NUMERICALLY STABLE COMPUTATION OF HEADING WITHOUT A REFERENCE AXIS

摘要

Systems and methods are described for computing device motion direction and orientation. A system as described herein includes an orientation sensor configured to collect data relating to orientation of the mobile device; an orientation analysis module communicatively coupled to the orientation sensor and configured to determine a three-dimensional orientation of the mobile device relative to an Earth- based coordinate system based on the data collected by the orientation sensor; and a motion direction tracker module communicatively coupled to the orientation analysis module, configured to compute a first direction, that is a three-dimensional direction of motion of the mobile device relative to a coordinate system of the mobile device, and configured to compute a second direction, that is a direction of motion of the mobile device relative to the Earth-based coordinate system, based on the first direction using the three-dimensional orientation of the mobile device relative to the Earth-based coordinate system.