System for generating electric power from a rotating tire's mechanical energy using reinforced piezoelectric materials

• US 6,725,713 B2
• Filed: 01/15/2003
• Issued: 04/27/2004
• Est. Priority Date: 05/10/2002
• Status: Expired due to Term

• Current Assignee: Michelin Recherche et Technique SA (Compagnie Generale DES Etablissements Michelin SCA)
• Original Assignee: Michelin Recherche et Technique SA (Compagnie Generale DES Etablissements Michelin SCA)
• Inventors: Adamson, John David, OʼBrien, George Phillips
• Primary Examiner(s): OEN, WILLIAM L
• Application Number:
  US10/345,040
• Publication Number:
  US 20030209064A1
• Time in Patent Office: 468 Days
• Field of Search: 731/46, 731/462, 731/465, 731/463, 731/468, 152/415, 152/416, 152/417, 152/152.1, 340/441-447
• US Class Current: 73/146.5
• CPC Class Codes: B60C 23/0411 Piezoelectric generators
• CPC Class Codes: B60C 23/0493 for attachment on the tyre
• CPC Class Codes: B60K 25/08 from a ground wheel, e.g. engaging the wheel tread or rim
• CPC Class Codes: B60K 25/10 directly from oscillating movements due to vehicle running motion, e.g. suspension movement resilient suspensions having dampers accumulating utilisable energy, e.g. compressing air, B60G13/14
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00

Abstract

A system for generating electric power from a rotating tire'"'"'s mechanical energy concerns a power generation device with a piezoelectric structure and an energy storage device. The piezoelectric structure preferably comprises a plurality of piezoelectric fibers embedded in a generally unidirectional fashion within an epoxy matrix. The piezoelectric structure may be mounted on a support substrate that helps distribute mechanical strain to which the piezoelectric fibers are subjected in a substantially uniform fashion. The piezoelectric structure is preferably mounted within a tire structure such that electric charge is generated therein as the wheel assembly moves along a ground surface. Electrode layers within the piezoelectric structure are coupled to a power conditioning module that rectifies the resultant electric current from the piezoelectric structure and stores it in an energy storage device, preferably an electrolytic capacitor. A rechargeable battery may also be provided for storing additional charge generated within the piezoelectric structure. A regulated voltage source is provided from the energy stored in the power generation device and can be used to power various electronics systems integrated within a tire or wheel assembly. An example of an integrated tire electronics system for use with the disclosed power generation device corresponds to a tire monitoring system that wirelessly transmits such information as tire pressure, temperature and identification variables to a remote receiver location.

Claims

1. A tire assembly with integrated self-powered electronic components, said tire assembly comprising:

a pneumatic tire structure characterized by a crown having an exterior tread portion for making contact with a ground surface, bead portions for seating said tire to a wheel rim, exterior sidewall portions extending between each bead portion and the crown, and interior crown and sidewall surfaces;

a patch of piezoelectric material integrated with a selected portion of said pneumatic tire structure, said patch of piezoelectric material configured to generate an electric charge therein upon said pneumatic tire structure being subjected to mechanical strains;

an energy storage device configured to receive said electric charge from said patch of piezoelectric material and to store selected amounts of said electric charge therein; and

an electronics assembly including said electronic components connected to said energy storage device such that selected electronic components of said electronics assembly are powered by the electric charge stored in said energy storage device.

2. A tire assembly as in claim 1, wherein said piezoelectric material is selected from the group consisting of quartz, barium titanate, cadmium sulfide, lead zicronate titanate (PZT), polyvinylidene fluoride (PVDF), and polyvinyl chloride (PVC).

3. A tire assembly as in claim 1, further including a support substrate provided adjacent to said patch of piezoelectric material for distributing the strain to which said piezoelectric material is subjected in a substantially uniform fashion across said patch of piezoelectric material.

4. A tire assembly as in claim 3, further including a rubber casing provided adjacent to at least one side of the combined support substrate and patch of piezoelectric material to facilitate integration with said pneumatic tire structure.

5. A tire assembly as in claim 2, wherein said patch of piezoelectric material comprises a fiber composite structure with a plurality of piezoelectric fibers embedded in an epoxy matrix.

6. A tire assembly as in claim 5, wherein the piezoelectric fibers of said fiber composite structure are all aligned in a generally unidirectional fashion and provided in a radial orientation as integrated with a selected sidewall portion of said pneumatic tire structure.

7. A tire assembly as in claim 5, wherein the piezoelectric fibers of said fiber composite structure are all aligned in a generally unidirectional fashion and provided in a circumferential orientation as integrated with a selected crown portion of said pneumatic tire structure.

8. A tire assembly as in claim 1, further comprising a power conditioning module provided in conjunction with said energy storage device for rectifying an electric current signal representative of said electric charge generated within the patch of piezoelectric material, providing the rectified current signal to said energy storage device, and generating a regulated voltage output.

9. A tire assembly as in claim 8, wherein said electronics assembly comprises a rechargeable battery.

10. A tire assembly as in claim 1, wherein said electronics assembly comprises at least one sensor to monitor predetermined characteristics of said pneumatic tire structure.

11. A tire assembly as in claim 10, wherein said electronics assembly comprises a radio frequency (RF) device for relaying selected sensor information and additional tire identification information to a remote location.

12. A tire assembly as in claim 10, wherein said predetermined characteristics are selected from the group consisting of temperature, pressure, number of tire revolutions, vehicle speed, and level of static and dynamic forces acting on a tire structure.

13. A tire assembly as in claim 1, wherein the dimensions defining said piezoelectric patch result in a patch area of between about 750 mm² and about 2500 mm².

14. A tire assembly as in claim 1, wherein said energy storage device is a capacitor.

15. A tire assembly with integrated self-powered electronic components, said tire assembly comprising:

a pneumatic tire structure characterized by a crown having an exterior tread portion for making contact with a ground surface, bead portions for seating said tire to a wheel rim, exterior sidewall portions extending between each bead portion and the crown, and interior crown and sidewall surfaces;

a patch of piezoelectric material carried by a selected portion of said pneumatic tire structure, said patch of piezoelectric material configured to generate electric charge therein upon said tire structure being subjected to mechanical strains;

a support substrate provided adjacent to said patch of piezoelectric material for distributing the strain to which said piezoelectric material is subjected in a substantially uniform fashion within said patch of piezoelectric material;

an energy storage device configured to receive said electric charge generated in said patch of piezoelectric material and to store selected amounts of said electric charge therein; and

an electronics assembly including said electronic components connected to said energy storage device such that selected electronic components of said electronics assembly are powered by the electric charge stored in said energy storage device.

16. A tire assembly as in claim 15, wherein said piezoelectric material is selected from the group consisting of quartz, barium titanate, cadmium sulfide, lead zirconate titanate (PZT), polyvinylidene fluoride (PVDF), and polyvinyl chloride (PVC).

17. A tire assembly as in claim 16, wherein said patch of piezoelectric material comprises a fiber composite structure with a plurality of piezoelectric fibers embedded in an epoxy matrix.

18. A tire assembly as in claim 15, further comprising a power conditioning module provided in conjunction with said energy storage device for rectifying an electric current signal generated within the patch of piezoelectric material, providing the rectified current signal to said energy storage device, and generating a regulated voltage output.

19. A tire assembly as in claim 18, further comprising a rechargeable battery configured to receive said regulated voltage output.

20. A tire assembly as in claim 15, wherein said electronics assembly comprises sensors for monitoring the temperature and pressure of said pneumatic tire structure.

21. A tire assembly as in claim 20, wherein said electronics assembly further comprises a radio frequency (RF) device for relaying selected sensor information and additional tire identification information to a remote location.

22. A tire assembly as in claim 15, wherein the length and width dimensions defining said piezoelectric patch result in a patch area of between about 750 mm² and about 2500 mm² and wherein said support substrate is characterized by length and width dimensions that are greater than or equal to the respective dimensions of said piezoelectric patch.

23. A tire assembly as in claim 15, wherein said support substrate comprises fiberglass.

24. An electronics assembly for integration with a pneumatic tire structure designed to measure and transmit information relating to selected tire conditions, said electronics assembly comprising:

an active piezoelectric fiber composite structure integrated in the pneumatic tire structure, wherein said piezoelectric fiber composite structure is characterized by a plurality of piezoelectric fibers embedded in an epoxy matrix and provided between at least two electrode layers;

a support substrate provided adjacent to said active piezoelectric fiber composite structure for distributing the strain to which said piezoelectric fibers are subjected in a substantially uniform fashion within said piezoelectric fiber composite structure;

a power conditioning module electrically coupled to selected electrode layers of said piezoelectric fiber composite structure for receiving electric charge generated within the piezoelectric fibers, for storing the charge in an energy storage device within the power conditioning module, and for generating a regulated voltage output;

a plurality of sensors for determining information about preselected tire conditions, wherein said sensors are powered by the regulated voltage output from said power conditioning module;

a microcontroller connected to said power conditioning module and to said plurality of sensors for processing the information received from said sensors, and for generating select information indicative of preselected tire conditions; and

an RF transmitter electrically connected to said microcontroller for receiving select information from said microcontroller, modulating the select information to a carrier signal, and transmitting the select information to a remote receiver location.

25. An electronics assembly as in claim 24, wherein said energy storage device is a device selected from the group consisting of an electrolytic capacitor, a non-electrolytic capacitor, a super capacitor, a rechargeable solid-state battery, and a rechargeable chemical battery.

26. An electronics assembly as in claim 24, wherein selected of said plurality of sensors provide information about the temperature and pressure within a pneumatic tire structure.

27. An electronics assembly as in claim 24, further comprising a rechargeable battery connected to the regulated voltage output from said power conditioning module.

28. An electronics assembly as in claim 24, further comprising a tire revolution counter powered by the regulated voltage output from said power conditioning module.

29. A tire assembly with integrated power generation features, said tire assembly comprising:

a pneumatic tire structure characterized by a crown having an exterior tread portion for making contact with a ground surface, bead portions for seating said tire to a wheel rim, exterior sidewall portions extending between each bead portion and the crown, and interior crown and sidewall surfaces;

a patch of piezoelectric material integrated with a selected portion of said pneumatic tire structure, said patch of piezoelectric material configured to generate an electric charge therein upon said pneumatic tire structure being subjected to mechanical strains;

at least one sensor for determining information about preselected tire conditions, wherein said at least one sensor is powered by the electric charge generated in said patch of piezoelectric material; and

an antenna coupled to said at least one sensor for radiating and receiving RF signals representative of said information about preselected tire conditions determined by said at least one sensor.

30. A tire assembly as in claim 29, further comprising a support substrate provided adjacent to said patch of piezoelectric material for distributing the strain to which said piezoelectric material is subjected in a substantially uniform fashion within said patch of piezoelectric material.

31. A tire assembly as in claim 29, wherein said at least one sensor provides information about the temperature and pressure within said pneumatic tire structure.

32. A tire assembly as in claim 29, further comprising a microcontroller powered by the electric charge generated in said patch of piezoelectric material and coupled to said at least one sensor for processing information received from said at least one sensor and for generating select information indicative of said preselected tire conditions.

33. A tire assembly as in claim 32, further comprising an RF transmitter coupled to said microcontroller for receiving select information from said microcontroller, modulating the select information to a carrier signal, and transmitting the select information via said antenna to a remote receiver location.