近地轨道航天器编队仅测距相对导航方法

针对地球中高轨道卫星导航信号不可用或不可信赖情况下的航天器编队自主相对导航问题,提出一种基于星载数据链仅测距的航天器相对导航新方法。首先,在地球非球形J2引力摄动条件下建立适用于椭圆轨道的线性化相对运动动力学模型,并建立基于星载数据链的飞行时间测距模型。然后,通过理论推导与数值仿真结合的方式对建立的仅测距相对导航系统进行可观测性分析,得出至少存在三种镜像模糊轨道的结论。接着,建立可用于提升系统可观测性的几何拓扑一致性约束模型,设计基于一致性无味卡尔曼滤波的分布式估计策略,并研究对应的相对导航误差传播规律。最后,通过标准蒙特卡洛打靶对所提算法进行仿真校验。仿真结果表明,相比于Tschauner Hempel(TH)动力学模型,利用建立的J2摄动相对运动动力学模型设计的仅测距相对导航系统能达到更高的相对导航精度,一致性无味卡尔曼滤波算法也能够有效提高编队导航的可观测性。

Range only Relative Navigation for Spacecraft Formation in Low Earth Orbit

Aiming at the autonomous relative navigation problem for spacecraft formation in medium and high earth orbit in the case of satellite navigation signals are not available or reliable, a new method of spacecraft relative navigation based on range only spaceborne data link is proposed. Firstly, under the condition of non spherical gravitational perturbation J2, a linearized relative motion dynamics model for elliptical orbit and a time of flight ranging model based on spaceborne data link are established. Then, through the combination of theoretical derivation and numerical simulation, the observability of the range only relative navigation system is analyzed, and the conclusion is drawn that there are at least three mirror ambiguous orbits. After that, a constraint model based on geometric topology is established to improve the observability of the system, and a distributed estimation strategy based on consensus based unscented Kalman filter is designed, and the corresponding relative navigation error propagation law is studied. Finally, the proposed algorithm is simulated and verified by standard Monte Carlo shooting method. The simulation results show that compared with the Tschauner Hempel (TH) dynamic model, the relative dynamics model considering J2 perturbation can achieve higher range only relative navigation accuracy, and the consensus based unscented Kalman filter algorithm can also effectively improve the observability of relative navigation system.