Research On Networking Techniques Of Unmanned Aerial Vehicle Formation

With the development of wireless communication and electronic technology,Un-manned Aerial Vehicles(UAVs)have been gradually applied in various fields because of its high flexibility,strong autonomy and easy deployment,such as reconnaissance,search and rescue,and agricultural remote sensing.Cooperative operation of multiple UAVs can make up for the limited capability of a single UAV,that makes performing tasks more effectively with better fault tolerance,which has attracted wide attention from researchers.Formations are the main form of UAV cooperative operation,and UAV ad hoc network is an effective technique to achieve the formation control.Ad-ditionally,clustering techniques are important to manage and control UAV ad hoc net-works.Area coverage is an important and common task requirement for the UAVs’cooperative operation in a region.The improvement of coverage efficiency requires UAVs to be dispersed as far as possible,which could affect the communication be-tween UAVs.This will bring new problems to the networking and clustering of UAVs.Therefore,the networking techniques of UAV formation are studied in this paper,and the clustering mechanisms for UAV ad hoc networks are designed for area coverage tasks.The main works are as follows:1)For UAV ad hoc networks,the formation control models of UAV are analyzed and summarized.The five formation control strategies(potential function-based,leader-follower-based,virtual structure-based,consensus-based and behavior-based strategy)are analyzed from three aspects:formation maintenance and reconfigura-tion,mission update,and formation reliability,in terms of the features and require-ments for the communication and networking.2)Based on the idea of the virtual forces and leader-follower,a mobility control based clustering mechanism is proposed for area coverage tasks of UAV ad hoc networks.The design of virtual forces takes into account both the connection and coverage overlap between UAVs.Based on that,the out-cluster,intra-cluster and inter-cluster mobility controls are designed respectively with respect to different nodes.The simulation results show that the coverage performance and the stability of clusters can be greatly improved while keeping high network connectivity.3)Considering the constraints of delays between nodes,the multi-hop delay model between nodes of UAV is built firstly.And then a joint optimization problem of clustering,relative positions and transmit powers with delay constraints for max-imizing coverage efficiency is formulated.To solve this problem,an iterative al-gorithm is presented based on the penalty function method and block coordinate descent algorithm.And its convergence is proven.The simulation is conducted for the coverage-efficient clustering mechanism based on the algorithm.The results show that the proposed approach can optimize effectively the formation structure and coverage efficiency while ensuring the delay constraints.Furthermore,the im-pacts on the system performances of the coverage radius,delay constraint,transmit power and interference rate are also presented.