Go Chase It Project

This is the 2nd project in the Robotics Software Engineer Nanodegree Program by Udacity.

Project Description

In this project, I created two ROS packages inside my catkin_ws/src:

1. my_robot:
   holds a robot designed with the Unified Robot Description Format, a white-colored ball, and a gazebo world.
2. ball_chaser:
   contains two C++ ROS nodes (drive_bot & process_image) to interact with the robot and make it chase the white ball.
   • drive_bot:
     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.
   • process_image
     reads my robot’s camera image, analyzes it to determine the presence and position of a white ball.
     If a white ball exists in the image, my node requests a service via a client to drive the robot towards it.

Step to test process_image

Step 1 Launch the robot inside the world

$ cd (your workspace)/catkin_ws/  
$ source devel/setup.bash  
$ roslaunch my_robot world.launch

Step 2 Run drive_bot and process_image.cpp

$ cd (your workspace)/catkin_ws/  
$ source devel/setup.bash  
$ roslaunch ball_chaser ball_chaser.launch

Now place the white ball at different positions in front of the robot and see if the robot is capable of chasing the ball.

References

1. The inertia matrix explained: GAZEBO ANSWERS
2. [ROS Projects] – Exploring ROS using a 2 Wheeled Robot: The Construct
3. uos_tools/uos_common_urdf/common.xacro: GitHub
4. List of moments of inertia: Wikipedia