US5838230A
Expired / Lapsed
US
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Method of detecting a deflated tire on a vehicle
Assignee: Sumitomo Rubber Industries Ltd
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Filing: 1993-07-02
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Granted: 1998-11-17
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Expires: 2013-07-02
Abstract
Abstract A method of detecting a deflated tire on a vehicle by comparing the rolling radii of the tires by means of comparing angular velocity speed signals from wheel speed sensors one at each wheel characterized by calculating an error value (DEL') where DEL'= (C1+C4)/2-(C2+C3)/2!×100!/ (C1+C2+C3+C4)/4! where C1, C2, C3 and C4 are angular velocity values for left-hand front, right-hand front, left-hand rear and right-hand rear wheels of the vehicle respectively, determining a correction factor LAT, calculating a corrected error value DEL wherein in the case that the sign of the product LAT×A of the correction factor LAT and the vehicle related constant A is opposite to the sign of the error value DEL' then the corrected error value DEL is given by DEL=DEL', and in the case that the product LAT×A and the error value DEL' have the same sign but the product LAT×A is greater in absolute magnitude then the error value DEL' the corrected error value DEL is given by DEL=0, otherwise the corrected error value DEL is given by DEL=DEL'-(LAT×A) and a tire warning indicator is operated in the vehicle to indicate that at least one tire is deflected when it is sensed that the magnitude of the corrected error value DEL is in the range 0.05 to 0.5.
Inventors
- 👤 David Jones
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 08:44
CPC Classifications
B; B60; B60C; B60C23/00; B60C23/06; B60C23/061
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
237 words
A method of detecting a deflated tire on a vehicle comprising the steps of: rotating each tire of the vehicle; providing one wheel speed sensor for each of the tires; detecting the angular velocity speed of the tires by the wheel speed sensors; comparing the rolling radii of the tires by means of comparing angular velocity speed signals from the wheel speed sensors characterized by calculating an error value DEL' where ##EQU7## where C1, C2, C3 and C4 are angular velocity values for left-hand front, right-hand front, left-hand rear and right-hand rear wheels of the vehicle, respectively, determining a correction factor LAT, calculating a corrected error value DEL wherein in the case that the sign of product LAT×A or the correction factor LAT and a vehicle related constant A is opposite to the sign of the error value DEL' then the corrected error value DEL is given by DEL=DEL' and in the case that the product LAT×A and the error value DEL' have the same sign but the product LAT×A is greater in absolute magnitude than the error value DEL' then the corrected error value DEL is given by DEL=0 otherwise the corrected error value DEL is given by DEL=DEL'-(LAT×A) and a tire warning indicator is operated in the vehicle to indicate that at least one tire is deflected when the magnitude of the corrected error value DEL is sensed in the range of 0.05 to 0.5.
Claim 2
Independent Claim
237 words
A method of detecting a deflated tire on a vehicle comprising the steps of: rotating each tire of the vehicle; providing one wheel speed sensor for each of the tires; detecting the angular velocity speed of the tires by the wheel speed sensors; comparing the rolling radii of the tires by means of comparing angular velocity speed signals from the wheel speed sensors characterized by calculating an error value DEL' where ##EQU7## where C1, C2, C3 and C4 are angular velocity values for left-hand front, right-hand front, left-hand rear and right-hand rear wheels of the vehicle, respectively, determining a correction factor LAT, calculating a corrected error value DEL wherein in the case that the sign of product LAT×A or the correction factor LAT and a vehicle related constant A is opposite to the sign of the error value DEL' then the corrected error value DEL is given by DEL=DEL' and in the case that the product LAT×A and the error value DEL' have the same sign but the product LAT×A is greater in absolute magnitude than the error value DEL' then the corrected error value DEL is given by DEL=0 otherwise the corrected error value DEL is given by DEL=DEL'-(LAT×A) and a tire warning indicator is operated in the vehicle to indicate that at least one tire is deflected when the magnitude of the corrected error value DEL is sensed in the range of 0.05 to 0.5.
Claim 3
Dependent Claim
142 words
The method of detecting a deflated tire according to claim 1, wherein the correction factor LAT is selected by calculating from the angular velocity values C1, C2, C3 and C4 respective first, second, third and fourth deciding factors MC1, MC2, MC3, and MC4 where ##EQU8## then summing the first, second, third and fourth deciding factors and multiplying this sum by a centralizing constant K to give a central deciding factor MPSD and selecting the correction factor LAT as follows, if the first or second deciding factor MC1 or MC2 is greater than the central deciding factor MPSD then LAT=2×(C3×C4)×(C1+C2+C3+C4), if the third or fourth deciding factor MC3 or MC4 is greater than the central deciding factor MPSD then LAT=2×(C1×C2)×(C1+C2+C3+C4), or if none of the deciding factors MC1, MC2, MC3 or MC4 is greater than the central deciding factor MPSD then LAT=(C1+C3-C2-C4)×(C1+C2+C3+C4). 3.
Claim 4
Dependent Claim
26 words
The method of detecting a deflated tire according to claim 2, wherein the centralizing constant K has a value in the range of 0.250125 to 0.250625.
Claim 5
Dependent Claim
21 words
The method of detecting a deflated tire according to claim 2, wherein the centralizing constant K has a value of 0.25025.
Claim 6
Dependent Claim
51 words
The method of detecting a deflated tire according to claim 2, wherein deflation indicating factors IMC1, IMC2, IMC3, IMC4 are calculated for each wheel, respectively, and the wheel having the numerically greatest of the deflation indicating factor is indicated as deflated, where the deflation indicating factors are calculated as follows: ##EQU9##
Claim 7
Dependent Claim
37 words
The method of detecting a deflated tire according to claim 2, wherein the range at which the tire warning indicator is operated when the magnitude of the corrected error value DEL is sensed is 0.1 to 0.3.
Claim 8
Dependent Claim
28 words
The method of detecting a defined tire according to claim 2, wherein the value of the vehicle related constant A is in the range of -2.0E-7 to +2.0E-7.
Claim 9
Dependent Claim
22 words
The method of detecting a deflated tire according to claim 2, wherein the value of the vehicle related constant A is -2.0E-7.
Claim 10
Dependent Claim
22 words
The method of detecting a deflated tire according to claim 2, wherein the value of the vehicle related constant A is -0.6E-7.
Claim 11
Dependent Claim
22 words
The method of detecting a deflated tire according to claim 2, wherein the value of the vehicle related constant A is +1.3E-7.
Claim 12
Dependent Claim
231 words
A deflated tire detector comprising: a plurality of speed sensors each provided for a corresponding tire of a plurality of tires on a vehicle, each of said speed sensors outputting an angular velocity of said corresponding tire; means for comparing rolling radii of said tires including means for calculating an error signal (DEL') where ##EQU10## where C1, C2, C3 and C4 are angular velocity output by said speed sensors for left-hand front, right-hand front, left-hand rear and right-hand rear tires of the vehicle respectively, means for determining a correction factor (LAT), means for determining a corrected error signal (DEL) wherein in the case that the sign of product LAT×A or the correction factor ACT and a vehicle related constant A is opposite to the sign of the error value DEL' then the corrected error value DEL is given by DEL=DEL' and in the case that the product LAT×A and the error value DEL' have the same sign but the product LAT×A is greater in absolute magnitude than the error value DEL' then the corrected error value DEL is given by DEL=0 otherwise the corrected error value DEL is given by DEL=DEL'-(LAT×A) means for determining when a magnitude of said corrected error signal is between 0.05 and 0.5 and for outputting a warning signal in response thereto; and a warning indicator, receiving said warning signal and providing a warning in accordance therewith.
Claim 13
Dependent Claim
231 words
A deflated tire detector comprising: a plurality of speed sensors each provided for a corresponding tire of a plurality of tires on a vehicle, each of said speed sensors outputting an angular velocity of said corresponding tire; means for comparing rolling radii of said tires including means for calculating an error signal (DEL') where ##EQU10## where C1, C2, C3 and C4 are angular velocity output by said speed sensors for left-hand front, right-hand front, left-hand rear and right-hand rear tires of the vehicle respectively, means for determining a correction factor (LAT), means for determining a corrected error signal (DEL) wherein in the case that the sign of product LAT×A or the correction factor ACT and a vehicle related constant A is opposite to the sign of the error value DEL' then the corrected error value DEL is given by DEL=DEL' and in the case that the product LAT×A and the error value DEL' have the same sign but the product LAT×A is greater in absolute magnitude than the error value DEL' then the corrected error value DEL is given by DEL=0 otherwise the corrected error value DEL is given by DEL=DEL'-(LAT×A) means for determining when a magnitude of said corrected error signal is between 0.05 and 0.5 and for outputting a warning signal in response thereto; and a warning indicator, receiving said warning signal and providing a warning in accordance therewith.
Claim 14
Dependent Claim
18 words
The deflated tire detector according to claim 11, wherein said warning indicator is a light in the vehicle.
Claim 15
Dependent Claim
25 words
The deflated tire detector according to claim 12, wherein said warning indicator comprises a plurality of warning indicators, corresponding to said plurality of speed sensors.
Claim 16
Dependent Claim
19 words
The deflated tire detector according to claim 13, wherein each of said speed sensors comprises a toothed wheel device.
Claim 17
Dependent Claim
146 words
The deflated tire detector according to claim 11, wherein said means for determining said correction factor LAT comprises: means for calculating, from the four angular velocity values C1, C2, C3 and C4, respective first, second, third and fourth deciding factors MC1, MC2, MC3, MC4 where ##EQU11## means for summing the four deciding factors and outputting a sum; means for muLtiplying said sum by a centralizing constant K to give a central deciding factor MPSD; and means for selecting the correction factor LAT as follows, if the first or second deciding factor MC1 or MC2 is greater than the central deciding factor MPSD then LAT=2×(C3-C4)×(C1+C2+C3+C4), if the third or fourth deciding factor MC3 or MC4 is greater than the central deciding factor MPSD then LAT=2×(C1-C2)×(C1+C2+C3+C4), or if none of the deciding factors MC1, MC2, MC3 or MC4 is greater than the central deciding factor MPSD then LAT=(C1+C3-C2-C4)×(C1+C2+C3+C4).
Claim 18
Dependent Claim
21 words
The deflated tire detector according to claim 15, wherein centralizing constant K has a value in the range 0.250125 to 0.250625.
Claim 19
Dependent Claim
17 words
The deflated tire detector according to claim 15, wherein centralizing constant K has a value of 0.25025.
Claim 20
Dependent Claim
52 words
The deflated tire detector according to claim 15, further comprising means for calculating a deflation indicating factor IMC1 , IMC2, IMC3, IMC4 for each wheel respectively and means for indicating the wheel having the numerically greater deflation indicating factor as being deflated, where the calculation of the deflation indicating factors comprises: ##EQU12##
Claim 21
Dependent Claim
24 words
The deflated tire detector according to claim 11 wherein the value of the vehicle related constant A is in the range -2.0E-7 to +2.0E-7.
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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) | 2001-11-16 | 2002-05-18 | 2002-11-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-11-16 | 2006-05-18 | 2006-11-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-11-16 | 2010-05-18 | 2010-11-17 | $7700.00 | Window Closed / Lapsed |