Hybrid Resonant Structure to Verify Parameters of a Tire
AssigneeMichelin Recherche et Technique S.A.
InventorsLionel Fagot-Revurat, Sylvain Ballandras, Jeremy Masson, William Steichen
Life of this patent
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Abstract
Control of running conditions, and particularly physical parameters of tires are recommended to increase automobile safety. A sensor according to the invention is used to determine various factors such as the temperature or pressure of tires. The sensor is a hybrid resonant passive structure that may be integrated in the vehicle ground connection, and particularly in the rubber of the tire when it is manufactured.
Claims14
1-13. (canceled)
An element of a vehicle ground connection comprising at least one hybrid resonant acoustic structure acting as a sensor, wherein the resonant structure comprises:
- (1) a support;
- and
- (2) a piezoelectric transducer, wherein the transducer comprises:
- (a) a first conducting electrode installed on the support;
- and
- (b) a second conducting electrode separated by a film of piezoelectric material, wherein a working frequency of the resonant structure is in the radiofrequency spectrum from about 300 MHz to about 3000 MHz.
The ground connection element according to claim 1, wherein the working frequency of the resonant structure in the radiofrequency spectrum, is a harmonic with rank N≠1 of the natural frequency (F0) of the resonant structure.
The ground connection element according to claim 1 or 2, wherein the support is a silicon monocrystal substrate blade.
The ground connection element according to claim 1, wherein the piezoelectric material film is a thin aluminum nitride layer.
The ground connection element according to claim 1, wherein the resonant structure further comprises an additional layer installed on the surface of the second electrode facing the piezoelectric layer, wherein the additional layer optimizes the acousto-electric density within the piezoelectric film by positioning a strain maximum in the piezoelectric layer.
The ground connection element according to claim 5, wherein the additional layer is the same nature as the support
The ground connection element according to claim 1, wherein the resonant structure further comprises a Bragg mirror on the second electrode or the additional layer and/or as support of the transducer, wherein the mirror comprises an alternation of layers of materials with different reflection coefficients and wherein the reflection coefficient of the mirror is maximum close to the resonant frequency of the resonant structure.
The ground connection element according to claim 7, wherein the resonant structure further comprises a coating layer at least at the Bragg mirror.
The ground connection element according to claim 1, further comprising an antenna associated with the resonant structure.
The ground connection element according to claim 9, further comprising at least one second resonant acoustic structure, wherein the characteristics of each resonant structure enable differential measurement of the temperature.
The ground connection element according to claim 1, wherein the resonant structure is integrated in the rubber of a tire.
The ground connection element according to claim 1, wherein the resonant structure is used to measure a running parameter of the vehicle.
The ground connection element according to claim 12, wherein the running parameter is the temperature of a tire.
Dependencies are inferred from the claim text.