Patent ID: 7487044

Claim:
An apparatus for predicting a length of a braking distance of a vehicle equipped with tires, when a breaking operation is performed for stopping the vehicle while the vehicle is traveling on a road, the braking distance referring to a distance at which the vehicle travels during a period from a commencement of the braking operation for stopping the vehicle to a complete stop of the vehicle, the apparatus including: an acquiring part for acquiring acceleration data in a time series of a predetermined site of the tire during traveling of the vehicle; a removing part for removing an acceleration component due to a deformation of the tire from the acquired acceleration data to obtain a deformation-component-removed acceleration data; an analyzing part for performing frequency analysis of the deformation-component-removed acceleration data to obtain a frequency spectrum; a calculating part for obtaining an accumulated value of the frequency spectrum, and calculating a braking distance parameter for predicting a braking distance based on the obtained accumulated value; and a predicting part for obtaining a predicted value of the braking distance of the vehicle based on the braking distance parameter calculated in the calculating part, wherein the acquiring part acquires acceleration data in a time series in a plurality of different directions of the predetermined site of the tire, the removing part obtains the deformation-component-removed acceleration data in the plurality of different directions from the acceleration data in the time series in the plurality of different directions, the analyzing part performs frequency analysis of the deformation-component-removed acceleration data in the plurality of different directions to obtain the frequency spectrum, in the plurality of different directions, the calculating part obtains accumulated values of the frequency spectrum in the plurality of different directions and calculates the braking distance parameter based on the accumulated values in the plurality of different directions.