The Research Of A Gossip-based Communication Mechanism In Swarm Robotic System

The wireless communication mechanism plays an important role inthe cooperation of the swarm robotic system (SRS). The communicationguarantees the information sharing and also affects the cooperationstrategy indirectly. However the classic Mobile Ad Hoc Network(MANET), which has been widely used in the robotic system, requires thesupport of routing protocols. On the other hand, the MANET needs robotsto have a high throughput rate when massive messages are transmitted. Allthese conditions limit the scalability of robots. The communication rangeand computing power of swarm robots are limited. Therefore it’s a littledifficult for them to build a P2P network having the ability of routing. Ifthe format of message is very simple, it will also cause the waste ofbandwidth. What’s more, the dynamic network topology will make themaintenance of route difficult and unpredictable.To solve the problems above, we research about the gossip protocolwhich has been used in the distributed information management. Havingresearched about the protocol, we find that this protocol is specificallyapplied to tasks of the SRS, in which only simple messages are transmitted.To certify the availability of gossip, we design two cooperation algorithmsbased on the protocol: scale statistic and route discovery. The results ofsimulation in Player/Stage show that gossip can utilize the characteristicsof swarm robots to achieve information transmitted quickly. Theredundancy mechanism can guarantee the data reliability. From the resultsof the experiment, we can see that the accuracy rate achieves100%when robots’ scale ranges from20to40. Moreover gossip can avoid the heavycommunication traffic caused by the increase of robots’ size, which meansthat the protocol is scalable.In this paper，we divide the robot into kinds of function modules.Besides, we define the architecture of robots which consists of centralcontrol, drive, sensors and communication modules. According to thedefined architecture, we introduce the self-developed SIMouse-5robots.One of the robot’s important characteristics is using two pieces of halfduplex wireless modules (nRF24L01) to realize the full duplexcommunication. This design greatly improves the efficiency ofcommunication. At last, we demonstrate the two gossip algorithms in thereal platform. The results show the feasibility of the communicationmechanism.