Vehicle Drive Control System and Sensor Unit and Tire

• US 20070260376A1
• Filed: 11/04/2005
• Published: 11/08/2007
• 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 7,970,510 B2
• Time in Patent Office: Days
• US Class Current: 701/36
• CPC Class Codes: B60C 23/064 comprising tyre mounted deformation sensors, e.g. to determine road contact area
• CPC Class Codes: B60G 2204/113 Tyre related sensors
• CPC Class Codes: B60G 2400/64 Wheel forces, e.g. on hub, spindle or bearing
• CPC Class Codes: B60G 2800/182 Traction
• CPC Class Codes: B60G 2800/22 Braking, stopping
• CPC Class Codes: B60G 2800/94 Electronic Stability Program (ESP, i.e. ABS+ASC+EMS)
• 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 10/18 including control of braking systems
• CPC Class Codes: B60W 10/20 including control of steering systems
• CPC Class Codes: B60W 2530/20 Tyre data
• CPC Class Codes: B60W 30/02 Control of vehicle driving stability
• CPC Class Codes: B60W 40/101 Side slip angle of tyre

Abstract

There is provided a vehicle drive control system performing the stability control of a vehicle by highly accurately and easily sensing accelerations generated in each tire and sensing a tire ground contact pattern, a sensor unit thereof and a tire. 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 and output the information to a stability control unit 700. The 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 vehicle drive control system including control means for driving each of drive actuators for an engine throttle, steering and brake according to a result of sensing a vehicle driving operation state to perform stability control during running of a vehicle, the system characterized by comprising:

a plurality of sensor sections having an acceleration sensor, disposed in each 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 sensing at least one of a first acceleration generated in association with rotation of the tire 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 sensed first acceleration and second acceleration to generate a ground contact pattern determination signal of each tire, for each sensor section;

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;

ground contact pattern specifying means for specifying a ground contact pattern of each tire with respect to running road surface 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 ground contact pattern information; and

means for performing the control of correcting the drive of a predetermined drive actuator from among the drive actuators based on the tire ground contact pattern of each tire outputted from the ground contact pattern specifying means.

2. The vehicle drive control system according to claim 1, wherein the sensor section 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 performing outputting, the vehicle drive control system 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 tire ground contact pattern information.

3. The vehicle drive control system according to claim 1, wherein the sensor section 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 performing outputting, the system characterized by comprising:

signal combining means for combining an electrical signal of the low frequency component and high frequency component and 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 tire ground contact pattern information.

4. The vehicle drive control system according to claim 1, characterized in that the sensor section senses accelerations in different directions at one given position.

5. The vehicle drive control system according to claim 1, 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.

6. The vehicle drive control system according to claim 1, characterized in that, in order to separate the low frequency component of the ground contact pattern determination signal, the separation means includes two or more low-pass filters or band-pass filters having a different pass band and has means for combining and outputting electrical signals outputted from each filter.

7. The vehicle drive control system according to claim 1, characterized in that, in order to separate the high frequency component of the ground contact pattern determination signal, the separation means includes two or more high-pass filters or band-pass filters having a different pass band and includes means for combining and outputting electrical signals outputted from each filter.

8. The vehicle drive control system according to claim 6, characterized in that the filter is an active type filter.

18. The vehicle drive control system according to claim 7, characterized in that the filter is an active type filter.

9. A sensor unit with an acceleration sensor disposed in a tire of a vehicle, sensing an acceleration generated in association with running of the vehicle, the unit characterized by comprising:

the acceleration sensor sensing at least one of a first acceleration generated in association with rotation of the tire in a direction orthogonal to a rotation axis and a second acceleration generated in a direction of rotation;

means for converting the sensing result of the acceleration sensor into an electrical signal and performing outputting;

means for eliminating a gravity acceleration component from at least one electrical signal of the sensed 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;

means for converting the low frequency component and high frequency component separated by the separation means into a digital value; and

means for transmitting digital information including the digital value.

10. The sensor unit according to claim 9, characterized by comprising:

means for sensing a third acceleration generated in a direction of the rotation axis and converting the sensing result into a digital value; and

means for transmitting the digital value of the third acceleration.

11. The sensor unit according to claim 9, characterized by comprising:

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

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

means for converting the combination signal obtained by the signal combining means into a digital value; and

means for transmitting the digital value of the combination signal.

12. The sensor unit according to claim 9, characterized in that the acceleration sensor senses accelerations in different directions at one given position.

13. The sensor unit according to claim 9, 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.

14. The sensor unit according to claim 9, characterized in that, in order to separate the low frequency component of the ground contact pattern determination signal, the separation means includes two or more low-pass filters or band-pass filters having a different pass band and has means for combining and outputting electrical signals outputted from each filter.

15. The sensor unit according to claim 9, characterized in that, in order to separate the high frequency component of the ground contact pattern determination signal, the separation means includes two or more high-pass filters or band-pass filters having a different pass band and includes means for combining and outputting electrical signals outputted from each filter.

16. The sensor unit according to claim 14, characterized in that the filter is an active type filter.

17. A tire characterized by comprising a sensor unit according to claim 9.

19. The sensor unit according to claim 15, characterized in that the filter is an active type filter.