Book Image

Mastering ROS for Robotics Programming - Second Edition

By : Jonathan Cacace, Lentin Joseph
Book Image

Mastering ROS for Robotics Programming - Second Edition

By: Jonathan Cacace, Lentin Joseph

Overview of this book

In this day and age, robotics has been gaining a lot of traction in various industries where consistency and perfection matter. Automation is achieved via robotic applications and various platforms that support robotics. The Robot Operating System (ROS) is a modular software platform to develop generic robotic applications. This book focuses on the most stable release of ROS (Kinetic Kame), discusses advanced concepts, and effectively teaches you programming using ROS. We begin with aninformative overview of the ROS framework, which will give you a clear idea of how ROS works. During the course of this book, you’ll learn to build models of complex robots, and simulate and interface the robot using the ROS MoveIt! motion planning library and ROS navigation stacks. Learn to leverage several ROS packages to embrace your robot models. After covering robot manipulation and navigation, you’ll get to grips with the interfacing I/O boards, sensors, and actuators of ROS. Vision sensors are a key component of robots, and an entire chapter is dedicated to the vision sensor and image elaboration, its interface in ROS and programming. You’ll also understand the hardware interface and simulation of complex robots to ROS and ROS Industrial. At the end of this book, you’ll discover the best practices to follow when programming using ROS.
Table of Contents (22 chapters)
Title Page
Copyright and Credits
www.PacktPub.com
Contributors
Preface
Index

Explaining the URDF file


When we check the code, we can add a <robot> tag at the top of the description:

<?xml version="1.0"?> 
<robot name="pan_tilt"> 

The <robot> tag defines the name of the robot that we are going to create. Here, we named the robot pan_tilt.

If we check the sections after the <robot> tag definition, we can see link and joint definitions of the pan-and-tilt mechanism:

  <link name="base_link"> 
    <visual> 
      <geometry> 
      <cylinder length="0.01" radius="0.2"/> 
      </geometry> 
      <origin rpy="0 0 0" xyz="0 0 0"/> 
      <material name="yellow"> 
        <color rgba="1 1 0 1"/> 
      </material> 
    </visual> 
  </link> 

The preceding code snippet is the base_link definition of the pan-and-tilt mechanism. The <visual> tag describes the visual appearance of the link, which is shown on the robot simulation. We can define the link geometry (cylinder, box, sphere...