Method and System for Remotely Inspecting Bridges and Other Structures

• US 20130216089A1
• Filed: 02/08/2013
• Published: 08/22/2013
• Est. Priority Date: 04/22/2010
• Status: Active Grant

• Current Assignee: University of North Carolina At Charlotte (University of North Carolina System)
• Original Assignee: University of North Carolina At Charlotte (University of North Carolina System)
• Inventors: Chen, Shen-En, Hauser, Edwin W., Boyle, Charles G., Natarajan, Meenu
• Granted Patent: US 9,036,861 B2
• Time in Patent Office: Days
• US Class Current: 382/100
• CPC Class Codes: G06T 2207/10024 Color image
• CPC Class Codes: G06T 2207/10032 Satellite or aerial image; Remote sensing
• CPC Class Codes: G06T 2207/30184 Infrastructure
• CPC Class Codes: G06T 7/0002 Inspection of images, e.g. flaw detection

Abstract

Spatially Integrated Small-Format Aerial Photography (SFAP) is one aspect of the present invention. It is a low-cost solution for bridge surface imaging and is proposed as a remote bridge inspection technique to supplement current bridge visual inspection. Providing top-down views, the airplanes flying at about 1000 feet can allow visualization of sub-inch (large) cracks and joint openings on bridge decks or highway pavements. On board Global Positioning System (GPS) is used to help geo-reference images collected and facilitate damage detection. Image analysis is performed to identify structural defects such as cracking. A deck condition rating technique based on large crack detection is used to quantify the condition of the existing bridge decks.

Claims

1. A method of inspecting a structure, comprising:

flying an aircraft over the structure at an altitude of between about 500 feet and 1500 feet above ground level;

capturing a plurality of images of the structure using an imaging device;

associating each of the plurality of images with unique global positioning system data;

spatially integrating the plurality of images into a composite image; and

analyzing the composite image to identify structural defects.

2. The method of claim 1, wherein the imaging device is a digital camera.

3. The method of claim 1, wherein the step of spatially integrating the plurality of images into a composite image comprises processing the plurality of images using a computer executing a global information system application.

4. The method of claim 1, wherein the step of analyzing the composite image to identify structural defects comprises identifying cracks, spalls, potholes, expanded joints, areas of delamination, efflourescence, mineralization, stressed regions, and/or collision damage.

5. The method of claim 1, wherein the step of analyzing the composite image to identify structural defects comprises the following steps:

loading the composite image into a computer software application adapted for image processing;

setting a tolerance value;

selecting a portion of the composite image to analyze;

converting the portion of the composite image to grayscale;

removing shadow regions from the portion of the composite image;

identifying the lowest pixel value corresponding to the structural defect;

associating with the structural defect all pixels within a predetermined bandwidth range of the lowest pixel value; and

marking all pixels associated with the structural defect.

6. A computerized method of inspecting a structure, comprising:

creating a plurality of still images of the structure using aerial photography;

creating a composite image of the structure from a combination of the still images;

marking structural defects of the structure on the composite image;

organizing the markings of the structural defects into image layers.

7. A computerized method according to claim 6, wherein respective image layers display each occurrence of a respective structural defect on the composite image.