Impact of the Earth Rotation Compensation on MEMS-IMU Preintegration of Factor Graph Optimization

作     者：Tang, Hailiang Zhang, Tisheng Niu, Xiaoji Fan, Jing Liu, Jingnan 

作者机构：Wuhan Univ GNSS Res Ctr Wuhan 430079 Peoples R China 

出 版 物：《IEEE SENSORS JOURNAL》 (IEEE Sensors J.)

年 卷 期：2022年第22卷第17期

页      面：17194-17204页

核心收录：

学科分类：0808[工学-电气工程] 08[工学] 0804[工学-仪器科学与技术] 0702[理学-物理学] 

基　　金：National Key Research and Development Program of China [2020YFB0505803] National Natural Science Foundation of China 

主　　题：Earth Micromechanical devices Global navigation satellite system Navigation Sensors Optimization Gravity MEMS-IMU preintegration factor graph optimization GNSS INS integration 

摘      要：In filtering-based global navigation satellite system (GNSS) / inertial navigation system (INS) integrated navigation systems, the precise INS mechanization has fully considered the impact of the Earth rotation, Coriolis acceleration, etc. However, most inertial measurement unit (IMU) preintegration models in factor graph optimization (FGO)-based integrated navigation systems are rough and ignore these factors. We propose an FGO-based GNSS/INS integrated navigation system to analyze and evaluate the impact of the Earth rotation on MEMS-IMU preintegration. The proposed FGO-based integration is based on a refined IMU preintegration, in which the Earth rotation is compensated. The proposed GNSS/INS integration is a sliding-window optimizer in which the GNSS positioning and the IMU preintegration are tightly fused within the FGO framework. The simulated GNSS outage in field tests, an effective method, is adopted to evaluate the IMU preintegration quantitatively. The results demonstrate that the refined IMU preintegration can achieve the same accuracy as the precise INS mechanization. In contrast, the rough IMU preintegration and INS mechanization without compensating for the Earth rotation yields notable accuracy degradation. When the GNSS-outage time is 60 seconds, the degradation can be 200% for the industrial-grade MEMS module and more than 10% for the consumer-grade MEMS chip. Besides, the degradation can be more significant if the GNSS-outage time is longer. The proposed FGO-based GNSS/INS integration (https://***/i2Nav-WHU/OB_GINS) and the employed datasets (https://***/i2Nav-WHU/awesome-gins-datasets) are open-sourced on GitHub.