Systems and methods for localization of tire pressure monitoring system wheel modules

• US 8,593,273 B2
• Filed: 02/07/2011
• Issued: 11/26/2013
• Est. Priority Date: 02/07/2011
• Status: Active Grant

• Current Assignee: Infineon Technologies AG
• Original Assignee: Infineon Technologies AG
• Inventors: Gotschlich, Martin, Lange, Thomas
• Primary Examiner(s): Bugg, George
• Assistant Examiner(s): Akhter, Sharmin
• Application Number:
  US13/022,345
• Publication Number:
  US 20120200408A1
• Time in Patent Office: 1,023 Days
• Field of Search: 340442-444, 340/447, 340/449, 340/426.33, 73146-1468, 701/49, 701/83, 157/1
• US Class Current: 340/445
• CPC Class Codes: B60C 23/0416 allocating a corresponding wheel position on vehicle, e.g. front/left or rear/right
• CPC Class Codes: B60C 23/0488 Movement sensor, e.g. for sensing angular speed, acceleration or centripetal force

Abstract

Embodiments relate to unidirectional TPMS utilizing information from a corresponding vehicle system in order to correlate with vehicle speed information to be used in a tire localization methodology. In an embodiment, the vehicle system is an anti-lock brake system (ABS), and the vehicle speed can be used in a localization scheme that reconstructs a +/−1 g ripple with waveform, amplitude, frequency and phase parameters. Because the waveform is known to be sinusoidal (due to the wheel rotation), the amplitude is known to be 2 g peak-to-peak (due to the gravitational +/−1 g), the frequency depends on vehicle speed (which can be estimated from centrifugal force measurements), and an algorithm is discussed herein for determining the phase by correlation, the +/−1 g ripple can be reconstructed and the wheels localized therefrom.

Claims

1. A method comprising:

receiving signals comprising tire pressure monitoring system (TPMS) module identification codes;

building a correlation table of counter values from counters coupled to anti-lock braking systems (ABS) at each wheel of a vehicle;

reviewing the correlation table for stable counter values associated with TPMS module identification codes;

determining a TPMS module identification code associated with the stable counter values;

localizing TPMS wheel modules by assigning an ABS counter associated with the stable counter values to the determined TPMS module identification code.

2. The method of claim 1, further comprising receiving counter values from the counters, the counter values of each counter related to pulses of a pole wheel associated with a wheel associated with the counter.

3. The method of claim 2, wherein the counters comprise modulo-N counters.

4. The method of claim 1, further comprising associating a unique identifier with each counter.

5. The method of claim 1, wherein building a correlation table comprises filling columns with a counter value from each counter upon receipt of a valid signal from a TPMS module and associating each column with the TPMS module identification code that sent the valid signal.

6. The method of claim 1, further comprising triggering counter readings for building the correlation table when a valid signal from a TPMS module is received.

7. A method comprising:

measuring a centrifugal acceleration of a tire pressure monitoring system (TPMS) wheel module;

determining a frequency of a +/−

1 g signal associated with the wheel module;

determining an optimized sampling frequency; and

determining a phase of the +/−

1 g signal by measuring the centrifugal acceleration of the wheel module at the optimized sampling frequency.

8. The method of claim 7, further comprising repeating the measuring, the determining of a frequency, the determining of an optimized frequency and the determining of a phase for each wheel of a vehicle.

9. The method of claim 7, further comprising determining a vehicle speed and an angular velocity of the wheel module.

10. The method of claim 7, further comprising determining a wheel angle associated with the wheel module.

11. The method of claim 10, further comprising communicating the wheel angle to a central receiver unit.

12. The method of claim 7, further comprising sensing a pressure by the TPMS wheel module.

13. The method of claim 7, further comprising measuring at least one additional centrifugal acceleration according to the optimized sampling frequency.

14. The method of claim 7, wherein determining an optimized sampling frequency comprises determining a minimum sampling frequency, and adjusting the minimum sampling frequency by an oversampling factor constant.

15. A method comprising:

determining an optimized sampling frequency;

sampling a centrifugal acceleration of a tire pressure monitoring system (TPMS) wheel module at the optimized sampling frequency;

transmitting signals from the wheel module to a central receiver unit;

building a correlation table of counter values from counters coupled to anti-lock braking systems (ABS) at each wheel of a vehicle, the counter values read when the transmitted signals are received by the central receiver unit;

reviewing the correlation table for stable counter values associated with TPMS module identification codes;

determining a TPMS module identification code associated with the stable counter values; and

localizing TPMS wheel modules by assigning an ABS counter associated with the stable counter values to the determined TPMS module identification code.

16. The method of claim 15, wherein determining an optimized sampling frequency comprises determining a phase of a +/−

1 g signal associated with a tire pressure monitoring system (TPMS) wheel module.

17. The method of claim 15, further comprising sensing a pressure by a pressure sensor of the TPMS wheel module.

18. A system comprising:

a plurality of wheel modules, each wheel module associated with a wheel of a vehicle and comprising a sensor configured to sense a condition related to the wheel;

a plurality of counters, each counter associated with an anti-lock braking system and a wheel of the vehicle; and

a central receiver unit configured to receive signals from the plurality of wheel modules, each signal comprising a wheel module identification code, to fill a correlation table of counter values taken from each of the plurality of counters when a signal is received from one of the plurality of wheel modules, and to localize each wheel of the vehicle by assigning a counter having stable counter values to a wheel module originating a signal when the stable counter values were obtained.

19. The system of claim 18, wherein each of the plurality of wheel modules comprises a tire pressure monitoring system (TPMS) wheel module.

20. The system of claim 19, wherein each TPMS wheel module comprises a pressure sensor.

21. The system of claim 20, further comprising analog-to-digital converter (ADC) circuitry coupled to the pressure sensor.

22. The system of claim 19, wherein each TPMS wheel module comprises an acceleration sensor.

23. The system of claim 18, wherein each of the plurality of wheel modules comprises a radio frequency (RF) communications unit.

24. The system of claim 18, wherein each of the plurality of counters comprises a unique identification code to associate each counter with a wheel of the vehicle.

25. The system of claim 18, wherein each of the plurality of counters comprises a modulo-N counter configured to measure pole wheels of the wheel.