Patent ID: 9688107
Date: 2017-06-27
CPC Classifications: B60C

Claim:
1. A tire pressure decreased detection apparatus comprising: a rotation speed sensor configured to regularly detect rotation speed information of tires of wheels of a vehicle; a band-pass filter; and a processor configured to: wherein in a case where the calculated correlation coefficient or contribution of the rotation acceleration information of the left and right wheels passing through the band-pass filter exceeds a predetermined threshold value, the processor is configured to determine that a periodic noise from the driving wheels of the vehicle is generated in the vicinity of the torsional resonance frequency and to stop estimating the torsional resonance frequency, the predetermined threshold value being determined based on correlation coefficients or contributions of a time of generating of a driving noise and of the time of non-generation obtained by an experiment in advance, and wherein the processor is further configured to generate a report regarding the tire pressure, which eliminates an erroneous alarm or non-alarm, based on the determined decrease in pressure in the determination step, to affect operation of the vehicle.