Methods, systems, and computer readable media for wireless crack detection and monitoring

• US 8,510,061 B2
• Filed: 08/03/2009
• Issued: 08/13/2013
• Est. Priority Date: 08/01/2008
• Status: Expired due to Fees

• Current Assignee: DRS C3 & Aviation Co. (Michigan) (Leonardo S.p.A.), North Carolina State University (University of North Carolina System)
• Original Assignee: DRS C3 & Aviation Co. (Michigan) (Leonardo S.p.A.), North Carolina State University (University of North Carolina System)
• Inventors: Grant, Edward, Merritt, Carey, Luthy, Kyle, Simmons, Jonathan, Roberts, Kyle, Roth, Robert C., Sanwald, Roger C., Strenkowski, John S., Mattos, Leonardo Serra, Craver, Matthew David, Scurria, Norman V. Jr.
• Primary Examiner(s): Huynh, Phuong
• Application Number:
  US12/534,724
• Publication Number:
  US 20100094566A1
• Time in Patent Office: 1,471 Days
• Field of Search: 702 38- 49, 702/104, 702116-124, 702182-189
• US Class Current: 702/38
• CPC Class Codes: G01M 5/0016 of aircraft wings or blades
• CPC Class Codes: G01M 5/0033 by determining damage, crack or wear
• CPC Class Codes: G01M 5/0083 by measuring variation of impedance, e.g. resistance, capacitance, induction
• CPC Class Codes: G01N 2203/0062 Crack or flaws
• CPC Class Codes: G01N 2203/0664 using witness specimens

Abstract

Methods, systems, and computer readable media for wireless crack detection and monitoring are disclosed. According to one system, a crack detector is affixed to a surface of a material for detecting a crack in the material. In response to detecting a crack, a crack indicator is generated, indicating the existence of the crack. A mote wirelessly communicates the crack indicator to an external device. The mote may also store multiple crack indicators in local memory before being downloaded to the external device.

In other embodiments, the mote may time-stamp the crack indicator for indicating a time when the crack was detected. Additionally, the mote may associate other information with the crack indicator such as temperature and acceleration information.

Claims

1. A system for wireless crack detection and monitoring, the system comprising:

a plurality of crack detectors configured to be attached to a plurality of different user-selected locations likely to experience cracks on a surface of a material of a pre-existing structure in its operational environment for detecting cracks in the material, wherein each crack detector comprises a single sensor configured to generate, by itself, a crack indicator in response to formation of a crack at its respective location and wherein the crack detectors collectively form a sensor network; and

a plurality of motes configured to be attached to the surface of the pre-existing structure in its operational environment, wherein each of the motes is paired with at least one of the crack detectors for receiving the crack indicator from the crack detector and wirelessly communicating the crack indicator to a remote device indicating the presence of a crack at the location of the corresponding crack detector.

2. The system of claim 1 wherein the mote is configured to associate a time-stamp with the crack indicator.

3. The system of claim 1 wherein the crack detector includes a single-filament detector for detecting initiation of the crack.

4. The system of claim 1 wherein the crack detector includes a multi-filament detector for detecting propagation of the crack.

5. The system of claim 1 wherein the mote is configured to store the information locally.

6. The system of claim 1 wherein the mote is configured to communicate the information to one of a laptop computer, a desktop computer, and a personal digital assistant (PDA).

7. The system of claim 1 wherein the mote includes a transceiver.

8. The system of claim 6 wherein the transceiver operates using radio frequency (RF).

9. The system of claim 1 wherein the mote includes a microcontroller.

10. The system of claim 1 wherein the mote includes a memory.

11. The system of claim 1 wherein the mote polls the crack detector periodically or aperiodically.

12. The system of claim 1 wherein the mote polls the crack detector, stores a history of signals generated by the crack indicator, and presents the history to a user.

13. The system of claim 9 wherein the memory includes one of random access memory (RAM) and flash memory.

14. The system of claim 1 wherein the mote includes a power source.

15. The system of claim 1 wherein the power source includes one of a battery, a solar cell, and an energy harvester.

16. The system of claim 1 wherein the mote includes an analog-to-digital converter (ADC).

17. A method for wireless crack detection and monitoring, the method comprising:

attaching a plurality of crack detectors to a plurality of different user-selected locations likely to experience cracks on a surface of a pre-existing structure in its operational environment;

attaching motes to the surface of the material of the pre-existing structure in its operational environment, wherein each of the motes is paired with at least one of the crack detectors;

detecting, by individually using the crack detectors, cracks in the material at the user-selected location;

generating a crack indicator, indicating the existence of the crack, wherein each crack detector comprises a single sensor configured to generate, by itself, a crack indicator in response to formation of a crack, at its respective location and wherein the crack detectors collectively form a sensor network; and

wirelessly communicating, using the motes, the crack indicators to a remote device indicating the presence of a crack at the location of the corresponding crack detector.

18. The method of claim 17 comprising associating a time-stamp with the crack indicator.

19. The method of claim 17 comprising storing the information locally.

20. The method of claim 17 comprising polling a crack detector, generating a history of time-stamped crack indicators, and presenting a history to a user.

21. A method for adhering a crack detector and mote to the surface of a material, the method comprising:

cleaning a surface of a material of a pre-existing structure to be monitored for cracks;

bonding a plurality of crack detectors to a plurality of different user-selected locations likely to experience cracks on the surface of the material of the pre-existing structure in its operational environment, wherein the crack detectors collectively form a sensor network;

bonding a plurality of motes associated with the crack detector to the surface of the material of the pre-existing structure in its operation environment, wherein each of the motes is paired with at least one of the crack detectors and wherein each mote is attached to the surface;

applying a protective coating over the plurality of crack detectors and the plurality of motes; and

detecting a crack in the material at the user-selected location by individually using the crack detector and wirelessly communicating an indication of the crack to an external device using the mote indicating the presence of a crack at the location of the corresponding crack detector.

22. A non-transitory computer readable medium containing computer executable instructions stored therein for causing a computer to perform steps comprising:

attaching a plurality of crack detectors to a plurality of different user-selected locations likely to experience cracks on a surface of a pre-existing structure in its operational environment;

attaching motes to the surface of the material of the pre-existing structure in its operational environment, wherein each of the motes is paired with at least one of the crack detectors;

detecting, by individually using the crack detectors, cracks in the material at the user-selected location;

generating, using the crack detector, a crack indicator, indicating the existence of the crack, wherein each crack detector comprises a single sensor configured to generate, by itself, a crack indicator in response to formation of a crack at its respective location and wherein the individual crack detectors form a sensor network; and

wirelessly communicating, using the motes, the crack indicators to a remote device indicating the presence of a crack at the location of the corresponding crack detector.