In the previous chapter, we learned how to use, configure, and explore some specific sensors and actuators that are broadly used in the world of robotics. However, working and programming with the real hardware and robot would be more exciting and compelling for a real-world application, but it is not possible and reasonable for every robotic developer to use a real robot during development. Hence, we will learn how to simulate the physical world and robot.

Simulators are great development tools when we have limited access to a real robot and hardware, which were developed for validating and testing the behavior of algorithms before applying them on a real robot during the development phase.

In this chapter, we will learn how to develop a 3D model of a robot that is required for a real-world application. This includes how to create joints and add texture to a model, as well as how to use a ROS node to control the robot.

We will also introduce Gazebo, a simulator framework that is widely used by the ROS community and already supports several real robots in the simulation. We can use Gazebo to load the 3D models of our robots and simulate their perception and control them in a virtual world. Moreover, we will learn how to use parts of other robots designed by the community, particularly grippers and sensors, such as a laser range finder and a camera.