Energy harvesting for wireless sensor operation and data transmission

• US 7,365,455 B2
• Filed: 12/24/2004
• Issued: 04/29/2008
• Est. Priority Date: 03/07/2002
• Status: Active Grant

• Current Assignee: Hottinger Bruel & Kjaer Incorporated
• Original Assignee: Micro Strain Incorporated
• Inventors: Arms, Steven W., Hamel, Michael John, Townsend, Christopher P, Churchill, David L.
• Primary Examiner(s): DeBeradinis; Robert L.
• Application Number:
  US11/023,197
• Publication Number:
  US 20050116544A1
• Time in Patent Office: 1,222 Days
• Field of Search: 307/151
• 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 electronic system, comprising:

a moving part;

an energy harvesting device mounted to convert mechanical energy of said moving part into electrical energy;

a rechargeable power supply connected to receive electrical energy derived from said energy harvesting device;

an electronic component connectable for receiving energy derived from said rechargeable power supply; and

a controller connected to receive a signal indicating state of charge of said rechargeable power supply, wherein said controller connects said electronic component to said rechargeable power supply based on magnitude of said signal and wherein said controller disconnects said electronic component from said rechargeable power supply based on magnitude of said signal.

2. A system as recited in claim 1, wherein said rechargeable power supply comprises at least one from the group including a battery and a capacitor.

3. A system as recited in claim 1, further comprising a monitoring device connected to said rechargeable power supply for monitoring said state of charge of said rechargeable power supply and for providing said signal derived from said state of charge.

4. A system as recited in claim 1, wherein said component comprises at least one from the group including a sensor, an A/D converter, a memory, a transmitter, a transceiver, and a micro-controller.

5. A system as recited in claim 4, wherein said micro-controller includes a clock, wherein said clock has a clock rate, wherein said micro-controller controls operation by controlling said clock rate.

6. A system as recited in claim 4, further comprising a receiver, wherein said micro-controller can be programmed with a program received by said receiver.

7. A system as recited in claim 1, wherein said controller is connected to control operation of said component by controlling provision of power.

8. A system as recited in claim 1, wherein said mechanical energy comprises at least one from the group consisting of vibrational energy, strain energy, and rotational energy.

9. A system as recited in claim 1, wherein said moving part comprises a rotating part.

10. A system as recited in claim 9, wherein said energy harvesting circuit is mounted on said rotating part wherein said energy harvesting circuit is for harvesting mechanical energy from motion of said rotating part and converting said mechanical energy into electrical energy.

11. A system as recited in claim 10, wherein said electronic component comprises a radio frequency communications device mounted on said rotating part and connected to receive electricity derived from said energy harvesting circuit for powering said radio frequency communications device.

12. A system as recited in claim 11, wherein said rechargeable source of power is mounted on said rotating part, wherein said rechargeable source of power is configured to store energy derived from said energy harvesting circuit.

13. A system as recited in claim 12, wherein said controller is mounted on said rotating part, wherein said controller is connected to said rechargeable source of power for monitoring the amount of electrical energy stored in said rechargeable source of power and for switchably connecting said rechargeable source of power to said radio frequency communications device when said stored energy exceeds a first threshold and for switchably disconnecting said rechargeable source of power from said radio frequency communications device when said stored energy is below a second threshold.

14. A system as recited in claim 13, wherein said rechargeable source of power comprises at least one from the group including a battery and a capacitor.

15. A system as recited in claim 13, wherein said controller is powered by energy stored in said rechargeable source of power.

16. A system as recited in claim 13, wherein said radio frequency communications device comprises a transmitter.

17. A system as recited in claim 16, wherein said radio frequency communications device further comprises a receiver.

18. A system as recited in claim 17, wherein said circuit comprises a transceiver.

19. A system as recited in claim 16, further comprising a sensor mounted on said rotating part, wherein data derived front said sensor is transmitted from said rotating part by said transmitter.

20. A system as recited in claim 13, wherein said mechanical energy comprises rotational energy of said rotating part.

21. A system as recited in claim 20, wherein said energy harvesting device is capable of harvesting energy from rotation of said rotating part.

22. A system as recited in claim 13, wherein said rotating part has a measurable parameter, said rotating part further comprising a sensor for measuring said measurable parameter of said rotating part, wherein said radio frequency communications device is connected for at least one from the group including transmitting said measurement and transmitting data derived from said measurement.

23. A system as recited in claim 22, wherein said sensor comprises at least one from the group consisting of a temperature sensor, a strain sensor, and a sensor to measure rate of rotation.

24. A system as recited in claim 22, further comprising a processor for receiving data from said sensor.

25. A system as recited in claim 24, wherein said processor contains a program to process said data before transmitting.

26. A system as recited in claim 24, wherein said processor controls operation of said transmitter.

27. A system as recited in claim 24, further comprising an A/D converter for converting sensor data to digital sensor data.

28. A system as recited in claim 27, further comprising memory for storing said digital sensor data.

29. A system as recited in claim 28, wherein said memory is integral with said processor.

30. A system as recited in claim 28, wherein said memory is connected to receive and store said digital sensor data.

31. A system as recited in claim 28, wherein said memory contains a unique address.

32. A system as recited in claim 22, wherein said rotating further comprises an actuator.

33. An electronic system, comprising a structure and a circuit, said circuit including:

an energy harvesting device mounted to convert mechanical energy of said structure into electrical energy;

a first rechargeable power supply connected to receive said electrical energy from said energy harvesting device;

an electronic component connectable to said first rechargeable power supply for receiving energy derived from said first rechargeable power supply; and

a controller connected for monitoring a parameter of said circuit and for directing transfer of said electrical energy from said first rechargeable power supply to said electronic component when said parameter reaches a specified value.

34. An electronic system as recited in claim 33, wherein said energy harvesting device includes a piezoelectric transducer.

35. An electronic system as recited in claim 33, further comprising a rectifier connected for rectifying an electrical signal from said energy harvesting device and for providing a rectified signal to said rechargeable power supply.

36. An electronic system as recited in claim 33, wherein said first rechargeable power supply includes at least one from the group consisting of a capacitor and a battery.

37. An electronic system as recited in claim 36, wherein said parameter is related to state of charge of said first rechargeable power supply.

38. An electronic system as recited in claim 37, wherein said controller includes a monitoring device connected to said first rechargeable power supply, wherein said monitoring device is for monitoring said parameter related to state of charge of said first rechargeable power supply and for providing energy derived from said first rechargeable power supply to said controller.

39. An electronic system as recited in claim 37, wherein said parameter is voltage across said first rechargeable power supply.

40. An electronic system as recited in claim 33, wherein said component comprises a second rechargeable power supply.

41. An electronic system as recited in claim 40, wherein said energy harvesting device has an energy harvesting device impedance, wherein said second rechargeable power supply includes a capacitor having a capacitor impedance, wherein said capacitor impedance approximately matches said energy harvesting device impedance.

42. An electronic system as recited in claim 33, wherein said component comprises at least one from the group consisting of a sensor, an A/D converter, a memory, a transmitter, a transceiver, and a micro-controller.

43. An electronic system as recited in claim 42, wherein said micro-controller can be programmed with a program received by said transceiver.

44. An electronic system as recited in claim 42, wherein said micro-controller includes a clock.

45. An electronic system as recited in claim 44, wherein said clock is for providing timing to said micro-controller.

46. An electronic system as recited in claim 44, wherein said clock bas a clock rate, wherein said micro-controller controls said clock rate.

47. An electronic system as recited in claim 33, wherein said controller includes a switch, wherein said electronic component is connectable to said first rechargeable power supply through said switch, wherein said switch is for turning on and turning off connection between said first rechargeable power supply and said component.

48. An electronic system as recited in claim 47, wherein said first rechargeable power supply includes a first capacitance and wherein said circuit further includes a second capacitance, a DC to DC converter, and a second controller, wherein said second capacitance is smaller than said first capacitance, wherein said DC to DC converter is connected between said second capacitance and said first capacitance, wherein said second controller is connected for controlling transfer of charge from said second capacitance to said first capacitance.

49. An electronic system as recited in claim 47, wherein said second capacitance has an impedance approximately matching impedance of said energy harvesting device.

50. An electronic system as recited in claim 33, wherein said circuit for converting mechanical energy of said structure into electrical energy includes a mechanical tuning element.

51. An electronic system as recited in claim 50, wherein said mechanical tuning element includes a mechanical resonance adjusting element.

52. An electronic system as recited in claim 33, wherein said mechanical energy includes at least one from the group consisting of vibrational energy, strain energy, and rotational energy.

53. An electronic system, comprising:

a rotating part;

an energy harvesting circuit mounted on said rotating part, said energy harvesting circuit for harvesting mechanical energy from motion of said rotating part and converting said mechanical energy into electricity;

a sensor for measuring a measurable parameter of said rotating part; and

an actuator, wherein energy for running and communicating with said actuator is derived from said energy harvesting circuit.