考虑地球自转的探月返回跳跃式再入制导研究

On the guidance for the Lunar return skip reentry considering the earth rotation

中文关键词  探月返回飞行器  跳跃式再入  地球自转  基于观测器的近似反馈线性化制导律  内动态  闭环性质

英文关键词  the Lunar return spacecraft  skip reentry  the Earth rotation  the observer-based approximate feedback linearization guidance law  internal dynamics properties  closed-loop properties

中文摘要

      本文考虑探月返回飞行器跳跃式再入的制导问题. 针对考虑地球自转的探月返回飞行器不确定非线性动 力学, 设计了基于观测器的近似反馈线性化制导律. 由于初始再入时空气密度近似为零, 因此阻力初始观测误差近 似为零. 针对该特点, 研究了基于观测器的控制律的峰值问题, 给出了无峰值现象的控制律的简化设计方法. 首次 证明了速度内动态是有界输入有界状态的, 为制导律的设计提供了基础. 证明了制导误差是一致最终有界的, 并且 界是随着初始观测误差的减小而趋于零; 进一步由于阻力初始观测误差近似为零, 因此制导误差近似为零. 最后, 针对Apollo命令舱, 通过数学仿真验证了本文方法的有效性. 本文为包括火星再入、月球再入等飞行器的制导问题 提供了研究途径和基础.

英文摘要

      We address the guidance problem for the Lunar return spacecraft skip reentry. Taking the Earth rotation into consideration, we perform an observer-based approximate feedback linearization guidance law design for the uncertain and nonlinear dynamics of the Lunar return spacecraft. Firstly, the peak phenomenon of observer-based controllers is considered. The air density approximates to zero when the initial reentry, so the initial observation error of drag is also zero approximately. Considering this feature, a simplified design for peak-free phenomenon is given for the observer-based controllers. Then, the guidance design problems are considered. It is first proved that the internal dynamics is boundedinput- bounded-state, which constructs the basis for the design of guidance law. The closed-loop properties are proved that the guidance errors are uniformly ultimately bounded, and tend to zero with the diminish of initial observed errors. Combining that the initial observation errors approximate to zero, the guidance errors are also zero approximately. Finally, simulation on Apollo Command Module illustrates the effectiveness of the proposed theoretical method. This paper has laid the foundations for the research on Mars reentry and the Lunar reentry etc.