Method for providing enhanced stability of a vehicle with a deflated tire

• US 7,677,095 B1
• Filed: 12/11/2006
• Issued: 03/16/2010
• Est. Priority Date: 12/11/2006
• Status: Active Grant

• Current Assignee: Kelsey-Hayes Co. (Zeppelin - Stiftung der Stadt Friedrichshafen)
• Original Assignee: Kelsey-Hayes Co. (Zeppelin - Stiftung der Stadt Friedrichshafen)
• Inventors: Bartol, Mark
• Primary Examiner(s): MCCALL, ERIC SCOTT
• Application Number:
  US11/636,844
• Time in Patent Office: 1,191 Days
• Field of Search: 731/150.1, 731/170.1, 731/21, 731/28, 731/29, 731/46, 731/462, 731/463, 731/464, 731/465
• US Class Current: 73/146.2
• CPC Class Codes: B60T 2240/03 Tire sensors
• CPC Class Codes: B60T 2270/402 Back-up
• 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: B60T 8/1755 Brake regulation specially adapted to control the stability of the vehicle, e.g. taking into account yaw rate or transverse acceleration in a curve road vehicle drive control systems for control of driving stability otherwise than by controlling a particular sub-unit B60W30/02
• CPC Class Codes: B60T 8/17616 Microprocessor-based systems
• CPC Class Codes: B60T 8/885 using electrical circuitry
• CPC Class Codes: G01M 17/06 Steering behaviour; Rolling behaviour

Abstract

In a motor vehicle equipped with pneumatic tires and a hydraulically actuated wheel brake system, a method for enhancing stability of the vehicle by determining whether any tire on the vehicle is deflated, determining the current magnitude of brake pressure at the wheel of the deflated tire when the brakes are applied, and reducing the current magnitude of brake pressure at the wheel of the deflated tire.

Claims

1. A method for stabilizing a motor vehicle that includes hydraulically actuated wheel brakes and pneumatic tires supporting the vehicle, comprising the steps of:

(a) determining whether any tire on the vehicle is deflated;

(b) determining the location on the vehicle of the wheel at which a deflated tire is located;

(c) determining the presence of excessive slip of any deflated tire determined in step (a); and

(d) reducing the magnitude of brake pressure applied to the wheels at the axle where the deflated tire is located, if the current wheel slip at the deflated tire is greater than a target wheel slip.

2. The method of claim 1, wherein step (a) further includes:

determining a reference tire pressure;

monitoring the magnitude of pressure in the tires; and

comparing the reference tire pressure to the magnitude of pressure in the tire.

3. The method of claim 1, wherein step (c) further includes:

determining a target wheel slip;

monitoring the magnitude of slip at the wheels; and

comparing the current wheel slip at the location of the deflated tire and the target wheel slip.

4. The method of claim 1, wherein step (c) further includes:

determining a target wheel slip;

monitoring the magnitude of slip at the wheels;

determining the current vehicle speed;

using the vehicle speed to determine the current wheel slip at the at the location of the deflated tire; and

comparing the current wheel slip at the location of the deflated tire and the target wheel slip.

5. The method of claim 1, wherein step (d) further includes:

when the brakes are applied, determining a current magnitude of brake pressure applied to the wheel at the location of the deflated tire; and

reducing, to a pressure that is less than said current magnitude of brake pressure, the magnitude of brake pressure applied to the wheels at the front or rear axles where the deflated tire is located.

6. The method of claim 1, wherein step (a) further includes:

determining a reference tire pressure;

monitoring the magnitude of pressure in the tires; and

comparing the reference tire pressure to the magnitude of pressure in the tires; and

the method further comprises;

if the reference tire pressure is greater than the magnitude of pressure in the tires, maintaining unchanged the magnitudes of brake pressure applied to the wheels.

7. The method of claim 1 further comprising:

determining the current vehicle speed;

comparing the current vehicle speed to a reference vehicle speed; and

performing steps (a), (b), (c) and (d) if the current vehicle speed is greater than the reference vehicle speed.

8. The method of claim 1, wherein step (c) further comprises:

reducing, to a pressure that is less than said current magnitude of brake pressure, the magnitude of brake pressure applied to the wheels at the front or rear axles where the deflated tire is located.

9. A method for stabilizing motor vehicle that includes hydraulically actuated wheel brakes and pneumatic tires supporting the vehicle, comprising the steps of:

(a) determining whether any tire on the vehicle is deflated;

(b) determining the location on the vehicle of the wheel at which the deflated tire is located;

(c) determining whether the vehicle is cornering; and

(d) reducing the magnitude of brake pressure applied to the wheels at axle where the deflated tire is located, if the vehicle is cornering and a tire is deflated.

10. The method of claim 9 further comprising:

determining the current vehicle speed;

comparing the current vehicle speed to a reference vehicle speed; and

performing steps (a), (b), (c) and (d) if the current vehicle speed is greater than the reference vehicle speed.

11. The method of claim 9, wherein step (a) further includes:

determining a reference tire pressure;

monitoring the magnitude of pressure in the tires; and

comparing the reference tire pressure to the magnitude of pressure in the tire.

12. The method of claim 9, wherein step (d) further includes:

when the brakes are applied, determining a current magnitude of brake pressure applied to the wheel at the location of the deflated tire; and

reducing, to a pressure that is less than said current magnitude of brake pressure, the magnitude of brake pressure applied to the wheels at the front or rear axles where the deflated tire is located.

13. The method of claim 9, wherein step (a) further includes:

determining a reference tire pressure;

monitoring the magnitude of pressure in the tires; and

comparing the reference tire pressure to the magnitude of pressure in the tires; and

the method further comprises;

if the reference tire pressure is greater than the magnitude of pressure in the tires, maintaining unchanged the magnitudes of brake pressure applied to the wheels.