| 摘要 |
PROBLEM TO BE SOLVED: To provide a navigation terminal that can easily use information on vehicle speed and is also suitable for carrying, and to accurately calculate the information on vehicle speed. SOLUTION: A signal of a frequency band according to the rotation of a tire is extracted with a BPF 201 from a magnetic detection signal which is output of a magnetometric sensor 12 including the effect of terrestrial magnetism or the like besides the variation of magnetism by rotation of a magnetic tire, and the vehicle speed is calculated based on the extracted signal. COPYRIGHT: (C)2009,JPO&INPIT |
