Store-Carry and Forward-Type M2M Communication Protocol Enabling Guide Robots to Work together and the Method of Identifying Malfunctioning Robots Using the Byzantine Algorithm

Abstract: This paper concerns a service in which multiple guide robots in an area display arrows to guide individual users to their destinations. It proposes a method of identifying malfunctioning robots and robots that give wrong directions to users. In this method, users’ mobile terminals and robots form a store-carry and forward-type M2M communication network, and a distributed cooperative protocol is used to enable robots to share information and identify malfunctioning robots using the Byzantine algorithm. The robots do not directly communicate with each other, but through users’ mobile terminals. We have introduced the concept of the quasi-synchronous number, so whether a certain robot is malfunctioning can be determined even when items of information held by all of the robots are not synchronized. Using simulation, we have evaluated the proposed method in terms of the rate of identifying malfunctioning robots, the rate of reaching the destination and the average length of time to reach the destination.