Method and system for measuring rotational speed of a motor vehicle wheels

• US 20040267493A1
• Filed: 08/06/2004
• Published: 12/30/2004
• Est. Priority Date: 10/31/2001
• Status: Abandoned Application

• Current Assignee: Johnson Controls Automotive Electronic (Johnson Controls International plc)
• Original Assignee: Johnson Controls Automotive Electronic (Johnson Controls International plc)
• Inventors: Michel, Nicolas, Hernando, Serge, Delaporte, Francis, Pinard, Thierry
• Application Number:
  US10/493,937
• Publication Number:
  US 20040267493A1
• Time in Patent Office: Days
• US Class Current: 702/145
• 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: G01P 3/44 for measuring angular speed G01P3/56 takes precedence
• CPC Class Codes: G01P 3/48 by measuring frequency of generated current or voltage in general G01R23/00

Abstract

A method for determining a rotational speed of a rotating object of a vehicle includes providing information unrelated to the rotational speed of the object of the vehicle using an electronic device and providing information related to the rotational speed of the object of the vehicle using the electronic device. One example of a system employing this method is a tire pressure sensor system. The tire pressure sensor provides information regarding the pressure of the tire of the vehicle. Likewise, a periodicity in a signal transmitted by a transmitter associated with the tire pressure sensor can be used to determine the rotational speed of the wheel of the vehicle to which the tire is attached.

Claims

1. Method for measuring rotational speeds of wheels (11) of an automobile, comprising:

detecting envelopes of signals from emitters of tire pressure sensors; and

determining the periods of the envelopes so as to deduce therefrom their rotational speeds.

2. Method as claimed in claim 1, wherein the signal emitted by the emitter of the pressure sensor of a wheel is processed cyclically, said cycle comprising an observation time during which the signal is stored, the amplitude maximums, which are substantially equal and successive, are detected and the times separating these maximums are deduced therefrom.

3. Method as claimed in claim 1, wherein the signal emitted by the pressure sensor is recovered in order to subject it to a filtering or smoothing process so as to isolate the envelope from the signal.

4. Method as claimed in claim 2, wherein said observation time is determined from the speed of the vehicle.

5. Method as claimed in claim 2, wherein the length of the cycle is determined from the speed of the vehicle.

6. Measuring system for implementing a method for measuring rotational speeds of wheels of an automobile, comprising:

a set of wheel tire pressure sensors and of emitters mounted on the wheels, the emitters configured to emit signals,

means for processing the signals in order to extract modulation envelopes from the signals emitted by the emitters,

means for processing the signals to calculate the periods of the modulation envelopes, and

means for processing the signals to deduce the rotational speeds from the periods.

7. Measuring system as claimed in claim 6, wherein the means for processing the signals in order to extract modulation envelopes is mounted in a branched manner on means for receiving the signals from the emitters.

8. Measuring system as claimed in claims 6, wherein means are provided to estimate the period of the modulation envelopes comprising means (15) indicating a speed of the automobile.

9. A method for determining a rotational speed of a rotating object of a vehicle, comprising:

providing information unrelated to the rotational speed of the object of the vehicle using an electronic device;

providing information related to the rotational speed of the object of the vehicle using the electronic device.

10. The method of claim 9, wherein the electronic device is a wireless transmitter configured to transmit data.

11. The method of claim 10, wherein the transmitter is configured to transmit a radio frequency signal.

12. The method of claim 10, wherein the transmitter is coupled to a processing circuit such that the transmitter may transmit data acquired by the processing circuit.

13. The method of claim 12, further comprising acquiring tire pressure data using the processing circuit and transmitting the tire pressure data using the transmitter.

14. The method of claim 10, further comprising determining an observation time during which data from the transmitter is analyzed to determine the rotational speed of the object.

15. The method of claim 14, further comprising determining the observation time from a speed of the vehicle.

16. The method of claim 10, further comprising filtering or smoothing a signal from the transmitter.

17. The method of claim 16, further comprising isolating an envelope of the signal after it has been filtered or smoothed.

18. The method of claim 10, wherein the object is a wheel of the vehicle.

19. The method of claim 18, wherein the electronic device is a wireless transmitter configured to transmit data.

20. The method of claim 19, further comprising determining an observation time during which data from the transmitter is analyzed to determine the rotational speed of the object.

21. The method of claim 19, further comprising filtering or smoothing a signal from the transmitter.

22. The method of claim 21, further comprising isolating an envelope of the signal after it has been filtered or smoothed.

23. The method of claim 9, further comprising determining an observation time during which data from the transmitter is analyzed to determine the rotational speed of the object.

24. The method of claim 23, further comprising determining the observation time from a speed of the vehicle.

25. The method of claim 9, further comprising filtering or smoothing a signal from the transmitter.

26. The method of claim 25, further comprising isolating an envelope of the signal after it has been filtered or smoothed.

27. An automobile, comprising:

a sensor configured to obtain data relating to a parameter of the automobile, the parameter unrelated to a rotational speed of a wheel of the automobile;

a transmitter coupled to the sensor and configured to transmit data obtained by the sensor; and

a processing circuit configured to determine the rotational speed of the wheel of the automobile using data obtained from a signal transmitted the transmitter.

28. The automobile of claim 27, wherein the processing circuit is configured to use a periodicity in the signal transmitted by the transmitter to determine the rotational speed of the wheel of the automobile.

29. The automobile of claim 27, wherein the processing circuit is configured to obtain data to use to determine the rotational speed of the wheel of the automobile only during an observation period.

30. The automobile of claim 27, wherein the sensor comprises a pressure sensor.

31. The automobile of claim 30, wherein the parameter comprises pressure of a tire of the automobile.