Passive self-tuning resonator system

• US 7,626,316 B2
• Filed: 09/28/2007
• Issued: 12/01/2009
• Est. Priority Date: 09/28/2007
• Status: Active Grant

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Stark, Brian, Kozinsky, Inna, Candler, Robert
• Primary Examiner(s): Benson; Walter
• Assistant Examiner(s): Addison; Karen B
• Application Number:
  US11/904,811
• Publication Number:
  US 20090085442A1
• Time in Patent Office: 795 Days
• Field of Search: 310319-321, 310/328, 310/317, 310/339, 310/318
• US Class Current: 310/339
• CPC Class Codes: H02K 35/00 Generators with reciprocating, oscillating or vibrating coil system, magnet, armature or other part of the magnetic circuit arrangements for handling mechanical energy structurally associated with generators H02K7/00, e.g. H02K7/06
• CPC Class Codes: H02K 7/1876 with reciprocating, linearly oscillating or vibrating parts
• CPC Class Codes: H02N 2/188 adapted for resonant operation
• CPC Class Codes: H10N 30/304 Beam type

Abstract

The invention is a system incorporating a self-tuning resonator and method of self-tuning a resonator within a system. In one embodiment, a method of powering a system with energy harvested from a vibrating surface includes receiving a first mechanical energy at a first driving frequency from the vibrating surface, transferring the received first mechanical energy to a suspended structure within the system, vibrating the suspended structure with the transferred first mechanical energy, passively adjusting the resonant frequency of the suspended structure to a first resonant frequency associated with the first driving frequency by moving a movable mass in response to the movement of the suspended structure, vibrating the adjusted suspended structure with the transferred first mechanical energy, generating electrical energy using the vibrations of the adjusted suspended structure, and powering the system with the generated electrical energy.

Claims

1. A method of powering a system with energy harvested from a vibrating surface, comprising:

receiving a first mechanical energy at a first driving frequency from the vibrating surface;

transferring the received first mechanical energy to a suspended structure within the system;

vibrating the suspended structure with the transferred first mechanical energy;

passively adjusting the resonant frequency of the suspended structure to a first resonant frequency associated with the first driving frequency by moving a movable mass in response to the movement of the suspended structure;

vibrating the adjusted suspended structure with the transferred first mechanical energy;

generating electrical energy using the vibrations of the adjusted suspended structure; and

powering the system with the generated electrical energy.

2. The method of claim 1, further comprising:

receiving a second mechanical energy at a second driving frequency from the vibrating surface;

transferring the received second mechanical energy to the suspended structure;

vibrating the suspended structure with the transferred second mechanical energy;

passively re-adjusting the resonant frequency of the suspended structure to a second resonant frequency associated with the second driving frequency by moving the movable mass in response to the movement of the suspended structure resulting from the second mechanical energy;

vibrating the re-adjusted suspended structure with the transferred second mechanical energy; and

generating electrical energy using the vibrations of the re-adjusted suspended structure.

3. The method of claim 1, wherein passively adjusting the resonant frequency of the suspended structure to a first frequency comprises:

moving a first component within a channel in the suspended structure to a first antinode.

4. The method of claim 3, wherein passively adjusting the resonant frequency of the suspended structure to a first frequency comprises:

moving a second component within the channel in the suspended structure to a second antinode.

5. The method of claim 1, wherein passively adjusting the resonant frequency of the suspended structure to a first frequency comprises:

moving a first support member to a first node.

6. The method of claim 5, wherein passively adjusting the resonant frequency of the suspended structure to a first frequency comprises:

moving a second support member to a second node.

7. The method of claim 1, wherein generating electrical energy using the vibrations of the passively re-adjusted suspended structure comprises:

flexing a piezoelectric material with the suspended structure.

8. The method of claim 1, wherein generating electrical energy using the vibrations of the re-adjusted suspended structure comprises:

vibrating a transfer member with the suspended structure; and

flexing a piezoelectric material with the transfer member.

9. A wireless device, comprising:

a support structure configured to receive mechanical energy generated by a vibrating source external to the device;

a vibratory member operatively connected to the support structure for receiving mechanical vibrations from the support structure; and

a power harvesting subsystem including a resonator with at least one resonant frequency adjustment mass movably responsive to the vibratory member, such that vibration of the vibratory member causes the at least one resonant frequency adjustment mass to move thereby changing the resonant frequency of the vibratory member from a first resonant frequency to a second resonant frequency.

10. The wireless device of claim 9, wherein:

the vibratory member comprises a channel having fluid therein; and

the at least one resonant frequency adjustment mass is a bead located within the channel.

11. The wireless device of claim 10, wherein the bead is negatively buoyant within the fluid.

12. The wireless device of claim 9, wherein:

the support structure includes at least one support beam;

the at least one resonant frequency adjustment mass is movably coupled to and supported by the support beam; and

the vibratory member is operatively connected to the support structure through the at least one resonant frequency adjustment mass.

13. The wireless device of claim 12, wherein;

the at least one support beam comprises a first support beam and a second support beam;

the at least one resonant frequency adjustment mass comprises

a first transfer arm movably coupled to and supported by the first support beam and the second support beam, and

a second transfer arm movably coupled to and supported by the first support beam and the second support beam; and

the vibratory member is operatively connected to and supported by the support structure through the first transfer arm and the second transfer arm.

14. The wireless device of claim 13, further comprising:

a piezoelectric member located at a first position on the vibratory member; and

a vibratory mass supported by the vibratory member such that when the vibratory member vibrates, the first position is an antinode area of the vibratory member.

15. The wireless device of claim 9, wherein:

the vibratory member comprises a channel having fluid therein; and

the at least one resonant frequency adjustment mass is the fluid.

16. The wireless device of claim 9, wherein

the support structure includes a first frame and a second frame;

the vibratory member includes a first end portion fixed to the first frame and a second end portion fixed to the second frame; and

the at least one resonant frequency adjustment mass is located within the vibratory member.