基于干扰估计的航天器大角度姿态机动鲁棒次优控制

针对存在系统参数不确定与外界干扰的航天器大角度姿态机动问题，提出一种基于干扰估计的鲁棒次优控制方法。该方法通过引入总干扰的概念，将不确定参数与外界干扰对系统的影响统一为各控制通道总干扰，而后采用非线性干扰观测器实现对系统总干扰的估计；借鉴状态相关的黎卡提方程（SDRE）方法，将系统模型改写为状态相关的线性形式，并采用近似方法实现基于干扰估计的次优控制参数的在线求解。通过对航天器大角度姿态机动问题的仿真分析，校验所提方法不仅较传统SDRE方法计算效率更高，而且较大程度上提高系统对参数偏差与外界干扰的鲁棒性能。

Spacecraft Large Angle Attitude Maneuver Robust Suboptimal Control Based on Disturbance Estimation

An improved disturbance estimation based robust suboptimal control is proposed for a class of spacecraft large angle attitude maneuver problem with parameter uncertainty and external disturbance in this paper. Firstly, the integrated effect of the system uncertainty and external disturbance is regarded as the lumped disturbance can be estimated by the nonlinear disturbance observer. And then the system is reconstructed as a state-dependent coefficient linear system, and an approximate method is used to online solve the suboptimal control by means of the optimal value of the state-dependent algebra Riccati equation. Considering the spacecraft large angle attitude maneuver problem, simulation results have demonstrated that the proposed approach not only performs the efficient calculation compared with the traditional state-dependent Riccati equation method, but also significantly enhances the robustness towards the parameter uncertainty and external disturbance.