SYSTEM, METHOD, AND PROGRAM FOR DETECTING DEFLATED TIRES

• US 20120304754A1
• Filed: 05/30/2012
• Published: 12/06/2012
• Est. Priority Date: 06/03/2011
• Status: Active Grant

• Current Assignee: Honda Motor Co., Ltd. (Honda Motor Company), Sumitomo Rubber Industries Limited
• Original Assignee: Honda Motor Co., Ltd. (Honda Motor Company), Sumitomo Rubber Industries Limited
• Inventors: Oshiro, Yuji, Kitano, Masashi, Kawasaki, Hiroaki, Sakagami, Seigou, Sakai, Tomonori, Notomi, Shinya, Okada, Kazunari
• Granted Patent: US 8,726,724 B2
• Time in Patent Office: Days
• US Class Current: 73/146
• CPC Class Codes: B60C 23/061 by monitoring wheel speed measuring distance traversed on the ground by vehicles G01C22/00
• CPC Class Codes: B60C 23/062 Frequency spectrum analysis of wheel speed signals, e.g. using Fourier transformation

Abstract

A system detects deflated tires based on a resonance frequency of tires with a vehicle and a relative comparison value of rotation speeds of the tires. The system includes: a rotation information detection means for detecting rotation information of the tires; a rotation speed calculation means for calculating rotation speeds of the tires; a resonance frequency assumption means for assuming a resonance frequency of the tires; and a determination means for detection of deflated tires using a decreased pressure determination index calculated by a relative comparison of the rotation speeds of the tires and the resonance frequency. The determination means is so configured as to reduce the second threshold to be compared with the decreased pressure determination index to a value equal to or higher than 1% and equal to or lower than 90% and to detect deflated tires when the decreased pressure determination index exceeds the reduced threshold.

Claims

1. A system for detection of deflated tires based on a resonance frequency of tires attached to a vehicle and a relative comparison index of rotation speeds of the tires, comprising:

a rotation information detection means for detecting rotation information of the tires;

a rotation speed calculation means for calculating rotation speeds of the tires based on the rotation information detected by the rotation information detection means;

a resonance frequency assumption means for assuming a resonance frequency of the tires based on the rotation information of the tires; and

a determination means for detection of deflated tires using a decreased pressure determination index calculated by a relative comparison of the rotation speeds of the tires and the resonance frequency assumed by the resonance frequency assumption means,

wherein the determination means is so configured, assuming that the first determination index at which warning is issued when the resonance frequency exceeds the first threshold a predetermined number of times is 100 in detecting deflated tires based on the resonance frequency and when the first determination index has a converted percentage equal to or higher than 10 and lower than 100, as to reduce the second threshold to be compared with the decreased pressure determination index to a value equal to or higher than 1% and equal to or lower than 90% and to detect deflated tires having a decreased pressure when the decreased pressure determination index exceeds the reduced threshold.

2. The system according to claim 1, wherein the determination means is so configured as to reduce, when the first determination index has a converted percentage equal to or higher than 70 and lower than 90, the second threshold to be compared with the decreased pressure determination index to an index equal to or higher than 1% and equal to and lower than 50% and to detect deflated tires when the decreased pressure determination index exceeds the reduced threshold.

3. A system for detection of deflated tires based on a resonance frequency of tires attached to a vehicle and a relative comparison index of rotation speeds of the tires, comprising:

a rotation information detection means for detecting rotation information of the tires;

a rotation speed calculation means for calculating rotation speeds of the tires based on the rotation information detected by the rotation information detection means;

a resonance frequency assumption means for assuming a resonance frequency of the tires based on the rotation information of the tires; and

a determination means for detection of deflated tires using a decreased pressure determination index calculated by a relative comparison of the rotation speeds of the tires and the resonance frequency assumed by the resonance frequency assumption means,

wherein the determination means is so configured, assuming that the first determination index at which warning is issued when the resonance frequency exceeds the first threshold a predetermined number of times is 100 in detecting deflated tires based on the resonance frequency and when the first determination index has a converted percentage equal to or higher than 10 and lower than 100, as to detect deflated tires, assuming that the second determination index at which warning is issued when the decreased pressure determination index exceeds the second threshold a predetermined number of times is 100 and when the second determination index has a converted percentage equal to or higher than 10 and lower than 100.

4. The system according to claim 3, wherein the determination means is so configured as to detect deflated tires when the first determination index has a converted percentage equal to or higher than 70 and lower than 90 and when the second determination index has a converted percentage equal to or higher than 50 and lower than 100.

5. A method of detecting deflated tires based on a resonance frequency of tires attached to a vehicle and a relative comparison index of rotation speeds of the tires, including:

a rotation information detection step for detecting rotation information of the tires;

a rotation speed calculation step for calculating rotation speeds of the tires based on the rotation information detected in the rotation information detection step;

a resonance frequency assumption step for assuming a resonance frequency of the tires based on the rotation information of the tires; and

a determination step for detection of deflated tires using a decreased pressure determination index calculated by a relative comparison of the rotation speeds of the tires and the resonance frequency assumed in the resonance frequency assumption step,

wherein the determination step is so configured, assuming that the first determination index at which warning is issued when the resonance frequency exceeds the first threshold a predetermined number of times is 100 in detecting deflated tires having a decreased air pressure based on the resonance frequency and when the first determination index has a converted percentage equal to or higher than 10 and lower than 100, as to reduce the second threshold to be compared with the decreased pressure determination index to an index equal to or higher than 1% and equal to or lower than 90% and to detect deflated tires when the decreased pressure determination index exceeds the reduced threshold.

6. The method according to claim 5, wherein the determination step is so configured as to reduce, when the first determination index has a converted percentage equal to or higher than 70 and lower than 90, the second threshold to be compared with the decreased pressure determination index to a value equal to or higher than 1% and equal to and lower than 50% and to detect deflated tires when the decreased pressure determination index exceeds the reduced threshold.

7. A method of detecting deflated tires based on a resonance frequency of tires attached to a vehicle and a relative comparison index of rotation speeds of the tires, including:

a rotation information detection step for detecting rotation information of the tires;

a rotation speed calculation step for calculating rotation speeds of the tires based on the rotation information detected in the rotation information detection step;

a resonance frequency assumption step for assuming a resonance frequency of the tires based on the rotation information of the tires; and

a determination step for detection of deflated tires using a decreased pressure determination index calculated by a relative comparison of the rotation speeds of the tires and the resonance frequency assumed by the resonance frequency assumption step,

wherein the determination step is so configured, assuming that the first determination index at which warning is issued when the resonance frequency exceeds the first threshold a predetermined number of times is 100 in detecting deflated tires based on the resonance frequency and when the first determination index has a converted percentage equal to or higher than 10 and lower than 100, as to detect deflated tires, assuming that the second determination index at which warning is issued when the decreased pressure determination index exceeds the second threshold a predetermined number of times is 100 and when the second determination index has a converted percentage equal to or higher than 10 and lower than 100.

8. The method according to claim 7, wherein the determination step is so configured as to detect deflated tires when the first determination index has a converted percentage equal to or higher than 70 and lower than 90 and when the second determination index has a converted percentage equal to or higher than 50 and lower than 100.

9. A program for detection of deflated tires causing, in order to detect deflated tires based on a resonance frequency of tires attached to a vehicle and a relative comparison value of rotation speeds of the tires, a computer to function as:

a rotation speed calculation means for calculating rotation speeds of the tires based on rotation information detected by a rotation information detection means for detecting rotation information of the tires;

a resonance frequency assumption means for assuming a resonance frequency of the tires based on the rotation information of the tires; and

a determination means for detection of deflated tires using a decreased pressure determination index calculated by a relative comparison of the rotation speeds of the tires and the resonance frequency assumed by the resonance frequency assumption means,

wherein the determination means is so configured, assuming that the first determination index at which warning is issued when the resonance frequency exceeds the first threshold a predetermined number of times is 100 in detecting deflated tires based on the resonance frequency and when the first determination index has a converted percentage equal to or higher than 10 and lower than 100, as to reduce the second threshold to be compared with the decreased pressure determination index to a value equal to or higher than 1% and equal to or lower than 90% and to detect deflated tires when the decreased pressure determination index exceeds the reduced threshold.

10. The program according to claim 9, wherein the determination means is so configured as to reduce, when the first determination value has a converted percentage equal to or higher than 70 and lower than 90, the second threshold to be compared with the decreased pressure determination index to an index equal to or higher than 1% and equal to and lower than 50% and to detect deflated tires when the decreased pressure determination index exceeds the reduced threshold.

11. A program for detection of deflated tires for causing, in order to detect deflated tires based on a resonance frequency of tires attached to a vehicle and a relative comparison index of rotation speeds of the tires, a computer to function as:

a rotation speed calculation means for calculating rotation speeds of the tires based on rotation information detected by a rotation information detection means for detecting rotation information of the tires;

a resonance frequency assumption means for assuming a resonance frequency of the tires based on the rotation information of the tires; and

a determination means for detection of deflated tires using a decreased pressure determination index calculated by a relative comparison of the rotation speeds of the tires and the resonance frequency assumed by the resonance frequency assumption means,

wherein the determination means is so configured, assuming that the first determination value at which warning is issued when the resonance frequency exceeds the first threshold a predetermined number of times is 100 in detecting deflated tires based on the resonance frequency and when the first determination has a converted percentage equal to or higher than 10 and lower than 100, as to detect deflated tires, assuming that the second determination index at which warning is issued when the decreased pressure determination index exceeds the second threshold index a predetermined number of times is 100 and when the second determination index has a converted percentage equal to or higher than 10 and lower than 100.

12. The program according to claim 11, wherein the determination means is so configured as to detect deflated tires when the first determination index has a converted percentage equal to or higher than 70 and lower than 90 and when the second determination index has a converted percentage equal to or higher than 50 and lower than 100.