Book Image

ROS Robotics Projects - Second Edition

By : Ramkumar Gandhinathan
Book Image

ROS Robotics Projects - Second Edition

By: Ramkumar Gandhinathan

Overview of this book

Nowadays, heavy industrial robots placed in workcells are being replaced by new age robots called cobots, which don't need workcells. They are used in manufacturing, retail, banks, energy, and healthcare, among other domains. One of the major reasons for this rapid growth in the robotics market is the introduction of an open source robotics framework called the Robot Operating System (ROS). This book covers projects in the latest ROS distribution, ROS Melodic Morenia with Ubuntu Bionic (18.04). Starting with the fundamentals, this updated edition of ROS Robotics Projects introduces you to ROS-2 and helps you understand how it is different from ROS-1. You'll be able to model and build an industrial mobile manipulator in ROS and simulate it in Gazebo 9. You'll then gain insights into handling complex robot applications using state machines and working with multiple robots at a time. This ROS book also introduces you to new and popular hardware such as Nvidia's Jetson Nano, Asus Tinker Board, and Beaglebone Black, and allows you to explore interfacing with ROS. You'll learn as you build interesting ROS projects such as self-driving cars, making use of deep learning, reinforcement learning, and other key AI concepts. By the end of the book, you'll have gained the confidence to build interesting and intricate projects with ROS.
Table of Contents (14 chapters)

Setting up the ROS workspace

After setting up ROS on a real PC, VirtualBox, or Docker, the next step is to create a workspace in ROS. The ROS workspace is a place where we keep ROS packages. In the latest ROS distribution, we use a catkin-based workspace to build and install ROS packages. The catkin system (http://wiki.ros.org/catkin) is the official build system of ROS, which helps us build the source code into a target executable or libraries inside the ROS workspace.

Building an ROS workspace is an easy task; just open a Terminal and follow these instructions:

  1. The first step is to create an empty workspace folder and another folder called src to store the ROS package in. The following command will do this for us. The workspace folder name here is catkin_ws:
$ mkdir -p catkin_ws/src
  1. Switch to the src folder and execute the catkin_init_workspace command. This command will initialize a catkin workspace in the current src folder. We can now start creating packages inside the src folder:
$ cd ~/catkin_ws/src 
$ catkin_init_workspace
  1. After initializing the catkin workspace, we can build the packages inside the workspace using the catkin_make command. We can also build the workspace without any packages:
$ cd ~/catkin_ws/ 
$ catkin_make
  1. This will create additional folders called build and devel inside the ROS workspace:
The catkin workspace folders
  1. Once you've built the workspace, to access packages inside the workspace, we should add the workspace environment to our .bashrc file using the following command:
$ echo "source ~/catkin_ws/devel/setup.bash" >> ~/.bashrc 
$ source ~/.bashrc
  1. When everything is done, you can verify that everything is correct by executing the following command:
$ echo $ROS_PACKAGE_PATH

This command will print the entire ROS package path. If your workspace path is in the output, you are done:

The ROS package path

You will see that two locations are sourced as ROS_PACKAGE_PATH. The former is the recent edition we made in step 5 and the latter is the actual ROS installed packages folder. With this, we have set up the ROS workspace. We will now look at the different opportunities for ROS in industries and research.