Tire pressure monitoring system auto learn algorithm

• US 8,115,613 B2
• Filed: 07/18/2008
• Issued: 02/14/2012
• Est. Priority Date: 07/18/2008
• Status: Active Grant

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: Patel, Dilip B., McQuade, Thomas Michael, Swadling, Greg, Katiba, Mohsen
• Primary Examiner(s): Lau, Hoi
• Application Number:
  US12/175,485
• Publication Number:
  US 20100013618A1
• Time in Patent Office: 1,306 Days
• Field of Search: 340/447, 340/686.1, 340/442, 340/449, 340/539.1, 701/1, 709/208, 731/46, 731/463
• US Class Current: 340/447
• 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: B60C 23/0462 Structure of transmission protocol

Abstract

A method of operating a tire pressure monitoring system on a vehicle comprising tracking number of burst transmissions sent by a sensor, building a pareto of potential sensor identifications based on the greatest number of burst transmissions received from the sensor associating a potential sensor identification to a respective tire location on the vehicle and storing the associated sensor identification in memory. A tire pressure monitoring system comprising a plurality of tires in respective locations, each of the plurality of tires having a sensor, at least one sensor capable of burst mode transmission, and an auto learn function in a controller coupled to the sensors in the plurality of tires, the controller receiving and counting burst transmissions from the sensor for a predetermined time, the controller creating a pareto of received sensor identifications, filtering the pareto of potential sensor identifications and assigning the potential sensor identifications to a respective tire in the plurality of tires.

Claims

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

receiving transmissions at the tire pressure monitoring system from at least one tire pressure sensor, the transmissions including at least a sensor identification and a counter value;

tracking a number of frames transmitted by at least one sensor;

tracking a number of burst transmissions sent by the at least one sensor;

building a pareto of potential sensor identifications based on the greatest number of frames received from the at least one sensor;

comparing the number of burst transmissions sent by the at least one sensor in the pareto of potential sensor identifications to a predetermined burst minimum value to determine a relevant potential sensor identification;

associating a relevant potential sensor identification to a respective tire location on the vehicle; and

storing the associated sensor identification in memory.

5. The method as claimed in claim 1 wherein the step of building a pareto of potential sensor identifications further comprises the step of:

calculating a number of frames received from a sensor from the number of tracked burst transmissions; and

comparing the calculated number of frames received to a predetermined number of frames to ensure each potential sensor identification has been included in the pareto.

6. The method as claimed in claim 5 wherein the step of building a pareto of potential sensor identifications further comprises the step of filtering potential sensor identifications based on the number of frames received from a sensor, whereby a potential sensor identification is determined for each sensor in a descending order of the number of frames received.

7. The method as claimed in claim 6 wherein the step of filtering potential sensor identifications further comprises:

comparing a received sensor burst counter to a predetermined burst counter minimum requirement to verify all sensor identifications have been received; and

selecting a comparison threshold value based on the number of known sensor identifications received.

8. The method as claimed in claim 7 wherein the step of selecting a comparison threshold based on the number of known sensor identifications received further comprises setting the comparison threshold to a value equal to an average of the burst counter values for the known sensor identifications plus or minus a predetermined threshold when at least one known sensor identification has been received.

9. The method as claimed in claim 7 wherein the step of selecting a comparison threshold further comprises setting the comparison threshold to a value equal to an average of the burst counter values for all of the new received identifications plus or minus a predetermined threshold value associated with none of the known sensor identifications having been received.

10. The method as claimed in claim 7 wherein the number of potential sensor identifications is greater than the number of missing sensor identifications and further comprising the step of identifying a factory true setting to determined actual potential sensor identifications.

2. The method as claimed in claim I wherein the step of building a pareto of potential sensor identifications further comprises the step of confirming an active ignition status of a vehicle.

3. The method as claimed in claim 2 wherein the step of building a pareto of potential sensor identifications further comprises the step of verifying a vehicle speed has met a predetermined speed threshold.

4. The method as claimed in claim 3 wherein the step of building a pareto of potential sensor confirming that a predetermined amount of time has elapsed at the verified vehicle speed.

11. A tire pressure monitoring system comprising:

a plurality of tires in respective locations, each of the plurality of tires having a sensor transmitting at least a sensor identification and a counter value;

at least one sensor in the plurality of tires capable of burst mode transmission; and

an auto learn function in a controller coupled to the sensors in the plurality of tires, the controller receiving and counting burst transmissions from the at least one sensor for a predetermined time, the controller creating a pareto of received sensor identifications, filtering the pareto of potential sensor identifications and assigning the potential sensor identifications to a respective tire in the plurality of tires.

12. The system claimed in claim 11 further comprising:

a signal indicating an active ignition;

a predetermined vehicle speed threshold; and

a predetermined time limit for maintaining the predetermined vehicle speed threshold after ignition is active to initiate the auto-learn function.

13. The system as claimed in claim 11 wherein the pareto of received sensor identifications further comprises at least one received sensor identification currently associated with a respective tire location being confirmed in memory and whereby each received sensor identification not currently associated with a respective tire location is stored as a potential sensor identification.

14. The system as claimed in claim 13 wherein the filtered pareto of potential sensor identifications is created from the pareto of potential sensor identifications and is based on sensor identifications with a number of burst transmissions received from the sensor, whereby the sensors transmitting the number of burst transmissions in comparison to a predetermined value representative of a burst counter of learned identifications are stored as potential identifications to be assigned to a respective tire location.

15. The system as claimed in claim 14 further comprising:

a comparison threshold set to a value calculated from an average of the burst counter values for any known sensor identifications stored in memory plus or minus a predetermined threshold used in the event at least one known sensor identification has been received.

16. The system as claimed in claim 14 further comprising:

a comparison threshold set to a value calculated from an average of the burst counter values for all newly received sensor identifications plus or minus a predetermined threshold used in the event none of the known sensor identifications has been received.

17. The system as claimed in claim 14 wherein the number of potential sensor identifications exceeds a number of missing sensor identifications and the potential sensor identifications are limited by identifying a factory true setting in the sensor.

18. The system as claimed in claim 14 wherein any potential sensor identification not currently associated with a respective location is assigned to a respective tire location.

19. A method of operating a tire pressure monitoring system on a vehicle comprising:

receiving transmissions at the tire pressure monitoring system from at least one tire pressure sensor, the transmissions including at least a sensor identification and a counter value;

tracking a number of burst transmissions sent by at least one sensor;

building a pareto of received sensor identifications based on the tracked burst transmissions;

filtering the pareto of received sensor identifications through comparisons with predetermined burst transmission count values thereby defining a pareto of potential sensor identifications;

associating a potential sensor identification to a respective tire location on the vehicle; and

storing the associated sensor identification in memory.

20. The method as claimed in claim 19 wherein the step of building a pareto of potential sensor identifications further comprises the step of:

calculating a number of frames received from a sensor from the number of burst transmissions in a burst counter; and

comparing the number of frames received to a predetermined number of frames to ensure each potential sensor identification has been included in the pareto.

21. The method as claimed in claim 20 wherein the step of building a pareto of potential sensor identifications further comprises the step of filtering potential sensor identifications based on the number of frames received from a sensor, whereby a potential sensor identification is made for each sensor having the greatest number of frames received in a descending order.

22. The method as claimed in claim 21 wherein the step of building a pareto of potential sensor identifications further comprises:

comparing a burst counter value of a potential sensor identification to an average of the burst counter values received for each known sensor identification plus or minus a first predetermined threshold value, the first predetermined threshold value being set in the event at least one known sensor identification has been received;

comparing a burst counter value of a potential sensor identification to an average of newly received but unknown sensor identification burst counter values for received sensor identifications plus or minus a second predetermined threshold value, the second predetermined threshold value being set in the event none of the known sensor identifications has been received; and

looking for a factory true setting on a received sensor identification to determined potential sensor identifications in the event more than a missing number of learned sensor identifications has been received.

23. The method as claimed in claim 22 wherein the step of building a pareto of received sensor identifications further comprises the step of confirming an active ignition status of a vehicle.

24. The method as claimed in claim 23 wherein the step of building a pareto of received sensor identifications further comprises the step of verifying a vehicle speed has met a predetermined speed threshold.

25. The method as claimed in claim 24 wherein the step of building a pareto of received sensor identifications further comprises the step of confirming a predetermined amount of time has elapsed at the vehicle speed threshold.