Research On Guidance Algorithm Of Ground Target Tracking For UAV Formation

Ground target tracking for UAV formation is one of the fundamental applications of UAVs,which is also a subject of high research value at present.The task of formation tracking executes complexly in the process,in which the design of route planning algorithm,formation maintenance control,tracking guidance law and multi-UAV cooperative guidance law need to be accomplished.In this dissertation,the fixed-wing UAV taken as research object,in order to achieve the ground target tracking for multi-UAV formation,the algorithm design of each phase of formation tracking task is completed.Firstly,the research background and status of UAV formation control and tracking guidance methods are described,and mathematical models of UAVs and ground targets are also established.Assuming that the schemes of target recognition and altitude channel guidance have been designed,the tracking guidance problem in three-dimensional space is transformed into the research in two-dimensional plane.The task process of the ground target tracking for UAV formation is analyzed.Secondly,the typical formation organization and formation construction methods of UAVs are analyzed,and for the task of this dissertation,the formation structure of "Leader-Follower" and centralized formation patterns are adopted.The formation of UAVs suitable for formation search task is designed to enable UAV formation to complete the target search process in response to formation control instructions.In the formation aggregation stage,based on Dubins shortest path theory,in this dissertation a formation route generation algorithm is designed which satisfies the constraints of mission conditions,and a collision avoidance strategy for UAV formation is proposed.In the formation maintenance stage,the possible deviation sources in engineering applications are analyzed,and the formation controllers acting on the lateral and forward channels are designed pertinently.Thirdly,when the UAV formation searches for the ground target,a new tracking guidance law based on range-rate signal and four new cooperative guidance laws based on range information are designed to automatically guide the ground target tracking for UAV formation.In this dissertation,UAV three-degree of freedom model is used to validate the formation route generation algorithm and formation tracking guidance law respectively in the environment of Matlab,and the performance of the algorithm and guidance law are analyzed and evaluated.Finally,based on the existing sample UAVs simulation system,the three-dimensional visual simulation software is designed through the secondary development of Google Earth software interface,and the algorithm of the ground target tracking for UAV formation is synthetically simulated and verified.The simulation results show that flying paths for multi-UAV aggregation can be generated by the formation route algorithm designed in this dissertation,based on the formation controller,the deviation appearing in the formation maintenance phase can be suppressed effectively,the tracking guidance law is designed,which is applicable to the ground target stable tracking for UAV formation,and the cooperative guidance law are adapted to the multi-UAV collaboration,all design objectives are attained.