在轨加注航天器的姿态动力学模型

Attitude dynamics model of on-orbit refueling spacecrafts

针对推进剂在轨加注的过程会使航天器转动惯量产生显著变化而影响航天器的稳定姿态,对航天器在轨加注整个物理过程进行详细分析,并对在轨加注航天器转动惯量的变化规律进行研究.在一定前提条件下,给出了一种转动惯量参数的有效计算方法,进而给出时变参数航天器姿态动力学模型.通过测量推进剂流速,该方法可实现在线计算.仿真结果表明方法的正确性以及航天器结构参数对转动惯量变化的影响.

Because the spacecraft moment-of-inertia changes obviously during the on-orbit propellant refueling process,this paper provides a detailed analysis of the change of moment-of-inertia.Based on some reasonable assumptions,the paper proposes an effective algorithm for computing the moment-of-inertia.Including only one variable,the propellant flow velocity,the proposed algorithm can compute the moment-of-inertia on-line.As a natural result,the time-varying attitude dynamic model for the on-orbit refueling spacecraft is established.Finally,the numerical simulation illustrates the algorithm correctness and the effect of the spacecraft related parameters on the moment-of-inertia.This result provides theoretical foundations for attitude control system design of on-orbit refueling spacecrafts.