US 5,553,491 A · Tire air pressure detecting device

Abstract

It is an object of the present invention to detect a tire air pressure indirectly with high detection precision. A tire air pressure detecting device includes a speed sensor for outputting a signal corresponding to a rotational speed of a tire, and an electronic control unit which inputs the signal from the speed sensor and performs predetermined arithmetic operations on that signal. The electronic control unit calculates a wheel speed based on the output signal of the speed sensor, performs a frequency analysis for the calculated vehicle speed, and derives a resonance frequency corresponding to the unsprung mass in the vertical and longitudinal directions. The tire air pressure is then detected based on this resonance frequency.

Claims7

Dependent claims

A tire air pressure detecting device comprising:

output means installed on a vehicle, for outputting a signal including a vibration frequency component of a tire while said vehicle is moving;
deriving means for deriving gains in regard to each frequency of said vibration frequency component;
extracting means for extracting a plurality of said gains which correspond to a predetermined frequency band;
estimation means for estimating a resonance frequency at which a peak gain exists, based on a distribution of said plurality of gains;
and
detecting means for detecting a tire air pressure condition based on said resonance frequency having said peak gain.

3 more elements

Dependencies are inferred from the claim text.

Tire air pressure detecting device

Life of this patent

Tire air pressure detecting device

Life of this patent

Abstract

Claims7