柔性航天器全局有限时间姿态容错控制

Global finite time attitude fault-tolerant control of flexible spacecraft

中文关键词  姿态控制  自适应控制  干扰观测器  柔性航天器

英文关键词  attitude control  adaptive control  disturbance observer  flexible spacecraft

中文摘要

      本文针对在模型不确定性、外界干扰与执行器故障影响下柔性航天器姿态控制问题, 设计一种自适应容错控制算法, 该算法包括标称控制部分和补偿控制部分. 首先, 标称控制部分用于实现不考虑综合不确定影响下航天器有限时间姿态控制; 其次, 补偿控制部分基于积分滑模理论进行设计, 该补偿控制器通过对综合不确定有效估计, 在控制器中作补偿, 减少对姿态控制精度的影响, 提高航天器姿态控制精度. 该算法特点在于可实现柔性航天器全局有限时间姿态控制, 放宽角速度或其导数、执行器故障或其导数有界的假设. 同时, 基于Lyapunov函数严格证明整个闭环系统的稳定性. 最后, 通过仿真验证该控制算法的有效性.

英文摘要

      In this paper, an adaptive fault-tolerant attitude control algorithm is designed for flexible spacecraft under model uncertainties, external disturbance, and actuator fault. The proposed control algorithm includes the nominal control part and the compensated control part. First, the nominal control algorithm is proposed to realize spacecraft attitude control in the absence of lumped uncertainties. Then, based on integral sliding mode control, an adaptive compensated control algorithm which acted as a disturbance observer, is designed to eliminate the lumped uncertainty. The main feature of the proposed control algorithm is that it is global finite time attitude control, i.e., the assumption that angular velocity or its derivative, as well as the actuator failure or its derivative, are bounded. Simultaneously, the stability of the whole closed loop system is strictly proved by Lyapunov techniques. Finally, numerical examples are given to illustrate the efficiency of the proposed control algorithm.