Research On Anti-jamming Control Algorithm Of Quadrotor Aircraft

Quadrotors are widely used in military and civilian applications due to their small size,low price,vertical take-off and landing,and hovering.However,a quadrotor is a complex system that is underactuated,strongly coupled,multivariable and nonlinear.It is also affected by disturbances such as kinetic model parameters,external factors and measurement noise.In order to make the quadrotor achieve stable flight in various environments,the anti-disturbance control performance of the quadrotor flight control system must be improved.This paper takes the quadrotor as the research object.Aim at improving its flight stability and anti-disturbance,analyze the dynamics model of a quadrotor.The disturbance observer is designed according to the characteristics of the disturbances.The backstepping control and the model reference adaptive control(MRAC)method are selected to achieve stable control of the quadrotor.The content of the research mainly includes the following aspects:1.Disturbance observer-based backstepping control for quadrotor.Firstly,the quadrotor dynamic model that is affected by various disturbances is established.Then,according to the slow time-varying characteristics of the external airflow disturbances,the six-channel disturbance observer of the quadrotor is designed.Based on this,the backstepping controller of the quadrotor is designed.The disturbances estimated by the disturbance observer compensate to the backstepping controller.The quantities of control are generated to achieve suppression of disturbances.Improve the anti-disturbance performance of the controller.The Lyapunov stability theory is used to prove the asymptotic stability of the closed-loop system.The effectiveness of the proposed algorithm is verified by the MATLAB\simulink experiment.2.MRAC-based backstepping control for quadrotor.The dynamic model of the quadrotor is decomposed into a horizontal position control subsystem and a height and attitude control subsystem.And linearize the dynamic model of the height and attitude subsystem.Design backstepping controllers for each of the two subsystems.For the external airflow disturbances and load disturbances,the MRAC is applied in the height and attitude control subsystem.Improve the anti-disturbance performance of the subsystem controller to achieve stable flight of the quadrotor.The Lyapunov stability theory is used to prove the asymptotic stability of the closed-loop system.Simulation results confirm that the algorithm has good adaptive ability to load disturbances.3.Disturbance observer-based backstepping adaptive position stability control for the quadrotor.For disturbances that affect horizontal position stability,add the disturbance observer to the horizontal position control subsystem on the basis of MRAC-based quadrotor backstepping controller.Compensate the disturbances estimated by the disturbance observer to the backstepping controller to generate control quantities.Achieve the suppression of disturbances by the horizontal position control subsystem.Since the horizontal position is indirectly controlled by the attitude angle,the stability of the horizontal position is achieved by continuously adjusting the attitude angle when the quadrotor is disturbed.Therefore,based on the design of the backstepping controller for the two subsystems,not only the horizontal position control subsystem is added to the disturbance observer to improve the anti-disturbance performance,but also the MRAC is applied in the height and attitude control subsystem.The stability of the quadrotor position is double guaranteed,ensuring stable and smooth tracking of the command signal by the quadrotor.Finally,the Lyapunov stability theory is used to prove the asymptotic stability of the closed-loop system.It is verified that the proposed algorithm can effectively suppress disturbances by the MATLAB\simulink experiment.