Abstract: Base on small deviation theory, an error linear model of three\|body dynamics model is deduced. The control problem under the supposition is belong to the problem of filed and point regulator within finite time. Then continuous small thrust control law in a halo orbit period is deduced by using optimal control and the convergence of control acceleration and state is also validated. Aim at the problem that convergence rate of state in total period control mode after overshoot is low, method for calculating the shortest sectional control time is given by using the sectional continuous thrust control mode to approximate the instantaneous impulse thrust control mode. Experiment shows that the SCTC mode speeds up convergence of orbit state and the practical orbit is able to be converged to the standard orbit by using only one control at orbit insertion error of grade of kilometers.

Key words: Halo orbit, Libration point, Optimal control, Orbit maintenance, Continuous thrust control