Magnetic Distortion Resistant Orientation Estimation

TL;DR

This paper introduces MDR, a system that models and corrects magnetic distortion in IMU sensors to improve orientation estimation accuracy, especially in indoor environments with magnetic interference.

Contribution

MDR is the first system to explicitly model and correct magnetic distortion using a database, with automatic updates to enhance real-world applicability.

Findings

MDR outperforms existing methods by 35.34% in accuracy.

The system effectively corrects magnetic distortion in indoor environments.

Experiments conducted on over 27 hours of arm motion data.

Abstract

Inertial Measurement Unit (IMU) sensors, including accelerometers, gyroscopes, and magnetometers, are used to estimate the orientation of mobile devices. However, indoor magnetic fields are often distorted, causing the magnetometer's readings to deviate from true north and resulting in inaccurate orientation estimates. Existing solutions either ignore magnetic distortion or avoid using the magnetometer when distortion is detected. In this paper, we develop MDR, a Magnetic Distortion Resistant orientation estimation system that fundamentally models and corrects magnetic distortion. MDR builds a database to record magnetic directions at different locations and uses it to correct orientation estimates affected by magnetic distortion. To avoid the overhead of database preparation, MDR adopts practical designs to automatically update the database in parallel with orientation estimation. Experiments on 27+ hours of arm motion data show that MDR outperforms the state-of-the-art method by 35.34%.