Research On Control Method Of Quadrotor Based On Predetermined Performance

With the rapid progress of modern science and technology,the quadrotor unmanned aerial vehicle(UAV)is developing towards the direction of high intelligence and has been playing an increasingly important role in the field of multiple domains.Meanwhile,the model of the UAV has the character of nonlinear,strong couple and higher order,which makes the controller design for the quadrotor UAV become more difficult.The research of its control method has received more and more attention from scholars.In this paper,according to the structure of the quadrotor UAV,flight principles,the dynamic model and control methods are researched.The controller is developed by a sliding mode controller(SMC)with prescribed performance,which is aimed to improve the robustness of parameter uncertainties and external disturbances of the quadrotor UAV.The main research work of this paper is illustrated as follows:(1)The background,the significance and the reality are introduced and the establishment and transformation of coordinate system are developed.The dynamic model of the quadrotor UAV is established based on the Newton-Euler equation.The mathematical model is obtained for the experimental platform,and the control method of the double closed loop control strategy is adopted.(2)The basic principle of the sliding mode control arithmetic and the advantages of fast terminal sliding mode are introduced.According to double loop control method,a fast time-varying terminal sliding mode controller with prescribed performance is presented.Simulation and experiment results prove the effectiveness of the method.(3)Because the robustness of the traditional SMC is bad during the reaching phase,the time-varying sliding mode controller(TVSMC)is introduced,and on the base of current theory,a time-varying fast terminal sliding mode surface(TVFTSMS)is designed by a tracking differentiator.This method can make initial states of the system on the surface at the beginning time,thus the reaching phase is eliminated and the robustness can exist all the time.Then the controller is developed by using the new sliding mode surface.Simulation and experiment results prove that all the signals in the resulting closed-loop system are bounded and that the tracking errors converge to a small residual set with the prescribed performance bounds in finite time.(4)Because there are unknown functions in the model due to the unknown moment of inertia and external disturbance,the universal approximation of fuzzy logic system is used to approximate the unknown function.A fuzzy adaptive controller is designed by combining the fuzzy logic system with TVFTSMS.Simulation results prove the effectiveness of the method.