Determination of wheel sensor position using radio frequency detectors in an automotive remote tire monitor system

• US 20030112138A1
• Filed: 02/05/2003
• Published: 06/19/2003
• Est. Priority Date: 04/25/2000
• Status: Active Grant

• Current Assignee: Sensata Technologies Incorporated (Sensata Technologies Holding Plc)
• Original Assignee: Schrader-Bridgeport International Incorporated (Pacific Industrial Company Limited)
• Inventors: Marguet, Emmanuel, Stewart, William David
• Granted Patent: US 6,809,639 B2
• Time in Patent Office: Days
• US Class Current: 340/447
• CPC Class Codes: B60C 23/0416 allocating a corresponding wheel position on vehicle, e.g. front/left or rear/right
• CPC Class Codes: B60C 23/0433 Radio signals

Abstract

In a remote tire monitor system, radio frequency (RF) signals including tire data are transmitted from a plurality of tire monitors at wheels of a vehicle. At an RF receiver, the signals are received and tire data is detected. The RF signals are detected at a receiving RF detector associated with the transmitting tire monitor. The receiving RF detector produces a transmission indication in response to the received RF signals. A control unit is coupled to the RF receiver and the RF detector. The control unit receives the tire data and the transmission indication and associates a position of the transmitting tire monitor with the tire data in response to transmission indication. This permits automatic update of the position of tire monitors on the vehicle.

Claims

1. A method for operating a remote tire monitor system, the method comprising:

at a transmitting tire monitor of a plurality of tire monitors, transmitting radio frequency (RF) signals including tire data;

at a RF receiver, receiving the RF signals and detecting the tire data;

at a receiving RF detector of a plurality of RF detectors each associated with a tire monitor, producing a transmission indication; and

at a control unit, receiving the tire data and transmission indication and associating a position of the transmitting tire monitor with the tire data in response to the transmission indication.

2. The method of claim 1 further comprising:

comparing the position of the transmitting tire monitor with a stored position of the transmitting tire monitor; and

updating the stored position with the position of the transmitting tire monitor when the position of the transmitting tire monitor differs from the stored position.

3. The method of claim 1 wherein receiving the RF signals comprises:

demodulating the RF signals;

decoding the tire data; and

conveying the tire data to the control unit.

4. The method of claim 3 wherein decoding the tire data comprises:

decoding a tire monitor identifier; and

decoding tire pressure data.

5. The method of claim 1 wherein producing a transmission indication comprises:

detecting an envelope of the RF signals; and

producing a wire line signal in response to the envelope of the RF signals.

6. The method of claim 5 wherein producing a wire line signal comprises:

modulating a current in a conductor coupled with the control unit.

7. The method of claim 6 further comprising:

detecting modulation of the current at the control unit to locate the transmitting tire monitor.

8. A control unit for a remote tire monitor system of a vehicle, the control unit comprising:

a radio frequency (RF) receiver configured to receive RF signals conveying tire data from at least one transmitting tire monitor of a plurality of tire monitors associated with wheels of the vehicle; and

a RF decoder configured to receive a transmission indication from at least one receiving RF detector of a plurality of RF detectors associated with wheels of the vehicle and identify a position of the transmitting tire monitor on the vehicle in response to the transmission indication.

9. The control unit of claim 8 further comprising:

a memory; and

a controller configured to store in the memory position of the plurality of tire monitors including the position of the transmitting tire monitor.

10. The control unit of claim 9 wherein the controller is further configured to compare the position of the transmitting tire monitor with a stored position of the transmitting tire monitor store the position of the transmitting tire monitor as the stored position when the position of the transmitting tire monitor does not match the stored position.

11. A radio frequency (RF) detector for use in association with a tire monitor of a remote tire monitor system of a vehicle, the RF detector comprising:

an antenna to sense RF signals from the tire monitor;

an envelope detector coupled to the antenna; and

an output circuit coupled to the envelope detector.

12. The RF detector of claim 11 wherein the output circuit comprises:

at least one transistor to produce a wire line signal.

13. The RF detector of claim 11 wherein the envelope detector comprises:

a circuit coupled with the antenna to detect an envelope of electrical signals produced by the antenna in response to the RF signals; and

an amplifier.

14. The RF detector of claim 13 wherein the output circuit comprises:

at least one transistor which modulates a wire line signal in response to the envelope.

15. A method for a remote tire monitor system, the method comprising:

receiving radio frequency (RF) signals including tire data from a transmitting tire monitor associated with a wheel of a vehicle;

receiving a wire line indication from an RF detector associated with the transmitting tire monitor; and

identifying position on vehicle of the transmitting tire monitor in response to the wire line indication.

16. The method of claim 15 further comprising:

storing position data for a plurality of tire monitors of the remote tire monitor system; and

updating the position data for the transmitting tire monitor when the position of the transmitting tire monitor varies from a stored position for the transmitting tire monitor.

17. The method of claim 15 wherein receiving a wire line indication comprises:

detecting a modulated electrical signal on a wire coupled to the RF detector near the transmitting tire monitor.

18. The method of claim 17 wherein detecting a modulated electrical signal comprises:

detecting current which has been modulated by an envelope of the RF signals at the RF detector.

19. A remote tire monitor system comprising:

a plurality of tire monitors, each tire monitor being associated with a wheel of a vehicle and configured to transmit radio frequency (RF) signals including tire data;

a plurality of RF detectors, each RF detector being mounted on the vehicle proximate an associated tire monitor to detect the RF signals from the associated tire monitor and produce a transmission indication in response to detected RF signals;

a RF receiver to receive tire data in RF signals transmitted by any tire monitor of the plurality of tire monitors; and

a control unit coupled with the plurality of RF detectors to receive transmission indications and coupled with the RF receiver to receive the tire data, the control unit being operative to associate a position of a transmitting tire monitor with a received transmission indication.

20. The remote tire monitor system of claim 19 wherein each RF detector comprises:

an envelope detector to detect an envelope of the RF signals from the associated tire monitor; and

an output circuit to modulate an electrical signal on a conductor as the transmission indication.

21. The remote tire monitor system of claim 20 wherein the output circuit comprises:

at least one transistor for modulating a current in the conductor.

22. A method for automatically identifying positions of a plurality of tire monitors on a vehicle, the method comprising:

initiating operation of the plurality of tire monitors upon operation of the vehicle;

receiving from the plurality of tire monitors radio frequency (RF) signals containing tire information;

receiving wireline indications from a plurality of RF detectors, each RF detector being associated on the vehicle with a tire monitor to detect but not demodulate RF signals transmitted by the tire monitor; and

associating the tire information from each tire monitor with an RF detector in response to the wireline indications.

23. The method of claim 22 further comprising:

at each tire monitor, detecting motion of the tire monitor; and

transmitting local tire information in response to detection of motion.

24. The method of claim 23 wherein transmitting local tire information comprises:

transmitting tire pressure data.

25. The method of claim 24 wherein transmitting local tire information further comprises:

transmitting a tire monitor identifier associated with the tire monitor.

26. The method of claim 22 wherein associating the tire information from each tire monitor with an RF detector comprises

determining an identifier associated with a transmitting tire monitor in the tire information;

identifying a receiving RF detector which originated a received wireline indication; and

storing the identifier at a memory location associated with the receiving RF detector.

27. The method of claim 22 further comprising:

receiving subsequent RF signals containing additional tire information;

receiving subsequent wireline indications from receiving RF detectors;

associating the additional tire information with the receiving RF detectors; and

verifying the tire information with the additional tire information.

28. The method of claim 27 further comprising:

after verification, storing the tire information in a memory location associated with the RF detector which is associated with the tire information.

29. A method for automatically updating a remote tire monitor system of a vehicle, the method comprising:

storing identification information for each tire monitor of a plurality of tire monitors of the vehicle;

receiving an identifier transmitted by a transmitting tire monitor;

receiving a transmission indication from a receiving radio frequency (RF) detector associated with the transmitting tire monitor; and

when the identifier does not produce a match with the identification information, updating the identification information using the identifier.

30. The method of claim 29 wherein receiving the identifier comprises:

receiving RF signals at an RF circuit;

demodulating the RF signals to receive tire information; and

locating the identifier in the tire information.

31. The method of claim 30 wherein receiving a transmission indication comprises:

detecting the RF signals at the receiving RE detector; and

without demodulating the RF signals, producing a wireline indication in response to the RF signals; and

at a control unit, detecting the wireline indication as the transmission indication.

32. The method of claim 31 further comprising:

in response to the wireline indication, reading the identification information from a storage location in memory, the storage location being associated with the receiving RF detector.