Patent ID: 8027803

Claim:
A traveling direction measuring apparatus including 3-axes acceleration detecting means for detecting acceleration, and acceleration data acquiring means for obtaining 3-axes acceleration data repeatedly by a number of prescribed times or more, said 3-axes acceleration data varies with walking of a pedestrian, said traveling direction measuring apparatus comprising: first gravity acceleration calculating means for calculating, when the pedestrian is walking with holding said traveling direction measuring apparatus in a generally fixed attitude, gravity acceleration by averaging acceleration data sets during several steps obtained by said acceleration data acquiring means; frequency component calculating means for calculating frequency components corresponding to duration of one step of the acceleration data sets projected on a plane perpendicular to the gravity acceleration calculated by said first gravity acceleration calculating means; first moving direction estimating means for estimating a moving direction of the pedestrian seen from a terminal coordinate system associated with said traveling direction measuring apparatus according to the frequency components; 3-axes geomagnetism detecting means for detecting geomagnetism; geomagnetism data acquiring means for obtaining 3-axes geomagnetism data repeatedly by a number of prescribed times or more, said 3-axes geomagnetism data varies with the walking of the pedestrian; and first walking direction estimating means for estimating, when the pedestrian is walking with holding said traveling direction measuring apparatus in a generally fixed attitude, the walking direction of the pedestrian with respect to a terrestrial coordinate system from geomagnetism data sets obtained by said geomagnetism data acquiring means and the moving direction of the pedestrian estimated by said first moving direction estimating means.