Tire air pressure detecting device
First Claim
1. 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.
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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.
51 Citations
7 Claims
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1. A tire air pressure detecting device comprising:
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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. - View Dependent Claims (2, 3, 4, 5, 6)
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7. A tire air pressure detecting device comprising:
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output means installed on a vehicle, for outputting a signal including a vibration frequency component of a tire while said vehicle is moving; analyzing means for analyzing a distribution of gains in regard to each frequency of said vibration frequency component; determining means for determining a frequency at which a peak gain among said distribution of gains exists, based on said distribution of gains; and detecting means for detecting a tire air pressure condition based on said frequency having said peak gain.
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Specification