中文摘要：

可重复使用运载器（RLV）再入面临严重的扰动影响,对此设计一种抗扰动非线性最优控制器（ADNOC）.首先,基于时标分离原理设计快、慢双回路控制结构;其次,将角速率动态变换处理成线性形式,通过依赖状态的黎卡提方程（SDRE）优化方法获得最优控制指令;然后,设计非线性扰动观测器用于估计外界干扰,并在非线性最优控制律中进行干扰补偿.仿真实验结果表明,所设计的控制器能良好地完成姿态跟踪控制,抑制扰动对姿态控制的影响,实现RLV的最优控制性能.

英文摘要：

The reentry attitude control of the reusable launch vehicle（RLV） is challenging due to disturbances. Therefore, an anti-disturbance nonlinear optimal controller（ADNOC） design scheme is presented. Firstly, a fast and slow dual-loop control system is designed based on time-scale separation principle. The linear transformation of attitude angular rate is developed.By the optimization of state dependent Riccati equation（SDRE）, the nonlinear optimal control law is designed to generate optimal control commands. Then the nonlinear disturbance observer（NDO） is implemented in order to estimate the unknown disturbances. The estimation of disturbances is utilized for compensation in the controller. Simulation results show that the ADNOC obtains good tracking performance and can be able to suppress the disturbances effectively.