Research And Implementation Of Flight Control And Formation Control On A Qball-X4 Quadrotor UAV

Due to the characteristics of simple mechanical structure,flexible flight and small volume is hovering,there is a great potential for quadrotor unmanned aerial vehicle(UAV)in the field of a small take-off space and need long time and low altitude hovering.However,compared with single UAV,it is easier to complete complex tasks,and has high fault tolerance,which makes multiple unmanned aerial vehicles(UAVs)formation control a hot research topic.In this thesis,the mathematical models of the quadrotor UAV and the multiple UAVs formation are established according to the feature that the number of quadrotor control inputs are less than that of the states,the nonlinear property of the quadrotor UAV and the strong coupling of the state variables.This thesis mainly studies on decoupling the state variables of the quadrotor,the real-time trajectory tracking of single quadrotor UAV and maintaining multiple UAVs formation shape.On this basis,the quadrotor UAV flight controller and two multiple UAVs formation controllers have been designed,and the effectiveness of the developed algorithms have been verified via MATLAB/Simulink simulations and also actual physical experiment on the Qball-X4 exp-erimental pltatform available at the Guidance,Navigation and Control Lab.The main works are as follows:Firstly,the flight principle of quadrotor UAV has been introduced briefly as well as the main components of the Qball-X4 UAV,The dyrnamic model of the quadrotor UAV has been established by combining the rigid body kinematics in three-dimensional space with the Newton-Euler equation.Secondly,based on the strong coupling between the attitude angle and displacement of quadrotor UAV,the sensitivity to the external disturbance of quadrotor system,a dual-loop closed-loop controller which adopts the sliding imode control(SMC)has been proposed,In order to reduce the buffeting effect of the SMC,a linear quadratic regulator(LQR)controller is introduced to the outer loop.Thirdly,on the basis of above designed quadrotor UAV flight controller,two multiple UAVs formation controllers have been introduced.The first is the leader-follower control strategy,which first specifies the leader's reference trajectory,and then calculates the reference trajectory of each follower based on desired formation shape;the second method is to control the quadrotor UAV's acceleration as its control and designing on this basis the multiple UAVs formation controller.In the end,the above multiple UAVs formation controllers have been simulated and verified by physical experiments,and the results show that the UAVs formation can be maintained by the proposed two multiple UAVs formation control algorithms.