Four-rotor Aircraft Control Based On Auto Disturbance Rejection Technology

Quadrotor aircraft is a kind of six degrees of freedom of the rotor unmanned aerial vehicle(UAV)which can realize vertically take-off and land.It is characterized by its low cost,simple structure and special way of flight,which makes it widely used in both military and civilian region.Meanwhile,quadrotor aircraft because of its multi variable,nonlinear,strong coupling and underactuated system characteristics has attracted the attention of the research lovers.This paper based on the summary of the development status of the quadrotor aircraft,the mathematical model is established according to its dynamic characteristics and kinematic characteristics.Control algorithm is studied of quadrotor aircraft,and the design of the controller is applied to aircraft system.The control algorithm is verified and analyzed by the simulation and real object experiment,the purpose is to improve the robustness and rapidity of system.The contents of the research mainly include the following aspects:Firstly,based on a survey of the research situation at home and abroad,aiming at the dynamic characteristics of aircraft,the mathematical model of aircraft system is derived by using newton's second law and external torque law.Based on this,according to the experimental flight condition,the mathematical model of the aircraft is simplified.Secondly,according to mathematical model of quadrotor,active disturbance rejection controller(ADRC)of quadrotor is designed,its based on the active disturbance rejection technology.First,we introduce the structure of ADRC in detail and the whole ADRC structure of aircraft is given.Then based on this,ADRC controller of the six channels is designed respectively for aircraft according to the principle of ADRC.Finally simulation experiment is made for the design of the controller.The simulation results indicate that the proposed control scheme can meet the requirements of the rapidity and robustness of the system,and the effectiveness of the designed controller is verified.Then,the linear active disturbance rejection controller(LADRC)and fuzzy active disturbance rejection controller(Fuzzy-ADRC)are proposed in order to solve the problems that ADRC has too many parameters and is hard to tune.At the same time,in order to control algorithm that we study comparison with the traditional mature backstepping adaptive control algorithm,use the backstepping adaptive to design the controller for aircraft and do the simple simulation contrast test.Controller design process and simulation results show that the designed LADRC controller parameter tuning easily and has only one adjustable parameter,and the rationality and validity of the designed controller is tested.Finally,in order to prove the effectiveness and practicability of the designed LADRC controller for quadrotor aircraft,apply Qball2 entity platform on the laboratory to conduct real-time control experiment.This article is focused on the experiments that realize fixed point hovering and flying of quadrotor aircraft.The experiment show that the proposed LADRC can effectively reduce the overshoot and tracking error of the position and attitude angle of the quadrotor,and have good robustness and meet the high precision performance requirements of the system.