Go Chase It

The purpose of this repository is to design and build a mobile robot, and house it in world. Then, program a robot with C++ nodes in ROS to chase a white colored ball!

The steps are listed as summary of tasks.

Description

Inside the Gazebo world one can identify:

Two wheeled Robot with caster.
Sensors (lidar and camera) mounted on the robot.
A white ball that is to be followed by the robot.

Getting Started

Directory structure

.GoChaseIt                              # Go Chase It Project
├── my_robot                            # my_robot package                   
│   ├── launch                          # launch folder for launch files   
│   │   ├── robot_description.launch    # Generate urdf from xacro
│   │   ├── world.launch                # launch Gazebo world along with robot
│   ├── meshes                          # meshes folder for sensors
│   │   ├── hokuyo.dae                  # Hokuyo lidar sensor
│   ├── urdf                            # urdf folder for xarco files
│   │   ├── my_robot.gazebo             # Plugin for sensor/actuator (Camera/Hokuyo lidar/Differential drive)
│   │   ├── my_robot.xacro              # Robot description
│   ├── world                           # world folder for world files
│   │   ├── office.world
│   ├── CMakeLists.txt                  # compiler instructions
│   ├── package.xml                     # package info
├── ball_chaser                         # ball_chaser package                   
│   ├── launch                          # launch folder for launch files   
│   │   ├── ball_chaser.launch
│   ├── src                             # source folder for C++ scripts
│   │   ├── drive_bot.cpp               # Node to command wheel joint velocities to robot
│   │   ├── process_images.cpp          # Node to request drive_bot in the direction of ball
│   ├── srv                             # service folder for ROS services
│   │   ├── DriveToTarget.srv
│   ├── CMakeLists.txt                  # compiler instructions
│   ├── package.xml                     # package info                  
└──

Dependencies

Operating System — Ubuntu Bionic 18.04 LTS or 20.04 LTS (Focal Fossa), and WSL on Windows
Software packages — CMake 2.8 or later, ROS Noetic, Gazebo 11
- Gazebo Classic 11.0 will reach its end of life by Feb 2025.
- ROS Noetic is supported for 20.04 and will reach its end of life in May 2025.

Installing

Install ROS Noetic using Ubuntu/WSL
Install Gazebo using Ubuntu packages
Install ROS Noetic using Robostack for Mac
Install Gazebo on Mac
To verify installation, run

gazebo

How to Run

Update and upgrade the Workspace

sudo apt-get update && sudo apt-get upgrade -y

Create a catkin workspace

$ mkdir -p ~/catkin_ws/src

Navigate to source directory

$ cd ~/catkin_ws/src

Initialize the catkin workspace which will create a CMakeLists.txt file.

catkin_init_workspace

Clone this repository.

git clone https://github.com/sidharth2189/RoboND-GoChaseIt.git

Copy my_robot and ball_chaser packages into the source folder for catkin workspace./catkin_ws/src
Navigate to catkin workspace.

cd ~/catkin_ws/

Build packages.Note that the command is issued from within the top level directory (i.e., within catkin_ws NOT catkin_ws/src)

catkin_make

Source the set up script of the workspace.

source devel/setup.bash

To check for missing package.

rosdep check <package name>

Launch the robot inside the world.

roslaunch my_robot world.launch

Run drive_bot and process_image nodes in another terminal.

cd ~/catkin_ws/
source devel/setup.bash
roslaunch ball_chaser ball_chaser.launch

To visualize the robot’s camera images, camera RGB image topic from RViz may be subscribed. Or the rqt_image_view node can be run in a new terminal as below.

cd ~/catkin_ws/
source devel/setup.bash
rosrun rqt_image_view rqt_image_view

sidharth2189/RoboND-GoChaseIt