Robotics lab (221LIA001) : Lab work

Lab 1 : 14/08/25

• Ubuntu 20.04 LTS installation
  • Ubuntu desktop install
• Ubuntu/Linux basics
  • Basic commands -Ubuntu command line tutorial
  • Linux File System/Structure Explained -Linux File System/Structure
• ROS basics
  • ROS installation basics

Tasks expected to be completed before Lab 2

• Install ROS on Windows 11 using Windows Subsystem for Linux 2 (WSL2)
  • Installing Ubuntu 20.04 LTS on Windows using WSL2
  • Installing ROS Noetic on Ubuntu
• Setting up ROS environment on your PC -Setting up ROS environment on your PC
• Navigating the ROS Filesystem -Navigating the ROS Filesystem

  Python Basics Refresher

• Python basics -PyFlo - A Free, Interactive Guide to Python Programming

Lab 2 : 21/08/25

• Completing ROS installation and remaining tasks from lab 1

• ROS basics

• Navigating the ROS Filesystem
  -Navigating the ROS Filesystem
• CMake basics [Lecture]

• Creating a ROS workspace

• Understanding ROS Nodes

  -ROS nodes - Learn about ROS nodes, topics, ROS commands - roscore, rosnode, rosrun

  • Understanding ROS Topics
    -ROS topics -video demo

Lab Task

• Create a new package named lab2_sub_pub in the src folder of your catkin_ws. The package dependencies are std_msgs and rospy
  -Video demo - Creating ROS package using catkin_create_pkg command

Lab 3 : 11/09/25 - Publisher Subscriber

• Understanding ROS Nodes (Review)
  -ROS nodes
  Learn about ROS nodes, topics, ROS commands - roscore, rosnode, rosrun - Understanding ROS Topics
  -ROS topics
  -video demo
• Simple Publisher and Subscriber
  -Simple Publisher and Subscriber
  -Examining the Simple Publisher and Subscriber
  -A ROS publisher node - line by line commented
  -A ROS subsriber node line by line commented

Lab Task

• Create a new package named lab3_sub_pub in the src folder of your catkin_ws. The package dependencies are std_msgs and rospy
  -Video demo - Creating ROS package using catkin_create_pkg command
• Create a simple publisher and Subscriber
• Create three publishers within a ROS node
• Create two ROS nodes that subscribes to the topics published (ROS node1 : subcribes to topic 1 & 3, ROS node 2 : subscribes to topic2)

Assignment 1

• Questions will be shared via Github Classroom

Preparatory work

(To be completed by all students before lab 4)

• GitHub fundamentals
  -GitHub Tutorial - Beginner’s Training Guide
  -installing git on Ubuntu 20.04
  -Git Tutorial for Beginners: Command-Line Fundamentals

Lab 4 : 18/09/25 - Service-Client

• Service and Client nodes
  -Basics of ROS Service-Client (Video )
  -Simple Service and Client nodes
  -Examining the Simple Service and Client
  -Changes to be made in CMakeLists.txt and package.xml files of the Service-Client package
  -Summary of changes to be made to CMakeLists.txt and package.xml
  -ROS Service - Server node (coding) Video tutorial
  -ROS Service - Client node (coding) Video tutorial

  Lab Task

• Create a new package lab4_serv_client
• Create a ROS service that finds the square of the number
• Create a ROS Client that uses the above service
• List the running ROS nodes, topics and services
• Explore details of the nodes using suitable ROS commands

Lab 5 : 25/09/25 - Turtlesim

• Turtlesim
  -Getting Started with Turtlesim
  -Understanding ROS using Turtlesim by Prof. Madhur Behl
  -Madhur Behl, University of Virginia
  -Tutorials Using Turtlesim Scroll to the bottom of the page to find the tutorials
  • Control the turtle with rqt_robot_steering GUI `rosrun rqt_robot_steering rqt_robot_steering`
• Launch files
  -launch files - Chapter from the book ‘A Gentle Introduction to ROS’ link 2
  -Launch multiple nodes using launch file (Video tutorial)

Lab Task

• Create a new package lab5_turtlesim
• Launch turtlesim turtle
  • List all the running topics
  • Using suitable commands find more info about the topic related to turtlesim turtle (cmd_vel, color_sensor, pose)
  • Using suitable commands find more info about the ROS message(s) of the above topics (geometry_msgs/Twist, turtlesim/Color,turtlesim/Pose)
  • Using the above messages control the turtlesim turtle
  • Write a single python script that makes the turtle do the following actions in sequence:
    • Move x units towards top (ensure the turtle does not hit the top wall), make a 90 degree right turn, draw a circle of radius y units, move z units to the right (ensure the turtle does not hit the right wall), move w units towards down, make a 45 degree turn and move to the top by p units and then stop.

Lab 6 : 9/10/25 - URDF

• URDF
  -How do we describe a robot? With URDF!
  -Create a visual model of a robot that you can view in Rviz
• Mobile robot URDF
  -Creating urdf model of a robot (Video demonstration)
  -Adding Physical and Collision Properties to a URDF Model
  -Using Xacro to Clean Up a URDF File
  -ROS mobile robot URDF , Xacros with Meshes(Video demonstration)

  Lab Task

• Create a new workspace _bot
• Source the above workspace to your bashrc below the ros noetic workspace
• Within this workspace create the package _bot_description
• Follow the above tutorials and material and write the urdf description of your bot

Lab 7 : 16/10/25 - Gazebo

• Gazebo
  Gazebo is an open-source 3D robotics simulator
  Read and understand the gazebo ros documentation in the two links below before you install gazebo
  -Which combination of ROS/Gazebo versions to use
  -Installing gazebo_ros_pkgs (ROS 1)

  Navigate your mobile robot (Lab 6 work) in the gazebo world
  To navigate your mobile robot in the gazebo world you may need to install additional controllers and packages (as given below)
  sudo apt-get install ros-kinetic-noetic-ros-pkgs ros-noetic-gazebo-ros-control ros-noetic-ros-control ros-noetic-ros-controllers
  Additional references:
  -Teleop twist keyboard
  -Steer drive controller

Lab Task

• Create a gazebo world for the mobile robot you built in lab 6.
  Building a Gazebo world
• Create a gazebo.launch file to launch the bot in the world you have created. \
• Create Rviz laaunch file for the bot
• Troubleshoot errors referring to online documentation