A Service Oriented Framework for Wireless Communication in Mobile Multi Robot Systems

Multi robot systems (MRS) have been an active research area for many years. With the robot systems leaving the laboratory environment, the aspect of wireless communication is getting more important. Especially in multi robot systems wireless communication is crucial, but existing middleware for robot systems does not regard the challenges of wireless communication. Among other aspects the fluctuation of link delay, bandwidth and availability is characteristic for wireless communication. A communication system in a multi robot system must be capable to manage these challenges. Another issue is efficient point to multipoint (multicast) communication. This allows the availability of the same data to multiple recipients without an unnecessary high increase of network load compared to unicast communication schemes. We therefore propose a multicast communication framework for a multi robot system based on wireless communication. The framework is organised in two parts. The first part is a general framework for a wireless multicast communication protocol, which is optimized to offer efficient multicast communication capabilities on wireless networks and takes the available link qualities into account. The second part is a framework for a robot middleware, which benefits from the multicast communication optimizations of the first part. The framework assumes unreliable communication, thus taking fluctuating link qualities into account. Both parts are already implemented on a real system and are used in an experimental multi robot system.