| 摘要 |
PROBLEM TO BE SOLVED: To provide a portable terminal, a program, and a method for determining as accurately as possible the traveling direction of a pedestrian by using only a geomagnetic sensor mounted on the portable terminal even where the pedestrian is walking with the portable terminal in hand. SOLUTION: This portable terminal, comprising a triaxial geomagnetic sensor and being carried by the pedestrian, comprises a traveling direction determination means for determining the traveling direction of the pedestrian from geomagnetic data. The determination means comprises a cone approximation means for plotting geomagnetic data corresponding to the passage of time on a three-dimensional coordinate system and approximately regarding a conically distributed geomagnetic vector group caused by arm swing as a cone, a cone height calculation means for calculating the height h of the cone, and a direction angle calculation means for calculating a direction angleθrelative to a geomagnetic plane based on the height h. The angle calculation means performs calculation based on an equation: direction angleθ=arcsin (h/sin I) by using an angle I which a gravitational direction forms with geomagnetism. COPYRIGHT: (C)2009,JPO&INPIT |
