Dropping this project into your catkin_ws/src/ directory, it will create two
ROS packages: the drive_bot and the ball_chaser. Tthe robot, housed it
inside your/a world, is programmed to chase white-colored balls:
drive_bot:
- my_robot ROS package to holds the robot, a white ball, and the world.
- It is designed as a 4-wheeled skid-steer robot in the Unified Robot Description Format.
- Two sensors are added robot: a lidar and a camera. Gazebo plugins are utilized for the robot’s skid-steer drive, lidar, and camera functionality.
- The robot is housed inside a previously built world.
- A white-colored ball has been added to the world.
- The world.launch file launches the world with the white-colored ball and the robot.
ball_chaser:
- a ball_chaser ROS package holds the C++ nodes.
- A
drive_botC++ node provides a ball_chaser/command_robot service to drive the robot by controlling its linear x and angular z velocities. The service publishes to the wheel joints and return back the requested velocities. - The
process_imageC++ node reads the robot’s camera image, analyzes it to determine the presence and position of a white ball. If a white ball exists in the image, the node requests makes a service request via a client to drive the robot towards it. - The ball_chaser.launch runs both the
drive_botand theprocess_imagenodes.
The usual
# if required
$ mkdir -p <some-path-of-your-choice>/catkin_ws/src
$ cd <some-path-of-your-choice>/catkin_ws/src
$ catkin_init_workspace
Launch the robot witin the world
$ cd /home/workspace/catkin_ws/
$ source devel/setup.bash
$ roslaunch my_robot world.launch
Run drive_bot and process_image
$ cd /home/workspace/catkin_ws/
$ source devel/setup.bash
$ roslaunch ball_chaser ball_chaser.launch
Visualize the robot’s camera images, via subscribing to camera RGB image topic from RViz. Or run the rqt_image_view node:
$ cd /home/workspace/catkin_ws/
$ source devel/setup.bash
$ rosrun rqt_image_view rqt_image_view