pointcloud_to_grid ROS 2 package

This package converts sensor_msgs/PointCloud2 LIDAR data to both nav_msgs/OccupancyGrid and grid_map_msgs/GridMap 2D map data based on intensity and / or height.

If you would like to use ROS 1 version (melodic, noetic), please go to ROS1 branch.

Build

cd ~/ros2_ws/src 
git clone https://github.com/jkk-research/pointcloud_to_grid -b ros2
cd ~/ros2_ws/ 
colcon build --packages-select pointcloud_to_grid --symlink-install

Don't foget to source ~/ros2_ws/install/setup.bash.

Features

• Few dependencies (ROS 2, PCL, and grid_map_msgs mainly) ROS installation
• Dual output format support: Publishes both nav_msgs/OccupancyGrid and grid_map_msgs/GridMap messages simultaneously
• Simple as possible
• Fast

Conventions & definitions

Getting started

In a new terminal go to your bag folder (e.g. ~/Downloads):

cd ~/Downloads

Download a sample rosbag (~3,3 GB) (TODO: update to ROS 2 `mcap``):

wget https://laesze-my.sharepoint.com/:u:/g/personal/herno_o365_sze_hu/EYl_ahy5pgBBhNHt5ZkiBikBoy_j_x95E96rDtTsxueB_A?download=1 -O leaf-2021-04-23-campus.bag

Play rosbag:

ros2 bag play -l ~/Downloads/leaf-2021-04-23-campus.bag

Start the algorithm in a new terminal :

ros2 launch pointcloud_to_grid demo.launch.py

Alternatively, start with subscribing to /my_custom_cloud_topic:

ros2 launch pointcloud_to_grid demo.launch.py topic:=my_custom_cloud_topic

Start the visualization in a new terminal :

ros2 launch pointcloud_to_grid rviz.launch.py

Dual Output Format Support

The package now supports publishing both nav_msgs/OccupancyGrid and grid_map_msgs/GridMap message types simultaneously. This allows for better integration with different ROS 2 packages that may prefer one format over the other.

New Parameters

In addition to the existing parameters, the following new parameters control the GridMap output topics:

Parameter	Type	Default	Description
mapi_gridmap_topic_name	string	intensity_gridmap	Topic name for intensity GridMap
maph_gridmap_topic_name	string	height_gridmap	Topic name for height GridMap

Output Topics

The node now publishes to four topics simultaneously:

OccupancyGrid format:

• intensity_grid (nav_msgs/OccupancyGrid)
• height_grid (nav_msgs/OccupancyGrid)

GridMap format:

• intensity_gridmap (grid_map_msgs/GridMap)
• height_gridmap (grid_map_msgs/GridMap)

Usage Example

# Launch with custom GridMap topic names
ros2 launch pointcloud_to_grid demo.launch.py topic:=my_pointcloud mapi_gridmap_topic_name:=my_intensity_map maph_gridmap_topic_name:=my_height_map

QoS Configuration

The package is configured to use BEST_EFFORT reliability QoS policy for the input point cloud subscription. This ensures compatibility with typical LiDAR sensor publishers that often use this policy for performance reasons. This prevents QoS compatibility warnings that might appear with the default RELIABLE policy.

Related solutions

• github.com/ANYbotics/grid_map - This is a C++ library with ROS interface to manage two-dimensional grid maps with multiple data layers.
• github.com/306327680/PointCloud-to-grid-map - A similar solution but instead PointCloud2 it uses PointCloud

Remarks

In VS code it is advised to add the following to include path:

${workspaceFolder}/**
/opt/ros/humble/include/**
/usr/include/pcl-1.12/**
/usr/include/eigen3/**

If you are not sure where your header files are use e.g.:

find /usr/include -name point_cloud.h
find /usr/include -name crop_box.h

Cite & paper

If you use any of this code please consider citing TODO: