GNSS/SINS紧耦合选星算法研究

Study on GNSS/SINS tightly coupled star selection algorithm

通过分析全球导航卫星系统(Global Navigation Satellite System,GNSS)和捷联惯性导航系统(Strap-down Inertial Navigation System,SINS)紧耦合导航系统中最小GDOP法的现有问题,提出一种改进的GNSS/SINS紧耦合选星算法。该算法的主要步骤包括:首先将可见卫星进行伪距异常值检测,并剔除异常值卫星;然后根据卫星的分布特点,利用卫星仰角信息选取最大的一颗作为天顶星,最后将剩余可见卫星随机组合选取三颗卫星和天顶星组成四颗星,得到最终的选星方案。经过与最小GDOP法仿真对比,该算法计算量明显减小,且在保证定位精度的前提下,减少了计算的卫星数目,降低了运算量,具有较好的选星效果。

By analyzing the existing problems of the minimum GDOP method in the tightly coupled navigation system of Global Navigation Satellite System(GNSS)and Strap-down Inertial Navigation System(SINS),this paper proposes an improved GNSS/SINS tightly coupled star selection algorithm.The main steps of the algorithm include:firstly,the visible satellites are detected by pseudo range outliers and the outlier satellites are eliminated;then,according to the distribution characteristics of the satellites,the largest one is selected as the zenith star by using the satellite altitude angle information,and finally,the remaining visible satellites are randomly combined to select three satellites and the zenith star to form four satellites,so as to get the final star selection scheme.After simulation comparison with the minimum GDOP method,the calculation of this algorithm is significantly reduced,and under the premise of guar⁃anteeing the positioning accuracy,it reduces the number of satellites calculated,reduces the amount of arithmetic,and has a better ef⁃fect of star selection.