Method for identifying vehicle wheels having low tire pressure

• US 20090173149A1
• Filed: 12/15/2008
• Published: 07/09/2009
• Est. Priority Date: 01/04/2008
• Status: Active Grant

• Current Assignee: ZF CV Systems Europe BV (Zeppelin - Stiftung der Stadt Friedrichshafen)
• Original Assignee: Wabco GmbH (Wabco Holdings Incorporated)
• Inventors: Schmidt, Detlef, Munko, Tobias, Bork, Andre
• Granted Patent: US 7,870,780 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

Abstract

A method for identifying low-pressure tires includes determining the number of revolutions of each wheel over a preselected driving distance, and comparing crosswise by summing the number of revolutions of the diagonally opposite front right/rear left and front left/rear right wheels and taking the difference between the sums, a diagonal containing a low-pressure tire being identifiable via the sign of the difference between the diagonals. A further comparison for each side of the vehicle is effected by summing the revolutions of the front left/rear left side and front right/rear right side wheels and comparing the difference between the sums, the side containing a low-pressure tire being identifiable via the sign of the difference between the sides. The difference between diagonals is compared with a low-pressure threshold value. If the threshold is exceeded, the signs of the difference between diagonals and between sides are logically combined to identify the low-pressure tire.

Claims

1. A method for identifying vehicle wheels having low tire pressure, comprising the steps of:

determining the number of revolutions of each wheel of a vehicle over a preselected driving distance;

comparing said number of wheel revolutions crosswise by (i) summing said number of wheel revolutions of a first diagonal of opposite front right and rear left wheels and of a second diagonal of opposite front left and rear right wheels, and (ii) calculating a first difference between the sums of said number of wheel revolutions of said first and second diagonals;

identifying at least one of said first and second diagonals as containing a wheel affected by low tire pressure based on the sign of said first difference;

comparing said number of wheel revolutions of each side of said vehicle by (iii) summing said number of wheel revolutions of a first side of said front left and rear left wheels and of a second side of said front right and rear right wheels, and (iv) calculating a second difference between the sums of said number of wheel revolutions of said first and second sides; and

identifying at least one of said first and second sides as containing a wheel affected by low tire pressure based on the sign of said second difference.

2. The method according to claim 1, wherein said step of determining said number of revolutions of each vehicle wheel is effected continuously over said preselected driving distance.

3. The method according to claim 1, further comprising the steps of comparing said first difference against a preselected low-pressure recognition threshold value and, when said first difference exceeds said low-pressure recognition threshold value, logically combining the sign of said first difference and the sign of said second difference to identify at least one of said vehicle wheels affected by low tire pressure.

4. A method for identifying vehicle wheels having low tire pressure, comprising the steps of:

determining the number of revolutions of each wheel of a vehicle over a preselected driving distance;

comparing said number of wheel revolutions crosswise by (i) summing said number of wheel revolutions of a first diagonal of opposite front right and rear left wheels and of a second diagonal of opposite front left and rear right wheels, and (ii) calculating a first difference between the sums of said number of wheel revolutions of said first and second diagonals;

identifying at least one of said first and second diagonals as containing a wheel affected by low tire pressure based on the sign of said first difference;

comparing said number of wheel revolutions of each axle of said vehicle by (iii) summing said number of wheel revolutions of a first axle including said front left and front right wheels and of a second axle including said rear left and rear right wheels, and (iv) calculating a second difference between the sums of said number of wheel revolutions of said first and second axles; and

identifying at least one of said first and second axles as containing a wheel affected by low tire pressure based on the sign of said second difference.

5. The method according to claim 4, wherein said step of determining said number of revolutions of each vehicle wheel is effected continuously over said preselected driving distance.

6. The method according to claim 4, further comprising the steps of comparing said first difference against a preselected low-pressure recognition threshold value and, when said first difference exceeds said low-pressure recognition threshold value, logically combining the sign of said first difference and the sign of said second difference to identify at least one of said vehicle wheels affected by low tire pressure.

7. A method for identifying vehicle wheels having low tire pressure, comprising the steps of:

determining the number of revolutions of each wheel of a vehicle over a preselected driving distance;

comparing said number of wheel revolutions crosswise by (i) summing said number of wheel revolutions of a first diagonal of opposite front right and rear left wheels and of a second diagonal of opposite front left and rear right wheels, and (ii) calculating a first difference between the sums of said number of wheel revolutions of said first and second diagonals;

identifying at least one of said first and second diagonals as containing a wheel affected by low tire pressure based on the sign of said first difference;

comparing said number of wheel revolutions of each side of said vehicle by (iii) summing said number of wheel revolutions of a first side of said front left and rear left wheels and of a second side of said front right and rear right wheels, and (iv) calculating a second difference between the sums of said number of wheel revolutions of said first and second sides;

identifying at least one of said first and second sides as containing a wheel affected by low tire pressure based on the sign of said second difference;

comparing said number of wheel revolutions of each axle of said vehicle by (v) summing said number of wheel revolutions of a first axle including said front left and front right wheels and of a second axle including said rear left and rear right wheels, and (vi) calculating a third difference between the sums of said number of wheel revolutions of said first and second axles; and

identifying at least one of said first and second axles as containing a wheel affected by low tire pressure based on the sign of said third difference.

8. The method according to claim 7, wherein said step of determining said number of revolutions of each vehicle wheel is effected continuously over said preselected driving distance.

9. The method according to claim 7, further comprising the steps of comparing said first difference against a preselected low-pressure recognition threshold value and, when said first difference exceeds said low-pressure recognition threshold value, logically combining the sign of said first difference and at least one of the sign of said second difference and the sign of said third difference to identify at least one of said vehicle wheels affected by low tire pressure.

10. The method according to claim 7, further comprising the step of logically combining the sign of said third difference and at least one of the sign of said second difference and the sign of said first difference to identify at least one of said vehicle wheels affected by low tire pressure.

11. A method for identifying vehicle wheels having low tire pressure, comprising the steps of:

determining the number of revolutions of each wheel of a vehicle over a preselected driving distance;

comparing said number of wheel revolutions of each side of said vehicle by (i) summing said number of wheel revolutions of a first side of front left and rear left wheels and of a second side of front right and rear right wheels, and (ii) calculating a first difference between the sums of said number of wheel revolutions of said first and second sides;

identifying at least one of said first and second sides as containing a wheel affected by low tire pressure based on the sign of said second difference;

comparing said number of wheel revolutions of each axle of said vehicle by (iii) summing said number of wheel revolutions of a first axle including said front left and front right wheels and of a second axle including said rear left and rear right wheels, and (iv) calculating a second difference between the sums of said number of wheel revolutions of said first and second axles; and

identifying at least one of said first and second axles as containing a wheel affected by low tire pressure based on the sign of said second difference.

12. The method according to claim 11, wherein said step of determining said number of revolutions of each vehicle wheel is effected continuously over said preselected driving distance.

13. The method according to claim 11, further comprising the step of logically combining the sign of said first difference and the sign of said second difference to identify at least one of said vehicle wheels affected by low tire pressure.