NavShoe paper summary
Tracking of users using systems like GPS has many useful applications. However it also suffers from issues like inaccuracy in exact positioning and uncertainty of the exact path being and to be followed by the user. The paper discusses an approach towards pedestrian tracking using shoe-mounted inertial sensors. The NavShoe concept performs robust tracking with and without GPS.
The inertial sensors alone, however, are not sufficient to track position for more than few seconds due to drift errors in gyro. The NavShoe circumvents this by navigating open loop for about 0.5 seconds and applying Zero-Velocity Updates in Ektended Kalman Filter(EKF). The heading drift is solved using ways such as using high-performance gyro, use magnetic compass for heading-correction or position correction using GPS or other devices. Each method has its own limitations. There were also hardware hurdles such as eliminating cables.
On the software side few key algorithms are described in detail. The drift corrections are performed on EKF. There are also calibration issues which the user has to take care of for accurate position tracking. Geomagnetic modeling is also applied and tests are run where user is asked to walk around the house. Issues of inaccurate tracking were observed in both indoor and outdoor experiments. Tests were also performed using GPS assistance. There were significant discrepancies due to ignored GPS fixes.
In the future work the plan is to integrate the system with a full MR system. The Navshoe will not replace the MR system but will make it more robust and reduce the load on computer vision system.
Comments are closed.