erl_geometry_ros

A ROS package providing geometry utilities and data processing nodes for robotics applications.

erl_geometry_ros is a ROS wrapper package for the erl_geometry library, offering nodes for point cloud processing, 2D simulation data publishing, and LiDAR information extraction. The package supports both ROS1 (Noetic) and ROS2 (Humble) distributions.

Features

• Point Cloud Processing: Load and publish point clouds from various file formats (PCD, PLY, etc.)
• Gazebo Room 2D Simulation: Publish synthetic 2D laser scan data for testing and development
• LiDAR Analysis: Extract angular information (azimuth/elevation ranges) from point cloud data
• ROS Support: Compatible with both ROS1 and ROS2
• Visualization: Pre-configured RViz configurations for data visualization

Getting Started

Create Workspace

mkdir -p <your_workspace>/src && \
vcs import --input https://raw.githubusercontent.com/ExistentialRobotics/erl_geometry/refs/heads/main/erl_geometry_msgs.repos <your_workspace>/src

Prerequisites

• ROS1 Noetic or ROS2 Humble
• C++17 compatible compiler
• CMake 3.24 or higher

Dependencies

This package depends on the following ERL packages:

• erl_cmake_tools
• erl_common
• erl_covariance
• erl_geometry

Standard ROS dependencies:

• geometry_msgs
• nav_msgs
• sensor_msgs
• tf2_ros
• std_msgs

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

Docker Option

The easiest way to get started is to use the provided Docker files, which contains all dependencies.

Building the Package

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

Available Nodes

gazebo_room_2d_node

Publishes synthetic 2D laser scan data from pre-recorded Gazebo simulation data.

Published Topics:

• scan (sensor_msgs/LaserScan): 2D laser scan data
• pose (geometry_msgs/PoseStamped): Robot pose in the map frame
• path (nav_msgs/Path): Robot trajectory

Parameters:

• data_folder (string): Path to the Gazebo data folder (default: "<erl_geometry_pkg>/data/gazebo")
• laser_frame (string): Frame ID for laser data (default: "front_laser")
• map_frame (string): Map frame ID (default: "map")
• topic_name (string): Laser scan topic name (default: "scan")
• publish_rate (double): Publishing frequency in Hz (default: 100.0)

point_cloud_node

Loads and publishes point cloud data from files (PCD, PLY, etc.).

Published Topics:

• point_cloud (sensor_msgs/PointCloud2): Point cloud data

Parameters:

• point_cloud_file (string): Path to the point cloud file
• frame_id (string): Frame ID for the point cloud (default: "map")
• publish_normals (bool): Whether to publish normal vectors (default: false)
• publish_colors (bool): Whether to publish color information (default: true)

get_lidar_info_from_point_cloud

Analyzes point cloud data to extract LiDAR angular information.

Subscribed Topics:

• Point cloud topic (configurable)

Functionality:

• Computes azimuth and elevation ranges from point cloud data
• Outputs angular statistics to console

Usage Examples

Gazebo Room 2D Simulation

Launch the 2D room simulation with visualization:

# ROS1
roslaunch erl_geometry_ros gazebo_room_2d.launch

# ROS2
ros2 launch erl_geometry_ros gazebo_room_2d_launch.py

This will start:

• The gazebo_room_2d_node publishing laser scan data
• Static transform publishers for coordinate frames
• RViz with pre-configured visualization

Cow and Lady Dataset Visualization

Launch the Cow and Lady dataset visualization:

# ROS1
roslaunch erl_geometry_ros cow_and_lady.launch

# ROS2
ros2 launch erl_geometry_ros cow_and_lady_launch.py

Note: You need to set the following environment variables or modify the launch file parameters:

• cow_and_lady_bag: Path to the dataset bag file
• gt_point_cloud_file: Path to the ground truth point cloud file

To run with ROS2, you need to first convert the bag file to a ROS2 compatible format. We provide a tool for this conversion. An alternative tool is rosbags-convert from rosbags.

Point Cloud Publishing

To publish a point cloud from a file:

# ROS1
rosrun erl_geometry_ros point_cloud_node _point_cloud_file:=/path/to/your/pointcloud.pcd _frame_id:=map

# ROS2
ros2 run erl_geometry_ros point_cloud_node --ros-args -p point_cloud_file:=/path/to/your/pointcloud.pcd -p frame_id:=map

RViz Configurations

Pre-configured RViz files are available in the rviz/ directory for ROS1 or rviz2/ for ROS2:

• gazebo_room_2d.rviz: Configuration for 2D simulation visualization
• cow_and_lady.rviz: Configuration for Cow and Lady dataset visualization