erl_common_ros

erl_common_ros is the ROS wrapper of erl_common.

Features

• Clock Synchronization: Programmable clock node for simulation and data replay
• Transform Broadcasting: Convert transform messages to TF broadcasts
• ROS Bridge Support: Tools for bridging between ROS1 and ROS2
• Bag File Conversion: Scripts for converting ROS1 bags to ROS2 format
• Cross-Platform: Compatible with both ROS1 and ROS2

Getting Started

Create Workspace

cd <your_workspace>
mkdir -p src
vcs import --input https://raw.githubusercontent.com/ExistentialRobotics/erl_common_ros/refs/head/main/erl_common_ros.repos src

Prerequisites

• Ubuntu 20.04 for ROS1
• Ubuntu 22.04 or later for ROS2
• ROS1 Noetic or ROS2 Humble or later
• C++17 compatible compiler
• CMake 3.24 or higher

Dependencies

This package depends on the following ERL packages:

• erl_cmake_tools
• erl_common

Standard ROS dependencies:

• geometry_msgs
• tf2_ros
• rosgraph_msgs

# Ubuntu 20.04
wget -qO - https://raw.githubusercontent.com/ExistentialRobotics/erl_common/refs/heads/main/scripts/setup_ubuntu_20.04.bash | bash
# Ubuntu 22.04, 24.04
wget -qO - https://raw.githubusercontent.com/ExistentialRobotics/erl_common/refs/heads/main/scripts/setup_ubuntu_22.04_24.04.bash | bash

We also provide docker files for easy setup.

Building the Package

cd <your_workspace>
# for ROS1
catkin build erl_common_ros
source devel/setup.bash
# for ROS2
colcon build --packages-up-to erl_common_ros
source install/setup.bash

Available Nodes

1. clock_node

Publishes clock messages at a configurable rate for simulation time control.

Published Topics:

• /clock (rosgraph_msgs/Clock): Clock messages for simulation time

Parameters:

• clock_rate (double): Publishing frequency in Hz (default: 100.0)
• start_time (double): Starting time in seconds (default: current time)

Usage:

# ROS1
rosrun erl_common_ros clock_node _clock_rate:=50.0 _start_time:=0.0

# ROS2
ros2 run erl_common_ros clock_node --ros-args -p clock_rate:=50.0 -p start_time:=0.0

2. transform_to_tf_node

Subscribes to transform messages and broadcasts them as TF transforms.

Subscribed Topics:

• transform (geometry_msgs/TransformStamped): Transform messages to broadcast

Parameters:

• transform_topic (string): Input transform topic name (default: "transform")

Usage:

# ROS1
rosrun erl_common_ros transform_to_tf_node _transform_topic:=/my_transform

# ROS2
ros2 run erl_common_ros transform_to_tf_node --ros-args -p transform_topic:=/my_transform

Utility Scripts

The package includes several utility scripts in the scripts/ directory:

1. convert_rosbag_1to2.bash

Converts ROS1 bag files to ROS2 format using rosbags-convert.

Usage:

./scripts/convert_rosbag_1to2.bash input_bag.bag output_directory [topic1 topic2 ...]

2. run_ros1_bridge.bash

Launches the ROS1-ROS2 bridge for cross-version communication.

Usage:

./scripts/run_ros1_bridge.bash

3. run_ros1_core.bash

Starts a ROS1 core with appropriate environment setup.

Usage:

./scripts/run_ros1_core.bash