高精度惯性导航系统垂线偏差影响与补偿

摘要

Gravimetric vertical deflection was a main error source of high accuracy inertial navigation system. In order to analyze and compensate it’s effect, the formula about attitude steady state error regarding vertical deflection in initial alignment stage was derived, and the error equation of inertial navigation system was established. Three different resolutions of grid data were used to compensate vertical deflection. The simulation results demonstrate that:the error of horizontal alignment caused by gravity disturbance is equal to the value of vertical deflection. The simulation study on error analysis and gravity compensation shows that the grid data of 10′×10′can satisfy the navigation precision requirement of<0.1 nm/h.%垂线偏差是高精度惯性导航系统的一项主要误差源，为对其进行研究及补偿，导出了初始对准阶段姿态的稳态误差值，建立了惯导系统速度、位置的误差方程，对比了不同地区垂线偏差引起的导航误差，并采用了三种分辨率的重力网格数据对垂线偏差进行插值补偿。初始对准仿真分析表明：垂线偏差大小与其引起的水平姿态误差角等值，航向误差角受水平姿态北向误差和纬度的影响。垂线偏差的补偿仿真结果表明：采用10′×10′的网格数据进行插值补偿可以满足0.1 nm/h的导航精度要求。