小行星不规则引力场中的轨道动力学与控制

太阳系中存在数量巨大的小行星，它们携带着太阳系早期演化的痕迹和信息，蕴含着丰富的矿藏，还存在近地小行星撞击地球的危险，这使得小行星成为当今天文观测和空间探索的重要关注对象。近年来，各航天大国纷纷提出了各自的小行星探测计划，我国也在大力开展自主探测小行星的相关研究。与其它深空探测任务相比，近距离探测小行星呈现独特而丰富的动力学特征，许多相关的基础问题亟待探索研究。本课题拟从小行星附近轨道和表面轨迹的理论问题入手，研究平衡点、周期解及其运动形式，分析共振轨道的形成机理和相空间分布特征；同时研究小行星附近和表面动力学环境的数值建模方法，以数值试验方法佐证理论分析的结果；在此基础上应用现代控制理论和方法，研究探测器在小行星附近飞行与着陆任务中的制导和控制问题，并考虑实际工程约束，提出相应的任务方案并解决其中的共性问题，为我国未来小行星探测任务的实施提供理论支持。

Hundreds of millions of asteroids are inside our solar system, and they have drawn significant attention because of scientists' curiosity for early materials of planets, information of solar system evolution, the visionaries' greed for extraterrestrial mineral wealth and most people's fear of the threat for life on Earth. To date, most space powers have put forward plans to send probes to asteroids, which also promoted Chinese researchers' works. The orbital motion and surface motion of probes close to asteroids could be extremely complicated in dynamics, in which both theoretical and technical difficulties abound. This project will first check several basic issues in orbital dynamics around the asteroids, such as the equilibria, invariant manifolds and periodic motion. Orbital resonance as a typical near-field phenomenon will be examined in detail with both theoretical methodology and numerical experiments. Advanced numerical techniques will be developed and applied to our research, which are expected to provide more accurate approximation for the dynamical environment of probes on and around asteroids. Then the control laws for probe's orbiting, hovering and landing processes will be investigated and the results should be verified with adequate model under actual circumstance parameters. The conclusions of this project will contribute to China's future in-situ exploration of asteroids.