US5801305A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for detecting a tire inflation pressure
Assignee: Aisin Corp
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Filing: 1996-10-28
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Granted: 1998-09-01
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Expires: 2016-10-28
Abstract
Abstract The invention is directed to a method and apparatus for detecting a tire inflation pressure of a vehicle tire. The apparatus includes a device for producing an oscillating electric signal having a vibration frequency component of the vehicle tire. A wavelet transformer transforms the oscillating electric signal by a wavelet function into a wavelet coefficient. The wavelet function is provided on the basis of a mother wavelet function localized in time, scaled in response to a scale parameter, and shifted in response to a shift parameter indicative of a time localization. Then, an extracting device extracts a resonance frequency from the vibration frequency component of the vehicle tire on the basis of the wavelet coefficient, and an estimating device estimates the tire inflation pressure on the basis of the resonance frequency. The apparatus may further include a warning device for warning a decrease of the tire inflation pressure when the resonance frequency decreases to an extent that a difference between the resonance frequency and the reference frequency exceeds a predetermined frequency.
Inventors
- 👤 Hiroaki Kawai
- 👤 Katsu Hattori
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 11:20
CPC Classifications
G; G06; G06F; G06F17/00; G06F17/10; G06F17/14; B; B60; B60C; B60C23/00; B60C23/06; B60C23/061; B60C23/062
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
174 words
A method for detecting a tire inflation pressure of a vehicle tire, comprising the steps of: producing an oscillating electric signal having a vibration frequency component of said vehicle tire; transforming the oscillating electric signal by a wavelet function into a wavelet coefficient, said wavelet function being provided on the basis of a mother wavelet function localized in time, scaled in response to a scale parameter, and shifted in response to a shift parameter indicative of a time localization; extracting a resonance frequency from the vibration frequency component of said vehicle tire on the basis of the wavelet coefficient, the step of extracting the resonance frequency including extracting a maximum frequency from the vibration frequency components of said vehicle tire obtained every first predetermined time period on the basis of the wavelet coefficient, and selecting a most frequent value of the maximum frequencies extracted in a second predetermined time period thereby to set the most frequent value for the resonance frequency; and estimating the tire inflation pressure on the basis of the resonance frequency.
Claim 2
Independent Claim
174 words
A method for detecting a tire inflation pressure of a vehicle tire, comprising the steps of: producing an oscillating electric signal having a vibration frequency component of said vehicle tire; transforming the oscillating electric signal by a wavelet function into a wavelet coefficient, said wavelet function being provided on the basis of a mother wavelet function localized in time, scaled in response to a scale parameter, and shifted in response to a shift parameter indicative of a time localization; extracting a resonance frequency from the vibration frequency component of said vehicle tire on the basis of the wavelet coefficient, the step of extracting the resonance frequency including extracting a maximum frequency from the vibration frequency components of said vehicle tire obtained every first predetermined time period on the basis of the wavelet coefficient, and selecting a most frequent value of the maximum frequencies extracted in a second predetermined time period thereby to set the most frequent value for the resonance frequency; and estimating the tire inflation pressure on the basis of the resonance frequency.
Claim 3
Dependent Claim
47 words
The method as defined in claim 1, wherein the step of producing the oscillating electric signal includes the step of detecting a rotational speed of said vehicle tire to output an electric signal which corresponds to the rotational speed and which serves as the oscillating electric signal.
Claim 4
Dependent Claim
57 words
The method as defined in claim 1, further comprising the step of comparing the resonance frequency with a predetermined reference frequency, and the step of warning of a decrease of the tire inflation pressure when the resonance frequency decreases to an extent that a difference between the resonance frequency and the reference frequency exceeds a predetermined frequency.
Claim 5
Independent Claim
197 words
An apparatus for detecting a tire inflation pressure of a vehicle tire, comprising: means for producing an oscillating electric signal having a vibration frequency component of said vehicle tire; means for transforming the oscillating electric signal by a wavelet function into a wavelet coefficient, said wavelet function being provided on the basis of a mother wavelet function localized in time, scaled in response to a scale parameter, and shifted in response to a shift parameter indicative of a time localization; means for extracting a resonance frequency from the vibration frequency component of said vehicle tire on the basis of the wavelet coefficient, said means for extracting the resonance frequency including means for extracting a maximum frequency from the vibration frequency components of said vehicle tire obtained every first predetermined time period on the basis of the wavelet coefficient obtained by said means for transforming the oscillating electric signal into the wavelet coefficient, and means for selecting a most frequent value of the maximum frequencies extracted in a second predetermined time period thereby to set the most frequent value for the resonance frequency; and means for estimating the tire inflation pressure on the basis of the resonance frequency.
Claim 6
Independent Claim
197 words
An apparatus for detecting a tire inflation pressure of a vehicle tire, comprising: means for producing an oscillating electric signal having a vibration frequency component of said vehicle tire; means for transforming the oscillating electric signal by a wavelet function into a wavelet coefficient, said wavelet function being provided on the basis of a mother wavelet function localized in time, scaled in response to a scale parameter, and shifted in response to a shift parameter indicative of a time localization; means for extracting a resonance frequency from the vibration frequency component of said vehicle tire on the basis of the wavelet coefficient, said means for extracting the resonance frequency including means for extracting a maximum frequency from the vibration frequency components of said vehicle tire obtained every first predetermined time period on the basis of the wavelet coefficient obtained by said means for transforming the oscillating electric signal into the wavelet coefficient, and means for selecting a most frequent value of the maximum frequencies extracted in a second predetermined time period thereby to set the most frequent value for the resonance frequency; and means for estimating the tire inflation pressure on the basis of the resonance frequency.
Claim 7
Dependent Claim
53 words
The apparatus as defined in claim 4, wherein said means for producing the oscillating electric signal includes a rotational speed sensor for detecting a rotational speed of said vehicle tire to output an electric signal corresponding to the rotational speed to said means for transforming the oscillating electric signal into the wavelet coefficient.
Claim 8
Dependent Claim
60 words
The apparatus as defined in claim 4, further comprising means for comparing the resonance frequency with a predetermined reference frequency, and means for warning of a decrease of the tire inflation pressure when said comparing means determines that the resonance frequency decreases to an extent that a difference between the resonance frequency and the reference frequency exceeds a predetermined frequency.
Claim 9
Dependent Claim
39 words
The method as defined in claim 1, wherein said step of extracting a resonance frequency involves extracting an initial resonance frequency and extracting a subsequent resonance frequency, and including comparing the initial resonance frequency to the subsequent resonance frequency.
Claim 10
Dependent Claim
39 words
The apparatus as defined in claim 4, wherein said means for extracting includes means for extracting an initial resonance frequency and a subsequent resonance frequency, and including means for comparing the initial resonance frequency with the subsequent resonance frequency.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2001-08-31 | 2002-03-02 | 2002-09-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-08-31 | 2006-03-02 | 2006-09-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-08-31 | 2010-03-02 | 2010-09-01 | $7700.00 | Window Closed / Lapsed |