未知风场扰动下无人机三维航迹跟踪鲁棒最优控制

摘要

This paper presents a robust optimal guidance control law for precise three-dimensional (3D) trajectory tracking of an Unmanned Aerial Vehicle (UAV) in wind disturbance. The wind disturbance is considered in the UAV''s kinematic model. The reference path is considered as a trajectory of a virtual target. Feedback linearization is used to transform the nonlinear dynamics of the UAV to linear state equations. Based on the assumption that the wind disturbance can be known precisely, an optimal control law is derived for the UAV''s 3D trajectory tracking using the LQR (Linear Quadratic Regulator). Then considering the unknown wind disturbance, a robust term is designed to replace the unknown wind disturbance, and a robust optimal control law is obtained. Global asymptotic stability of the closed-loop system is proved by Lyapunov stability theory. Simulations show that the proposed control law can achieve precise 3D UAV trajectory tracking with wind disturbance attenuation, and has good tracking performance.%该文提出一种未知风场扰动下无人机精确3维航路跟踪的鲁棒最优控制律.该控制律基于跟踪虚拟目标的思想,将风场扰动加入无人机运动方程,采用反馈线性化将无人机的非线性动力学方程变换为线性状态方程.假设风场扰动已知的条件下,采用线性二次型调节器推导出能够跟踪3维航路的最优控制律.进一步考虑未知的风场扰动,设计鲁棒控制项代替最优控制律中的风场参数,得到能够抑制未知有界风场干扰的鲁棒最优控制律,并采用Lyapunov稳定性理论证明该闭环系统的全局渐近稳定性.仿真表明该控制律能够实现在未知风场扰动下无人机精确3维航迹跟踪,且具有良好的跟踪性能.