基于地球坐标系的SINS/GNSS极区组合导航算法

SINS/GNSS Integrated Navigation Algorithm Based on the Earth Coordinate Frame in Polar Region

针对极区范围经线收敛速度加快并汇聚于极点,使航向失去参考基准,定位误差急剧增大的问题,结合极区航行过程中对导航精度的需求,提出了一种适用于极区的基于地球坐标系的SINS/GNSS组合导航方案。给出了基于地球椭球模型的横向坐标系定义以及与地球坐标系之间的转换关系;设计了地球坐标系下的SINS/GNSS组合导航算法;最后将地球坐标系下的导航结果转换到横向坐标系。仿真结果表明,基于地球坐标系的极区组合导航方案的导航误差收敛迅速,在1800s的仿真时间内,姿态精度达到0.4′,定位精度达到2m,速度精度达到0.02m/s;其中定位和航向精度略优于横向地理坐标系下的组合导航方法,且可为载体穿越极点时提供稳定的导航信息。

In polar regions,the convergence speed of the longitude is accelerated and concentrated at the pole,which makes the heading lose the reference datum and the positioning error increase sharply.Combined with the demand for navigation accuracy during the polar region navigation,a kind of SINS/GNSS integrated navigation scheme based on the earth coordinate frame in polar region is proposed.The definition of the transversal coordinate frame based on the Earth ellipsoid model and the conversion relationship with the earth coordinate frame are given.The SINS/GNSS integrated navigation algorithm in the earth coordinate frame is designed.Finally,the navigation results in the earth coordinate frame are converted to the horizontal transversal coordinate frame.The simulation results show that the navigation error of this scheme converges rapidly.During the simulation time of 1800 seconds,the attitude accuracy reaches 0.4′.The positioning accuracy reaches 2m and the velocity accuracy reaches 0.02m/s.The positioning and heading accuracy is better than the integrated navigation method in the transversal geographic coordinate frame,and providing stable navigation information to the carrier as it passes through the pole.