Pseudorandom binary sequence apparatus and method for in-line inspection tool

• US 8,322,219 B2
• Filed: 08/07/2009
• Issued: 12/04/2012
• Est. Priority Date: 08/08/2008
• Status: Active Grant

• Current Assignee: Pure Technologies Limited (Xylem, Inc.)
• Original Assignee: Pure Technologies Limited (Xylem, Inc.)
• Inventors: Hoyt, Philip M.
• Primary Examiner(s): SAINT SURIN, JACQUES M
• Application Number:
  US12/538,104
• Publication Number:
  US 20100288049A1
• Time in Patent Office: 1,215 Days
• Field of Search: 736/02, 73/52, 73/614.9, 73/617.5, 73/644.2, 73/645.3, 735/99, 736/43, 324/240
• US Class Current: 73/602
• CPC Class Codes: G01N 2291/2636 cylindrical from inside
• CPC Class Codes: G01N 27/82 for investigating the presence of flaws
• CPC Class Codes: G01N 29/043 in the interior, e.g. by shear waves

Abstract

An in-line inspection tool is disclosed for inspecting the wall of a pipeline while traveling therethrough. The in-line inspection tool may include a transmitter, a signal generator, one or more receivers, and a decoder. The signal generator may generate a pseudorandom signal, generate an inspection signal, and drive the transmitter with a convolution of the pseudorandom signal and the inspection signal. The transmitter may transmit the convoluted signal to the wall of the pipeline. One or more receivers may receive from the wall of the pipeline a received signal comprising at least one of the convoluted signal and a reflection of the convoluted signal. The decoder may identify the inspection signal within the received signal by cross correlating the received signal and the pseudorandom signal.

Claims

1. An in-line inspection tool for inspecting the wall of a pipeline while traveling through the pipeline, the in-line inspection tool comprising:

a transmitter;

a signal generator generating a pseudorandom signal, generating an inspection signal, and driving the transmitter with a convolution of the pseudorandom signal and the inspection signal;

the transmitter transmitting, in the form of a transmitted stress wave traveling primarily circumferentially, the convolution to the wall of the pipeline; and

one or more receivers detecting in the wall of the pipeline a received stress wave after the received stress wave has traveled circumferentially at least about 120 degrees within the wall of the pipeline, the one or more receivers outputting a received signal comprising at least one of the convolution and a reflection of the convolution.

2. The in-line inspection tool of claim 1, wherein the transmitter and receiver each comprise one or more magnetostrictive electromagnetic acoustic transducers.

3. The in-line inspection tool of claim 1, wherein the transmitter and receiver each comprise one or more Lohrentz force electromagnetic acoustic transducers.

4. The in-line inspection tool of claim 1, wherein the transmitter and receiver each comprise an electromagnetic acoustic transducer.

5. The in-line inspection tool of claim 1, wherein the transmitter and receiver each comprise one or more piezoelectric ultrasonic transducers.

6. The in-line inspection tool of claim 5, wherein the one or more piezoelectric ultrasonic transducers operate at one of normal incidence and oblique incidence.

7. The in-line inspection tool of claim 5, wherein the one or more piezoelectric ultrasonic transducers operate as a phased array.

8. The in-line inspection tool of claim 1, further comprising a decoder identifying the inspection signal within the received signal by cross correlating the received signal and the pseudorandom signal.

9. A method comprising:

selecting an in-line inspection tool comprising a transmitter, signal generator, and one or more receivers;

inserting the in-line inspection tool within a pipeline having a wall;

generating, by the signal generator, a pseudorandom signal;

generating, by the signal generator, an inspection signal;

driving, by the signal generator, the transmitter with a convolution of the pseudorandom signal and the inspection signal;

transmitting, by the transmitter in response to the driving, the convolution to the wall of the pipeline in the form of a transmitted stress wave traveling primarily circumferentially within the wall;

receiving, by the one or more receivers, a received stress wave from the wall of the pipeline after the received stress wave has traveled at least about 360 degrees circumferentially around the pipeline;

generating, by the one or more receivers in response to the receiving, a received signal comprising at least one of the convolution and a reflection of the convolution; and

identifying the inspection signal within the received signal by cross correlating the received signal and the pseudorandom signal.

10. The method of claim 9, wherein the transmitter and one or more receivers each comprise one or more magnetostrictive electromagnetic acoustic transducers.

11. The method of claim 9, wherein the transmitter and one or more receivers each comprise one or more Lohrentz force electromagnetic acoustic transducers.

12. The method of claim 9, wherein:

the transmitter and receiver each comprise one or more piezoelectric ultrasonic transducers; and

the one or more piezoelectric ultrasonic transducers operate at one of normal incidence and oblique incidence.

13. The method of claim 9, wherein:

the transmitter and receiver each comprise one or more piezoelectric ultrasonic transducers; and

the one or more piezoelectric ultrasonic transducers operate as a phased array.

14. A method of inspecting a pipeline, the method comprising:

selecting a pipeline having a wall;

selecting an in-line inspection tool comprising a transmitter and a receiver;

traveling, by the in-line inspection tool, within the pipeline;

transmitting, by the transmitter during the traveling, a convolution of a pseudorandom signal and a inspection signal to the wall of the pipeline in the form of a transmitted stress wave traveling primarily circumferentially within the wall;

receiving, by the receiver, a received stress wave from the wall of the pipeline after the received stress wave has traveled at least about 120 degrees circumferentially around the pipeline;

generating, by the receiver in response to the receiving, a received signal comprising at least one of the convolution and a reflection of the convolution; and

identifying the inspection signal within the received signal by cross correlating the received signal and the pseudorandom signal.

15. The method of claim 14, wherein the transmitter and receiver each comprise one or more magnetostrictive electromagnetic acoustic transducers.

16. The method of claim 14, wherein the transmitter and receiver each comprise one or more Lohrentz force electromagnetic acoustic transducers.

17. The method of claim 14, wherein the transmitter and receiver each comprise an electromagnetic acoustic transducer.

18. The method of claim 14, wherein the transmitter and receiver each comprise one or more piezoelectric ultrasonic transducers.

19. The method of claim 18, wherein the one or more piezoelectric ultrasonic transducers operate at one of normal incidence and oblique incidence.

20. The method of claim 18, wherein the one or more piezoelectric ultrasonic transducers operate as a phased array.