Book Image

Learning ROS for Robotics Programming

By : Aaron Martinez, Enrique Fernández
Book Image

Learning ROS for Robotics Programming

By: Aaron Martinez, Enrique Fernández

Overview of this book

<p>Both the amateur and the professional roboticist who has ever tried their hand at robotics programming will have faced with the cumbersome task of starting from scratch, usually reinventing the wheel. ROS comes with a great number of already working functionalities, and this book takes you from the first steps to the most elaborate designs possible within this software framework.</p> <p>"Learning ROS for Robotics Programming" is full of practical examples that will help you to understand the framework from the very beginning. Build your own robot applications in a simulated environment and share your knowledge with the large community supporting ROS.</p> <p>"Learning ROS for Robotics Programming" starts with the basic concepts and usage of ROS in a very straightforward and practical manner. It is a painless introduction to the fascinating world of robotics, covering sensor integration, modeling, simulation, computer vision, and navigation algorithms, among other topics.</p> <p>After the first two chapters, concepts like topics, messages, and nodes will become daily bread. Make your robot see with HD cameras, or navigate avoiding obstacles with range sensors. Furthermore, thanks to the contributions of the vast ROS community, your robot will be able to navigate autonomously, and even recognize and interact with you, in a matter of minutes.</p> <p>"Learning ROS for Robotics Programming" will give you all the background you need to know in order to start in the fascinating world of robotics and program your own robot. Simply, you put the limit!</p>
Table of Contents (16 chapters)
Learning ROS for Robotics Programming
Credits
About the Authors
About the Reviewers
www.PacktPub.com
Preface
Index

Making your own USB camera driver with OpenCV


Although we have the two options previously mentioned, this book comes with its own USB camera driver, implemented on top of OpenCV, using the cv::VideoCapture class. It runs the camera and also allows changing some of its parameters, as long as they are supported. This is very simple and it allows setting the calibration information in the same way as with FireWire cameras. Indeed, with usb_cam this is not possible because the CameraInfo message is not available. Hence, params/usb_cam/logitech.yaml the camera_info_url is not set in the parameters file. With regard to gscam, we will have more control.

We can change the camera configuration and also see how to publish the camera images and information in ROS from scratch. In order to implement a camera driver using OpenCV, we have two options regarding the way in which to read images from the camera. First, we can do a polling according to a given number of frames per second (FPS). Second, we can...