INERTIAL POSITIONING AND TRACKING METHOD AND SYSTEM WITH INNOVATIVE FUNCTIONALITY FOR MAGNETOMETER AUTO-CALIBRATION AND FOR ANGULAR DRIFT COMPENSATION/CORRECTION

摘要

PROBLEM: An inertial tracker, attached to a pedestrian's foot, can be used track his movements. To improve tracking accuracy, the tracker may use a magnetometer to provide angular drift correction in the horizontal plane. Such use of the magnetometer requires its calibration ahead of time, but this may not always be possible, e.g. because of a magnetically polluted urban environment.;SOLUTION: Inertial position and tracking method comprising (at a high level): step detection based on inertial measurements; path construction through integration of inertial (accelerometer / gyroscope) measurements, and compensation of angular drift and alignment to magnetic north based on magnetic field readings. T he method provides for gradual calibration (avoiding initial calibration) by averaging magnetic field readings over longer path lengths to mitigate locally magnetically polluted environments.