Book Image

Effective Robotics Programming with ROS - Third Edition

By : Anil Mahtani, Luis Sánchez, Aaron Martinez, Enrique Fernandez Perdomo
Book Image

Effective Robotics Programming with ROS - Third Edition

By: Anil Mahtani, Luis Sánchez, Aaron Martinez, Enrique Fernandez Perdomo

Overview of this book

Building and programming a robot can be cumbersome and time-consuming, but not when you have the right collection of tools, libraries, and more importantly expert collaboration. ROS enables collaborative software development and offers an unmatched simulated environment that simplifies the entire robot building process. This book is packed with hands-on examples that will help you program your robot and give you complete solutions using open source ROS libraries and tools. It also shows you how to use virtual machines and Docker containers to simplify the installation of Ubuntu and the ROS framework, so you can start working in an isolated and control environment without changing your regular computer setup. It starts with the installation and basic concepts, then continues with more complex modules available in ROS such as sensors and actuators integration (drivers), navigation and mapping (so you can create an autonomous mobile robot), manipulation, Computer Vision, perception in 3D with PCL, and more. By the end of the book, you’ll be able to leverage all the ROS Kinetic features to build a fully fledged robot for all your needs.
Table of Contents (18 chapters)
Effective Robotics Programming with ROS Third Edition
About the Authors
About the Reviewer
Customer Feedback

Inspecting the system

When our system is running, we might have several nodes and many more topics publishing messages amongst each other. We might also have nodes providing actions or services. For large systems, it is important to have tools that let us see what is running at a given time. ROS provides basic but very powerful tools with this goal in mind, from the CLI to GUI applications.

Listing nodes, topics, services, and parameters from our perspective, we should start with the most basic level of introspection. We are going to see how to obtain the list of nodes running and topics and services available at a given time:

Obtain the list of all


Nodes running

rosnode list

Topics of all nodes running

rostopic list

Services of all nodes running

rosservice list

Parameters on the server

rosparam list

We recommend that you go back to Chapter 2, ROS Architecture and Concepts, to see how these commands also allow us to obtain the message type sent by a particular topic...