Acta Geodaetica et Cartographica Sinica ›› 2025, Vol. 54 ›› Issue (8): 1389-1403.doi: 10.11947/j.AGCS.2025.20240473

• Geodesy and Navigation • Previous Articles     Next Articles

Left-handed symmetry equivariant filtering model and algorithm for GNSS/INS integrated navigation

Yarong LUO1(), Wentao LU2, Chi GUO1,3(), Jingnan LIU1   

  1. 1.GNSS Research Center, Wuhan University, Wuhan 430079, China
    2.School of Electronic Information, Wuhan University, Wuhan 430079, China
    3.Hubei Luojia Laboratory, Wuhan 430079, China
  • Received:2024-11-21 Revised:2025-07-07 Online:2025-09-16 Published:2025-09-16
  • Contact: Chi GUO E-mail:yarongluo@whu.edu.cn;guochi@whu.edu.cn
  • About author:LUO Yarong (1993—), male, PhD, assistant researcher, majors in geometric state estimation theory and applications. E-mail: yarongluo@whu.edu.cn
  • Supported by:
    The National Natural Science Foundation of China(42404025);China Postdoctoral Science Foundation(2023TQ0248);Major Science and Technology Project of Hubei Province(2022AAA009)

Abstract:

The current equivariant filtering theory is mainly built for local observation in the field of robotics, and cannot be naturally applied to inertial based integrated navigation systems with global observation. To solve the above problems, this paper constructs an equivariant filtering framework which is suitable for global observation through left-handed symmetry, and applies it to GNSS/SINS integrated navigation system which includes gyroscope bias and accelerometer bias states. Different from the left invariant extended Kalman filtering (EKF) on matrix Lie group, firstly, the left-handed symmetry is used to construct the equivariant filtering. Secondly, a two-frame group is employed to derive the linearized error dynamic matrix and the noise driven matrix of equivariant error for a biased inertial navigation system. Finally, a Cartan-Schouten connection is used for covariance parallel transport to complete the curvature correction on the manifold. The experimental results show that the proposed filtering algorithm has better transient response under different large misalignment angles compared with left invariant EKF. Additionally, when the initial yaw error is 90°, the average position error of the proposed filter reduces by 36% compared to left invariant EKF. At the same time, the integrated navigation system can effectively improve the robustness of the filter after curvature correction, and compared to the proposed filter without curvature correction, the average position error reduces by 14% after curvature correction.

Key words: left-handed symmetry, group action, equivariant system, two-frame group, GNSS/SINS integrated navigation, curvature correction

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