Jetbot-ros2

explore_lite.mp4

This is an implementation of a mobile robot in ros2. The software includes the following functionalities:

• Teleoperation through websockets with live video feed using webrtc (aiortc).

• Integration of Intel realsense d435 and t265 cameras for depth estimation and localization respectively.

• Autonomous Navigation using Nav2

• Autonomous Exploration using m-explore

• 2D SLAM with slam-toolbox.

• 3D SLAM using rtabmap.

I used the Xiaor Geek Jetbot as a base platform and modified it to include a wide-angle camera, as well as the Intel Realsense d435 and t265.

Requirements

• ROS2 eloquent.
• librealsense2.
• Motor Drivers - In this case, installed from the jetbot's repository.

Installation

1. Clone this repo and its submodules.

   git clone --recurse-submodules https://github.com/jdgalviss/jetbot-ros2.git

2. Clone additional thirdparty packages

   1. SLAM-TOOLBOX

      cd jetbot-ros2/dev_ws/src
      git clone -b eloquent-devel git@github.com:stevemacenski/slam_toolbox.git 

   2. Navigation2

      git clone https://github.com/ros-planning/navigation2.git --branch eloquent-devel

   3. m-explore

      git clone -b eloquent https://github.com/robo-friends/m-explore-ros2.git

   4. BehaviorTree.CPP

      git clone https://github.com/BehaviorTree/BehaviorTree.CPP.git
      cd BehaviorTree.CPP
      git checkout 3.5.1
      cd ../..

3. Copy our modified files

   cd thirdparty_files
   source copy_files.sh
   cd ../..

Teleoperation support

4. Install aiortc for webrtc support.

   pip3 install crc32c==2.0
   pip3 install aiortc==0.9.28
   pip3 install aiohttp==3.6.2

5. Install pyfakewebcam so that camera frames can be modified inside a ROS2 node and then shared through webrtc:

   apt-get install v4l2loopback-utils
   pip3 install pyfakewebcam==0.1.0

6. Write a service that creates fake webcam devices that can be used to share camera frames.

   gedit /etc/rc.local

   Copy and paste in file:

   #!/bin/sh -e
   modprobe v4l2loopback devices=2 # will create two fake webcam devices
   exit 0

   Save the file and make it executable with this command:

   chmod +x /etc/rc.local

SLAM Support

Install rtabmap and rtabmap_ros following these instructions in the branch ros2.

Build ros 2 workspace

cd dev_ws
rosdep install -y -r -q --from-paths src --ignore-src --rosdistro eloquent
colcon build --symlink-install

Run

Teleoperation

1. Run local teleoperation server.

   python3 local_server/webcam.py

   In a browser, open the teleoperation interface by going to: <jetson_nano's ip-address>:8080

2. In a new terminal, run the motion control launchfile to start streaming video and receiving motion commands.

   ros2 launch motion_control jetbot_launch.py

Navigation

3. In a new terminal, run nav2

   ros2 launch nav2_bringup nav2_navigation_launch.py

SLAM

5. To Run SLAM.
   • For 2D-SLAM, in another terminal:

     ros2 launch realsense_ros2 realsense_launch.py

     In another terminal:

     ros2 launch slam_toolbox online_async_launch.py

   • For 3D-SLAM, in another terminal:

   ros2 launch realsense_ros2 slam_rtabmap_launch.py

   3D Dense SLAM is too resource consuming for the Jetson Nano, in this case it is recommended to run it on a remote host. For this, simply set the same DOMAIN_ID on both the Jetson Nano and the remote host. (e.g. export DOMAIN_ID=0) and run the cameras in the Jetson Nano:

   ros2 launch realsense_ros2 realsense_launch.py

   Comment the nodes corresponding to the cameras on the host and run the rtabmap launch:

   ros2 launch realsense_ros2 slam_rtabmap_launch.py

Exploration

4. In a new terminal, run explore_lite

   ros2 run explore_lite explore --ros-args -p costmap_topic:=/map -p visualize:=true -p use_sim_time:=false -p min_frontier_size:=0.4 -p planner_frequency:=0.5

Some Results

Video

explore_lite.mp4