Multi channel multiplexed inspection system and method

• US 7,254,519 B2
• Filed: 09/24/2004
• Issued: 08/07/2007
• Est. Priority Date: 09/24/2004
• Status: Active Grant

• Current Assignee: The Boeing Co.
• Original Assignee: The Boeing Co.
• Inventors: Fetzer, Barry A.
• Primary Examiner(s): Tsai; Carol S. W.
• Assistant Examiner(s): Charioui; Mohamed
• Application Number:
  US10/949,625
• Publication Number:
  US 20060074577A1
• Time in Patent Office: 1,047 Days
• Field of Search: 702/57, 702/62, 702/64, 702/69, 702/75, 702 77- 81, 702/83, 702/93, 702/104, 702/116, 702/122, 702/159, 702/171, 702/183, 702/189, 702/191, 702/16, 736/02, 736/31, 356/432, 340/561, 375/360
• US Class Current: 702/183
• CPC Class Codes: G01N 2291/02854 Length, thickness
• CPC Class Codes: G01N 2291/106 one or more transducer arrays
• CPC Class Codes: G01N 2291/2694 Wings or other aircraft parts
• CPC Class Codes: G01N 29/11 by measuring attenuation of acoustic waves
• CPC Class Codes: G01N 29/30 Arrangements for calibrating or comparing, e.g. with standard objects
• CPC Class Codes: G01N 29/348 with frequency characteristics, e.g. single frequency signals, chirp signals measuring frequency of mechanical vibrations or acoustic waves in general G01H1/06, G01H3/04; measuring frequency or analysing frequency spectra G01R23/00

Abstract

Provided are systems and methods for multi-channel non-destructive inspection which provide high data throughput, logarithmic amplification of large dynamic range, and simplicity of supporting electronics. More specifically, provided are systems and methods for inspecting a structure that may use an interface board, two pulser boards, each coupled to 16 transmit channels, and two receiver boards, each coupled to 16 receive channels, where the receiver boards are capable of processing data from the 32 receive channels by logarithmically amplifying at least 70 dB of dynamic range. A receiver board may include a serial connection of two layers of multiplexing switches to provide 70 dB isolation between channels, a logarithmic amplifier for logarithmically amplifying 70 dB of dynamic range, a linear amplifier, and an analog-to-digital converter.

Claims

1. A system for inspecting a structure, comprising:

an interface board;

at least one pulser board communicably coupled to said interface board;

a plurality of transmit channels communicably coupled to said pulser board;

at least one receiver board communicably coupled to said interface board;

a plurality of inspection data receive channels communicably coupled to said receiver board, wherein said receiver board is comprising a logarithmic amplifier for processing inspection data signals from said plurality of inspection data receive channels and providing logarithmic amplification to each channel for at least 70 dB of dynamic range.

2. The system of claim 1, wherein said receiver board further comprises a mulitplexer for providing 70 dB of isolation between inspection data receive channels, and wherein said receiver board is capable of processing data from said plurality of inspection data receive channels with 70 dB of isolation provided by said multiplexer and with logarithmic amplification of 70 dB of dynamic range provided by said logarithmic amplifier.

3. The system of claim 1, wherein said multiplexer is a series of multiplexing chips and wherein said 70 dB of isolation is provided by a 60 dB multiplexing chip serially coupled to a 10 dB multiplexing chip of said multiplexer.

4. The system of claim 3, wherein said multiplexing chips are capable of switching between said inspection data receive channels.

5. The system of claim 3, wherein said logarithmic amplifier is capable of logarithmic amplification of −

67 dB to +3 dB of dynamic range.

6. The system of claim 3, wherein said multiplexing chips are capable of switching between said receive channels.

7. The system of claim 3, wherein said logarithmic amplifier is capable of logarithmic amplification of −

67 dB to +3 dB of dynamic range.

8. The system of claim 1, wherein said receiver board comprises:

a plurality of tuned filters, one of said tuned filters communicably coupled to each of said inspection data receive channels;

a multiplexer serially coupled to said plurality of tuned filters;

a logarithmic amplifier serially coupled to said multiplexer;

a linear amplifier serially coupled to said logarithmic amplifier; and

an analog-to-digital converter serially coupled to said linear amplifier.

9. The system of claim 8, further comprising an envelope peak detector, serially coupled between said linear amplifier and said analog-to-digital converter, for capturing the voltage peaks of the signal that has been multiplexed, logarithmically amplified, and linearly amplified.

10. The system of claim 9, further comprising a diode, serially coupled between said linear amplifier and said envelope peak detector, for isolating positive voltage from the signal that has been multiplexed, logarithmically amplified, and linearly amplified.

11. The system of claim 10, wherein said 10 dB multiplexing chips are capable of switching up to eight inspection data receive channels.

12. The system of claim 8, wherein said multiplexer comprises a series of multiplexing chips, wherein said 70 dB of isolation between inspection data receive channels is provided by a 60 dB multiplexing chip serially coupled to at least one 10 dB multiplexing chip of said multiplexer, and wherein said multiplexer is capable of switching between said plurality of inspection data receive channels.

13. The system of claim 1, wherein said interface board is capable of transmitting digitized data from said receiver board though a communication channel.

14. The system of claim 13, wherein said communication channel comprises an Ethernet communication channel.

15. The system of claim 13, wherein said communication channel is capable of transmitting scan data at a 12-bit resolution.

16. The system of claim 13, wherein said interface board is further capable of transmitting digitized data form said receiver board through said communication channel in real time.

17. The system of claim 1, wherein said interface board is capable of receiving data provided by encoders.

18. The system of claim 17, further comprising an encoder interface communicably coupled to said interface board for receiving data from said encoders and providing said data to said interface board.

19. The system of claim 18, wherein said encoder interface comprises at least one counter chip communicably coupled to said interface board and said encoders.

20. The system of claim 18, wherein said encoder interface is capable of receiving data selected from the group consisting of position data, speed data, velocity data, and distance data.

21. The system of claim 1, wherein said receiver board comprises a logarithmic amplifier serially coupled to a linear amplifier.

22. The system of claim 21, wherein said logarithmic amplifier is capable of −

67 dB to +3 dB of logarithmic amplification.

23. The system of claim 21, wherein said linear amplifier is capable of providing 20 dB of linear amplification.

24. The system of claim 1, comprising:

two pulser boards, each coupled to 16 transmit channels; and

two receiver boards, each coupled to 16 inspection data receive channels.

25. The system of claim 24, wherein each pulser board is a printed circuit board and comprises 16 pulsers communicably coupled to said 16 transmit channels.

26. The system of claim 1, wherein both said receiver board and said interface board are capable of processing inspection data signals from said plurality of inspection data receive channels at a resolution of 12 bits.

27. The system of claim 1, wherein said interface board and said pulser board are capable of communicating data to said transmit channels at a cycling rate of 200 microseconds (μ

s) per transmit channel, said receiver board is further capable of receiving and processing data from said inspection data receive channels at a cycling rate of 200 microseconds (μ

s) per receive channel, and said interface board is further capable of communicating data from said receiver board at a cycling rate of 200 microseconds (μ

s) per inspection data receive channel.

28. The system of claim 1, wherein said receiver board comprises a tuned filter communicably coupled to each of said inspection data receive channels and capable of processing data at a 5 MHz inspection frequency.

29. A 32 channel multiplexing system for inspecting a structure, comprising:

thirty-two transmit transducers;

thirty-two receive transducers capable of receiving signals emitted by said transmit transducers following propagation of said emitted signals through the structure;

thirty-two receive channels coupled to said receive transducers;

a multiplexing system coupled to said thirty-two inspection data receive channels and comprising a logarithmic amplifier for processing data from said thirty-two receive transducers transmitted through said thirty-two inspection data receive channels and providing logarithmic amplification to each channel with at least 70 dB of dynamic range.

30. The system of claim 29, wherein said multiplexing system is further adapted to switch between said inspection data receive channels.

31. The system of claim 30, wherein said linear amplification has a 20 dB gain.

32. The system of claim 30, wherein said multiplexing system is further capable of converting from analog to digital said data that has been previously processed with logarithmic amplification and linear amplification.

33. The system of claim 29, wherein said transmit transducers comprise a pulsing sensor and said receive transducers comprise a receiving sensor communicably coupled to a corresponding pulsing sensor, and wherein each pulsing sensor is coupled to a transmit channel and each receiving sensor is coupled to an inspection data receive channel.

34. The system of claim 29, further comprising an interface for remote communication to an analysis computer.

35. The system of claim 29, wherein said multiplexing system is further adapted to filter said data received from said inspection data receive channels before switching and logarithmically amplifying said data.

36. The system of claim 29, wherein said multiplexing system is further capable of linearly amplifying said data that has been previously processed with logarithmic amplification of at least 70 dB of dynamic range.

38. The system of claim 29, wherein said multiplexing system is further adapted to convert said data from an analog signal to a digital signal.

37. The system of 29, wherein said multiplexing system is further capable of processing data from said thirty-two inspection data receive channels at a cycling rate of 5 kHz to process data from each of said receive channels once every 6.4 milliseconds (ms).

40. The method of claim 37, further comprising the step of transmitting signals to a plurality of transmit channels.

41. The method of claim 40, further comprising the steps of:

controlling timing requirements for said step of transmitting signals to a plurality of transmit channels; and

transmitting said multiplexed signals in real time to a remote processor.

42. The method of claim 41, wherein said step of transmitting said mulitpelxed signals in real time to a remote processor comprises the step of transmitting said multiplexed signals from said inspection data receive channels at a cycling rate of 200 microseconds (μ

s) per inspection data receive channel, and wherein said multiplexed signals are represented by 12 bit signals.

43. The method of claim 40, wherein the step of transmitting signals to a plurality of transmit channels comprises the step of communicating data to said transmit channels at a cycling rate of 200 microseconds (μ

s) per transmit channel.

39. A method for multiplexing channels of an inspection system comprising repeating the steps of:

receiving signals from a plurality of inspection data receive channels; and

multiplexing said received signals, wherein said multiplexing comprises;

filtering said received signals;

switching between said plurality of inspection data receive channels to select one inspection data receive channel and define a switched received signal;

logarithmically amplifying said switched received signal;

linearly amplifying said switched, logarithmically amplified received signal; and

converting said switched, logarithmically amplified, linearly amplified received signal from analog to digital;

correlating the multiplexed signals to a physical structure of a part under inspection; and

presenting the correlated information on a display for review by a user.

44. The method of claim 39, further comprising the step of capturing peak voltage of said switched, logarithmically amplified, and linearly amplified received signal.

45. The method of claim 44, further comprising the step of isolating positive voltage from said switched, logarithmically amplified, and linearly amplified received signal prior to the step of capturing peak voltage.

46. The method of claim 39, wherein the step of logarithmically amplifying said switched received signal comprises providing logarithmic amplification for at least a 70 dB of dynamic range.

47. The method of claim 46, wherein the step of providing logarithmic amplification for at least 70 dB of dynamic range comprises providing amplification from −

67 dB to +3 dB.

48. The method of claim 39, further comprising the step of processing said multiplexed signals from said inspection data receive channels at a cycling rate of 200 microseconds (μ

s) per inspection data receive channel.

49. A system for inspecting a structure, comprising:

an interface board;

at least one pulser board communicably coupled to said interface board;

a plurality of transmit channels communicably coupled to said pulser board;

at least one receiver board communicably coupled to said interface board; and

a plurality of receive channels communicably coupled to said receiver board, wherein said receiver board is comprising a logarithmic amplifier for processing signals from said plurality of receive channels and providing logarithmic amplification to each channel for at least 70 dB of dynamic range,

wherein said receiver board further comprises a mulitplexer for providing 70 dB of isolation between inspection data receive channels, and wherein said receiver board is capable of processing data from said plurality of inspection data receive channels with 70 dB of isolation provided by said multiplexer and with logarithmic amplification of 70 dB of dynamic range provided by said logarithmic amplifier, and

wherein said multiplexer is a series of multiplexing chips and wherein said 70 dB of isolation is provided by a 60 dB multiplexing chip serially coupled to a 10 dB multiplexing chip of said multiplexer.