Tire Ground Contact Pattern Specifying Method And Apparatus Thereof

• US 20080125947A1
• Filed: 11/04/2005
• Published: 05/29/2008
• Est. Priority Date: 11/05/2004
• Status: Active Grant

• Current Assignee: Yokohama Rubber Company Limited
• Original Assignee: Yokohama Rubber Company Limited
• Inventors: Hattori, Yutaka
• Granted Patent: US 7,783,405 B2
• Time in Patent Office: Days
• US Class Current: 701/70
• CPC Class Codes: B60G 2204/113 Tyre related sensors
• CPC Class Codes: B60T 8/1725 Using tyre sensors, e.g. Sidewall Torsion sensors [SWT] for tyre pressure and temperature detection B60C23/00
• CPC Class Codes: B60W 10/06 including control of combustion engines
• CPC Class Codes: B60W 10/184 with wheel brakes
• CPC Class Codes: B60W 30/02 Control of vehicle driving stability
• CPC Class Codes: B60W 40/064 Degree of grip
• CPC Class Codes: G01M 17/02 Tyres

Abstract

There is provided a tire ground contact pattern specifying method and an apparatus thereof for specifying a tire ground contact pattern usable to perform the stable control of a running vehicle. Using a sensor unit 100 mounted in each tire 2 of a vehicle 1, accelerations generated in X, Y and Z directions are sensed and at the same time, a low frequency noise component and high frequency noise component added to the Z axis direction acceleration signal are extracted. Digital values being the sensing result are transmitted as digital information to a monitor device 200 by radio wave. The monitor device 200 compares many pieces of tire ground contact pattern information preliminarily stored with the digital information to thereby specify a tire ground contact pattern. A stability control unit 700 performs, based on the acceleration values and the information on tire ground contact pattern obtained, the correction control of driving of a sub-throttle actuator 412 or a brake drive actuator 640.

Claims

1. A tire ground contact pattern specifying method for using a device to specify a ground contact pattern with respect to running road surface for a tire of a running vehicle, the device comprising:

a sensor unit, disposed in a rotation mechanism section including a rotation body positioned in the vehicle body side, for securing a tire and allowing the tire to rotate and the tire, and having an acceleration sensor sensing at least one of a first acceleration generated in association with tire rotation in a direction orthogonal to a rotation axis and a second acceleration generated in a direction of rotation, and converting the sensing result into an electrical signal and performing outputting; and

pattern information storage means for associating a predetermined low frequency component and a predetermined high frequency component of a ground contact pattern determination signal with tire ground contact pattern information including at least information on tire ground contact area with respect to running road surface, and preliminarily storing the resultant information, the method characterized in that the device;

eliminates a gravity acceleration component from at least one electrical signal of the sensed first acceleration and second acceleration to generate the ground contact pattern determination signal;

separates the predetermined low frequency component and predetermined high frequency component of the ground contact pattern determination signal; and

specifies a tire ground contact pattern with respect to running road surface based on the low frequency component and high frequency component obtained by the separation and the information stored in the pattern information storage means.

2. The tire ground contact pattern specifying method according to claim 1, characterized in that:

the pattern information storage means associates the tire ground contact pattern information and the low frequency component and high frequency component obtained at the time of running at a predetermined reference speed, and preliminarily stores the resultant information as reference information; and

the device specifies a tire ground contact pattern with respect to running road surface based on the low frequency component and high frequency component obtained by the separation and the reference information stored in the pattern information storage means.

3. The tire ground contact pattern specifying method according to claim 1, characterized in that:

the sensor unit has means for sensing a third acceleration generated in a direction of the rotation axis and converting the sensing result into an electrical signal and perform outputting;

the pattern information storage means has means for associating tire ground contact pattern information including at least information on tire ground contact area and information on tire ground contact region with respect to running road surface and the low frequency component and high frequency component and the third acceleration, and preliminarily storing the resultant information; and

the device specifies a tire ground contact pattern with respect to running road surface based on the low frequency component and high frequency component, the third acceleration and the information stored in the pattern information storage means.

4. The tire ground contact pattern specifying method according to claim 3, characterized in that:

the pattern information storage means associates the tire ground contact pattern information and the low frequency component and high frequency component and the third acceleration obtained at the time of running at a predetermined reference speed and preliminarily stores the resultant information as reference information;

the device specifies a tire ground contact pattern with respect to running road surface based on the low frequency component and high frequency component and the third acceleration and the reference information stored in the pattern information storage means.

5. The tire ground contact pattern specifying method according to claim 1, characterized in that:

the sensor unit has means for sensing a third acceleration generated in a direction of the rotation axis, converting the sensing result into an electrical signal and performing outputting;

the device has means for combining an electrical signal of the low frequency component and high frequency component with an electrical signal of the third acceleration and outputting an electrical signal obtained by combining these three signals;

the pattern information storage means has means for associating tire ground contact pattern information including at least information on tire ground contact area and information on tire ground contact region with respect to running road surface and the low frequency component and high frequency component and the combination signal, and preliminarily storing the resultant information; and

the device specifies a tire ground contact pattern with respect to running road surface based on the low frequency component and high frequency component and the combination signal obtained by the signal combining means and the information stored in the pattern information storage means.

6. The tire ground contact pattern specifying method according to claim 5, characterized in that:

the pattern information storage means associates the tire ground contact pattern information and the low frequency component and high frequency component and the combination signal obtained at the time of running at a predetermined reference speed and preliminarily stores the resulting information as reference information; and

the device specifies a tire ground contact pattern with respect to running road surface based on the low frequency component and high frequency component and the combination signal and the reference information stored in the pattern information storage means.

7. The tire ground contact pattern specifying method according to claim 2, characterized in that the reference speed is 10 kilometers per hour.

19. The tire ground contact pattern specifying method according to claim 4, characterized in that the reference speed is 10 kilometers per hour.

20. The tire ground contact pattern specifying method according to claim 6, characterized in that the reference speed is 10 kilometers per hour.

8. A tire ground contact pattern specifying device specifying a ground contact pattern with respect to running road surface for a tire of a running vehicle, the device characterized by comprising:

a sensor unit, disposed in a rotation mechanism section including a rotation body positioned in the vehicle body side, for securing a tire and allowing the tire to rotate and the tire, and having an acceleration sensor sensing at least one of a first acceleration generated in association with tire rotation in a direction orthogonal to a rotation axis and a second acceleration generated in a direction of rotation, and converting the sensing result into an electrical signal and performing outputting;

means for eliminating a gravity acceleration component from at least one electrical signal of the first acceleration and second acceleration to generate a ground contact pattern determination signal;

separation means for separating a predetermined low frequency component and a predetermined high frequency component of the ground contact pattern determination signal;

pattern information storage means for associating tire ground contact pattern information including at least information on tire ground contact area with respect to running road surface and the low frequency component and high frequency component, and preliminarily storing the resultant information; and

ground contact pattern specifying means for specifying a tire ground contact pattern based on the low frequency component and high frequency component obtained by the separation means and the information stored in the pattern information storage means, and outputting this tire ground contact pattern information.

9. The tire ground contact pattern specifying device according to claim 8, characterized in that:

the pattern information storage means has means for associating the tire ground contact pattern information and the low frequency component and high frequency component obtained at the time of running at a predetermined reference speed, and preliminarily storing the resultant information as reference information;

the device has the ground contact pattern specifying means for specifying a tire ground contact pattern with respect to running road surface based on the low frequency component and high frequency component obtained by the separation means and the reference information stored in the pattern information storage means, and outputting this tire ground contact pattern information.

10. The tire ground contact pattern specifying device according to claim 8, wherein the sensor unit has means for sensing a third acceleration generated in a direction of the rotation axis, converting the sensing result into an electrical signal and performing outputting, the device characterized by comprising:

the pattern information storage means having means for associating tire ground contact pattern information including at least information on tire ground contact area and information on tire ground contact region with respect to running road surface and the low frequency component and high frequency component and the third acceleration, and preliminarily storing the resultant information; and

the ground contact pattern specifying means for specifying a tire ground contact pattern with respect to running road surface based on the low frequency component and high frequency component and the third acceleration and the information stored in the pattern information storage means, and outputting this ground contact pattern information.

11. The tire ground contact pattern specifying device according to claim 10, characterized in that:

the pattern information storage means has means for associating the tire ground contact pattern information and the low frequency component and high frequency component and the third acceleration obtained at the time of running at a predetermined reference speed, and preliminarily storing the resulting information as reference information;

the device has the ground contact pattern specifying means for specifying a tire ground contact pattern with respect to running road surface based on the low frequency component and high frequency component, the third acceleration and the reference information stored in the pattern information storage means, and outputting this tire ground contact pattern information.

12. The tire ground contact pattern specifying device according to claim 8, wherein the sensor unit has means for sensing a third acceleration generated in a direction of the rotation axis, converting the sensing result into an electrical signal and performing outputting, the device characterized by comprising:

signal combining means for combining an electrical signal of the low frequency component and the high frequency component with an electrical signal of the third acceleration and outputting an electrical signal obtained by combining these three signals;

the pattern information storage means having means for associating tire ground contact pattern information including at least information on tire ground contact area and information on tire ground contact region with respect to running road surface and the low frequency component and high frequency component and the combination signal, and preliminarily storing the resultant information; and

the ground contact pattern specifying means for specifying a tire ground contact pattern with respect to running road surface based on the low frequency component and high frequency component and the combination signal obtained by the signal combining means and the information stored in the pattern information storage means, and outputting this ground contact pattern information.

13. The tire ground contact pattern specifying device according to claim 12, characterized in that:

the pattern information storage means has means for associating the tire ground contact pattern information and the low frequency component and high frequency component and the combination signal obtained at the time of running at a predetermined reference speed, and preliminarily storing the resulting information as reference information;

the device has the ground contact pattern specifying means for specifying a tire ground contact pattern with respect to running road surface based on the low frequency component and high frequency component and the combination signal and the reference information stored in the pattern information storage means, and outputting this tire ground contact pattern information.

14. The tire ground contact pattern specifying device according to claim 9 characterized in that the reference speed is 10 kilometers per hour.

15. The tire ground contact pattern specifying device according to claim 8, characterized in that the sensor unit senses accelerations in different directions at one given position.

16. The tire ground contact pattern specifying device according to claim 8, characterized in that sensing can be performed by the acceleration sensor up to an acceleration larger by a predetermined amount than a maximum acceleration generated by rotation of the tire.

17. The tire ground contact pattern specifying device according to claim 8, characterized in that in order to separate the low frequency component, the separation means includes two or more low-pass filters or band-pass filters having a different pass band and has means for performing a parallel processing of the ground contact pattern determination signal by use of each filter and combining and outputting electrical signals outputted from each filter.

18. The tire ground contact pattern specifying device according to claim 8, characterized in that in order to separate the high frequency component, the separation means includes two or more high-pass filters or band-pass filters having a different pass band and has means for performing a parallel processing of the ground contact pattern determination signal by use of each filter and combining and outputting electrical signals outputted from each filter.