If you’re new to ROS and want to learn how to work with the software, you can start with a simple tutorial. The main components of this type of tutorial are topics, Nodes, and Tools. After reading the tutorial, you should be able to work with the program on your PC.
Nodes
In this ROS tutorial, we will learn about the concept of nodes. Nodes are objects that communicate with each other using the ROS language. A node can be written in any language, although Python and C++ are the most common languages used. Some libraries let you use other languages.
When starting a node, it needs to connect to the master. This can be done with Ctrl+C. You must also make sure that the ROS master is still running. This is a good workflow. In addition, you can open terminals and use the master to run ROS. However, remember that all ROS nodes connect to the master when they start. ROS will not try to reconnect if the connection is broken. If you terminate the roscore, you will also block all new connections.
The tutorial also introduces the concept of ROS parameters and services. It also introduces the rosservice command-line tool. The tutorial shows you how to create subscriber and publisher nodes in C++ and Python. This way, you can create your service network and learn the language practically. As you continue to learn, don’t forget to apply the concepts to an actual robotics project.
The tutorial also explains how to set up a workspace in ROS. It also describes ROS package structure, code sharing, and layering concepts.
Topics
In this Ros tutorial, you will learn about topics. A topic is a data packet multiple nodes can read and write. Each message type has a different format and structure. For example, a message type called velocity will publish commands at a rate of 1 Hz. Each message type has an identifier that can be used to identify a particular topic.
In ROS, a topic is like an organ of the system. It defines what types of data a node can publish and receive. For example, a robot that can see images must access the camera/image_raw topic. Each topic has an associated subscriber, a process, or an executable program that reads data from the topic. The subscriber cannot publish the data itself.
Topics communicate by sending ROS messages between nodes. A publisher sends a message to subscribers to publish data on a topic. To subscribe to a topic, one uses the rostopic tool. This tool returns the list of active topics. You can also use the rostopic tool to read data about a topic.
The ROS tutorial uses the R language. Topics are the base of most ROS operations. They are used to create nodes, messages, and services. The code for this tutorial is in the src/ros_basics/talker_listener package of gaitech_edu.
Tools
Tools in ROS include catkin, a build system that automates the development process for ROS applications. This custom build system is based on the CMake workflow and adds automatic package infrastructure and support for building multiple projects simultaneously. This tutorial will show you how to install and use catkin. Before starting, ensure you’ve downloaded the latest Ubuntu version and set up your workspace folders.
Before starting the tutorial, you should understand the basics of C++, Git, and the ROS build system. In addition, you should be familiar with the locations of the different components of the toolchain. The commands you need to execute to generate an executable file are well-defined, but they may differ depending on your process. To demonstrate the differences between methods, we’ll use the Hello, world! C++ program, a gentle introduction to the catkin tutorial.
Besides the tutorial itself, there are other resources online. You can find video tutorials made by individuals and institutions. You can also look for an official forum, ROS answers. This forum is used by many universities, including HP, 3M, and Softbank. It is also a great place to ask questions about ROS and read other people’s answers.
Tools in ROS are available in a wide variety of packages. These tools are designed to facilitate the development of complex robotic systems. You can learn about these tools using the tutorials provided by Husarion Robotics.
Books
ROS is a programming language that allows robots to communicate with one another via sensors. It can also manipulate an abstract data stream without needing hardware drivers. This book aims to provide complete coverage of the ROS programming language. It will cover the basic concepts and advanced research papers that make ROS an excellent choice for robotics applications. It will also include working code to help readers understand the concepts presented in the book.
Currently, there are eight books available in the ROS tutorial. You should start from the Introduction page and move through the Packages section. The end of each chapter also includes a Recommended Next Step. Cheatsheets are also provided to aid readers. The authors wrote the tutorial themselves after they learned ROS. This means they took the time to document the problems and questions they encountered while learning the programming language.
Another great resource is the Open Robotics website, which is available in many languages. It contains documentation on the ROS programming language and details on installing it. These guides are also free and can be used by anyone who wants to learn more about ROS. The website offers a variety of tutorials in multiple languages. These tutorials follow the same philosophy as traditional academic learning materials. They begin by explaining the concepts one by one. However, navigating the Open Robotics website can be challenging and requires patience and some time before you can grasp the spirit of ROS.
Another important factor to consider is the book’s content. A good book should provide step-by-step instructions and a chance to experiment with the language. It should also present real-world examples and emphasize the similarities between robotic systems.
Forum
The Ros Tutorial Forum is great for asking questions, sharing ideas, and learning how to code in R. The site has a very friendly community, and many users are eager to help you. You can find posts from newbies to experienced programmers as well. There are a lot of helpful resources, such as the Ros documentation, to help you get started with the language.
