Method and system for monitoring the deformations of a tire in motion

• US 6,782,739 B2
• Filed: 01/16/2002
• Issued: 08/31/2004
• Est. Priority Date: 02/22/2000
• Status: Expired due to Fees

• Current Assignee: Pirelli Pneumatici S.P.A. (Pirelli & C SPA)
• Original Assignee: Pirelli Pneumatici S.P.A. (Pirelli & C SPA)
• Inventors: Caretta, Renato, Ratti, Alessandro
• Primary Examiner(s): OEN, WILLIAM L
• Application Number:
  US09/959,250
• Publication Number:
  US 20020166371A1
• Time in Patent Office: 958 Days
• Field of Search: 731/46, 737/05, 731/462, 731/464, 731/465, 250/559.29, 250/559.31, 250/559.4, 250/204, 318/577, 318/640, 356/348, 356/347, 356/375, 356/376, 356/360, 356/3.01, 356/3.03
• US Class Current: 73/146
• CPC Class Codes: B60C 23/06 Signalling devices actuated by deformation of the tyre , e.g. tyre mounted deformation sensors or indirect determination of tyre deformation based on wheel speed, wheel-centre to ground distance or inclination of wheel axle
• CPC Class Codes: B60C 23/066 by monitoring wheel-centre to ground distance

Abstract

A system for monitoring deformations of a tire fitted on a rim associated with a vehicle includes a reflecting element positioned on an inner surface of the tire and a moving station located in a predetermined position on the rim. The reflecting element reflects an optical beam and includes a region having at least one area of high light reflection and at least one area of low light reflection. The moving station sends the optical beam toward the inner surface, receives one or more reflections of the optical beam from the inner surface or the reflecting element, and emits a signal proportional to the deformations of the tire in a longitudinal direction, in a transverse direction, and in a vertical direction.

Claims

1. A system for monitoring deformations of a moving tyre fitted on a rim associated with a vehicle, comprising:

a reflecting element positioned on an inner surface of the tyre for reflecting an optical beam and comprising a region having at least one area of high light reflection and at least one area of low light reflection; and

a moving station located in a predetermined position on the rim for sending the optical beam toward the inner surface, receiving one or more reflections of the optical beam from the inner surface or the reflecting element, and emitting a signal proportional to the deformations of the tyre in a longitudinal direction, in a transverse direction, and in a vertical direction.

2. The system of claim 1, further comprising a fixed station located on the vehicle for receiving the signal from the moving station.

3. The system of claim 1, wherein the at least one area of high light reflection is formed by coloring the inner surface of the tyre with reflective paint.

4. The system of claim 1, wherein the region comprises a plurality of triangles adjacent to each other.

5. The system of claim 2, wherein the fixed station enables a measurement made by the moving station.

6. The system of claim 1, wherein the moving station comprises at least one sensor comprising an electronic circuit board including an optical beam emitting device, a first lens, an optical beam receiving device, and a second lens.

7. The system of claim 2, wherein the fixed station comprises:

a supporting element fixed at one end to a hub on which the rim is mounted; and

an electronic circuit board fixed to the supporting element.

8. The system of claim 7, wherein the electronic circuit board comprises:

an oscillator circuit supplying a drive circuit for a first antenna;

a radio-frequency receiver connected to the first antenna; and

an electrical demodulator device connected to the radio-frequency receiver.

9. The system of claim 2, wherein the fixed station is powered by a battery of the vehicle.

10. The system of claim 6, wherein the electronic circuit board comprises:

a second antenna connected to a power supply unit which supplies a drive circuit for the optical beam emitting device;

a drive circuit for the optical beam receiving device; and

a circuit for reading an electrical signal emitted by the optical beam receiving device.

11. The system of claim 6, wherein the optical beam emitting device comprises a light emitting diode (LED) or a laser diode.

12. The system of claim 6, wherein the optical beam receiving device comprises at least one charge coupled device (CCD) element or at least one complementary metal oxide semiconductor (CMOS) element.

13. A method for monitoring deformations of a moving tyre fitted on a rim associated with a vehicle, comprising the steps of:

emitting a signal within the tyre from a predetermined position on the rim;

reflecting the signal from an inner surface of the tyre or a reflecting element positioned on the inner surface, wherein the inner surface or the reflecting element comprises a region having at least one area of high light reflection and at least one area of low light reflection;

receiving the reflected signal; and

processing the received signal to generate a signal proportional to the deformations of the tyre in a longitudinal direction, in a transverse direction, and in a vertical direction.

14. The method of claim 13, wherein the step of emitting a signal comprises:

enabling a moving station located on the rim to emit the signal when the moving station passes near a footprint area of the tyre.

15. The method of claim 13, further comprising the step of transferring the processed signal from the moving station to a fixed station located on the vehicle.

16. The method of claim 14, wherein the step of enabling the moving station is carried out by a fixed station.

17. The method of claim 14, wherein the step of enabling the moving station comprises supplying power to the moving station for a time interval during which a step of transferring the processed signal from the moving station to a fixed station is also carried out.

18. The method of claim 14, wherein the step of enabling the moving station comprises generating a magnetic field at a fixed station in a direction of the moving station and supplying power by means of the magnetic field to a drive circuit for an optical beam emitting device.

19. The method of claim 15, wherein the step of transferring the processed signal from the moving station to the fixed station comprises:

generating a magnetic field corresponding to the processed signal at the moving station in a direction of the fixed station;

converting the magnetic field to an electrical signal; and

decoding the electrical signal to obtain a corresponding processed signal.

20. A wheel for a vehicle, comprising:

a tyre;

a supporting rim;

a moving station; and

a reflecting element;

wherein the tyre is fitted on the supporting rim,

wherein the moving station is located at a predetermined position on the rim,

wherein the moving station sends an optical beam toward an inner surface of the tyre, receives the optical beam reflected from the inner surface, and transmits a signal proportional to deformations of the tyre in a longitudinal direction, in a transverse direction, and in a vertical direction, and

wherein the reflecting element reflects the optical beam and is positioned on the inner surface and comprises a region having at least one area of high light reflection and at least one area of low light reflection.