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

• US 20030046992A1
• Filed: 09/13/2002
• Published: 03/13/2003
• Est. Priority Date: 12/22/1999
• Status: Active Grant

• Current Assignee: Pirelli Pneumatici S.P.A. (Pirelli & C SPA)
• Original Assignee: Pirelli Pneumatici S.P.A. (Pirelli & C SPA)
• Inventors: Caretta, Renato
• Granted Patent: US 6,959,592 B2
• Time in Patent Office: Days
• US Class Current: 73/146
• CPC Class Codes: B60C 23/0413 Wireless charging of active radio frequency circuits
• CPC Class Codes: B60C 23/066 by monitoring wheel-centre to ground distance

Abstract

A system for monitoring deformations of a moving tyre mounted on a rim associated with a vehicle includes a moving station and a fixed station. The moving station is operatively coupled to the rim. The moving station measures, at least intermittently and in at least one direction, a distance between the moving station and an inner surface of the tyre. The fixed station is operatively coupled to the vehicle. The fixed station receives from the moving station, at least intermittently, at least one first signal associated with the measurement. The moving station measures the distance within a time interval when a first antenna associated with the moving station and a second antenna associated with the fixed station are in proximity to each other. Related methods for monitoring deformations of a moving tyre mounted on a rim associated with a vehicle are also disclosed.

Claims

1. System for monitoring the deformations of a moving tyre (1) fitted on a rim (2) associated with a vehicle, characterized in that it comprises:

a moving station (20) located in a predetermined position on the said rim (2) and capable of measuring in at least one direction the distance between the said predetermined position and the inner surface of the tyre (111),

a fixed station (30) located on the said vehicle and capable of receiving the said measurement from the said moving station.

2. System according to claim 1, characterized in that the said fixed station (30) is capable of enabling the said measurement made by the said moving station (20).

3. System according to claim 1, characterized in that the said moving station comprises at least one sensor (11) capable of sending a signal within the tyre in a predetermined direction, and of receiving this signal when reflected.

4. System according to claim 3, characterized in that the said sensor (11) comprises an electronic circuit board (15) with which are associated an optical beam emitting device (16), a first lens (17), an optical beam receiving device (18), and a second lens (19).

5. System according to claim 1, characterized in that the said fixed station (20) comprises a supporting element (21), fixed at one of its ends to a hub on which the said rim is mounted, and an electronic circuit board, (22), fixed to the said supporting element.

6. System according to claim 5, characterized in that the said electronic circuit board (22) of the fixed station (20) comprises an oscillator circuit (23) which supplies a drive circuit (24) for a first antenna (25), a radio-frequency receiver (26) connected to the said first antenna, and an electrical demodulator device (27) connected to the said radio-frequency receiver.

7. System according to claim 1, characterized in that the said fixed station is powered by the battery of the vehicle on which the tyre is fitted.

8. System according to claim 4, characterized in that the said electronic circuit board (15) of the sensor (11) comprises a second antenna (31), connected to a power supply unit (32), which supplies a drive circuit (33) for the said optical beam emitter (16) and a drive circuit for the said optical beam receiver (35), and a circuit (37) for reading the electrical signal emitted by the said optical beam receiver.

9. System according to claim 4, characterized in that the said optical beam emitter (16) comprises an LED.

10. System according to claim 4, characterized in that the said optical beam receiver (35) comprises a pair of p-i-n diodes.

11. Method for monitoring the deformations of a moving tyre fitted on a rim associated with a vehicle, characterized in that it comprises the following stages:

emitting a signal from a predetermined position on the said rim in at least one predetermined direction within the tyre,

reflecting this signal from the inner surface of the tyre,

receiving this reflected signal,

processing the received signal in such a way as to generate a processed signal proportional to the distance of the point of reflection on the tyre from the said predetermined position in the said at least one predetermined direction.

12. Method according to claim 11, characterized in that the said stage of emitting a signal comprises:

enabling a moving station (30) located on the said rim to emit the said signal when the said moving station passes through the footprint area of the tyre.

13. Method according to claim 11, characterized in that it additionally comprises the stage of transferring the said signal processed by the said moving station to a fixed station (20) located on the said vehicle.

14. Method according to claim 12, characterized in that the said stage of enabling a moving station is carried out by the said fixed station (20).

15. Method according to claims 11 to 14, characterized in that the said stage of enabling the moving station comprises supplying power to the moving station for a time interval during which the stage of transferring the processed signal from the said moving station to the said fixed station is also carried out.

16. Method according to claim 12, characterized in that the said stage of enabling a moving station comprises generating a magnetic field at the said fixed station (20) in the direction of the said moving station and supplying power by means of the said magnetic field to a drive circuit (33) in the said moving station (30) for an optical beam emitter (16).

17. Method according to claim 13, characterized in that the said stage of transferring the said processed signal from the said moving station to the said fixed station comprises:

generating a magnetic field corresponding to the said processed signal at the said moving station (30) in the direction of the said fixed station (20),

converting the said magnetic field to an electrical signal,

decoding the said electrical signal in such a way that the corresponding processed signal is obtained.

18. Wheel for vehicles, comprising a tyre (1) fitted on a supporting rim (2), characterized in that it comprises a moving station (20) located at a predetermined position on the said rim (2) and capable of measuring in at least one direction the distance between the said predetermined position and the inner surface of the tyre (111), and capable of transmitting the said measurement to a vehicle on which the said wheel is fitted.