nvblox_ROS1

This is the ROS1 wrapper of nvblox, intended to make nvblox usable for the wider robotics community (especially for research). This is a work in progress by Turcan Tuna and Helen Oleynikova.

See the TODO list for a complete list.

Overview

Isaac ROS Nvblox contains ROS 1 packages for 3D reconstruction. The mapping pipeline is mainly designed to work with stereo cameras, which provide a depth image, and the corresponding pose uses GPU acceleration to compute 3D reconstruction and 2D costmaps using nvblox. However, this ROS 1 wrapper also supports LiDAR point cloud input.

nvblox_ros1 builds the reconstructed map in the form of a TSDF (Truncated Signed Distance Function) stored in a 3D voxel grid. This approach is similar to 3D occupancy grid mapping approaches in which occupancy probabilities are stored at each voxel. However, TSDF-based approaches like nvblox store the (signed) distance to the closest surface at each voxel. The surface of the environment can then be extracted as the zero-level set of this voxelized function. Typically, TSDF-based reconstructions provide higher quality surface reconstructions.

In addition to their use in reconstruction, distance fields are also useful for path planning because they provide an immediate means of checking whether potential future robot positions are in collision.

People are common obstacles for mobile robots, and while part of a costmap, people should not be part of the 3D reconstruction. Planners that provide behavioral awareness by navigating differently depending on their proximity to people, benefit from a costmap for people. Person segmentation is computed using the color image, with the resulting mask applied to the depth image separating depth into scene depth and person depth images. The scene depth image is forwarded to TSDF mapping as explained above, the depth image for people is processed to an occupancy grid map.

To relax the assumption that occupancy grid maps only capture static objects, Nvblox applies an occupancy decay step. At a fixed frequency, all voxel occupancy probabilities are decayed towards 0.5 over time. This means that the state of the map (occupied or free) becomes less certain after it has fallen out of the field of view, until it becomes unknown (0.5 occupancy probability).

Table of Contents

• nvblox_ROS1
  • Overview
  • Table of Contents
  • Latest Update
  • Supported Platforms
• Installation
  • Docker
  • Native Install
• Details
  • Packages Overview
  • ROS 1 Parameters
  • ROS 1 Topics and Services
  • Troubleshooting
  • Updates

Latest Update

Update 2023-07-01: Adaptations from ROS 2 to ROS 1.

Supported Platforms

This package is designed and tested to be compatible with ROS 1 Noetic running on Jetson or an x86_64 system with an NVIDIA GPU.

Note: Versions of ROS 1 earlier than Noetic are not tested.

Installation

There’s 2 options: docker

Docker

To simplify development, we strongly recommend using the docker images in the docker subfolder

First check out this repo into ~/nvblox_ws/src/ and create ~/data to store data:

mkdir -p ~/nvblox_ws/src/
mkdir -p ~/data
cd ~/nvblox_ws/src/
git clone https://github.com/ethz-asl/nvblox_ros1.git
cd nvblox_ros1
git submodule update --init --recursive

Then build the docker using:

cd ~/nvblox_ws/src/nvblox_ros1/docker
./run_docker.sh -b

Within the docker, make sure to set up the workspace with:

cd ~/nvblox_ws/
catkin init
catkin config --extend /opt/ros/noetic
catkin config --cmake-args -DCMAKE_BUILD_TYPE=Release
catkin build
echo "source ~/nvblox_ws/devel/setup.bash" >> ~/.bashrc

For future iterations you can run it with just:

./run_docker.sh

(Check out ./run_docker.sh -h for more settings, such as the docker name).

To launch additional terminal sessions into the docker, use:

docker exec -it nvblox bash

Native Install

This is meant for Ubuntu 20.04 and will not work on other versions. Use the docker instead.

First, install ROS1 noetic, preferably desktop-full, following instructions here: ROS installation

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