ABSTRACT
This chapter introduces simulation in robot operating system (ROS), starting with a simple two-dimensional mobile-robot simulator and extending to Gazebo-a powerful dynamic simulator. It describes robot modeling in unified robot description format (URDF). An important difference of the URDF model in Gazebo versus the simple two-dimensional robot simulator (STDR) simulator is that the Gazebo simulation includes physics. Inertias, friction, controller dynamics and actuator saturation are taken into account. Modeling details are organized within three broad categories: a dynamic model, a collision model and a visual model. A common default world model consists only of a flat ground plane oriented perpendicular to the direction of gravity. The mobile-robot simulation can be made more interesting by introducing elements in the world model. Displaying a high-fidelity model is less demanding than computing collisions using a model with a large number of facets. Our one-DOF minimal robot URDF now contains kinematic, inertial, visual and collision information.
