Apparatus and method for detecting pipelwe defects

• US 20040021858A1
• Filed: 10/29/2002
• Published: 02/05/2004
• Est. Priority Date: 05/30/2000
• Status: Active Grant

• Current Assignee: OYO Corporation
• Original Assignee: OYO Corporation
• Inventors: Sano, Ko, Iinuma, Hiroyuki, Iseley, David Thomas, Karasaki, Kenzi, Goebuchi, Toru, Shima, Hiromasa
• Granted Patent: US 7,164,476 B2
• Time in Patent Office: Days
• US Class Current: 356/241.1
• CPC Class Codes: G01N 2021/9544 with emitter and receiver on the probe
• CPC Class Codes: G01N 21/954 Inspecting the inner surface of hollow bodies, e.g. bores

Abstract

An apparatus and method are disclosed for scanning and detecting defects in sewer and similar pipelines that eliminate the need to stop and pan-and-tilt areas of concern. In the method of the invention, a pipeline (15) inspection probe (10) of the apparatus of the invention comprising a CCD camera (14) with fish-eye lens (12) travels through the pipeline (15) on a self-propelled tractor automatically collecting data and transmitting it to a computer to provide a real-time display of the pipeline (15) interior with quasi three-dimensional information for effective and quick data analysis and management. The data includes digitized forward views and unfolded 360 degree laid-flat side-san (22) views of the pipeline (15) interior. Additionally, the digitized data may be stored for further analysis, tabulation, and for use with pipeline infrastructure maintenance software.

Claims

1. A method for detecting defects or damage in the interior wall of a pipe or pipeline, comprising:

obtaining a probe comprising or having associated therewith a light source, an optical sensor or viewer comprising a lens capable of viewing about 360 degrees, a direction locator or location detector, and a distance measurer, wherein said probe is in communication with a computer or data processor for processing data from said probe;

passing said probe through the interior of said pipeline while illuminating at least a portion of said pipeline interior wall with said light source and viewing and recording or transmitting for recording views of said pipeline interior wall where illuminated with said probe;

recording said location and distance of said probe in said pipeline as data for at least some of said views; and

processing said recorded views and direction and distance data such that said views are digitized and displayed in real-time as forward views and side-scan views and wherein said side-scan views are unfolded images showing approximately 360 degrees of the pipeline wall.

2. The method of claim 1 further comprising saving for later analysis said digitized views and data in a data file format suitable for images.

3. The method of claim 1 wherein said location and distance data comprises angle of inclination and axial rotation of probe.

4. The method of claim 1 wherein said probe is returned through said pipeline after passing through said pipeline, said direction locator is a gyroscope or gyro sensor, and said direction locator data is recorded as the probe passes through the pipeline and as the probe is returned through said pipeline.

5. The method of claim 4 wherein said direction data from said gyroscope or gyro sensor is adjusted for noise according to the compensation method.

6. The method of claim 4 wherein said direction is obtained from pipeline deflection calculated using gyroscope or gyro sensor data by integrating the compensated angle with distance.

7. The method of claim 6 wherein the compensated angle is calculated using the following formula:

Theta-c(t)=Theta(t)−

Theta-error/T*t

where;

Theta-error is the difference in angle observed between gyro data measured as the probe goes forward and comes back through the pipeline;

T is total time;

Theta(t) is the time from the beginning of the measurement; and

Theta-c(t) is the compensated angle.

8. The method of claim 1 wherein said optical viewer is a video camera or a CCD camera.

9. The method of claim 8 wherein said views are transmitted by the probe to said computer as analog data which is converted to digital data by said computer and wherein pixels are manipulated on a frame capture board to obtain real-time digitized forward and side-scans views of the pipeline interior.

10. The method of claim 8 wherein said views comprise digital data that has been compressed and wherein said views are digitally transmitted by the probe to said computer for display and storage.

11. The method of claim 8 where said views comprise digital data whose pixels are manipulated to obtain real time digitized forward and side-scan views of the pipeline interior.

12. An apparatus for detecting defects or damage in the interior of a pipeline comprising a pipeline inspection probe and data processing software that digitizes data from said probe in real time, providing both forward and unfolded side-scan images of the pipeline interior.

13. The apparatus of claim 12 wherein said probe comprises a light source for illuminating the pipeline interior and an optical sensor or camera comprising a fish-eye lens for obtaining forward and side-scan views in the pipeline.

14. The apparatus of claim 12 wherein said software includes instructions for manipulating the pixels from the digitized views such that at least one sampling circle is obtained for each frame of the forward view and successive scans can be concatenated so that the side-scan view may be displayed as an unfolded, laid-flat, side-scan image encompassing about 360 degrees.

15. The method for detecting defects or damage in a pipeline comprising:

passing the apparatus of claim 12 through said pipeline;

taking forward views of the interior wall of said pipeline;

digitizing and processing said views;

simultaneously displaying digitized forward and side-scan images in real time, wherein said side-scan images are unfolded 360 degree images; and

saving said images for further evaluation.

16. The method of claim 15 wherein said pipeline is a sewer line or similar pipeline for transporting liquids, gases, or slurries.

17. A method for obtaining real-time unfolded side-scan images of an interior pipeline wall substantially simultaneously or synchronously with forward images of the pipeline interior for use in inspecting the pipeline wall for defects or damage, said method comprising:

passing a lighted probe comprising a camera with a fish-eye lens through said pipeline obtaining forward or frontal views having about a 360 degree radius at periodic intervals;

relaying said views in analog data format to a data processor or computer;

converting said analog data to digital data;

manipulating pixels from said digital data on a frame capture board such that at least one sampling circle is obtained for each side-scan view;

displaying an unfolded 360 degree image of the side-scan view of said interior pipeline wall.

18. The method of claim 17 further comprising displaying substantially simultaneously with said side-scan image, a forward or frontal view said interior pipeline wall.

19. The method of claim 17 wherein said side-scan views are recorded about every 0.01 millimeter to about every 100 millimeters along the pipeline interior wall and said forward views are recorded at least about every 10 millimeters to about 1000 millimeters along the pipeline interior wall.

20. The method of claim 17 wherein said pipeline is a sewer line and said side-scan views are recorded about every 1 or 2 millimeters along the pipeline interior wall and said forward views are recorded about every 100 millimeters along the pipeline interior wall.

21. The method of claim 17 wherein said side-scan views are recorded more frequently than said forward views but where said side-scan views and said forward views are recorded synchronously.

22. The method of claim 19 wherein said pipeline is a sewer line or similar line for transporting liquids or gases or slurries.

23. A method for detecting internal pipeline defects or damage, comprising:

passing a lighted probe comprising a video camera with a fish-eye type of lens through at least a portion of the interior of said pipeline, illuminating said pipeline and recording forward and side-scan images periodically and synchronously during said passing;

noting simultaneously with said recording of at least said side-scan images the location of the probe in the pipeline at the time of recording of said image; and

digitizing and processing said images for display wherein said processing comprises pixel manipulation on at least one line of a sampling circle to obtain an unfolded image of the side-scan view.

24. The method of claim 23 wherein said pixel manipulation is done on a frame capture board.

25. The method of claim 23 wherein said display includes both forward views and side-scan

26. The method of claim 23 further comprising saving said digitized images for later evaluation or use.

27. The method of claim 26 wherein said images are saved in a data file format for images.

28. A pipeline scanner comprising a field data collection apparatus and data processing software that allows a real-time forward view of the pipeline as well as an unfolded side-scan view of the pipeline walls.

29. The scanner of claim 28 wherein said field data collection apparatus acquires a forward-looking view of the pipe interior and a 360 degree unfolded side-scan view of the pipe interior surface together with information on distance and direction of the apparatus in the pipe.

30. The scanner of claim 28 wherein said data collection apparatus comprises an LED light source.

31. The scanner of claim 28 wherein said data collection apparatus comprises a camera with a fish-eye lens.

32. The scanner of claim 28 wherein said data collection apparatus employs a compensated method to correct for gyro sensor noise.