Step-by-Step Guide to Installing ROS on Your Computer

Understanding ROS and its components

When it comes to developing and programming robotics applications, Robot Operating System (ROS) is one of the most popular choices among robotics enthusiasts because of its ease of use and robust functionality. Unlike traditional operating systems that run on a computer, ROS is a middleware framework that runs on top of a conventional operating system. ROS provides a comprehensive set of libraries, visualizers, and tools to use, test, and develop robotics applications.

The ROS framework is built on a collection of independent software units called packages that break down the complex aspects of robot systems into manageable modules. These packages are carefully designed to carry out recurring tasks and functions, independent of the hardware platform or the operating system. In essence, ROS defines a standard communication protocol or message format between modules, enabling different components of a robot system to exchange data and information seamlessly.

The ROS platform consists of various system components that are essential for development ranging from a communications protocol to visualization framework. In the following section, we will delve into the different ROS components that make up the Robotics Operating System.

ROS Client Libraries

ROS client libraries are the backbone of the entire ROS framework, making it possible to create robust robotics applications by enabling communication between different modules and components. These libraries are available in several programming languages, including C++, Python, and Lisp, making it easy for developers of different backgrounds to work with ROS.

The client libraries provide several frameworks that help in developing complex robotics applications by interfacing with Hardware Abstraction Layers (HAL), Messages, Service, and Parameters. The client libraries also include tools to create and control the overall system, including ROS nodes, which are the software modules that carry out specific tasks that communicate with other nodes in the system.

ROS Nodes

The ROS nodes are vital software units that work together to create robot systems. A node can be thought of as a software module that carries out specific tasks and communicates with other Nodes in the application. The nodes can publish to/subscribe to a topic, which is a channel for communication between nodes. Messages are sent over topics, which are the standard communication protocol used in ROS.

Each node can have its own topic that can either receive information from other nodes or send information to other nodes. By adding or removing nodes in the system, you can change the robot’s behavior, making it perform new tasks or improving existing ones.

ROS Topics

ROS Topics are the messaging protocol that forms the backbone of ROS applications. They are channels for communication between nodes, which are the software modules of the robot system. Nodes send and receive messages over topics, which are the standard means of communication in ROS.

ROS Topics are named buses that are used to transmit data between nodes. Each node communicates with other nodes by publishing or subscribing to a topic. So, one node publishes data to a topic, and other nodes that are subscribed to that topic get the published data. This system allows for an easy-to-use, yet flexible mode of communication between nodes in a ROS application.

ROS Services

Services are similar to topics but require a request and a response message. Using ROS Services, clients can request certain tasks from other nodes, and the server node responds with the results. Services can be used for one-time data transfer between nodes, such as image acquisition or reading a sensor value.

ROS services complement topics by allowing for more complex communication between nodes. The services framework facilitates the communication of data between two nodes in a more structured and organized way than through the use of topics alone.

ROS Parameters

ROS Parameters are a means of storing information that is persistent and globally accessible to all nodes in a system. They are the mechanism to configure a node at runtime, so the operation of the robots is altered in real-time. Parameters often control critical settings that can affect the robot’s overall performance, ranging from motion control parameters to video processing settings.

ROS Parameters provide a central location to store and configure settings that impact all nodes in a system. By allowing global access to these parameters, developers can modify the operation of their robot system without the need to alter multiple separate configurations.

In summary, the ROS framework is built on a collection of independent software units called packages that break down the complex aspects of robot systems into manageable modules. These packages work together using client libraries, which provide frameworks that interface with hardware abstractions, messages, services, and parameters. These modules communicate with each other using the ROS messaging protocol formed by topics and services. Parameters provide a central location for storing persistent variable values within the entire system. By using ROS, developers can build complex robotics applications and manage their communication in a straightforward and robust way.

Preparing your system for ROS installation

If you want to use the Robot Operating System (ROS) framework, you’ll need to prepare your system to run it. Here are some steps you can take to get your system ready for ROS installation.

1. Install Ubuntu Operating System

ROS is designed to run on Ubuntu, so you’ll need to have Ubuntu installed on your computer. If you are not already running Ubuntu, you can download it from the official website. Make sure to select the version that is compatible with the version of ROS that you plan to use.

2. Check System Requirements

Besides installing Ubuntu, you will also have to verify that your system meets the ROS operating requirements. ROS requires at least 2GB RAM and 25GB of hard disk space. Check if your computer meets these requirements before proceeding with the installation, failure to meet these requirements can cause the installation to fail or ROS to work improperly.

3. Update your Operating System

Ensure that your Ubuntu operating system is up-to-date using the command below:

“`
sudo apt-get update
“`

This ensures that you have the latest software packages installed before ROS installation.

4. Configure your sources.list

Add ROS repositories to your sources.list by using this command below:

“`
echo “deb http://packages.ros.org/ros/ubuntu $(lsb_release -sc) main” | sudo tee /etc/apt/sources.list.d/ros-latest.list
“`

The above command will set your computer to accept software from packages.ros.org. ROS has different versions, therefore choose a version from the official website that works with your Ubuntu version.

5. Install ROS

You can install ROS using the following command in the terminal:

“`
sudo apt-get install ros-$DISTRO-ros-base
“`

Where “$DISTRO” is the name of your ROS version. For e.g. for geometric version, the command is:

“`
sudo apt-get install ros-geoemetric-ros-base
“`

This command installs the standard packages that are required to develop and use ROS packages.

6. Initialize rosdep

Rosdep is a package manager that is used to install dependencies. You need to initialize rosdep after installing ROS using the following command:

“`
sudo rosdep init
rosdep update
“`

7. Setup Environment Variables

Add ROS environment variables to your .bashrc file using command:

“`
echo “source /opt/ros/$DISTRO/setup.bash” >> ~/.bashrc
source ~/.bashrc
“`

The above command appends the ROS environment variables to your .bashrc file to automatically set up your environment whenever a new terminal is opened.

After following the steps provided, you are now ready to use ROS on your computer. You can also install additional packages depending on your needs. ROS installation can be complex, but if you follow these steps, you’ll have a working ROS setup in no time.

Installing ROS on Ubuntu or other Linux distributions

Robot Operating System, or ROS, is an open-source robotics software framework that provides a library of tools, algorithms, and drivers for building robotics applications. ROS installation is a straightforward process on Linux distributions, including Ubuntu. This article will guide you through the installation of ROS on Ubuntu or any other Linux distributions.

Prerequisites

In order to install ROS on your machine, the following prerequisites must be met:

1. Ubuntu or any other Linux distribution, we recommend you use Ubuntu 18.04 “Bionic Beaver” LTS version
2. Full Desktop version of Ubuntu, not the Server version
3. Terminal or command line interface
4. Superuser or sudo access to install packages

Step-by-Step Installation of ROS on Ubuntu

Here are the steps to follow to install ROS on Ubuntu:

Step 1: Set up sources and keys

The first step is to add the ROS repository to the sources list and add the ROS key to the system keys:

sudo sh -c 'echo "deb http://packages.ros.org/ros/ubuntu $(lsb_release -sc) main" > /etc/apt/sources.list.d/ros-latest.list'

sudo apt-key adv --keyserver 'hkp://keyserver.ubuntu.com:80' --recv-key 421C365BD9FF1F717815A3895523BAEEB01FA116

Step 2: Installation of ROS

The next step is to update the package list and install ROS:

sudo apt update

sudo apt install ros-melodic-desktop-full

Note that the above command installs the full version of ROS, including all the packages available. You can choose to install a different version of ROS by changing the “melodic” to a different version name. For example, to install ROS Noetic Ninjemys version, replace “melodic” with “noetic”.

Step 3: Initialize rosdep

Rosdep is a package manager that is used to install dependencies for building ROS packages. Initialize rosdep using the following command:

sudo rosdep init

rosdep update

Step 4: Set up the Environment

The next step is to set up the ROS environment variables by adding them to your bashrc file:

echo "source /opt/ros/melodic/setup.bash" >> ~/.bashrc

source ~/.bashrc

Step 5: Verify the Installation

To verify that ROS has been installed correctly, open a new terminal and type:

rosversion -d

If ROS has been installed correctly, this command will output the version of ROS you have installed.

Conclusion

Installing ROS on Ubuntu and other Linux distributions is a simple process that requires few prerequisites and can be completed in just a few steps. After completing the installation, you will have access to a vast library of tools, algorithms, and drivers for building robotics applications.

By following the steps outlined above, you can quickly get started with using ROS on Ubuntu and other Linux distributions for your robotics application development.

ROS Configuration and Environment Setup

Robot Operating System or ROS is an open-source framework designed to aid in the development of robotic software. It is widely used in the robotics community for building robots, drones, and other autonomous vehicles. In this tutorial, we will go through the process of installing ROS in Ubuntu and configuring the environment.

Prerequisites

The first step in installing ROS is to ensure that your system meets the required prerequisites. ROS currently supports Ubuntu distributions, including Ubuntu Mate, Kubuntu, and Lubuntu. You will also need a computer running a 64-bit version of Ubuntu 16.04 LTS or 18.04 LTS. Your system should also have a reasonable amount of RAM, preferably 2GB or more, and a fast internet connection for downloading the required packages.

Installation

The installation process for ROS can be quite complex, but the following steps should guide you:

1. Open a terminal window by pressing Ctrl+Alt+T or by navigating to the terminal application via the Ubuntu Dash.
2. Update the package list and upgrade the system packages by executing the following command:

sudo apt-get update && sudo apt-get upgrade

3. Add the ROS repository to your system. The ROS repository contains all the packages and dependencies required to install ROS. To add the ROS repository, execute the following commands in the terminal window:

sudo sh -c 'echo "deb http://packages.ros.org/ros/ubuntu $(lsb_release -sc) main" > /etc/apt/sources.list.d/ros-latest.list'

sudo apt-key adv --keyserver 'hkp://keyserver.ubuntu.com:80' --recv-key C1CF6E31E6BADE8868B172B4F42ED6FBAB17C654

4. Update the package list again to reflect the changes made to the repository by executing the following command:

sudo apt-get update

5. Install ROS by executing the following command:

sudo apt-get install ros-melodic-desktop-full

This command installs the complete ROS package, including libraries, tools, and other dependencies needed to develop and test your own ROS applications. If you prefer a lightweight installation, you can visit the ROS installation guide to learn how to install specific ROS components.

6. Initialize ROS package

After installation, the next step is to initialize the ROS environment by executing the following command in the terminal window:

echo "source /opt/ros/melodic/setup.bash" >> ~/.bashrc

This command appends the ROS setup file to your .bashrc file, which is executed every time you open a new terminal window. To immediately start using ROS, enter the following command in the terminal window:

source ~/.bashrc

Environment Setup

ROS environment setup involves creating a workspace where you can store and organize your ROS packages. A workspace is a directory where you can keep your own custom packages, as well as third-party packages that you may want to use in your projects. To set up your workspace, follow these steps:

1. Create a workspace directory by executing the following command:

mkdir -p ~/catkin_ws/src

2. Navigate to the created source directory:

cd ~/catkin_ws/src

3. Create a beginner tutorial package by executing the following command:

catkin_create_pkg beginner_tutorials std_msgs rospy roscpp

This command creates a beginner tutorial package with dependencies on the standard ROS messages, rospy, and roscpp packages. You can modify the dependencies as needed.

4. Build the workspace by executing the following command in the catkin workspace directory:

catkin_make

This command compiles the packages in your workspace and generates the necessary files.

5. Source the workspace setup file by executing the following command in the terminal window:

source ~/catkin_ws/devel/setup.bash

This command makes the newly created workspace available for use.

With these steps, you have successfully installed ROS on Ubuntu and configured the environment to start developing your own ROS applications. With the beginner tutorial package, you can begin exploring ROS features and start building your own projects.

Testing your ROS installation with sample programs and tools

After you have successfully installed ROS on your system, it is important to test if everything is working properly. In this section, we will show you how to test your installation using sample programs and tools provided by ROS.

1. Launching ROS master

The first step in testing your ROS installation is to launch the ROS master. The ROS master is a centralized hub that enables communication between different nodes in your ROS system. To launch the ROS master, open a new terminal window and type the following command:

$ roscore

If everything is working properly, you should see a bunch of log messages in the terminal indicating that the ROS master has started successfully.

2. ROS publisher and subscriber

After launching the ROS master, the next step is to test the communication between different nodes using ROS publisher and subscriber. ROS publisher publishes data on a topic and ROS subscriber subscribes to that topic to receive the published data. Let’s create a publisher and subscriber node to test this functionality.

Open a new terminal window and create a new package:

$ cd catkin_ws/src
$ catkin_create_pkg my_demo rospy

This command creates a new package named ‘my_demo’ with rospy as its dependency. Now create a new file named talker.py inside my_demo/src directory and add the following code:

#!/usr/bin/env python

import rospy
from std_msgs.msg import String

def talker():
        pub = rospy.Publisher('chatter', String, queue_size=10)
        rospy.init_node('talker', anonymous=True)
        rate = rospy.Rate(10) # 10hz
        while not rospy.is_shutdown():
            hello_str = "hello world %s" % rospy.get_time()
            rospy.loginfo(hello_str)
            pub.publish(hello_str)
            rate.sleep()

if __name__ == '__main__':
        try:
            talker()
        except rospy.ROSInterruptException:
            pass

Now create a new file named listener.py inside my_demo/src directory and add the following code:

#!/usr/bin/env python

import rospy
from std_msgs.msg import String

def callback(data):
        rospy.loginfo(rospy.get_caller_id() + "I heard %s", data.data)

def listener():
        rospy.init_node('listener', anonymous=True)
        rospy.Subscriber("chatter", String, callback)
        rospy.spin()

if __name__ == '__main__':
        listener()

The talker node publishes a message to the ‘chatter’ topic and the listener node listens to the ‘chatter’ topic and prints the received message to the console. To test this functionality, open a new terminal window and run the following commands:

$ cd catkin_ws
$ catkin_make
$ source devel/setup.bash
$ rosrun my_demo talker.py

In a new terminal window, run the following command to launch the listener:

$ rosrun my_demo listener.py

You should now see the published message “hello world” in the listener terminal window.

3. RQT graph

The ROS visualization tool, RQT graph, gives a graphical representation of all the nodes and topics in your ROS system. It helps you visualize the communication flow between different nodes and topics. To launch RQT graph, make sure you have installed the following packages:

$ sudo apt-get install ros-kinetic-rqt ros-kinetic-rqt-common-plugins

Then, open a new terminal window and run the following command:

$ rosrun rqt_graph rqt_graph

This will open a window displaying the graphical representation of your ROS system.

4. RViz

RViz is a 3D visualization tool provided by ROS that helps you visualize the data published on different topics. It can be used to display robot models, sensor data, and other visualizations. To launch RViz, make sure you have installed the following package:

$ sudo apt-get install ros-kinetic-rviz

Then, open a new terminal window and run the following command:

$ rosrun rviz rviz

This will open the RViz window displaying an empty workspace. To add a visualization, click on the ‘Add’ button on the left-hand side and select the visualization you want to add.

5. ROS bag

ROS bag is a tool provided by ROS that records and plays back all the messages published on different topics. It can be used to test your ROS system in a simulated environment. To record a bag, open a new terminal window and run the following command:

$ rosbag record -a

This will start recording all the messages published on different topics. To stop recording, press Ctrl+C. The recorded messages are stored in a .bag file which you can play back later.

To play back a bag, open a new terminal window and run the following command:

$ rosbag play [name of the bag file].bag

This will play back the recorded messages and you can see how your ROS system behaves in a simulated environment.

In conclusion, testing your ROS installation is an essential step to ensure that everything works properly. By using the sample programs and tools provided by ROS, you can test the communication between different nodes, visualize the data on different topics, and even simulate your ROS system. With the help of these tools, you can avoid unexpected errors and ensure a smooth running of your ROS project.