FTIN: Frequency-Time Integration Network for Inertial Odometry

Abstract: In recent years, machine learning has achieved significant advancements in inertial odometry. However, most existing inertial odometry methods primarily rely on CNNs in the time domain. These methods often struggle to capture long-term dependency in inertial measurement unit data, thereby constraining the potential for further improvements in localization accuracy. To address these issues, we propose a novel network architecture that integrates both frequency-domain and time-domain information. Specifically, we leverage the global view and energy compaction properties of frequency-domain learning to effectively model long-term dependency and reduce redundancy in IMU data. Additionally, we introduce a Scalar LSTM to capture sequential dependencies in the time domain, enabling cross-domain information fusion and providing a stable and reliable reference for localization. Experimental evaluations on multiple public datasets (e.g., RIDI, RoNIN, OxIOD, RNIN, TLIO, and IMUNet) demonstrate the effectiveness of the proposed frequency-time domain fusion strategy. Notably, on the RoNIN dataset, our method achieves a 43.0% reduction in absolute trajectory error and a 13.1% reduction in relative trajectory error compared to RoNIN ResNet.