Method for allocating identifiers of wheel electronics of a tire pressure monitoring system of a vehicle to the positions of the wheels on the vehicle

• US 20120065832A1
• Filed: 09/09/2011
• Published: 03/15/2012
• Est. Priority Date: 09/13/2010
• Status: Active Grant

• Current Assignee: Huf Baolong Electronics Bretten GmbH (Huf Hulsbeck & Furst GmbH & Co. KG)
• Original Assignee: Huf Hulsbeck & Furst GmbH & Co. KG
• Inventors: Kessler, Ralf, Wagner, Markus, Kraft, Andreas, Schoenbeck, Juergen, Brand, Peter
• Granted Patent: US 8,600,607 B2
• Time in Patent Office: Days
• US Class Current: 701/29.1
• CPC Class Codes: B60C 23/0416 allocating a corresponding wheel position on vehicle, e.g. front/left or rear/right
• CPC Class Codes: B60C 23/0488 Movement sensor, e.g. for sensing angular speed, acceleration or centripetal force

Abstract

The invention describes a method for allocating identifiers of wheel electronics of a tire pressure monitoring system to positions of wheels of a vehicle, the simultaneously occurring rotation speeds of the wheels, normalized on a consistently chosen rolling radius of the wheels differ during cornering because of the different positions of the wheels on the vehicle, so that the positions of the wheels can be sorted according to increasing speed of the wheels during cornering, the wheel electronics of each wheel comprising a pressure sensor, a motion sensor, a memory and a transmitter, which transmits signals to a receiver being connected to an evaluation device, which receives the transmitted identifiers and compares the distances which the corresponding wheels have traveled in a defined time span, sorts the identifiers according to the length of the distance traveled in the defined time span and allocates the identifiers to the wheel positions.

Claims

1. A method for allocating identifiers of units of a tire pressure monitoring system of a vehicle to positions of wheels of the vehicle,

said identifiers being contained in signals emitted by the units—

called wheel electronics in the following—

, which are attached to the wheels, which are mounted on the vehicle and whose simultaneously occurring rotation speeds, normalized on a consistently chosen rolling radius of the wheels differ during cornering because of the different positions of the wheels on the vehicle, so that the positions of the wheels can be sorted according to increasing speed of the wheels during cornering,

the wheel electronics of each wheel comprising

a pressure sensor, which is sensitive to the tire pressure of the wheel, a motion sensor, which provides information on the rotation speed of the wheel,

a memory with the individual identifier of the wheel electronic stored therein,

and a transmitter, which transmits signals, which contain the individual identifier and information on the rotation speed of the respective wheel, to a receiver, which is provided with or connected to an evaluation device and provided with or connected to an antenna provided on the body of the vehicle;

wherein the evaluation device receives the transmitted identifiers and compares the distances which the corresponding wheels have traveled in a defined time span,

sorts the identifiers according to the length of the distance traveled in the defined time span

and allocates the identifiers to the wheel positions in such a way that the identifier, for which the longest distance has been traveled in the defined time span, is allocated to the wheel position in which the longest distance is expected during cornering, and that the identifier, for which the shortest distance has been traveled in the defined time span, is allocated to that wheel position, in which the shortest distance is expected during cornering.

2. The method according to claim 1, wherein the evaluation device compares the information transferred along with the identifiers and transmitted to the evaluation device, on the number of rotations of the wheels which occurred in a defined time span,

sorts the identifiers according to increasing number of rotations of the wheels, a number which is normalized on a consistently chosen rolling radius,

and allocates the identifiers to the wheel positions in such a way that the identifier, for which the largest normalized number of rotations has been observed, is allocated to the wheel position in which the largest normalized rotation speed is expected during cornering, and that the identifier, for which the smallest normalized number of rotations has been observed, is allocated to that wheel position, in which the smallest normalized rotation speed is expected during cornering.

3. The method according claim 2, wherein the defined time span is selected in such a way that in the increasing series of the observed numbers of rotations of the wheels, the ratio between any two consecutive rotational speeds exceeds a preselected first threshold value, which is preferably derived from empirical values.

4. The method according to claim 3, wherein the first threshold value is 1.004, preferably 1.006.

5. The method according to claim 2, wherein the comparison of the number of rotations of the wheels is carried out repeatedly in consecutive defined time spans,

that it is counted how often a certain identifier is respectively allocated to a certain wheel position as a result of the repeated comparisons,

and that this certain identifier is stored under that wheel position to which it has been allocated most frequently.

6. The method according to claim 5, wherein the most frequent allocation to a wheel position is then stored, if the counted frequency is greater by a predefined number than the counted frequencies of the allocation of the same identifier to the other wheel positions involved in the comparison.

7. The method according to claim 6, wherein the predefined number is derived from empirical values.

8. The method according to claim 6, wherein the allocation of an identifier to a certain wheel position is then stored, if it has been counted at least 10 times, preferably 20 times more frequently than the allocation of the same identifier to the other wheel positions involved in the comparison.

9. The method according to claim 1, wherein it is carried out for the wheels on the left-hand side of the vehicle separately from the wheels on the right-hand side of the vehicle.

10. The method according to claim 1, wherein for two wheels mounted behind one another on the same side of the vehicle, the difference of the distances is determined, which both wheels have traveled in a defined time span, and that the greater distance is allocated to the front wheel and the smaller distance to the rear wheel.

11. The method according to claim 10, wherein the cases, in which a certain identifier has been allocated to a front wheel of the vehicle, are counted, and that the cases, in which the same identifier has been allocated to a rear wheel on the same side of the vehicle, are counted separately therefrom, and that this identifier is stored under that wheel position for which the counted allocations first of all reach a preset second threshold value, which is preferably derived from empirical values.

12. The method according to claim 11, wherein the second threshold value is equal to the number 50, preferably the number 80.

13. The method according to claim 10, wherein the individual allocations are formed by determining two consecutive measurements of the rotational speeds for each of two wheels mounted behind one another on the same side of the vehicle, which rotational speeds are normalized on a consistently chosen rolling radius, and the results for each of both wheels are subtracted from one another, and that the difference of the thus formed differences is thereafter calculated, which is a measurement for the difference of the distances, which both wheels have traveled in the defined time span.

14. The method according to claim 10, wherein only such signals transferred from the wheel electronics are evaluated, which originate from wheels with the same direction of rotation and which are temporally close to one another.

15. The method according to claim 14, wherein the maximum time interval, which the signals emitted from the wheel electronics may have, in order to be evaluated, is derived from empirical values.

16. The method according to claim 14, wherein the time interval, which two signals emitted from the wheel electronics may have, in order to be evaluated, is smaller than 2 seconds.

17. The method according to claim 1, wherein a motion sensor is used in the wheel electronics, which also provides information on the rotation direction of the respective wheel, and that according to the information on the rotation direction of the respective wheel contained in the signals it is determined whether the respective wheel is mounted on the right side or on the left side of the vehicle.

18. The method according to claim 1, wherein different rolling radii of the wheels of a vehicle are taken into account in such a way that the rotation speed acquired by means of a motion sensor or the number of rotations occurring in a defined time span is normalized on a consistently chosen rolling radius for each wheel.

19. The method according to claim 18, wherein different rolling radii of the wheels are acquired from rotation speed signals, which are transmitted from the wheel electronics of the wheels, in that rotation speed signals of the wheels acquired when the vehicle driving straight are compared to one another.

20. The method according to claim 1, wherein the influence of slippage between the wheels of the vehicle is determined from irregularities in the rotation speed signal from ABS sensors, which are allocated to the individual wheels, and that the influence of the slippage on the comparison of the number of rotations, which the wheels perform in a defined time span when driving through a curve, is mathematically compensated in the evaluation device.