一种新型卫星携气瓶推力器喷气时长计算方法

卫星自主编队保持通常采用开环控制模式,需要星载计算机(AOCC)根据推进系统的工作状态实时计算喷气时长。由于AOCC计算能力有限,在携气瓶推力器仿真测试过程中采用的速度增量关机方式不适用于在轨喷气时长的计算。为减小AOCC运算量,提高控制精度,开展了携气瓶推力器的动力学建模仿真,进行了寿命期间的性能分析。针对该时变推力模型,设计了AOCC喷气时长计算方法。通过推力的状态传递和推力预测,构造了以喷气时长为变量的代数方程,并将该方法应用到一组多次喷气情况下的喷气时长计算。仿真结果显示:与以往基于单点测量的推力器喷气时长的计算方法相比,采用该方法计算的喷气时长更接近理论值,能够有效提高卫星自主编队保持的控制精度。

Novel Fire-Time Algorithm of Attitude and Orbit Control Computerfor Thruster with Gas-Repository

Open-loop control modes are commonly used in autonomous formation maintenance of satellites. The AOCC (attitude and orbit control computer) is required to compute the fire-time in real time according to the thruster state. Given the limitation of AOCC, the delta-v shut-down method used in simulation is no longer suitable for in-orbit computation. In order to reduce the on-board computation amount and improve the precision of fire-time computation, a simulation model of thruster is constructed, by which the capability of the thruster during the operating life is analyzed. Based on the time-varying thrust, a novel algorithm of fire-time is introduced for AOCC. A state transition and thrust estimation method is considered in the suggested approach, based on which an algebraic equation is constructed with fire-time as an unknown variable. Later, the new algorithm is applied to the computation for multiple fires. The simulation results suggest that the new algorithm is more approximate to theoretical fire-time than traditional method. It means that the new algorithm can effectively improve the control precision of autonomous formation maintenance.