北极东北航道商船陀螺罗经航向误差修正算法

针对商船上常用的指向仪器设备陀螺罗经在北极东北航道航行时由于高纬度带来的指向力矩变小而导致指向精度下降问题, 基于北极东北航道罗经历史数据, 考虑纬度和航向对航向误差的影响, 利用最小二乘法对GPS卫星罗经与陀螺罗经的航向误差进行多项式拟合, 建立并比对3种拟合模型, 遴选出均方误差最小的陀螺罗经航向修正模型; 当GPS信号异常时, 利用该模型对陀螺罗经航向误差进行一次修正; 修正后陀螺罗经航向精度保持在±2.0°内, 精度在±1°以内的修正率达88.4%;当GPS信号正常时, 在一次修正的基础上利用卡尔曼滤波进行二次修正, 修正后的陀螺罗经航向精度在±1.0°以内的修正率为98.9%, 精度在±0.5°以内的修正率达88.9%。

A Correction Algorithm for Course Errors from the Gyrocompass Along the Northeast Channel of the Arctic

This work focuses on the problem of the decreased pointing accuracy caused by the reduced pointing torque in high latitudes when the gyrocompass commonly used on merchant ship is navigated in the Northeast Passage of the Arctic. Based on the historical data of the Northeast Passage of the Arctic, the influences of latitude and heading on heading error are considered. The least-square method is used to fit the heading error of GPS satellite compass and gyrocompass by the polynomial. Three fitting models are established to select the gyrocompass heading correction model with the smallest mean square error. When the GPS signal is abnormal, the model is used to correct the heading error of the gyrocompass. After correction, the accuracy of the gyrocompass heading remains within ±2.0°, and the correction rate within ±1° reaches 88.4%. When the GPS signal is normal, the Kalman filter is used for the second correction based on the first correction. The correction rate of the corrected gyrocompass heading accuracy within ±1.0° is 98.9%, and that within ±0.5° is 88.9%.