摘要
对月球着陆器从约100m到30m之间高度的最终下降段的制导与控制方法进行了研究。提出了一种保证推力有界的简单制导方案,并从理论上严格证明了制导与姿态控制系统的几乎全局渐近稳定的性质。本文的创新之处在于:设计了嵌套饱和函数形式的特殊制导律,该制导律不仅满足主推力有界和可以防止姿态控制中的奇异问题,而且具有形式更为简单和调节着陆器的最大允许偏斜角等优点;得益于制导律的嵌套饱和函数形式,证明了目标角速度的全局有界性质,从而可以获得姿态子系统相对于制导子系统的分离性质。
A control method is investigated for lunar lander＇ s final descent phase, at about 100m to 30m altitude above the surface of the moon. A simple guidance law is proposed and it is proved rigorously that the combined guidance and attitude control system is almost globally asymptotically stable. The main contributions of the study are that based on the form of nested saturation function, the simple guidance law can not only guarantee the boundness of the main thrust force and avoid the singularity in the attitude control, but are simpler compared with existing literature and are flexible in adjusting the maximum permissible inclination angle of the lander; thanks to the guidance law in the form of nested saturation function, the desired angular velocity is proven to be globally bounded, and a separation property between the guidance and the attitude subsystems is also obtained.
出处
《宇航学报》
EI
CAS
CSCD
北大核心
2012年第11期1577-1585,共9页
Journal of Astronautics
关键词
月球着陆器
制导与控制
嵌套饱和函数
饱和控制
最终下降段
Lunar lander
Guidance and control
Nested saturation function
Saturated control
Final descent phase
