Method and system for detection of a tire's change of state

• US 6,705,157 B2
• Filed: 09/10/2002
• Issued: 03/16/2004
• Est. Priority Date: 09/10/2001
• Status: Active Grant

• Current Assignee: Continental Automotive GmbH (Continental AG)
• Original Assignee: Siemens AG
• Inventors: Fischer, Martin, Hillenmayer, Franz, Fuessel, Dominik
• Primary Examiner(s): Lefkowitz, Edward
• Assistant Examiner(s): ALLEN, ANDRE J
• Application Number:
  US10/237,660
• Publication Number:
  US 20030070478A1
• Time in Patent Office: 553 Days
• Field of Search: 731/46, 731/462, 731/463, 731/464, 731/465, 731/468, 340/442, 340/444
• 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

Systems and methods for detecting a change of tire state may include measuring at least first and second quantities representing a tire characteristic. A new first value is then calculated by at least, in part, adding the second measured quantity to a previously calculated first value, which has been multiplied by a pre-selected parameter. A second value is then calculated by at least, in part, subtracting the previously calculated first value from the new first value. A change of tire state is indicated when the second value crosses a predetermined threshold value. In an alternative embodiment, the difference between second values for two different tires may be determined and a change of tire state is indicated when this difference crosses a predetermined threshold value.

Claims

1. A method for detecting a change of state of at least one tire, comprising:

measuring a first quantity representative of a characteristic of the tire,

measuring a second quantity representative of the characteristic of the tire, the second quantity being measured after the first quantity,

multiplying a previously calculated first value by a pre-selected parameter, the previously calculated first value having been calculated at least in part based upon the first measured quantity,

calculating a new first value by at least, in part, adding the second measured quantity to the previously calculated first value multiplied by the pre-selected parameter,

calculating a second value by at least, in part, subtracting the previously calculated first value from the new first value, and

comparing the second value with a predetermined threshold value, wherein a change of state of the tire is indicated when the second value crosses the predetermined threshold value.

2. A method according to claim 1, wherein the pre-selected parameter is a constant.

3. A method according to claim 1, wherein the pre-selected parameter is between zero and one.

4. A method according to claim 1, further comprising:

generating at least one second value for a plurality of tires, and

comparing the respective second values for each tire in order to determine a change of state of each tire.

5. A method according to claim 1, wherein the tire characteristic is representative of air pressure inside the tire.

6. A method according to claim 1, wherein the tire characteristic is representative of the temperature inside the tire.

7. A method for detecting a status change of at least one of a first and second tire, comprising:

measuring first and second quantities representative of a characteristic of the first tire, the second quantity being measured after the first quantity,

measuring first and second quantities representative of the characteristic of the second tire, the second quantity being measured after the first quantity,

multiplying a previously calculated first value for the first tire by a pre-selected parameter, the previously calculated first value having been calculated at least in part based upon the first measured quantity for the first tire,

calculating a new first value for the first tire by at least, in part, adding the second measured quantity of the first tire to the previously calculated first value for the first tire, which has been multiplied by the pre-selected parameter,

calculating a second value for the first tire by at least, in part, subtracting the previously calculated first value for the first tire from the new first value for the first tire,

calculating a difference between the second value for the first tire and a second value calculated for the second tire, and

comparing the difference with a predetermined threshold value, wherein a change of state of at least one of the first and second tires is indicated when the difference crosses the predetermined threshold value.

8. A method according to claim 7, wherein the pre-selected parameter is a constant.

9. A method according to claim 7, wherein the pre-selected parameter is between zero and one.

10. A method according to claim 7, further comprising:

generating second values for at least four tires, and

comparing the respective second values for each tire in order to determine a change of state of each tire.

11. A method according to claim 7, wherein the tire characteristic is representative of air pressure inside the tire.

12. A method according to claim 7, wherein the tire characteristic is representative of the temperature inside the tire.

13. An apparatus suitable for detecting a change of state of a tire, comprising:

means for measuring first and second quantities representative of a characteristic of the tire, the second quantity being measured after the first quantity,

means for multiplying a previously calculated first value by a pre-selected parameter, the previously calculated first value having been calculated at least in part based upon the first measured quantity,

means for calculating a new first value by at least, in part, adding the second measured quantity to the previously calculated first value multiplied by the pre-selected parameter,

means for calculating a second value by at least, in part, subtracting the previously calculated first value from the new first value, and

means for comparing the second value with a predetermined threshold value, wherein a change of state of the tire is indicated when the second value crosses the predetermined threshold value.

14. An apparatus according to claim 13, wherein the pre-selected parameter is a constant.

15. An apparatus according to claim 13, wherein the pre-selected parameter is between zero and one.

16. An apparatus according to claim 13, further comprising:

means for generating at least one second value for a plurality of tires, and

means for comparing the respective second values for each tire in order to determine a change of state of each tire.

17. An apparatus according to claim 13, wherein the tire characteristic is representative of air pressure inside the tire.

18. An apparatus according to claim 13, wherein the tire characteristic is representative of the temperature inside the tire.

19. An apparatus suitable for detecting a change of state of a tire, comprising:

means for measuring first and second quantities representative of a characteristic of the first tire, the second quantity being measured after the first quantity,

means for measuring first and second quantities representative of the characteristic of the second tire, the second quantity being measured after the first quantity,

means for multiplying a previously calculated first value for the first tire by a pre-selected parameter, the previously calculated first value having been calculated at least in part based upon the first measured quantity for the first tire,

means for calculating a new first value for the first tire by at least, in part, adding the second measured quantity of the first tire to the previously calculated first value for the first tire, which has been multiplied by the pre-selected parameter,

means for calculating a second value for the first tire by at least, in part, subtracting the previously calculated first value for the first tire from the new first value for the first tire,

means for calculating a difference between the second value for the first tire and a second value calculated for the second tire, and

means for comparing the difference with a predetermined threshold value, wherein a change of state of at least one of the first and second tires is indicated when the difference crosses the predetermined threshold value.

20. An apparatus according to claim 19, wherein the pre-selected parameter is a constant.

21. An apparatus according to claim 19, wherein the pre-selected parameter is between zero and one.

22. An apparatus according to claim 19, further comprising:

means for generating second values for at least four tires, and

means for comparing the respective second values for each tire in order to determine a change of state of each tire.

23. An apparatus according to claim 19, wherein the tire characteristic is representative of air pressure inside the tire.

24. An apparatus according to claim 19, wherein the tire characteristic is representative of the temperature inside the tire.

25. An apparatus, comprising:

means for receiving at least first and second measurements of a quantity representing a tire characteristic, the second measured quantity being taken after the first measured quantity, and

a processor programmed to execute;

an instruction to multiply a previously calculated first value by a pre-selected parameter, the previously calculated first value having been calculated at least in part based upon the first measured quantity,

an instruction to calculate a new first value by at least, in part, adding the second measured quantity to the previously calculated first value multiplied by the pre-selected parameter,

an instruction to calculate a second value by at least, in part, subtracting the previously calculated first value from the new first value, and

an instruction to compare the second value with a predetermined threshold value, wherein a change of state of the tire is indicated when the second value crosses the predetermined threshold value.

26. An apparatus according to claim 25, wherein the pre-selected parameter is a constant.

27. An apparatus according to claim 25, wherein the pre-selected parameter is between zero and one.

28. An apparatus according to claim 25, further comprising:

means for generating at least one second value for a plurality of tires, and

means for comparing the respective second values for each tire in order to determine a change of state of each tire.

29. An apparatus according to claim 25, wherein the tire characteristic is representative of air pressure inside the tire.

30. An apparatus according to claim 25, wherein the tire characteristic is representative of the temperature inside the tire.

31. An apparatus, comprising:

means for receiving at least first and second measured quantities representing a characteristic for at least first and second tires, the second measured quantities being taken after the first measured quantities, and

a processor programmed to execute;

an instruction to multiply a previously calculated first value for the first tire by a pre-selected parameter, the previously calculated first value having been calculated at least in part based upon the first measured quantity for the first tire,

an instruction to calculate a new first value for the first tire by at least, in part, adding the second measured quantity of the first tire to the previously calculated first value for the first tire, which has been multiplied by the pre-selected parameter,

an instruction to calculate a second value for the first tire by at least, in part, subtracting the previously calculated first value for the first tire from the new first value for the first tire,

an instruction to calculate a difference between the second value for the first tire and a second value calculated for the second tire, and

an instruction to compare the difference with a predetermined threshold value, wherein a change of state of at least one of the first and second tires is indicated when the difference crosses the predetermined threshold value.

32. An apparatus according to claim 31, wherein the pre-selected parameter is a constant.

33. An apparatus according to claim 31, wherein the pre-selected parameter is between zero and one.

34. An apparatus according to claim 31, further comprising:

means for generating at least one second value for a plurality of tires, and

means for comparing the respective second values for each tire in order to determine a change of state of each tire.

35. An apparatus according to claim 31, wherein the tire characteristic is representative of air pressure inside the tire.

36. An apparatus according to claim 31, wherein the tire characteristic is representative of the temperature inside the tire.