The goal of this challenge-based learning (CBL) course is to collaboratively create a cyber-physical system for mobile robots, using digital twins technology. This system is designed to be accessible to a group of target users, e.g., warehouse operators and elderly home caretakers. As a result, a virtual environment should be created based on a physical environment in which a real robot is located. This virtual environment contains a virtual version of our real-life robot as well. These two environments (and the robots) provide at least two different functionalities: (i) they have bidirectional communication between them, and (ii) their live status should be synchronized as well. For example, if the physical robot were to be moved, then the virtual robot should move to the same position, and vice versa. In this course, you will experiment with Python PL (and C# PL), Robot Operating System (ROS), a ROS Visualization tool (RViz), a 3D robotic simulator (Gazebo/Unity Game Engine), and TurtleBot3. You should illustrate the usefulness of your work by demonstrating how the virtual environment has been designed and developed to mimic the real-life environment and help the group of target users. The final outcome should be presented in a written report and an on-campus (and video) presentation