Stable Tracking Control Research Of Position And Attitude For Quadrotor Uav Based On Sliding Mode Control

The quadrotor UAV is a kind of rotorcraft autonomous aircraft which can vertical takeoff landing,low-speed flight and fixed-point hovering in a narrow space.Because it has small structure,is easy to operate and it is often applied to civil and military fields,such as rescuing,surveillance,aerial photography,agricultural reconnaissance,etc.However,due to the non-linearity,strong coupling and underactuated of the quadrotor UAV system,and it is susceptible to external disturbances,uncertainties and other factors,the control problems of quadrotor UAV have become a challenge.The tracking control of quadrotor UAV is researched in this paper and the main contents include the following aspects:Firstly,considering the tracking control problem of the quadrotor UAV under external disturbance,a finite-time non-singular terminal sliding mode controller is designed.By introducing the flying principle of the quadrotor UAV,analyzing the coordinate system and coordinate transformation,and the mathematical model of quadrotor UAV is obtained by the dynamics and kinematics theory.Then,the external disturbance is estimated by a finite time disturbance observer and the non-singular terminal sliding mode controller is designed under the framework of sliding mode control.Based on Lyapunov stability theory,the finitetime stability of the system and the convergence of tracking error are proved.Finally,the effectiveness of the designed control strategy is verified by simulation comparison.Secondly,a terminal sliding mode fault-tolerant control strategy based on a disturbance observer is proposed to solve the tracking control problem of the quadrotor UAV under external disturbance and actuator additive fault.The model of the quadrotor UAV is decoupled into position subsystem and attitude subsystem,and disturbance observer is designed to effectively suppress external disturbance and actuator additive fault.Based on this,Combined with sliding mode control,a sliding mode fault-tolerant control strategy is designed,and then Lyapunov stability theory is used to guarantee system asymptotic stability,the superiority and effectiveness of the designed control strategy are verified by simulation.Finally,an adaptive sliding mode controller is designed to track the attitude and position of the quadrotor UAV under external disturbance and uncertain parameters.The adaptive control technique is introduced to estimate the external disturbance and uncertain parameters.Combined with sliding mode control,the adaptive sliding mode controller is designed for attitude and position,and the asymptotic stability of closed-loop system is analyzed by Lyapunov stability theory.The effectiveness of the designed control scheme is verified by simulation.