Energy harvesting for wireless sensor operation and data transmission

• US 7,170,201 B2
• Filed: 12/24/2004
• Issued: 01/30/2007
• Est. Priority Date: 03/07/2002
• Status: Expired due to Term

• Current Assignee: Hottinger Bruel & Kjaer Incorporated
• Original Assignee: MicroStrain, Inc. (Spectris PLC)
• Inventors: Arms, Steven W., Hamel, Michael John, Townsend, Christopher P, Churchill, David L.
• Primary Examiner(s): Deberadinis; Robert L.
• Application Number:
  US11/023,212
• Publication Number:
  US 20050140212A1
• Time in Patent Office: 767 Days
• Field of Search: 307/151, 310/339
• US Class Current: 307/151
• CPC Class Codes: B60C 23/0411 Piezoelectric generators
• CPC Class Codes: H02J 7/32 for charging batteries from a charging set comprising a non-electric prime mover rotating at constant speed
• CPC Class Codes: H02J 7/345 using capacitors as storage or buffering devices
• CPC Class Codes: H02N 2/186 Vibration harvesters
• CPC Class Codes: H10N 30/306 Cantilevers

Abstract

A device for powering a load from an ambient source of energy is provided. The device includes an energy harvesting device for harvesting energy from the ambient source of energy wherein the rate energy is harvested from the ambient source of energy is below that required for directly powering the load. A storage device is connected to the energy harvesting device. The storage device receives electrical energy from the energy harvesting device and is for storing the electrical energy. A controller is connected to the storage device for monitoring the amount of electrical energy stored in the storage device and for switchably connecting the storage device to the load when the stored energy exceeds a first threshold. The system can be used for powering a sensor and for transmitting sensor data, such as tire pressure.

Claims

1. An energy harvesting system comprising:

a piezoelectric transducer;

a rectifier connected for rectifying an electrical signal from said piezoelectric transducer;

a reactive device having a high impedance approximately matching impedance of said piezoelectric transducer at its operating frequency connected for efficiently transferring electrical energy derived from said piezoelectric transducer to said reactive device;

a low impedance high capacity storage device; and

a circuit for monitoring voltage across said reactive device and for transferring said electrical energy from said reactive device to said low impedance high capacity storage device when said voltage across said reactive device reaches a specified voltage value.

2. A system as recited in claim 1, wherein said circuit provides impedance transformation.

3. A system as recited in claim 2, wherein said circuit includes a DC-DC converter and a device for switching on said DC-DC converter at said specified voltage value.

4. A system as recited in claim 3, wherein said circuit further includes a device for switching off said DC-DC converter when said reactive device discharges to a specified discharged voltage value.

5. A system as recited in claim 4, wherein said device for switching off said DC-DC converter when said reactive device discharges to a specified discharged voltage value comprises a timing circuit.

6. A system as recited in claim 1, wherein said high capacity storage device comprises at least one from the group consisting of a first capacitor and a battery.

7. A system as recited in claim 6, wherein said reactive device comprises a second capacitor.

8. A system as recited in claim 1, wherein said high capacity storage device is for powering at least one from the group consisting of a wireless transmitter and a first transceiver for wireless communication of information.

9. A system as recited in claim 8, further comprising a sensor, wherein said at least one of said wireless transmitter and said first transceiver is for wireless communication of sensor information.

10. A system as recited in claim 9, wherein said sensor comprises at least one from the group consisting of a temperature sensor, a strain gauge, a pressure sensor, a magnetic field sensor, an accelerometer, and a DVRT.

11. A system as recited in claim 9, wherein said sensor comprises a device to monitor machine health through sensor values.

12. A system as recited in claim 9, further comprising a processor and a data logger for recording sensor data.

13. A system as recited in claim 12, wherein said data logger comprises non-volatile memory.

14. A system as recited in claim 8, further comprising a base station for receiving said wirelessly transmitted information.

15. A system as recited in claim 14, wherein said base station comprises at least one from the group consisting of a receiver and a second transceiver.

16. A system as recited in claim 14, further comprising a bi-directional RF transceiver, wherein said base station orchestrates sample triggering and high speed logging of said sensor data.

17. A system as recited in claim 14, wherein data is processed locally then uploaded when polled by said base station.

18. A system as recited in claim 15, further comprising a plurality of said systems, each said system capable of wirelessly transmitting information to said base station.

19. A system as recited in claim 18, wherein each of said systems further comprises an address.

20. A system as recited in claim 18, wherein each of said systems comprises a unique identification code.

21. A system as recited in claim 19, wherein each of said systems is capable of at least one from the group consisting of transmitting and recognizing said address.

22. A system as recited in claim 14, wherein said base station comprises an Ethernet enabled receiver.

23. A system as recited in claim 22, wherein said Ethernet enabled receiver uses extensible markup language (XML) data output format to enable multiple users on a local area network to view said information using a standard internet browser.

24. A system as recited in claim 8, wherein time division multiple access (TDMA) is used to control communications, wherein said systems are in sleep mode except when awakened to transmit bursts of data.

25. A system as recited in claim 8, wherein said wireless transmitter comprises at least one from the group consisting of differential and pseudo-differential channels.

26. A system as recited in claim 25, wherein said wireless transmitter further comprises a data logger including on-board non-volatile memory, user programmable digital filter, gain, and sample rates, and built-in error checking of pulse code modulated (PCM) data.

27. A system as recited in claim 26, wherein said data logger is for storing said information for later transmission by said transmitter.

28. A system as recited in claim 1, wherein said wireless transmitter can transmit frequency shift keyed digital sensor data with checksum bytes.

29. A system as recited in claim 1, wherein said high capacity storage device is for powering at least one from the group consisting of a data storage device and an actuator.

30. A system as recited in claim 1, wherein said high capacity storage device is for at least one from the group consisting of powering and reading a sensor.

31. A system as recited in claim 30, further comprising a processor wherein said sensor is programmable by said processor.

32. A system as recited in claim 1, wherein said piezoelectric transducer is excited by at least one from the group consisting of wind, water, wave, tide, strain, and vibrational energy.

33. A system as recited in claim 1, wherein the system is resistant to degradation from at least one from the group consisting of moisture, salt, and vibration.

34. A system as recited in claim 1, further comprising a tire, wherein said device is for mounting on said tire for sensing and transmitting at least one from the group consisting of tire temperature and tire pressure information.