Adaptive Control Based Formation Control Technology For Unmanned Aerial Vehicles

Compared with single unmanned aerial vehicle(UAV),multiple UAVs formation has many advantages in military and civilian fields.Therefore,research of UAVs formation control technology has been pushed to the forefront,becoming a research hotspot in international aviation control field.At present,modern control methods for UAVs formation are widely used,which develop the existing classical control methods to some extent,making multiple UAVs formation control more intelligent.However,the uncertainties in the actual formation flight have a direct impact on the effect of UAVs formation flight,which becomes a difficult problem for formation control.In view of the uncertainties in UAVs formation flight,the problems of UAVs formation maintenance control and formation reconfiguration control are studied in this paper.The main contributions are as follows.Firstly,based on the literature review of research status at home and abroad about UAVs,the main performance parameters of Silver Fox are briefly introduced,and the mathematical model of UAV is built.At the same time,the two dimensional and three dimensional relative kinematics equations of the UAVs formation based on leader-follower mode are also built,respectively.All these work lays foundation for the later research on cooperative operation of UAVs formation.Secondly,based on the algebraic graph theory,the distributed UAVs formation control strategy is designed.By analyzing the characteristics of UAVs formation,a state feedback state tracking adaptive control based method is proposed for UAVs formation maintenance control.The stability and asymptotic tracking performance of the distributed adaptive formation control strategy are proved based on the Lyapunov theory,which guarantees the global boundedness.Thirdly,considering that the state feedback state tracking adaptive control based method needs to meet restrictive matching conditions for UAVs formation design,and the unknown external disturbances in UAVs formation flight,a state feedback output tracking adaptive control based method is proposed for UAVs formation control.The proposed adaptive control method makes the wing UAVs bounded and track the given commands asymptotically under parametric uncertainties and unknown external disturbances.Based on the UAV flight control system,the adaptive formation controller is designed to reject the disturbances and eliminate the relative position error of formation,so as to obtain the control commands for the wing UAVs.It is ensured that UAVs formation maintenance control and formation reconfiguration control can be realized.Finally,considering the structural damage of the UAVs in formation flight,based on the invariance of the infinite zero structures and signs of high frequency gain matrix before and after damage occurs,an adaptive fault tolerant flight control system is designed to guarantee that the wing UAVs track the given commands asymptotically before and after damage.At the same time,the proposed adaptive formation controller is used to reject the constant dynamics offset caused by failure,and UAVs formation control can be realized.The result of this thesis is meaningful for both theoretical research and practical application of UAVs formation.