Improved Pedestrian Navigation Based on Drift-Reduced MEMS IMU Chip

Sheng Wan and Eric Foxlin

Abstract:	We previously presented a prototype of a personal navigation system called NavShoe™ which uses shoe-mounted inertial sensors and magnetometers to achieve GPS-denied navigation with very low drift rates in most circumstances [1]. Zero-velocity updates (ZUPTs) were obtained during the stance phase of each step to correct position and velocity drift, and carefully-screened and compensated magnetometer readings helped constrain the heading drift of the low-cost MEMS gyroscopes. The system worked extremely well in many environments, but the heading accuracy would gradually degrade in environments where no usable readings of earth’s magnetic field can be obtained for an extended period of time, or where distorted readings are very difficult to distinguish and reject from the Kalman filter. In an effort to make the NavShoe more robust and less dependent on compass measurements which can sometimes cause accuracy problems, we set out to design a new IMU called NavChip™ with better performance and smaller size than the InertiaCube3 that was used in the original NavShoe prototype system. This paper introduces the new NavChip sensor, and evaluates the improvement in raw dead-reckoning performance of the NavShoe obtained by using it, without aiding from magnetometer, GPS or any other complementary technology. The improvement in heading drift is substantial, which will facilitate the development of more robust and accurate pedestrian localization systems by fusing the NavShoe inertial dead-reckoning data with complementary technologies. A simplistic error accumulation model for gyro-based dead-reckoning systems is provided to help understand the way errors accumulate as a function of time, distance and path.
Published in:	Proceedings of the 2010 International Technical Meeting of The Institute of Navigation January 25 - 27, 2010 Catamaran Resort Hotel San Diego, CA
Pages:	220 - 229
Cite this article:	Wan, Sheng, Foxlin, Eric, "Improved Pedestrian Navigation Based on Drift-Reduced MEMS IMU Chip," Proceedings of the 2010 International Technical Meeting of The Institute of Navigation, San Diego, CA, January 2010, pp. 220-229.
Full Paper:	ION Members/Non-Members: 1 Download Credit Sign In