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

Plotting scalar data

Scalar data can be easily plotted with generic tools already available in ROS. Even non-scalar data can be plotted, but with each scalar field plotted separately. That is why we talk about scalar data, because most non-scalar structures are better represented with ad-hoc visualizers, some of which we will see later; for instance, images, poses, orientation/attitude, and so on.

Creating a time series plot with rqt_plot

Scalar data can be plotted as a time series over the time provided by the timestamps of the messages. Then, in the y axis, we can plot our scalar data. The tool for doing so is rqt_plot. It has a powerful argument syntax, which allows you to specify several fields of a structured message in a concise manner; we can also add or remove topics or fields manually from the GUI.

To show rqt_plot in action, we are going to use the example4 node, as it publishes a scalar and a vector (non-scalar) in two different topics, which are temp and accel, respectively. The...