Implementation of distributed consensus with guaranteed real-time communication on an outdoor quadrotor testbed

This article describes the outdoor implementation of a decentralized consensus algorithm which drives multiple quadrotors to an autonomously decided consensus point. The quadrotors use a GPS module for localization and Xbee modules for data exchange in order to autonomously achieve consensus. A novel synchronized, time-slotted and scalable communication protocol is proposed, which avoids data packet collisions and ensures real-time connectivity between agents. This protocol can address changing communication graph topologies and temporary link breaks and additions. The performance of this protocol and its effect on consensus performance is characterized. The consensus and communication experiments are implemented on a testbed of six quadrotors in an outdoor environment. Details regarding the consensus experiment and communication protocol are presented.