基于光滑二阶滑模的可重复使用运载器有限时间再入姿态控制

Finite time smooth second-order sliding-mode controller design for reentry reusable launch vehicle

中文关键词  可重复使用运载器(RLV)  再入姿态控制  二阶滑模控制  干扰观测器  多时间尺度  有限时间稳定

英文关键词  reusable launch vehicle (RLV)  reentry attitude control  second-order sliding mode control  disturbance observer  multiple time scale  finite time stability

中文摘要

      针对可重复使用运载器(reusable launch vehicle, RLV)的六自由度再入模型, 考虑模型不确定和外界干扰对再入姿态控制的影响, 提出了一种非线性鲁棒控制策略. 首先, 根据多时间尺度特性将RLV的再入姿态模型分为姿态角子系统和姿态角速率子系统. 其次, 对每个子系统分别设计光滑二阶滑模控制器和滑模干扰观测器实现子系统的有限时间稳定. 利用干扰观测器可以实现对不确定和外界干扰的精确估计, 从而对控制器进行有效的补偿. 进而, 基于Lyapunov理论证明了整个系统的有限时间稳定. 最后, 通过仿真验证了提出的控 制策略具有良好的控制性能和鲁棒性.

英文摘要

      A nonlinear robust control strategy is proposed for the attitude tracking of reusable launch vehicle (RLV) in the presence of model uncertainty and external disturbances. Firstly, according to the multiple time scale features, the dynamics of attitude motion are divided into attitude angle subsystem and attitude angle rate subsystem. Then the smooth second-order sliding-mode controller and disturbance observer are designed to ensure the finite time stability of each subsystem. The model uncertainty and external disturbances are estimated accurately by using disturbance observer which compensates for the controller effectively. Moreover, finite time stability of the whole closed-loop system is proved based on the Lyapunov theory. Finally, simulations are carried out to validate the effectiveness and robustness of the proposed control strategy.