engahmed53 / roboticsnd-go-chase-it

Robotics nanodegree Go-Chase-It project

Go-Chase-It!

This project involves designing a differential drive mobile robot which is able to detect and chase white-colored balls inside a custom Gazebo world.

The mobile robot is designed with the Unified Robot Description Format (URDF) and employs two sensors:

• LiDAR
• Camera

Gazebo plugins are utilized for the differential drive and the sensors. Two nodes are implemented to detect a white ball and to drive the robot around in order to chase the ball.

Key Concepts

Concepts explored in this project:

• Gazebo models and building worlds
• Gazebo plugins
• URDF
• Launch files
• ROS Publishers, Subscribers and Services
• C++

Structure

There are two packages in this project.

• my_robot: This package holds the robot, the white ball and the Gazebo world.

• ball_chaser: The ball_chaser package has two nodes: the drive_bot and process_image.

  • drive_bot: This server node provides a service to drive the robot by controlling its linear x and angular z velocities. This service publishes a message containing the requested robot velocities.
  • process_image: This client node subscribes to the robot's camera images and analyzes each image to determine the presence and position of a white ball. If a white ball exists in the image, the node will request a service via a client to drive the robot towards it.

Technologies

The project is created with:

• ROS Noetic
• Gazebo 11.5.1

Installation

To run this project, you must have ROS and Gazebo installed.

Create a catkin_ws, if you do not already have one.

$ mkdir -p /catkin_ws/src/
$ cd catkin_ws/src/
$ catkin_init_workspace

Clone the project in catkin_ws/src/.

$ git clone https://github.com/EngAhmed53/RoboticsND-Go-Chase-It.git

Build the packages.

$ cd /catkin_ws/
$ catkin_make

Source your environment.

$ source devel/setup.bash

Launch the simulation environment.

$ roslaunch my_robot world.launch

Launch the ball chaser.

In a new terminal (Ctrl+Shift+T), type:

$ source devel/setup.bash
$ roslaunch ball_chaser ball_chaser.launch

Play around!

Pick up the white ball and place it in front of the robot. The robot will start chasing the ball!

License

The contents of this repository are covered under the MIT License.