Book Image

Effective Robotics Programming with ROS - Third Edition

By : Sánchez, Fernandez Perdomo, Mahtani
Book Image

Effective Robotics Programming with ROS - Third Edition

By: Sánchez, Fernandez Perdomo, Mahtani

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 (12 chapters)
11
Index

Logging messages

It is good practice to include messages that indicate what the program is doing; we must do it without compromising the efficiency of our software and the clarity of its output. In ROS, we have an API which covers both features, built on top of log4cxx (a port of the well-known log4j logger library). In brief, we have several levels of messages, which might have a name (named messages) and depend on a condition or even throttle. All of them have a negligible footprint on performance if they are masked by the current verbosity level (even at compile time). They also have full integration with other ROS tools to visualize and filter the messages from all the nodes running.

Outputting logging messages

ROS comes with a great number of functions/macros to output logging messages. It supports different levels, conditions, STL streams, throttling, and other features that we will see in this section. To start with something simple, an information message is printed with this code...