On 3D simulators for multi-robot systems in ROS: MORSE or Gazebo?

Realistically simulating a population of robots has been an important subject to the robotics community for the last couple of decades. Multi-robot systems are often challenging to deploy in the real world due to the complexity involved, and researchers often develop and validate coordination mechanisms and collaborative robotic behavior preliminarily in simulations. Thus, choosing a useful, flexible and realistic simulator becomes an important task. In this paper, we overview several 3D multi-robot simulators, focusing on those that support the Robot Operating System (ROS). We also provide a comparative analysis, discussing two popular open-source 3D simulators compatible with ROS - MORSE and Gazebo -, using a multi-robot patrolling application, i.e. a distributed security task, as a case study.