The Research On Optimization Technology In Cooperative Formation Rendezvous Of Multi-UAVs

With the higher mission requirements of modern warfare to UAVs with inherent performance constraints,the multi-UAVs cooperative formation flight(CFF)has been more and more important.As the prerequisite of CFF,the formation rendezvous of multi-UAVs has been the focus of scholars’ study.In this paper,the cooperative formation rendezvous of multi-UAVs has been analyzed,and the optimization schemes has been proposed based on the study of path planning,time coordination,real-time obstacle avoidance and real-time path adjustment.To solve the problem of path planning,an improved cellular genetic algor ithm(CGA)– talent introduction cellular genetic algor ithm(TCGA)is proposed.The improvement thinking and operating steps of the algorithm are introduced in detail,and the testing and analysis of the performance proved the effectiveness of the algorithm.Then,the detailed steps of path planning based on TCGA are given,includeing the production of initial path,the design of objective function,operations of genetic evolution and the smoothing of final path,with the corresponding optimization schemes.To solve the problem of time coordination,2 strategies are proposed.In the alternative path strategy,the cost of all pathes can take minimum value when the trategy is feasible.In the second planning strategy,the air-ranges and velocities of all UAVs can be identical.In order to adjusting the speeds of all UAVs in real time,a speed adjustment strategy is proposed.Further more,a improve speed adjustment strategy is also proposed used under the communication failure.To solve the problem of real-time obstacle avoidance,a strategy based on logistic regression(LR)curve is proposed.The smoothness and sharp-adjustablility of LR curve has proved the feasibility of its application in obstacle avoidance.The selection condition of curve parameters and the design methods of LR curve under various conditions have been given.To solve the problem of real-time path adjustment under the limit of speed adjustment strategy,a path adjustment strategy based on muti-circular pathes is proposed.The time coordination can be satisfied by the strategy,so does the speed coordination.To track the muti-circular path expediently,a path-tracking strategy based on time varying vector field is proposed.The construction method of the time varying vector field is provided and the stability is also proved.Finally,the validity and feasibility of all the optimization schemes proposed in this paper is proved by the simulation of the cooperative formation rendezvous of multi-UAVs.