Method for monitoring the pressure of motor vehicle tires

• US 20070186634A1
• Filed: 12/11/2004
• Published: 08/16/2007
• Est. Priority Date: 12/20/2003
• Status: Active Grant

• Current Assignee: Daimler AG (Mercedes-Benz Group AG)
• Original Assignee: DaimlerChrysler AG (Mercedes-Benz Group AG)
• Inventors: Kipping, Jan, Schlosser, Frank, Kiesewetter, Wolfgang, Burghardt, Joerg
• Granted Patent: US 7,502,704 B2
• Time in Patent Office: Days
• US Class Current: 73/146
• CPC Class Codes: B60C 23/0408 transmitting the signals by non-mechanical means from the wheel or tyre to a vehicle body mounted receiver

Abstract

A method for monitoring the pressure of motor vehicle tires is provided. In the method, a tire pressure value of the filling pressure and a tire temperature value are determined. While taking into account the tire temperature values, the determined tire pressure value is compared with a stored nominal value and the comparison result is used to determine whether the motor vehicle tire is at an incorrect tire pressure, in particulars, a low tire pressure. If the tire pressure is incorrect, when a characteristic change in the tire pressure occurs, the stored nominal value is replaced by a new nominal value, and the comparison result is used to determine the new nominal value of the determined tire pressure value.

Claims

1-14. -14. (canceled)

15. A method for monitoring the pressure of motor vehicle tires,

comprising the acts of:

determining a tire pressure value indicative of a tire filling pressure;

comparing the determined tire pressure value with a stored nominal value; and

determining whether a motor vehicle tire is at an incorrect tire pressure, based upon a result of the comparison;

wherein when the tire pressure changes in a manner characteristic of a filling process, the stored nominal value is replaced by a new nominal value, with the determined tire pressure value being used to determine the new nominal value.

16. The method as claimed in claim 15, wherein the comparison of the determined tire pressure value with the stored nominal value, determined at an earlier time, is used to determine whether a characteristic change has occurred in the tire pressure value.

17. The method as claimed in claim 16, wherein the characteristic change in the tire pressure value occurs when the difference between the determined tire pressure value and the stored nominal value is greater than a predetermined threshold value.

18. The method as claimed in claim 17, wherein the characteristic change in the tire pressure value occurs when the difference between the determined tire pressure value and the stored nominal value is greater than a predetermined threshold value for at least two wheels.

19. The method as claimed in claim 17, wherein the threshold value is 0.2 bar.

20. The method as claimed in claim 17, wherein the characteristic change in the tire pressure value occurs only when the vehicle has been stopped or started between a time of determination of the determined tire pressure value and the earlier time of storage of the stored nominal value.

21. The method as claimed in claim 16, wherein:

the determined tire pressure value is subjected to a plausibility check if the characteristic change in the tire pressure value has been determined; and

the determined tire pressure value is stored as a comparison value only if the determined tire pressure value is classified as plausible.

22. The method as claimed in claim 21, wherein the tire pressure value is classified as plausible only if the difference between the tire pressure value and a further tire pressure value associated with a same vehicle axle and an opposite vehicle side is less than a predetermined threshold value of 0.4 bar.

23. The method as claimed in claim 21, wherein the tire pressure value is classified as plausible only when all of the determined tire pressure values are above a predetermined threshold value of 1.6 bar.

24. The method as claimed in claim 21, wherein the tire pressure value is classified as plausible only when the determined tire pressure value associated with a rear vehicle axle is greater than a mean value of determined tire pressure values associated with a front vehicle axle minus a predetermined constant.

25. The method as claimed in claim 21, wherein a tire temperature and an ambient temperature are determined, and the tire pressure value is classified as plausible only when a difference between the tire pressure and the ambient temperature is less than a predetermined threshold value of 40 K.

26. The method as claimed in claim 21, wherein the tire pressure value is classified as plausible only when the respective plausibility conditions are satisfied for at least 3 minutes.

27. The method as claimed in claim 15, wherein a tire temperature value is determined, and the tire temperature value is used for determination of the tire pressure values.

28. The method as claimed in claim 27, wherein temperature influence is compensated for in the determination of the tire pressure values.

29. The method as claimed in claim 18, wherein the threshold value is 0.2 bar.

30. The method as claimed in claim 18, wherein the characteristic change in the tire pressure value occurs only when the vehicle has been stopped or started between a time of determination of the determined tire pressure value and the earlier time of storage of the stored nominal value.

31. The method as claimed in claim 19, wherein the characteristic change in the tire pressure value occurs only when the vehicle has been stopped or started between a time of determination of the determined tire pressure value and the earlier time of storage of the stored nominal value.

32. The method as claimed in claim 20, wherein the characteristic change in the tire pressure value occurs only when the vehicle has been stopped or started between a time of determination of the determined tire pressure value and the earlier time of storage of the stored nominal value.

33. The method as claimed in claim 17, wherein:

the determined tire pressure value is subjected to a plausibility check if the characteristic change in the tire pressure value has been determined; and

the determined tire pressure value is stored as a comparison value only if the determined tire pressure value is classified as plausible.

34. The method as claimed in claim 18, wherein:

the determined tire pressure value is subjected to a plausibility check if the characteristic change in the tire pressure value has been determined; and

the determined tire pressure value is stored as a comparison value only if the determined tire pressure value is classified as plausible.