3D SLAM and Point Cloud Colourisation

The package implements 3D SLAM using the Rtab-map ROS package on a Jackal UGV. The Jackal is equipped with a Velodyne lidar and a Realsense camera. A point cloud colorization algorithm and an extrinsic calibration package are also developed in the project. A detailed explanation of the project can be found in my portfolio post. The instructions of calibration can be found in the README of the calibration package.

Dependencies

• Jackal
• tf2_ros
• move_base
• rtabmap_ros
• pcl library
• cv_bridge
• velodyne_pointcloud
• realsnese2_camera
• velo2rs

Jackal setup

Please follow the instructions in Mingqing Yuan's repository to setup the Jackal UGV in ROS.

• instructions

In addtion to his instruction

• Include the Realsense bringup launch file to the jackal_bringup launch file.

  • set the "align_depth" argument to be true; this is because the rtabmap requires to input a depth-registered image
  • set the "filters" to be "pointcloud" this is because we need to use "sensor_msgs/PointCloud2" message for the calibration

• In the jackal_control launch file.

  • set the "joystick" to be true to use a PS4 controller
  • set the "joy_dev" to be "/dev/input/js0," which is the port to receive the PS4 controller signal through Bluetooth

3D SLAM

• The rtabmap-related node and the parameter setups are all include in "3d_odom_rtabmap.launch" file for our configurations
• To launch the 3D slam in simulation, in the terminal, run the following command:

roslaunch slam gazebo_simulation.launch use_rtab:=true

• To run the 3D slam in the real Jackal, follow the steps below:
  • turn on your Jackal and connect the PS4 controller through Bluetooth
  • ssh to your Jackal computer
  • source the jackal setup bash "setup_jackal.bash" under the slam package directory
  • run the 3d slam launch file in the terminal:

  roslaunch slam 3d_slam.launch

  • in the client (your personal linux pc), source the pc setup bash "setup_pc.bash" under the slam package directory
  • run the interface launch file by:

  roslaunch slam jackal_interface.launch slam:=true

  • control the Jackal to move around using the PS4 controller and enjoy slamming

Calibration

To calibrate and obtain the extrinsic parameters between lidar and the camera in the real robot, follow the steps below:

• turn on your Jackal and place your target object in the front of the robot
• ssh to your Jackal computer
• source the jackal setup bash "setup_jackal.bash" under the slam package directory
• run the Jackal find points launch file in the terminal:

roslaunch slam jackal_find_points.launch 

• in the client (your personal linux pc), source the pc setup bash "setup_pc.bash" under the slam package directory
• run the interface launch file by:

roslaunch slam jackal_interface.launch calib:=true

• follow the instructions in the README of the calibration package to find and update the reference points
• after collecting and saving all six reference points, run the calibration node to get the extrinsic parameters by:

rosrun velo2rs calibration

• update the static transform in the "jackal_bringup.launch" with the calibrated extrinsic parameters

Point Cloud Colourization

• To run it in simulation, follow the steps below:
  • run the simulation environment by:

  roslaunch slam color_cloud_simulation.launch

  • run the color cloud node by:

  rosrun slam color_cloud

• To run it in the real robot without SLAM, follow the steps below:
  • turn on your Jackal and connect the PS4 controller through Bluetooth
  • ssh to your Jackal computer
  • source the jackal setup bash "setup_jackal.bash" under the slam package directory
  • run the basic setup of the robot by:

  roslaunch slam color_cloud_real.launch

  • run the color cloud node by:

  rosrun slam color_cloud_real

  • in the client (your personal linux pc), source the pc setup bash "setup_pc.bash" under the slam package directory
  • run the interface launch file by:

  roslaunch slam jackal_interface.launch color_cloud:=true

  • use the PS4 controller to move the robot and visualize the colorized cloud in Rviz
• To run it in the real robot with SLAM, follow the steps below:
  • turn on your Jackal and connect the PS4 controller through Bluetooth
  • ssh to your Jackal computer
  • source the jackal setup bash "setup_jackal.bash" under the slam package directory
  • run the 3d slam launch file in the terminal:

  roslaunch slam 3d_slam.launch

  • run the color cloud node by:

  rosrun slam color_cloud_real

  • in the client (your personal linux pc), source the pc setup bash "setup_pc.bash" under the slam package directory
  • run the interface launch file by:

  roslaunch slam jackal_interface.launch slam:=true

  • control the Jackal to move around using the PS4 controller and enjoy slamming with colorized cloud