Research On UAVs Formation Flight Control Based On The Guidance Of Desired Path

As interrelated technologies get prepared,UAVs(Unmanned Aerial Vehicles)have been playing a more and more important role in the national defense industry and the civilian applications.Among that the UAVs formation flight has turned out a dominating research hotpot.In considering the hazard of a single UAV during a task,UAVs formation will consolidate the reliability,enhance the capability and advance the performance of the flight systems.The UAVs formation flights are discussed in the paper,of which the emphases are the formation strategy and the flight co ntroller.Main aspects are as follow:In this paper,the NLGL(Nonlinear Guidance Law)for a single UAV's path following is investigated firstly.After learning the main ideology of NLGL,which is based on the guidance points on the desired path,an improved N LGL method with feedback term is proposed accordingly.The improved one has the ability to compensate for the modeling uncertainty of the UAV,stand against the disturbance of environment,and enhance the precision and the stability of path following for an UAV.Then the existing multi-UAVs formation flight control strategies are put forward and analyzed in detail.The merits of each strategy are discussed as well as the disadvantages.This paper finally adopts the distributed strategy,and uses the leader-follower mode to realize the formation flight,which will guarantee the dependability of the formation controller,and be able to extend the whole formation system when the number of UAVs increases.Meanwhile,the communication and computation loads of the actual system are also reduced.Finally,the multi-UAVs formation flight controller is designed and presented,with the NLGL method,which is based on the guidance points on the desired path.The path following process of the leader vehicle is done well primarily with the N LGL.Then the guidance commands of the follower vehicles will be computed by the NLGL,in considering of the practical states of the UAVs in formation.To intensify the controller,a velocity adjuster is incorporated into the computation of the guidance control commands for fol ower vehicles.Series of experiments are carried out to validate the performance of the improved NLGL method and the formation flight controller.The comparison between NLGL and the PLOS(pure pursuit with line of sight)guidance law indicates the performance of NLGL for path following.And the three UAVs formation flight simulations during different states also testify the validity of the investigated formation flight controller.