| 摘要 |
PROBLEM TO BE SOLVED: To provide a portable terminal or the like for determining accurately a traveling direction of a pedestrian by using an acceleration sensor and a geomagnetic sensor in the portable terminal, when the pedestrian is walking with the portable terminal in hand. SOLUTION: This portable terminal includes: a walking reference vector calculation means for calculating a walking reference vector which is a normal vector to an acceleration surface based on arm swing; an azimuth reference vector calculation means for deriving a gravity vector and a geomagnetic vector corresponding thereto, and calculating an azimuth reference vector which is a normal vector to an azimuth reference surface of both vectors; and an azimuth angle calculation means for calculating an azimuth angle in the traveling direction based on both vectors. The walking reference vector calculation means measures a time interval between each minimal point in a change of a synthetic acceleration following elapse of time, and compares two adjacent time intervals. A minimal point at the end point time of a long time interval shows an acceleration surface front (traveling direction front), and a minimal point at the end point time of a short time interval shows an acceleration surface rear (traveling direction rear). COPYRIGHT: (C)2011,JPO&INPIT |
