WHEEL THEFT DETECTOR, WHEEL THEFT DETECTING METHOD, WHEEL THEFT DETECTING PROGRAM, AND ITS RECORDING MEDIUM

摘要

A wheel theft detector (1) comprises a vibration sensor (2) for measuring the vibration of a vehicle, a frequency converting section (16) for converting the result of the measurement by the vibration sensor (2) into data on a frequency range, a feature value extracting section (17) for extracting feature values corresponding to the frequency components of the converted data on the frequency range, and a recognizing section (18) for discriminating, out of the vibration measured by the vibration sensor (2), the vibration of the vehicle caused when a rotating force is exerted on a nut fixing a wheel to the vehicle from the vibration caused by other factors. Consequently, detachment of a wheel from the vehicle can be accurately detected.