Method and apparatus for determining the mileage of a tire

• US 9,050,865 B2
• Filed: 01/07/2011
• Issued: 06/09/2015
• Est. Priority Date: 01/07/2010
• Status: Active Grant

• Current Assignee: Continental Automotive GmbH (Continental AG)
• Original Assignee: Continental Automotive GmbH (Continental AG)
• Inventors: Kammann, Stefan
• Primary Examiner(s): Feliciano, Eliseo Ramos
• Assistant Examiner(s): Ishizuka, Yoshihisa
• Application Number:
  US12/986,712
• Publication Number:
  US 20110166825A1
• Time in Patent Office: 1,614 Days
• Field of Search: 702/165, 702/163, 340/442, 340/426.33, 731/46, 731/463, 731/465, 73/8
• US Class Current: 1/1
• CPC Class Codes: B60C 2019/004 Tyre sensors other than for detecting tyre pressure
• CPC Class Codes: B60C 23/0408 transmitting the signals by non-mechanical means from the wheel or tyre to a vehicle body mounted receiver
• CPC Class Codes: G01C 22/02 by conversion into electric waveforms and subsequent integration, e.g. using tachometer generator G01C22/002, G01C22/004, G01C22/006 take precedence

Abstract

A method and an apparatus for determining the mileage of a tire, include measuring a first current mileage over a limited period a first time, measuring a second current mileage over a limited period a second time, providing a measurement-free rest period between the first measurement and the second measurement, and estimating the mileage during the rest period on the basis of the first current mileage and/or the second current mileage. In addition, the method is repeated, with the already performed second measurement replacing the first measurement. Since a supply of power is not needed or at least can be significantly reduced during the rest period, the power requirement for mileage determination during the life of the tire can be significantly reduced, which allows simplified supply of power for mileage determination.

Claims

1. A method for determining a mileage of a tire, the method comprising the following steps:

determining a first current mileage over a first limited period of time using a measurement sensor system by one of;

1) measuring, while the tire is rolling on the road, a first number of wheel revolutions occurring during a first prescribed measurement time;

or

2) measuring, while the tire is rolling on the road, a first time during which a first prescribed number of wheel revolutions occur;

determining a second current mileage over a second limited period of time using the measurement sensor system by one of;

1) measuring, while the tire is rolling on the road, a second number of wheel revolutions occurring during a second prescribed measurement time;

or

2) measuring, while the tire is rolling on the road, a second time during which a second prescribed number of wheel revolutions occur;

providing a measurement-free rest period between the first current mileage measurement and the second current mileage measurement in which the measurement sensor system changes to a sleep mode or is isolated from a provided power source, a duration of the measurement-free rest period extending over a plurality of wheel revolutions N;

estimating the mileage during the measurement-free rest period with a computation unit configured to estimate the mileage based on at least one of the first current mileage or the second current mileage; and

repeating the method with the already performed second measurement replacing the first measurement.

2. The method according to claim 1, which further comprises using a profile of the mileage during the rest period, linearly interpolated between the first current mileage and the second current mileage, to estimate the mileage during the rest period in the estimating step.

3. The method according to claim 1, which further comprises using a constant profile of the mileage during the rest period at a level of the first current mileage or at a level of the second current mileage or an intermediate value between the first current mileage and the second current mileage, to estimate the mileage during the rest period in the estimating step.

4. The method according to claim 1, which further comprises varying a duration of the measurement-free rest period on a basis of at least one current mileage, decreasing the duration of the measurement-free rest period when the second current mileage is higher than the first current mileage and increasing the duration of the measurement-free rest period when the first current mileage is higher than the second current mileage.

5. The method according to claim 1, which further comprises carrying out the first measurement during a first prescribed measurement time by measurement of a first number of wheel revolutions for determining the first current mileage and/or carrying out the second measurement during a second prescribed measurement time by measurement of a second number of wheel revolutions for determining the second current mileage.

6. The method according to claim 1, which further comprises carrying out the first measurement during a first prescribed number of wheel revolutions by measurement of a first measurement time for determining the first current mileage and/or carrying out the second measurement during a second prescribed number of wheel revolutions by measurement of a second measurement time for determining the second current mileage.

7. The method according to claim 1, which further comprises measuring an internal pressure of the tire with a pressure sensor and using the measured internal pressure of the tire and the mileage for estimating a current load on the tire.

8. The method according to claim 1, wherein the tire is a motor vehicle tire.

9. The method according to claim 1, which further comprises calculating a duration of the measurement-free rest period based on at least one of the measured first current mileage or the measured second current mileage causing a number N of wheel revolutions of 5≦

N≦

1000 to fall into the measurement-free rest period.

10. The method according to claim 9, wherein 10≦

N≦

250.

11. The method according to claim 9, wherein 15≦

N≦

80.

12. The method according to claim 9, wherein 20≦

N≦

25.

13. An apparatus for determining the mileage of a tire, the apparatus comprising:

a measurement sensor for performing a first measurement, over a first limited period of time, of a first current mileage and a second measurement, over a second limited period of time, of a second current mileage, said measurement sensor configured to obtain each of said first current mileage and said second current mileage by one of;

1) measuring, while the tire is rolling on the road, a number of wheel revolutions occurring during a prescribed measurement time;

or

2) measuring, while the tire is rolling on the road, a time during which a prescribed number of wheel revolutions occur;

a voltage source for operating measurement electrics for said measurement sensor;

a switch for at least one of interrupting or connecting said voltage source for supplying power to said measurement sensor to provide a measurement-free rest period between the first measurement and the second measurement during which the measurement sensor is not measuring, a duration of said measurement-free rest period extending over a plurality of wheel revolutions N; and

a computation unit connected to said measurement sensor for estimating the mileage during the rest period on a basis of at least one of the first current mileage or the second current mileage.

14. The apparatus according to claim 13, wherein the tire is a motor vehicle tire.

15. The apparatus according to claim 13, wherein said voltage source is a battery.

16. The apparatus according to claim 13, wherein the apparatus is configured to:

a) measure a first current mileage over a first limited period of time;

b) measure a second current mileage over a second limited period of time;

c) provide a measurement-free rest period between the first current mileage measurement and the second current mileage measurement;

d) estimate the mileage during the measurement-free rest period with a computation unit configured to estimate the mileage based on at least one of the first current mileage or the second current mileage; and

e) after d) repeat b)-d) with the already performed second measurement replacing the first measurement.

17. The apparatus according to claim 13, which further comprises a time sensor connected to said computation unit for measuring periods.

18. The apparatus according to claim 13, which further comprises at least one of a volatile or permanent memory for storing at least one of the mileage, the first current mileage, the second current mileage, a number of wheel revolutions or periods.

19. The apparatus according to claim 13, wherein said measurement sensor is a contact area pass counter connected to said computation unit for counting wheel revolutions.

20. The apparatus according to claim 19, wherein said contact area pass counter has a piezoelectric element connected to a counting unit.