着陆小天体的自主GNC技术

由于目标小天体和地面站之间存在较长的通讯延迟，加之小天体的动力学环境复杂多变，传统的基于深空网的导航、制导与控制（GNC）模式已不再适合探测着器着陆小天体。为了实现安全着陆小天体，探测器必须具有自主导航、制导和控制的能力。本文提出了一种着陆小天体极区的自主GNC方案：首先，基于对自然特征点的自动提取、跟踪，给出了一种着陆小天体的自主光学导航方案；接着，为了安全垂直着陆小天体的极区，设计了比例-微分控制器跟踪理想的下降轨迹、消除侧向位置和速度偏差；最后，通过数值仿真对本文所提方案的可行性进行了验证。

Autonomous GNC Technology for Landing on Small Bodies

Due to long communication delay between target asteroid and base stations and complex mutable dynamic environment of small body, the traditional GNC mode based on deep space network (DSN) is no more suitable for landing spacecraft on small body. Probe must have the ability of autonomous GNC to perform landing safely. An autonomous GNC scheme for landing on small body polar region is presented in this paper. First, based on autonomous detection and tracking nature feature points, an autonomous optical navigation algorithm is built out; second, in order to achieve vertical landing, PD guidance control laws are designed to track desired descent trajectory and eliminate lateral position errors and velocity errors. Finally, the validity of the proposed scheme is confirmed by numerical simulation.