Method and apparatus for providing refill or bleed alerts in a tire pressure monitoring system

• US 20060015225A1
• Filed: 07/16/2004
• Published: 01/19/2006
• Est. Priority Date: 07/16/2004
• Status: Active Grant

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: McQuade, Thomas, Zoepf, Stephen
• Granted Patent: US 7,092,804 B2
• Time in Patent Office: Days
• US Class Current: 701/29
• 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 tire pressure monitoring system for a vehicle has bleed and refill pressure thresholds in addition to high and low pressure thresholds. If a tire pressure remains at a level below the refill pressure threshold and above the low pressure threshold for a specific period of time, based on amount of deviation from the refill pressure threshold, a refill alert is generated. If a tire pressure remains at a level above the bleed pressure threshold and below the high pressure threshold for a specific period of time, based on amount of deviation from the bleed pressure threshold, a bleed alert is generated.

Claims

1. A method of operating a tire pressure monitoring system for a vehicle comprising:

selecting a refill pressure threshold;

monitoring a tire pressure;

calculating a difference between said tire pressure and said refill pressure threshold when said tire pressure falls below said refill pressure threshold;

determining a time period based on said difference; and

generating a refill alert when said difference remains approximately constant during said time period.

2. The method of claim 1, wherein said time period is inversely proportional to said difference.

3. The method of claim 2, wherein said time period is linearly related to said difference.

4. The method of claim 1, further comprising the step of generating a refill alert when said difference gets larger during said time period.

5. The method of claim 1, further comprising the steps of selecting a low pressure threshold and generating a low pressure warning when said tire pressure falls below said low pressure threshold.

6. The method of claim 5, wherein said time period is inversely proportional to said difference.

7. The method of claim 6, wherein said time period is linearly related to said difference.

8. The method of claim 5, further comprising the step of generating said refill alert when said difference gets larger during said time period.

9. The method of claim 1, further comprising the steps of:

selecting a bleed pressure threshold;

calculating a bleed difference between said tire pressure and said bleed pressure threshold when said tire pressure increases above said bleed pressure threshold;

determining a bleed time period based on said bleed difference; and

generating a bleed alert when said bleed difference remains approximately constant during said bleed time period.

10. The method of claim 9, wherein said bleed time period is proportional to said bleed difference.

11. The method of claim 10, wherein said bleed time period is linearly related to said bleed difference.

12. The method of claim 9, further comprising the step of generating a bleed alert when said bleed difference gets larger during said time period.

13. A tire pressure monitoring system of a vehicle comprising:

a tire;

a tire pressure sensor, said tire pressure sensor being capable of determining a tire pressure for said tire;

a refill pressure threshold, said refill pressure threshold being less than a normal operating pressure of said tire; and

a controller coupled to said tire pressure sensor, said controller being capable of calculating a difference between said tire pressure and said refill pressure threshold when said tire pressure falls below said refill pressure threshold, and being further capable of determining a time period based on said difference,

wherein said controller generates a refill alert when said difference remains approximately constant for said time period.

14. The system of claim 13, wherein said time period is inversely proportional to said difference.

15. The system of claim 14, wherein said time period is linearly related to said difference.

16. The system of claim 13, wherein said controller generates said refill alert when said difference gets larger during said time period.

17. The system of claim 13, further comprising a low pressure threshold, wherein said controller generates a low pressure warning when said tire pressure falls below said low pressure threshold.

18. The system of claim 17, wherein said time period is inversely proportional to said difference.

19. The system of claim 18, wherein said time period is linearly related to said difference.

20. The system of claim 17, wherein said controller generates said refill alert when said difference gets larger during said time period.

21. The system of claim 13, wherein said refill alert comprises a display.