An improved LG-EKF for SINS/ODO integrated navigation
CUI Jia-rui
ZHANG Li-lian
WANG Mao-song
WU Wen-qi
DU Xue-yu
Abstract：The nonlinear error state-based extended Kalman filter method,known as Lie group extended Kalman filter expressed in i-frame(LG-EKF-i),is employed in satellite-denial scenarios such as unmanned platform strapdown inertial navigation system/odometer(SINS/ODO)integrated navigation.In this context,the position and velocity vectors relative to geocentric are coupled with attitude errors,which may result in numerical inaccuracies and reduced precision when neglecting higher-order terms.Therefore,in this paper,an improved LG-EKF is proposed.Replace the resolving frame and reference frame with the world frame,which could effectively reduce the accumulation of numerical calculation error.The algorithm was verified by using 21-states Kalman filter which considered the installation angles between the odometer and the SINS,the lever-arm and the odometer scale factor error.Results of four long-time high-precision SINS/ODO integrated navigation experiments with small initial alignment error angles show that the proposed improved LG-EKF-w has higher numerical calculation accuracy than traditional extended Kalman filter(EKF),state transform extended Kalman filter(ST-EKF)and original LG-EKF-i.The superiority of the proposed LG-EKF-w is further verified by open-loop trajectory experiments with large initial alignment error angles.
Keywords：satellite-denial environmentSINS/ODO integrated navigationimproved LG-EKF
Publication Date：2023-12-28
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：8( 2179-2186 )