Research On Key Technologies Of UAV Cluster Networking For Collaborative Control

With the advancement of aviation technology,Unmanned Aerial Vehicle(UAV)cluster for collaborative control have been widely used in both military and civilian fields due to their advantages of information sharing,task coordination,and efficiency multiplication.The cluster forms an Unmanned Aerial Vehicle Ad Hoc Network(UANET)spontaneously,which doesn’t need a fixed central infrastructure,and is flexible and invulnerable.When each node in the UANET performs tasks,in addition to requiring low latency to meet the needs of real-time control and real-time collaboration,it also needs to transmit a large amount of perception information.Therefore,how to achieve efficient utilization of channel resources while maintaining network delay performance is also a big challenge.MAC protocol and routing protocol have an important impact on network throughput and delay performance.Therefore,this paper will study these two types of protocols for UANET with the goal of further reducing delay and improving network throughput,including the following contents:(1)The MAC protocols in the UANET mainly include competition protocols represented by CSMA/CA and scheduling protocols represented by TDMA.Through comparative analysis,the distributed fixed TDMA protocol enables each node to use channel resources in an orderly manner,and it maintains the controllable delay by setting the frame length,which is more suitable as a research basis for the MAC protocol of UANET than the CSMA/CA protocol.The routing protocols in the UANET mainly include three types: proactive routing,reactive routing,and routing based on geographic location information.Through comparative analysis,the GPSR protocol based on geographic location information has lower overhead and faster convergence speed,and is more suitable for highly dynamic UANET.(2)The distributed fixed TDMA protocol lacks certain flexibility in the fixed allocation mechanism of time slot resources,so there is a problem of wasting time slot resources.Some current improved protocols based on distributed fixed TDMA use idle time slots by introducing different mechanisms.However,as the network load increases and the number of idle time slots decreases,the throughput improvement of this method is limited.In order to solve the above problems,a TDMA protocol for time slot reusing is designed for multi-hop scenarios.On the basis of using idle time slots,the protocol introduces a time slot reuse mechanism according to network topology and the transmission direction of data packets,so that the channel utilization rate is further improved.(3)In GPSR routing protocol,the current node selects the neighbor close to the destination node within a single hop range as the next hop destination and completes data transmission.However,in a TDMA network,the characteristics of each node sending data according to the time slot may cause the next hop node to be unable to quickly forward the received data.Aiming at the above problems,this paper designs a Time slot DistanceGPSR(TD-GPSR)protocol,which introduces the "time slot distance".When TD-GPSR performs routing,in addition to considering the spatial distance between the next hop node and the destination node,it also takes into account the "time slot distance" between the next hop node and the current node,and realizes the cross-layer cooperation between the routing protocol and the MAC protocol.Through simulation analysis,TD-GPSR protocol has lower delay and packet loss rate.