Indoor way-finding method using IMU and magnetic tensor sensor measurements for visually impaired users

Abstract

This paper introduces a new indoor way-finding method for the visually impaired person (VIP) by utilizing the naturally-generated inertial and geomagnetic information. Reliable and accurate indoor orientation and localization are provided by newly designed sensor fusion algorithms, which take advantage of inertial and geomagnetic information and overcome the inherent problems of the naturally-generated signals, such as low signal-to-noise ratio (SNR) and high environmental sensitivity. Geomagnetic information compensates the sensor drift and accumulative error of the inertial sensors whereas the inertial sensors help to correct the orientation-related errors and drift of the magnetic fields. A parameter derived from the magnetic tensor is introduced for obstacle avoidance and object/destination approach, especially when the relatively large localization uncertainty exists. With a prototype developed based on the system design, several experiments under different indoor scenarios demonstrate that the proposed indoor-way finding method can guide the VIPs and avoid obstacles indoor efficiently and accurately.