ros-dds-bridge

Small ROS1 <-> DDS bridge framework (architecture-focused)

Overview

This repository hosts a small bridge node that converts messages between ROS (roscpp) and DDS (eProsima Fast DDS). The current work focuses on a clean architecture so additional bridge implementations (in particular DDS->ROS) can be added easily.

Key design points

• Two clear bridge directions and directories:
  • src/ros_to_dds/ — bridges that subscribe to ROS topics and publish DDS samples.
  • src/dds_to_ros/ — bridges that subscribe to DDS topics and publish ROS messages (future work / placeholder present).
• Direction-prefixed concrete bridge classes to avoid name collisions. Example: ros_to_dds::RosToDdsPoseBridge.
• BridgeManager centralizes creation of (shared) DDS resources (DomainParticipant and Publisher). It manages the lifecycle and initializes registered bridges.
• Bridges accept a set_dds_context(...) call so they can reuse a shared participant/publisher provided by BridgeManager, or create their own participant/publisher as fallback.

Files of interest

• src/BridgeManager.hpp/.cpp — manages bridge registration and shared DDS context.
• src/RosDdsBridge.cpp — main() that creates BridgeManager and registers bridges.
• src/ros_to_dds/ — ROS->DDS bridge interfaces and implementations. Example: RosToDdsPoseBridge.
• src/dds_to_ros/ — DDS->ROS bridge interfaces (skeleton) and place to add implementations later.
• CMakeLists.txt — cmake build. The node is built as RosDdsBridge.

How to add a new bridge

1. Decide the direction:
   • ROS->DDS: create a new class deriving from ros_to_dds::RosToDdsBridge.
   • DDS->ROS: create a new class deriving from dds_to_ros::DdsToRosBridge.
2. Implement ros_topic()/dds_topic() and init() plus set_dds_context(...) if you want to receive the shared participant/publisher/subscriber.
3. In src/RosDdsBridge.cpp register your bridge using:
   • mgr.register_ros_to_dds_bridge(...) or
   • mgr.register_dds_to_ros_bridge(...).
4. Rebuild the package.

Notes / TODOs

• DDS->ROS implementations are intentionally left for later. Current structure supports adding them with minimal friction.
• Decide whether BridgeManager should create a shared Subscriber for DDS->ROS bridges. Right now DDS->ROS bridges can create their own Subscriber.
• There are a few places where ROBOT_ID environment variable is used to name participants. Keep that in mind when running multiple bridge nodes.

Building

This is a catkin-style package (ROS1). Typical build (from workspace root):

# from containing catkin workspace
catkin_make
# or, using colcon/catkin_tools, run the appropriate build command

Running

Set ROBOT_ID before launching (some code paths require it when creating a shared participant):

export ROBOT_ID=my_robot
rosrun ros_dds_bridge RosDdsBridge

If you prefer to use the included ros_dds_bridge.launch, use roslaunch.