Robot Bridge Manager Python Package

Overview

This Python package automatically generates a .yaml file specifying a ROS Gazebo bridge. It does so by parsing a URDF (XML) file and looking for custom <bridge> tags within it.

Installation

pip install .

Usage

Defining Bridge Components in URDF

To use this tool, you need to embed <bridge> tags within your URDF file. Each <bridge> tag should define a single ROS-Gazebo bridge.

Example <bridge> tag:

<bridge
  ros_topic="/my_robot/cmd_vel"
  gz_topic="/model/my_robot/cmd_vel"
  ros_type="geometry_msgs/msg/Twist"
  gz_type="gz.msgs.Twist"
  direction="ros_to_gz"
/>

Attributes:

• ros_topic: The ROS 2 topic name.
• gz_topic: The Gazebo topic name.
• ros_type: The ROS 2 message type (e.g., geometry_msgs/msg/Twist).
• gz_type: The Gazebo message type.
• direction: The direction of the bridge. Can be ros_to_gz, gz_to_ros, or bidirectional.

Generating the Bridge YAML

Once your URDF file contains the necessary <bridge> tags, you can use the urdf-bridge-builder command-line tool to generate the bridge.yaml file.

urdf-bridge-builder generate path/to/your_robot.urdf --output bridge.yaml

• path/to/your_robot.urdf: The path to your URDF file.
• --output bridge.yaml (optional): Specifies the output file name for the generated YAML. If not provided, it defaults to bridge.yaml in the current directory.

Example: If my_robot.urdf contains:

<robot name="my_robot">
  <link name="base_link"/>
  <bridge ros_topic="/joint_states" gz_topic="/model/my_robot/joint_states" ros_type="sensor_msgs/msg/JointState" gz_type="gz.msgs.Model" direction="gz_to_ros"/>
  <bridge ros_topic="/cmd_vel" gz_topic="/model/my_robot/cmd_vel" ros_type="geometry_msgs/msg/Twist" gz_type="gz.msgs.Twist" direction="ros_to_gz"/>
</robot>

Running urdf-bridge-builder generate my_robot.urdf will create bridge.yaml:

- ros_topic: /joint_states
  gz_topic: /model/my_robot/joint_states
  ros_type: sensor_msgs/msg/JointState
  gz_type: gz.msgs.Model
  direction: gz_to_ros
- ros_topic: /cmd_vel
  gz_topic: /model/my_robot/cmd_vel
  ros_type: geometry_msgs/msg/Twist
  gz_type: gz.msgs.Twist
  direction: ros_to_gz

This bridge.yaml file can then be used with ros_gz_bridge.

Development

Running Tests

To run the unit tests, ensure you have pytest installed and run it from the project root:

pip install pytest
pytest urdf-bridge-builder/src/tests/