Structural damage detection and analysis system

• US 8,290,747 B2
• Filed: 10/23/2006
• Issued: 10/16/2012
• Est. Priority Date: 10/21/2005
• Status: Active Grant

• Current Assignee: Lord Corporation (Parker-Hannifin Corporation)
• Original Assignee: MicroStrain, Inc. (Spectris PLC)
• Inventors: Hamel, Michael J., Arms, Steven W.
• Primary Examiner(s): SUGLO, JANET L
• Application Number:
  US11/585,059
• Publication Number:
  US 20070144396A1
• Time in Patent Office: 2,185 Days
• Field of Search: 702/33, 702/42, 702/187, 702/189
• US Class Current: 702/187
• CPC Class Codes: F41A 19/01 Counting means indicating the number of shots fired

Abstract

A system for electronically recording an event that provides mechanical energy to a structure includes the structure and an event sensing and recording node. The event sensing and recording node is mounted on the structure and includes a sensor and a first electronic memory. The sensor includes a device for converting the mechanical energy into an electrical signal. The first electronic memory uses energy derived from the electrical signal for electronically recording the event. All energy for sensing the event and recording the event in the first electronic memory is derived from the mechanical energy.

Claims

1. A system for electronically recording data about an energy producing event, comprising an event sensing and recording node, wherein said event sensing and recording node includes an energy converting device, a first electronic memory device, and a reading circuit, wherein said energy converting device provides a first voltage, wherein said first voltage varies over a continuous range of values, wherein said energy converting device is connected to record a second voltage in said first electronic memory device when an energy producing event occurs, wherein all energy for recording said second voltage is derived from energy provided by said energy converting device, wherein said reading circuit is connected to said first electronic memory device, wherein said reading circuit is powered from a source of energy other than said energy converting device, wherein when said reading circuit is powered, data having discrete voltage values is provided in said reading circuit determined by said recorded second voltage in said first electronic memory device.

2. A system as recited in claim 1, wherein said event sensing and recording node further includes a communications circuit for communicating information about the energy producing event.

3. A system as recited in claim 2, wherein said communications circuit includes a wired communications circuit.

4. A system as recited in claim 3, wherein said wired communications circuit includes at least one from the group consisting of a USB and a CAN bus.

5. A system as recited in claim 2, wherein said communications circuit includes a wireless communications circuit.

6. A system as recited in claim 5, further comprising a reader, wherein said wireless communications circuit communicates said information to said reader.

7. A system as recited in claim 5, wherein said wireless communications circuit includes at least one from the group consisting of a switched reactance circuit and an RF transmitter.

8. A system as recited in claim 2, wherein said communications circuit is powered from a source of energy other than said energy converting device.

9. A system as recited in claim 8, wherein said reading circuit and said communications circuit are powered by at least one from the group consisting of strain, vibration, and electromagnetic radiation.

10. A system as recited in claim 9, further comprising a device for converting at least one from the group consisting of strain, vibration, and electromagnetic radiation into electricity for use in powering said reading circuit and said communications circuit.

11. A system as recited in claim 2, further comprising a housing, wherein said event sensing and recording node, and said communications circuit are included in said housing.

12. A system as recited in claim 11, wherein said housing is hermetically sealed.

13. A system as recited in claim 11, wherein said housing has a volume that is less than 1 cubic inch.

14. A system as recited in claim 11, wherein said energy converting device is external to said housing.

15. A system as recited in claim 1, further comprising an array of said event sensing and recording nodes.

16. A system as recited in claim 15, wherein each event sensing and recording node of said array comprises an energy converting device for converting mechanical energy into an analog voltage, wherein each said energy converting device is tuned to be responsive to a frequency different from other energy converting devices of said array.

17. A system as recited in claim 16, wherein said different members of said array that are tuned to be responsive to different frequencies each includes a vibrating member and a proof mass.

18. A system as recited in claim 1, wherein said event sensing and recording node further includes a reset device for automatically resetting said first electronic memory device to a discharged state.

19. A system as recited in claim 1, wherein said event sensing and recording node further includes a protect device for limiting voltage supplied to said first electronic memory device.

20. A system as recited in claim 1, wherein said reading circuit includes a processor, wherein said processor is connected to read state of said first electronic memory device.

21. A system as recited in claim 20, wherein said processor includes a sleep mode.

22. A system as recited in claim 20, further comprising a second memory device, wherein said processor is connected for transferring information from said first electronic memory device to said second memory device.

23. A system as recited in claim 22, wherein said second memory device includes at least one from the group consisting of SRAM, DRAM, and non-volatile memory.

24. A system as recited in claim 23, wherein said second memory device includes said non-volatile memory and wherein said non-volatile memory includes at least one from the group consisting of flash memory and FRAM.

25. A system as recited in claim 20, further comprising a real time clock, wherein said real time clock is connected for providing a time stamp along with information stored in said first electronic memory device.

26. A system as recited in claim 25, further comprising an energy storage device connected for exclusively powering said real time clock.

27. A system as recited in claim 25, wherein said time stamp includes date and time.

28. A system as recited in claim 25, wherein said real time clock is programmable to provide a signal at a programmably determined interval.

29. A system as recited in claim 25, wherein said real time clock is connected for providing an interrupt signal to said processor to wake said processor.

30. A system as recited in claim 29, wherein power to said processor is turned off during a portion of time between said interrupt signals.

31. A system as recited in claim 20, further comprising a second energy converting device for converting at least one from the group consisting of strain, vibration, and electromagnetic radiation into electricity, wherein said processor receives all its power derived from said second energy converting device.

32. A system as recited in claim 31, wherein said second energy converting device includes at least one from the group consisting of a coil, a solar cell, and a piezoelectric transducer.

33. A system as recited in claim 31, further comprising a rechargeable energy storage device, wherein said rechargeable energy storage device is connected for recharging from energy derived from said second energy converting device.

34. A system as recited in claim 20, wherein said processor is connected to provide compensation for data in said first electronic memory as temperature changes.

35. A system as recited in claim 20, further comprising a communications device, wherein said processor is connected for controlling operation of said communications device.

36. A system as recited in claim 35, wherein said communications device includes a wireless communications device, wherein said processor is connected for controlling operation of said wireless communications device.

37. A system as recited in claim 36, wherein said processor is connected for providing calculations for transmission by said wireless communications device.

38. A system as recited in claim 20, further comprising a network of event sensing and recording nodes, wherein each said node includes one said processor, wherein said processor includes a program to support network communications.

39. A system as recited in claim 20, further comprising a plurality of said event sensing and recording nodes and a multiplexer, wherein said multiplexer is connected to provide data derived from said plurality of event sensing and recording nodes to said processor.

40. A system as recited in claim 20, wherein said processor includes a power off mode, wherein said first electronic memory is connected to store data when said processor is in said power off mode.

41. A system as recited in claim 20, wherein said processor includes a sleep mode, wherein said first electronic memory is connected to store data when said processor is in said sleep mode.

42. A system as recited in claim 1, wherein said energy converting device comprises at least one from the group consisting of a piezoelectric sensor, a Weigand device, and a magnetoelectric effect device.

43. A system as recited in claim 1, wherein said first electronic memory device includes a capacitance and a transistor.

44. A system as recited in claim 1, wherein said event sensing and recording node includes a Zener diode electrically connected between said energy converting device and said first electronic memory device.

45. A system as recited in claim 1, wherein said reading circuit includes a processor.

46. A system as recited in claim 1, further comprising a rechargeable energy storage device and a device for converting electromagnetic radiation energy into electricity, wherein said rechargeable energy storage device is connected for recharging from energy derived from said device for converting electromagnetic radiation energy into electricity, wherein said reading circuit is connected for receiving power from said rechargeable energy storage device.

47. A system as recited in claim 1, further comprising a counter for counting events sensed by said energy converting device.

48. A system as recited in claim 1, further comprising a first structure, wherein said event sensing and recording node is mounted on said first structure, wherein said first structure includes at least one from the group consisting of a vehicle, a bridge, a building, a machine, and a weapon.

49. A system as recited in claim 48, wherein said first structure includes said weapon, and wherein said energy converting device is located within said weapon and converts energy from firing said weapon into said voltage and current.

50. A system as recited in claim 49, wherein said energy converting device comprises at least one from the group consisting of an accelerometer and a piezoelectric transducer.

51. A system as recited in claim 50, further comprising a second memory device, wherein said second memory device is arranged to accumulate a signal derived from said first electronic memory device for counting number of firings.

52. A system as recited in claim 48, wherein said first structure includes said weapon, further comprising a processor, wherein said processor is connected to determine at least one parameter from the group consisting of number of firings and time between firings.

53. A system as recited in claim 48, wherein said first structure includes said weapon, further comprising a projectile fired by said weapon, wherein said event sensing and recording node is located to convert mechanical energy from said projectile into electrical charge.

54. A system as recited in claim 53, further comprising a second structure, wherein said event sensing and recording node is located on said second structure.

55. A system as recited in claim 48, wherein said first structure includes said vehicle, and wherein said vehicle includes an aircraft.

56. A system as recited in claim 55, wherein said aircraft includes at least one from the group consisting of a helicopter, an airplane, and a space vehicle.

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

58. A system as recited in claim 57, wherein said periodic motion includes at least one motion from the group consisting of vibration and rotational motion.

59. A system as recited in claim 1, wherein said event sensing and recording node further comprises at least one sensing device 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, a location sensor, and a magnetic field sensor.

60. A system as recited in claim 59, further comprising a second memory device, wherein said second memory device includes configuration and calibration data for said at least one sensing devices.

61. A system as recited in claim 1, wherein said energy converting device is included in a Wheatstone bridge configuration.

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

63. A system as recited in claim 62, wherein said communications network includes a wired network.

64. A system as recited in claim 63, wherein said wired network includes a CAN bus.

65. A system as recited in claim 62, wherein said communications network includes a wireless multihop network.

66. A system as recited in claim 1, wherein said event sensing and recording node further comprises an actuator.

67. A system as recited in claim 66, wherein said actuator includes a piezoelectric transducer.

68. A system as recited in claim 66, further comprising a structure, wherein said event sensing and recording node is mounted on said structure, wherein said actuator is connected for providing a signal to said structure for material testing said structure.

69. A system as recited in claim 1, wherein said first electronic memory has a capacitance on the order of a MOSFET gate capacitance.

70. A system as recited in claim 67, further comprising at least one from the group consisting of a processor and a communications device powered by said energy harvesting device.

71. A system as recited in claim 1, wherein said reading device is powered by a source of energy other than said energy converting device.

72. A system as recited in claim 1, wherein said event sensing and recording node includes a plurality of said first electronic memory devices arranged to record magnitude of the event, wherein said reading circuit is connected to read said plurality of first electronic memory devices and to determine magnitude of the event.

73. A system as recited in claim 72, wherein said event sensing and recording node includes a plurality of said first electronic memory devices arranged to record magnitude of the event, further comprising recording said second voltage in said plurality of first electronic memory devices, reading said plurality of first electronic memory devices, and determining magnitude of the event.

74. A system as recited in claim 73, wherein said plurality of first electronic memory devices are connected to said energy converting device through threshold setting circuits, one threshold setting circuit for each first electronic memory device, wherein each threshold setting circuit sets a different threshold, wherein said determining magnitude of the event is based on at least one from the group consisting of which of said plurality of first electronic memory devices have charge stored and which of said plurality of first electronic memory devices do not have sufficient stored charge.

75. A system as recited in claim 74, wherein said threshold setting circuits are Zener diodes, wherein each said Zener diode has a different turn-on voltage.

77. A system as recited in claim 1, further comprising a resetting device to remove charge stored in said first electronic memory.

76. A system, comprising a sensor, an energy harvesting device, a first load, and a reading circuit, wherein said sensor includes a device for converting mechanical energy into electricity, wherein said energy harvesting device includes a device for converting electromagnetic radiation energy into electricity, wherein said first load includes a first electronic memory device, wherein said device for converting mechanical energy into electricity provides a first voltage, wherein said first voltage varies over a continuous range of values, wherein said device for converting mechanical energy into electricity is connected to record a second voltage in said first electronic memory device when an energy producing event occurs, wherein all energy for recording said second voltage is derived from energy provided by said energy converting device, and wherein said reading circuit is connected to be powered from electricity derived by said energy harvesting device from said electromagnetic radiation energy, wherein said reading circuit is connected to said first electronic memory device, wherein when said reading circuit is powered, data having discrete voltage values is provided in said reading circuit determined by said recorded second voltage.

78. A system as recited in claim 76, wherein said sensor includes a piezoelectric transducer.

79. A system as recited in claim 76, wherein said sensor is capable of converting energy of an impact into electricity.

80. A system as recited in claim 79, further comprising a weapon, wherein said impact arises as a result of firing said weapon, wherein said sensor converts energy resulting from firing said weapon into electricity.

81. A system as recited in claim 80, wherein said sensor is mounted to said weapon and wherein said impact arises within said weapon.

82. A system as recited in claim 80, further comprising a projectile and a substrate, wherein said projectile is fired by said weapon, wherein said sensor is mounted to said substrate, and wherein said impact arises from a collision of said projectile with said substrate.

83. A system as recited in claim 76, wherein said energy harvesting device includes at least one from the group consisting of a coil and a solar cell.

84. A system as recited in claim 76, wherein said sensor converts energy from periodic motion into electricity.

85. A system as recited in claim 84, wherein said periodic motion includes at least one from the group consisting of vibration and rotational motion.

86. A system as recited in claim 76, wherein said device for converting electromagnetic radiation into electricity includes a coil.

87. A system as recited in claim 76, wherein said electromagnetic radiation includes light, wherein said device for converting electromagnetic radiation into electricity includes a photovoltaic cell.

88. A system as recited in claim 87, further comprising a source of light.

89. A system as recited in claim 76, further comprising a plurality of said first electronic memory devices arranged to record magnitude of the event, wherein said reading circuit is connected to read said plurality of first electronic memory devices and to determine magnitude of the event.

90. A system as recited in claim 89, wherein said event sensing and recording node includes a plurality of said first electronic memory devices arranged to record magnitude of the event, further comprising recording said second voltage in said plurality of first electronic memory devices, reading said plurality of first electronic memory devices, and determining magnitude of the event.

91. A system as recited in claim 90, wherein said plurality of first electronic memory devices are connected to said energy converting device through threshold setting circuits, one threshold setting circuit for each first electronic memory device, wherein each threshold setting circuit sets a different threshold, wherein said determining magnitude of the event is based on at least one from the group consisting of which of said plurality of first electronic memory devices have charge stored and which of said plurality of first electronic memory devices do not have sufficient stored charge.

92. A system as recited in claim 91, wherein said threshold setting circuits are Zener diodes, wherein each said Zener diode has a different turn-on voltage.

93. A sensing and memory device, comprising a transducer, a threshold setting circuit, a memory, and a reading circuit, wherein said transducer provides a first voltage, wherein said first voltage varies over a continuous range of values, wherein said threshold setting circuit is connected to set a voltage threshold of at least 2 volts, wherein said transducer and said memory are connected so that when a signal from said transducer exceeds said voltage threshold sufficient charge is provided by said transducer to said memory to record a second voltage in said memory, wherein all energy for recording said second voltage is derived from said transducer, wherein said reading circuit is connected to said memory, wherein said reading circuit is powered by a source other than said transducer, wherein when said reading circuit is powered, data having discrete voltage values is provided in said reading circuit determined by said recorded second voltage in said memory.

94. A sensing and memory device as recited in claim 93, wherein said memory includes a capacitance, wherein said capacitance is charged exclusively with charge derived from said transducer when said signal exceeds said voltage threshold.

95. A sensing and memory device as recited in claim 94, further comprising a transistor, wherein said transistor includes a gate and a gate capacitance wherein said memory includes said gate capacitance, wherein said reading circuit is connected for detecting charge on said gate capacitance.

96. A sensing and memory device as recited in claim 94, wherein said capacitance consists of said transistor gate capacitance.

97. A sensing and memory device as recited in claim 94, wherein said capacitance includes capacitance that is external to said transistor.

98. A sensing and memory device as recited in claim 97, wherein said capacitance includes a capacitor in parallel with said gate capacitance.

99. A sensing and memory device as recited in claim 95, wherein said transistor is a MOSFET.

100. A sensing and memory device as recited in claim 93, wherein said threshold setting circuit includes a Zener diode.

101. A sensing and memory device as recited in claim 93, wherein said reading device includes a processor connected for detecting state of said memory.

102. A sensing and memory device as recited in claim 101, further comprising a timing device, wherein said processor is connected for waking up and periodically detecting state of said memory based on a signal from said timing device.

103. A sensing and memory device as recited in claim 93, further comprising a circuit for actuating said transducer and a circuit for acquiring a signal from said transducer.

104. A sensing and memory device as recited in claim 93, further comprising a plurality of transducers connected so any of said transducers can change state of said memory.

105. A sensing and memory device as recited in claim 104, further comprising a circuit for actuating each said transducer and a circuit for acquiring a signal from each said transducer.

106. A method of sensing and recording a potentially damaging event happening to a structure, comprising:

a. providing an event sensing and recording node on the structure, wherein said event sensing and recording node includes an energy converting device, a memory, and a reading circuit, wherein said energy converting device provides a first voltage, wherein said first voltage varies over a continuous range of values, wherein said energy converting device is connected to record a second voltage in said memory when an event occurs, wherein said reading circuit is connected to said memory, wherein when said reading circuit is powered, data having discrete voltage values is provided in said reading circuit determined by said recorded second voltage;

b. sensing the event with said energy converting device and converting energy of the event into said first voltage;

c. recording said second voltage in said memory, wherein all energy for recording said second voltage in said memory is derived from energy provided by the event; and

d. powering said reading circuit from a source of energy other than said energy converting device, and reading said memory to provide data having discrete voltage values in said reading circuit determined by said recorded second voltage in said memory.

107. A method as recited in claim 106, further comprising communicating data obtained by said reading circuit.

108. A method as recited in claim 107, further comprising directing inspection of the structure based on said data obtained by said reading circuit.

109. A method as recited in claim 106, wherein said event sensing and recording node includes a plurality of said memories arranged to record magnitude of the event, further comprising recording said second voltage in said plurality of memories, reading said plurality of memories, and determining magnitude of the event.

110. A method as recited in claim 109, wherein said plurality of memories are connected to said energy converting device through threshold setting circuits, one threshold setting circuit for each memory, wherein each threshold setting circuit sets a different threshold, wherein said determining magnitude of the event is based on at least one from the group consisting of which of said plurality of memories have charge stored and which of said plurality of memories do not have sufficient stored charge.

111. A method as recited in claim 110, wherein said threshold setting circuits are Zener diodes, wherein each said Zener diode has a different turn-on voltage.

112. A system for electronically recording and reading data, comprising a sensor, a memory, a power supply, and a reading circuit, wherein said sensor provides a first voltage, wherein said first voltage varies over a continuous range of values, wherein said sensor is connected to provide a second voltage to said memory, wherein all energy for providing said second voltage to said memory is derived from energy provided by said sensor, wherein said reading circuit is connected to receive power derived from said power supply, wherein said power supply is powered by a source of energy independent of said sensor, wherein said sensor is connected to provide said first voltage during a time when said reading circuit is not receiving power from said power supply, wherein said reading circuit is connected to said memory, wherein when said power supply is providing power to said reading circuit, data having discrete voltage values is provided in said reading circuit determined by said recorded second voltage across said memory.

113. A system for electronically recording an energy producing event, comprising an energy converting device, a memory and a reading circuit, wherein said energy converting device provides a first voltage, wherein said first voltage varies over a continuous range of values, wherein said energy converting device is connected to record a second voltage in said memory when an energy producing event occurs, wherein all energy for recording said second voltage is derived from energy provided by said energy converting device, wherein said reading circuit is connected to said memory, wherein when said reading circuit is powered data having discrete voltage values is provided in said reading circuit determined by said recorded second voltage in said memory, wherein all energy for operating said reading device is provided by a source of energy other than said energy converting device.

114. A method as recited in claim 113, further comprising a plurality of said memories, further comprising recording said second voltages in said plurality of memories, reading said plurality of memories, and determining magnitude of the energy producing event.

115. A method as recited in claim 114, wherein said event sensing and recording node includes a plurality of said memories arranged to record magnitude of the event, further comprising recording said second voltage in said plurality of memories, reading said plurality of memories, and determining magnitude of the event.

116. A method as recited in claim 115, wherein said plurality of memories are connected to said energy converting device through threshold setting circuits, one threshold setting circuit for each memory, wherein each threshold setting circuit sets a different threshold, wherein said determining magnitude of the event is based on said different thresholds.

117. A method as recited in claim 116, wherein said threshold setting circuits are Zener diodes, wherein each said Zener diode has a different turn-on voltage.

118. A method of measuring an energy producing event, comprising:

a) providing an energy converting device, a memory and a reading device, wherein said energy converting device is mounted to receive energy from the energy producing event, wherein said energy converting device provides a first voltage, wherein said first voltage varies over a continuous range of values, wherein the energy converting device is connected to record a second voltage in said memory when the energy producing event occurs, wherein said reading circuit is connected to said memory, wherein when said reading circuit is powered data having discrete voltage values is provided in said reading circuit determined by said recorded second voltage;

b) recording said second analog voltage from the energy producing event in said memory;

c) providing said reading device in a sleep mode while recording said second voltage in said memory, wherein all energy for said recording is derived from the energy producing event; and

d) waking said reading device and providing power to said reading device, reading said memory with said reading device, and determining magnitude of the energy producing event based on said recording in said memory wherein all energy for operating said reading device is provided by a source of energy other than the energy converting device.

119. A method as recited in claim 118, further comprising providing a clock and recording time of said energy producing event.

120. A method as recited in claim 118, further comprising determining from the magnitude of the energy producing event that the event was a damaging event.

121. A method as recited in claim 118, further comprising a plurality of said memories, further comprising recording said second voltages in said plurality of memories, reading said plurality of memories, and determining magnitude of the energy producing event.

122. A method as recited in claim 121, wherein said event sensing and recording node includes a plurality of said memories arranged to record magnitude of the event, further comprising recording said second voltage in said plurality of memories, reading said plurality of memories, and determining magnitude of the event.

123. A method as recited in claim 122, wherein said plurality of memories are connected to said energy converting device through threshold setting circuits, one threshold setting circuit for each memory, wherein each threshold setting circuit sets a different threshold, wherein said determining magnitude of the event is based on said different thresholds.

124. A method as recited in claim 123, wherein said threshold setting circuits are Zener diodes, wherein each said Zener diode has a different turn-on voltage.