Trajectory Tracking Control Of Quadrotor With Random Disturbances

This paper focuses on the random modelling and trajectory tracking control of the quadrotor system.Firstly,a nonlinear mathematical model of the quadrotor with random disturbances is established.Then,trajectory tracking control strategies are proposed for the quadrotor under reasonable assumptions,and the effectiveness of the proposed control strategies are verified by simulation results.The main contents are given as follows:(1)The problem of mathematical modelling of the quadrotor is studied for the controller design of the quadrotor.Firstly,the inertial frame and the body frame are established,then,based on the theoretical knowledge of Newtonian mechanics and Eulerian dynamics,the nonlinear mathematical model of the quadrotor is established in certain circumstances.Taking into account the random disturbances in the external environment,coloured noises are introduced to obtain the mathematical model of the quadrotor with random disturbances.(2)The problem of backstepping sliding mode tracking control is studied for the quadrotor system with random disturbances.Firstly,the default quadrotor system for low speed flight,Then the system is divided into two subsystems: the attitude subsystem and the position subsystem.For the attitude subsystem,a control strategy combining backstepping control and sliding mode control is proposed,and according to the underactuated and strong coupling characteristics of the quadrotor,the backstepping control method is adopted for the position subsystem.And the trajectory tracking control of the quadrotor are realized such that the closed-loop system satisfies noise-to-state stability in probability.Finally,the accuracy of the proposed control strategies are verified by simulation results.(3)The problem of adaptive fuzzy tracking control based on barrier function and command filtering is studied for the quadrotor system with random disturbances.Firstly,a combination method of adaptive control and fuzzy control is used for the case of the uncertainty of system parameters.Then,we propose the command filtering method for the problem of “complexity explosion” caused by the traditional backstepping method in the derivation process.The barrier Lyapunov functions are given for the problem that output states don’t violate the constraints.To address these problems,based on the barrier function and command filtering,an adaptive fuzzy tracking control strategy is proposed so that the tracking error can be adjusted to be sufficiently small,and the system states can be kept limited.Finally,simulation results are given to verify the proposed control strategy.