Polar Region Integrated Navigation Method Based on Covariance Transformation

Yongjian Zhang,Chunfeng Gao,Lin Wang,Guo Wei

doi:10.3390/app11209572

Abstract

Aircraft flying the trans-arctic routes usually apply inertial navigation mechanization in two different navigation frames, e.g., the local geographic frame and the grid frame. However, this change of navigation frame will cause filter overshoot and error discontinuity. To solve this problem, taking the inertial navigation system/global navigation satellite system (INS/GNSS) integrated navigation system as an example, an integrated navigation method based on covariance transformation is proposed. The relationship of the system error state between different navigation frames is deduced as a means to accurately convert the Kalman filter’s covariance matrix. The experiment and semi-physical simulation results show that the presented covariance transformation algorithm can effectively solve the filter overshoot and error discontinuity caused by the change of navigation frame. Compared with non-covariance transformation, the system state error is thereby reduced significantly.

Highlights

College of Advanced Interdisciplinary Studies, National University of Defense Technology, Abstract: Aircraft flying the trans-arctic routes usually apply inertial navigation mechanization in two different navigation frames, e.g., the local geographic frame and the grid frame
In order to solve the problem of filter discontinuity caused by the change of navigation frame, this paper proposes a polar-region airborne INS/GNSS integrated navigation method, based on covariance transformation
The GNSS positioning error is less than 10 m, which is used as the position reference

Summary

Introduction

Considering that the distance of a great circle flight route is shorter, using trans-arctic routes can accomplish great savings in flying time when aircraft make transcontinental flights. The studies of [11,16] introduce a position matrix to decouple the height channel and three rectangular coordinates, which can solve the problem of position error divergence In this way, the continuity of global navigation is guaranteed. In order to solve the problem of filter discontinuity caused by the change of navigation frame, this paper proposes a polar-region airborne INS/GNSS integrated navigation method, based on covariance transformation. A purely mathematical simulation cannot accurately reflect real aircraft situations [19] To solve this problem, the authors of [19,20] proposed a virtual polar-region method based on the t-frame or the G-frame.

Grid Frame and Grid SINS Mechanization

Dynamic Model of the Grid SINS

E Φa cos L sin σcosσ sin L

Experimental Results

Semi-Physical Simulation Experiment

Conclusions