Characteristic Model -based Station -keeping Control for Halo Orbits about Sun -Earth Li Point

Halo orbits about libration points are believed to be useful in future deep-space missions. In this work, a station keeping strate*, based on characteristic model theory is proposed within the elliptic restricted three -body problem. A golden -section controller for velocity tracking and a PD controller for position tracking are designed respectively for the station-keeping control of halo orbit about the Li point of the Sun -Earth system. The simulation shows that this strategy can reach a relatively high precision in station-keeping control, where the tracking errors are no more than 2508.8 m in position and 0.251 m/s in velocity. The velocity increment required during the stable stage is only 3.7873 m/s per period.