Migrating Kelo Tulip to ROS2

Migrating Kelo Tulip to ROS2
robotics
ros2
Published

January 13, 2023

Migration of ROS2

  1. As per the blog the migration steps are (ROS2 migration guide)[https://docs.ros.org/en/foxy/The-ROS2-Project/Contributing/Migration-Guide.html]

    • Package manifests
    • Metapackages
    • Message, service, and action definitions
    • Build system
    • Update source code

  2. Step 1 : Package manifests

  3. Migration Gazebo

    • https://github.com/ros-simulation/gazebo_ros_pkgs/wiki

  4. Messages

    • For messages and services replace the message using the formulation below
    • #include <sensor_msgs/JointState.hpp> ➡️ #include <sensor_msgs/msg/joint_state.hpp>
    • #include <nav_msgs/Odometry.hpp> ➡️ #include <nav_msgs/msg/odometry.hpp>
    • You add the msg and in small letters

  5. Main.cpp

    • #include "ros/ros.h" ▶️ #include "rclcpp/rclcpp.hpp"

  6. Launching robot in Gazebo : Error model visalization

For ROS2 usage, by changing the following in any of the cameras' urdf file
<mesh filename="package://realsense2_description/meshes/d415.stl" />
into
<mesh filename="file://$(find realsense2_description)/meshes/d415.stl" />
will resolve the issue, as it will evaluate to the full path when xacro generates the URDF.

  1. Adding laser scanner in gazebo . Errors

    • Used the xacro method from ros1
    • xacro method works but plugins have changed
    • libgazebo_ros_laser.so is now changed to ➡️ libgazebo_ros_ray_sensor.so
    • Also the paraeter to initialize it is different
    • Check the github issue for proper initialization

  2. Ros2 node with both cpp and python then do the following

    • I have a mixed C++/Python package. To install a Python executable in this package, I’ve found it sufficient to do this:
    • Add the Python source file to my_package/scripts
    • Add this line at the top of ^that file: #!/usr/bin/env python3
    • Make it executable with chmod +x
    • Add an empty init.py file in my_package/scripts
    • Add this to CMakeLists: ``` install(PROGRAMS
      scripts/my_python_file.py
      DESTINATION lib/${PROJECT_NAME} )

``` * from https://answers.ros.org/question/299269/ros2-run-python-executable-not-found/

Errors

  1. Starting gazebo in the launch file gives “camera assertion error”
    • The solution is to source Gazebo’s setup file, i.e.: . /usr/share/gazebo/setup.sh
    • https://answers.gazebosim.org//question/28066/is-libgazebo_ros_multicameraso-deprecated/
    • echo "source /usr/share/gazebo/setup.bash" >> ~/.bashrc ▶️ for persistence