws/install/local_setup.bash
ros2 run bt_ros2 bt_ros2 --ros-args -p bt_xml:=$HOME/bt_ros2_ws/src/BT_ros2/bt_xml/bt_nav_mememan_interrupt.xml

• Open 4th terminal and pub interrupt event.

source /opt/ros/<ROS2_DISTRO>/local_setup.bash
ros2 topic pub -1 /interrupt_event std_msgs/msg/String data:\ \'gohome\'

Advanced Example - Take a snapshot

The demo is to show how to take snapshots with BT example. You need to install OpenVINO and its ROS 2 wrapper before using the example.

• Open 1st terminal and run OpenVINO object detection

# Source ROS 2 environment
# Setup OpenVINO environment and source wrapper
ros2 launch dynamic_vino_sample pipeline_object.launch.py

• Open 2nd terminal and run image_saver
  • If you don't have image_view, please run sudo apt install ros-${ROS_DISTRO}-image-view

# Source ROS 2 environment
ros2 run image_view image_saver image:=ros2_openvino_toolkit/image_rviz

• Open 3rd terminal and run BT

# Source ROS 2 environment
source ~/bt_ros2_ws/install/local_setup.bash
ros2 run bt_ros2 bt_ros2 --ros-args -p bt_xml:=$HOME/bt_ros2_ws/src/BT_ros2/bt_xml/bt_snapshot.xml

Advanced Example - OpenVINO object detection

This demo shows an integrated application with object detection and robot navigation. With different signal triggered by OpenVINO, the robot will navigate to certain position. The objects in the BT file are animals, which are cat, dog, cow.

• Open 1st terminal and run mememan world.

# Source ROS 2 environment
source ~/neuronbot2_ros2_ws/install/local_setup.bash
ros2 launch neuronbot2_gazebo neuronbot2_world.launch.py world_model:=mememan_world.model

• Open 2nd terminal and run OpenVINO object detection

# Source ROS 2 environment
# Setup OpenVINO environment and source wrapper
ros2 launch dynamic_vino_sample pipeline_object.launch.py

• Open 3rd terminal and run navigation.

# Source ROS 2 environment
source ~/neuronbot2_ros2_ws/install/local_setup.bash
ros2 launch neuronbot2_nav bringup_launch.py map:=$HOME/neuronbot2_ros2_ws/src/neuronbot2/neuronbot2_nav/map/mememan.yaml open_rviz:=true use_sim_time:=true

• Open 4th terminal and run BT

# Source ROS 2 environment
# Setup OpenVINO environment and source wrapper
source ~/bt_ros2_ws/install/local_setup.bash
ros2 run bt_ros2 bt_ros2 --ros-args -p bt_xml:=$HOME/bt_ros2_ws/src/BT_ros2/bt_xml/bt_openvino.xml
# An additional bt_xml file is prepared, which switch the action after trigger from navigation to teleop command.
#ros2 run bt_ros2 bt_ros2 --ros-args -p bt_xml:=$HOME/bt_ros2_ws/src/BT_ros2/bt_xml/bt_openvino_teleop.xml

Note

If you want to get the coordinate for navigation, you can run navigation2 and listen to the topic /goal_pose or open rviz2 to monitor tf.

The position and orientation should be put into BT file and the orientation value we use here is Quaternion.

Record X, Y in positoin and Z, W in orientation.

Open xml file in bt_xml and modify robot checkpoint with " X ; Y ; Z ; W " format in SetBlackboard.

If you only have Euler Angle and want to transfer to Quaternion, please refer to online tools, such as https://quaternions.online/