WHEEL ATTITUDE CONTROL METHOD AND WHEEL ATTITUDE CONTROL DEVICE

• US 20090171531A1
• Filed: 12/16/2008
• Published: 07/02/2009
• Est. Priority Date: 12/26/2007
• Status: Active Grant

• Current Assignee: Yokohama Rubber Company Limited
• Original Assignee: Yokohama Rubber Company Limited
• Inventors: Miyashita, Naoshi, Matsuda, Jun, Kitazaki, Tsuyoshi
• Granted Patent: US 8,160,775 B2
• Time in Patent Office: Days
• US Class Current: 701/37
• CPC Class Codes: B60G 17/0164 mainly during accelerating or braking
• CPC Class Codes: B60G 17/01908 Acceleration or inclination sensors characterised by the use of gyroscopes B60G21/08
• CPC Class Codes: B60G 17/0195 characterised by the regulation being combined with other vehicle control systems conjoint control of vehicle sub-units including control of suspension systems B60W10/22
• CPC Class Codes: B60G 2200/46 camber angle
• CPC Class Codes: B60G 2200/462 Toe-in/out
• CPC Class Codes: B60G 2204/113 Tyre related sensors
• CPC Class Codes: B60G 2400/05 Attitude
• CPC Class Codes: B60G 2400/10 Acceleration; Deceleration
• CPC Class Codes: B60G 2400/104 lateral or transversal with regard to vehicle
• CPC Class Codes: B60G 2400/1042 using at least two sensors
• CPC Class Codes: B60G 2400/39 Brake pedal position
• CPC Class Codes: B60G 2401/10 Piezoelectric elements
• CPC Class Codes: B60G 2600/02 Retarders, delaying means, dead zones, threshold values, cut-off frequency, timer interruption
• CPC Class Codes: B60G 2600/60 Signal noise suppression; Electronic filtering means
• CPC Class Codes: B60G 2800/22 Braking, stopping
• CPC Class Codes: B60G 2800/912 Attitude Control; levelling control
• 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: B62D 17/00 Means on vehicles for adjusting camber, castor, or toe-in

Abstract

A wheel attitude control method of the invention comprises the steps of: chronologically obtaining acceleration data in a radial direction of a tire at a center position of a tire tread and at an off-center position spaced apart from the center position toward a shoulder; obtaining respective contact lengths at the center position and the off-center position from the acceleration data; and controlling a wheel attitude, which varies in accordance with changes in a load applied to the wheel when the braking force is imparted to the wheel, based on the obtained contact length at the center position and the obtained contact length at the off-center position.

Claims

1. A wheel attitude control method for controlling an attitude of a wheel when braking a vehicle by imparting a braking force to the wheel attached to the vehicle, the method comprising the steps of:

chronologically obtaining acceleration data in a radial direction of a tire at a center position of a tire tread and at an off-center position spaced apart from the center position toward a shoulder;

obtaining respective contact lengths at the center position and the off-center position from the acceleration data; and

controlling a wheel attitude, which varies in accordance with changes in a load applied to the wheel when the braking force is imparted to the wheel, based on the obtained contact length at the center position and the obtained contact length at the off-center position.

2. The wheel attitude control method according to claim 1, wherein the off-center position is spaced apart from the center position toward the shoulder on a vehicle inner side of the tire.

3. The wheel attitude control method according to claim 1, wherein a difference between the contact length at the center position and the contact length at the off-center position is compared with a pre-set first threshold value, in the wheel attitude controlling step, to control the wheel attitude in accordance with a result of the comparison.

4. The wheel attitude control method according to claim 3, wherein a camber angle or a toe angle of the wheel is controlled when the difference exceeds the first threshold value.

5. The wheel attitude control method according to claim 1, wherein a ratio of the contact length at the center position to the contact length at the off-center position is compared with a pre-set second threshold value, in the wheel attitude controlling step, to control the wheel attitude in accordance with a result of the comparison.

6. The wheel attitude control method according to claim 5, wherein a camber angle or a toe angle of the wheel is controlled when the ratio exceeds the second threshold value.

7. The wheel attitude control method according to claim 1, wherein the off-center position is situated within a range of 25% of a tire contact width as measured from a contact width end in a tire width direction.

8. A wheel attitude control device for controlling an attitude of a wheel when braking a vehicle by imparting a braking force to the wheel attached to the vehicle, the device comprising:

acceleration data obtaining means for chronologically obtaining acceleration data in a radial direction of a tire at a center position of a tire tread and at an off-center position spaced apart from the center position toward a shoulder;

contact length obtaining means for obtaining respective contact lengths at the center position and the off-center position from the acceleration data; and

control signal generating means for generating a control signal for controlling the wheel attitude, which varies in accordance with changes in a load applied to the wheel when the braking force is imparted to the wheel, based on the obtained contact length at the center position and the obtained contact length at the off-center position.