关键词: 推力矢量, 微纳卫星, 抵近交会, 姿态控制, 序列凸优化, 无损凸化

Abstract: To address the problems of complex propulsion systems and low overall integration in traditional fully actuated micro-nano satellites, this paper proposes a closed-loop guidance and control method based on improved Second-Order Cone Programming (SOCP) for the proximity rendezvous mission of a thrust-vectoring micro-nano satellite. First, the attitude control dynamics of the thrust-vectoring micro-nano satellite are derived based on multi-rigid-body dynamics and actuator characteristics, and the additional disturbances caused by thruster swinging are analyzed. Second, according to the requirements of micro-nano satellite proximity missions, a trajectory optimization method based on improved SOCP is proposed, which addresses the nonlinear dynamic effects caused by satellite mass variation and achieves lossless convexification of the second-order equality constraint introduced by thrust vectoring. Finally, to compensate for trajectory deviations during the actual flight process, the improved SOCP is applied to fixed-period closed-loop re-planning, and closed-loop control is realized by tracking the attitude profile. Simulation results show that the proposed method can generate an optimal proximity trajectory and achieve closed-loop tracking, with a boundary activation error less than 1×10-8, a final relative position error of less than 1 m, and a relative velocity error of less than 0.3 m/s.

Key words: thrust vector, micro-nano satellite, proximity rendezvous, attitude control, sequential convex optimization, lossless convexification