自主空中加油输油阶段无人机建模与控制

针对自主空中加油输油阶段无人机位置保持控制问题，将无人机分为飞机本体和油箱两部分，利用变质量系统理论建立了无人机非线性方程，解决了常规模型无法反映出无人机重量、重心变化的问题。控制律设计方面，通过将变化的油箱转化为外界干扰，提出了基于干扰观测器控制（disturbance observer based control, DOBC）的复合控制结构。复合控制器由位置保持控制器和干扰观测器组成，位置保持控制器采用带积分的线性二次型方法，干扰观测器由比例积分观测器和补偿单元构成，并证明了复合控制器的稳定性。仿真结果表明，将该控制器应用于某型高空无人机非线性模型，可有效减小输油过程带来的影响，实现了输油阶段的位置保持控制。

Modeling and control of UAV in fueling phase of automated aerial refueling

To slove the station keeping control problem for the receiver in fueling phase of automated aerial refueling (AAR), the receiver is divided into the plane body and the fuel tank. The receiver nonlinear dynamics equations which reflect the mass and center of gravity (CG) variations of the fuel tank are established based on the variable mass system theory. By transforming the fuel tank into unknown external disturbance, a compound controller based on the disturbance observer based control (DOBC) method is proposed. The compound controller consists of two parts: the station keeping controller via linear quadratic regulator (LQR) method and the disturbance observer, which is composited by a proportional integral observer (PIO) and a compensation unit. Then, the stability of the compound controller is proved. The results of simulation demonstrate that the proposed control system is efficient and meets the station keeping control requirements in fueling period.