一种天文/加速度计的HEO卫星自主导航新方法

摘要

Directly sensing horizon is a typical autonomous celestial navigation method which is reliable and simply. But its navigation precision is low due to mainly depending on satellite orbit dynamics J2 model and earth sensor. Accelerometer is a typical navigation equipment to measure vehicle linear acceleration. For a satellite moving on orbit, the accelerometer can be used to measure the divergent forces acted on satellite. This paper presents a new method of satellite autonomous navigation based on accelerometer and celestial navigation. The coefficient model of atmospheric drag and solar radiation pressure are proposed as part of autonomous navigation system state equation. The accelerometer measurement equation is established on space environment. The autonomous navigation method and algorithm are designed, and the simulations are made which show that the location precision and the velocity precision can be improved by 74.8%and76.4%respectively with the proposed system.%直接敏感地平是一种典型自主天文导航方法，该方法简单可靠，易于实现，但是由于常用卫星轨道动力学J2模型精度有限，地球敏感器精度较低，因此导航精度不高。加速度计是测量运载体线加速度的常用惯性导航设备，当卫星在轨运行时，星载加速度计能够测量航天器所受发散力。结合这两种方法的特点，提出一种将加速度计和天文相结合的自主天文导航新方法。在常用卫星轨道J2模型基础上，引入大气阻力和太阳光压系数模型作为自主导航系统状态方程的一部分，并建立近地空间环境下星载加速度计的测量模型，将其与直接敏感地平均作为导航系统观测方程。设计基于信息融合的自主导航滤波方法，通过对多种导航模式进行数值仿真及结果分析，结果表明所设计方法提高了系统定位精度74.8%和速度精度86.2%，增强了系统可靠性。