Energy Harvesting, Wireless Structural Health Monitoring System with Time Keeper and Energy Storage Devices

• US 20100164711A1
• Filed: 03/12/2010
• Published: 07/01/2010
• Est. Priority Date: 09/09/2005
• Status: Active Grant

• Current Assignee: Hottinger Bruel & Kjaer Incorporated
• Original Assignee: Lord Corporation (Parker-Hannifin Corporation)
• Inventors: Arms, Steven W., Hamel, Michael John, Townsend, Chris Pruyn, Churchill, David Lawrence
• Granted Patent: US 8,638,217 B2
• Time in Patent Office: Days
• US Class Current: 340/539.100
• CPC Class Codes: B64C 2027/002 mounted between the rotor drive and the fuselage
• CPC Class Codes: B64C 27/006 Safety devices
• CPC Class Codes: G01M 5/00 Investigating the elasticity of structures, e.g. deflection of bridges or air-craft wings G01M9/00 takes precedence
• CPC Class Codes: G07C 5/085 using electronic data carriers

Abstract

A system comprises a sensing node that includes a sensor, a processor, an energy harvesting circuit, a time keeper, a first energy storage device, and a second energy storage device. The energy harvesting circuit is connected for recharging the first energy storage device. The processor is connected for receiving all its power derived from the energy harvesting circuit. The second energy storage device is connected for powering the time keeper.

Claims

1. A system, comprising a sensing node wherein said sensing node includes a sensor, a processor, an energy harvesting circuit, a time keeper, a first energy storage device, and a second energy storage device, wherein said energy harvesting circuit is connected for recharging said first energy storage device, wherein said processor is connected for receiving all its power derived from said energy harvesting circuit, wherein said second energy storage device is connected for powering said time keeper.

2. A system as recited in claim 1, wherein said sensing node includes no electrical connection between said second energy storage device and said processor.

3. A system as recited in claim 1, wherein when connection between said first energy storage device and said processor is completely off said second energy storage device remains connected for powering said time keeper.

4. A system as recited in claim 1, wherein said second energy storage device is exclusively connected for powering said time keeper.

5. A system as recited in claim 1, wherein said second energy storage device includes a battery.

6. A system as recited in claim 1, further comprising a housing, wherein said processor, said energy harvesting circuit, said time keeper, said first energy storage device, and said second energy storage device are included in said housing.

7. A system as recited in claim 6, wherein said housing has a volume that is less than 1 cubic inch.

8. A system as recited in claim 6, wherein said sensor is external to said housing.

9. A system as recited in claim 1, wherein said time keeper is connected for providing a time stamp to said processor.

10. A system as recited in claim 9, wherein said time stamp includes date and time.

11. A system as recited in claim 1, wherein said time keeper is programmable.

12. A system as recited in claim 11, wherein said time keeper is programmable to provide a signal at a programmably determined interval.

13. A system as recited in claim 1, wherein said time keeper is connected for providing a signal to said processor to wake said processor.

14. A system as recited in claim 13, wherein said signal results in power being provided to said processor.

15. A system as recited in claim 13, further comprising a plurality of said signals, wherein power to said processor is turned off during a portion of time between said signals.

16. A system as recited in claim 1, wherein said processor is connected to provide compensation to data as temperature changes.

17. A system as recited in claim 1, further comprising a communication device wherein said processor is connected for controlling operation of said communication device.

18. A system as recited in claim 17, wherein said communications device receives all its power derived from said energy harvesting circuit.

19. A system as recited in claim 17, wherein said processor is connected for providing calculations for transmission by said communications device.

20. A system as recited in claim 17, wherein said communication device includes a wireless communications device.

21. A system as recited in claim 20, wherein said wireless communication device includes an IEEE 802.15.4 transceiver.

22. A system as recited in claim 1, further comprising a plurality of said sensors and a multiplexer, wherein said multiplexer is connected to provide data derived from said plurality of sensors to said processor.

23. A system as recited in claim 1, wherein said energy harvesting circuit is capable of converting energy from periodic motion into electricity.

24. A system as recited in claim 23, wherein said periodic motion includes at least one from the group consisting of vibration and rotational motion.

25. A system as recited in claim 1, wherein said sensor includes a piezoelectric transducer.

26. A system as recited in claim 1, wherein said sensor includes at least one from the group consisting of a temperature sensor, an accelerometer, a pressure sensor, a strain sensor, a load sensor, a force sensor, a moisture sensor, and a magnetic field sensor.

27. A system as recited in claim 1, wherein said sensor includes a programmable triaxial strain gauge, further comprising a programmable triaxial strain gauge signal conditioner with integral self calibration.

28. A system as recited in claim 1, wherein said sensor includes at least one from the group consisting of an inertial sensing suite and a GPS.

29. A system as recited in claim 1, wherein said sensor is included in a Wheatstone bridge configuration.

30. A system as recited in claim 1, further comprising a plurality of said sensing nodes configured in a communications network.

31. A system as recited in claim 30, wherein said communications network includes a wired network.

32. A system as recited in claim 31, wherein said wired network includes a CAN bus.

33. A system as recited in claim 30, wherein said communications network includes a wireless multihop network.

34. A system as recited in claim 1, further comprising a memory.

35. A system as recited in claim 34, wherein said memory is connected to said processor, wherein said memory includes configuration and calibration data for said sensor.

36. A system as recited in claim 34, wherein said memory includes a non-volatile memory.

37. A system as recited in claim 36, wherein said memory includes a volatile memory portion and a non-volatile memory portion.

38. A system as recited in claim 34, wherein said memory includes at least one from the group consisting of SRAM and flash memory.

39. A system as recited in claim 34, wherein said memory is connected for direct memory access.

40. A system as recited in claim 39, further comprising an input circuit, wherein said input circuit includes a high speed analog to digital converter, wherein an output of said analog to digital converter is directly connected to said memory for said direct memory access.

41. A system as recited in claim 1, further comprising an input circuit including an instrumentation amplifier with digitally programmable gain, wherein said sensor is connected to said instrumentation amplifier.

42. A system as recited in claim 1, wherein said processor includes a program to provide a digital filter.

43. A system as recited in claim 1, further comprising a structure, wherein said sensing node is mounted on said structure.

44. A system as recited in claim 1, wherein said sensing node is for sensing data about said structure.

45. A system as recited in claim 44, wherein said structure includes a vehicle.

46. A system as recited in claim 45, wherein said vehicle comprises an aircraft.

47. A system as recited in claim 46, wherein said aircraft comprises a helicopter.

48. A system as recited in claim 1, wherein said sensor module further comprises an actuator.

49. A system as recited in claim 48, wherein said actuator includes a piezoelectric transducer.

50. A system as recited in claim 48, wherein said actuator is connected for providing a signal to said structure for material testing.

51. A system as recited in claim 1, further comprising a plurality of said sensing nodes, wherein each said sensing node further includes a two-way communications device.

52. A system as recited in claim 51, wherein said two-way communications device includes two-way wireless communication.

53. A system as recited in claim 1, wherein said sensing node provides data related to at least one from the group consisting of strain, load, remaining life, accumulated damage, and peak data.

54. A system as recited in claim 1, wherein said sensor includes a strain gauge calibrated to provide at least one from the group consisting of load and moment.

55. A system as recited in claim 1, wherein said sensor includes a strain gauge and a piezoelectric transducer.

56. A system as recited in claim 55, wherein said sensing node provides an output that includes a ratio of foil strain gauge amplitude to piezoelectric transducer amplitude.

57. A method, comprising:

a. providing a structure and a sensing node, said sensing node including a sensor, a processor, an energy harvesting circuit, a time keeper, a first energy storage device, and a second energy storage device, wherein said energy harvesting circuit is connected for recharging said first energy storage device, wherein said processor is connected for receiving all its power derived from said energy harvesting circuit, wherein said second energy storage device is connected for powering said time keeper; and

b. using said sensing node to provide data about said structure related to at least one from the group consisting of strain, load, remaining life, and accumulated damage.

58. A method as recited in claim 57, wherein said data about said structure includes peak data.

59. A method as recited in claim 57, further comprising using said accumulated damage data to determine when to perform maintenance.

60. A method as recited in claim 57, further comprising using said accumulated damage data to predict and prevent failure.

61. A method as recited in claim 57, further comprising adjusting operation of said structure based on said data.

62. A method as recited in claim 57, wherein said structure includes a component, further comprising replacing said component when information provided by said sensing node shows that said component has experienced accumulated damage sufficient to require replacement.

63. A system as recited in claim 57, wherein said sensor includes a foil strain gauge and a piezoelectric transducer and wherein said information includes a ratio of foil strain gauge amplitude to piezoelectric transducer amplitude.

64. A system, comprising a structure and a sensing node wherein said sensing node is mounted on said structure, wherein said sensing node includes a sensor, a processor, an energy harvesting circuit, a time keeper, a first energy storage device, and a second energy storage device, wherein said energy harvesting circuit is connected for recharging said first energy storage device, wherein said processor is connected for receiving all its power derived from said energy harvesting circuit, wherein said second energy storage device is connected for powering said time keeper.