High speed stereoscopic pavement surface scanning system and method

• US 9,970,758 B2
• Filed: 08/02/2017
• Issued: 05/15/2018
• Est. Priority Date: 01/15/2016
• Status: Active Grant

• Current Assignee: Fugro Roadware Inc. (Fugro N.V.)
• Original Assignee: Fugro Roadware Inc. (Fugro N.V.)
• Inventors: Shah, Hitesh, Sivakumar, Prasanna Kumar, Singh, Ishar Pratap, Galchinsky, Miroslava, Lowe, David
• Primary Examiner(s): Adams, Eileen M
• Application Number:
  US15/666,846
• Publication Number:
  US 20170350698A1
• Time in Patent Office: 286 Days
• Field of Search: None
• CPC Class Codes: E01C 23/01 Devices or auxiliary means for setting-out or checking the configuration of new surfacing, e.g. templates, screed or reference line supports form rails E01C19/50; Applications of apparatus for measuring, indicating, or recording the surface configuration of existing surfacing, e.g. profilographs E01C23/07 takes precedence; measuring roughness or irregularity in general G01B
• CPC Class Codes: E01C 23/07 Apparatus combining measurement of the surface configuration of paving with application of material in proportion to the measured irregularities measuring means only E01C23/01 G01B
• CPC Class Codes: E01C 23/08 for roughening or patterning; for removing the surface down to a predetermined depth high spots or material bonded to the surface, e.g. markings; for maintaining earth roads, clay courts or like surfaces by means of surface working tools, e.g. scarifiers, levelling bladesremoving matter not bonded to the surface E01H1/00; roughening or detaching ice E01H5/12
• CPC Class Codes: G01B 11/30 for measuring roughness or irregularity of surfaces
• CPC Class Codes: G01B 11/303 using photoelectric detection means
• CPC Class Codes: G01C 7/04 involving a vehicle which moves along the profile to be traced
• CPC Class Codes: G06T 2207/10021 Stereoscopic video; Stereoscopic image sequence
• CPC Class Codes: G06T 2207/20081 Training; Learning
• CPC Class Codes: G06T 2207/30252 Vehicle exterior; Vicinity of vehicle
• CPC Class Codes: G06T 7/593 from stereo images
• CPC Class Codes: H04N 13/122 Improving the 3D impression of stereoscopic images by modifying image signal contents, e.g. by filtering or adding monoscopic depth cues H04N13/128 takes precedence
• CPC Class Codes: H04N 13/239 using two 2D image sensors having a relative position equal to or related to the interocular distance H04N13/243 takes precedence
• CPC Class Codes: H04N 13/282 for generating image signals corresponding to three or more geometrical viewpoints, e.g. multi-view systems
• CPC Class Codes: H04N 2013/0081 Depth or disparity estimation from stereoscopic image signals
• CPC Class Codes: H04N 23/56 provided with illuminating means
• CPC Class Codes: H04N 23/90 Arrangement of cameras or camera modules, e.g. multiple cameras in TV studios or sports stadiums
• CPC Class Codes: H04N 5/2226 Determination of depth image, e.g. for foreground/background separation determining depth by image analysis in general G06T7/50; segmentation by image analysis in general G06T7/10

Abstract

There is disclosed a mobile pavement surface scanning system and method, In an embodiment, the system comprises one or more stereoscopic image capturing devices synchronised with one or more light sources mounted on the platform for illuminating a pavement surface, mounted on a mobile survey platform that provides a trigger mechanism to capture sequential image pairs of the illuminated pavement surface and a movement sensor that continuously measures the movement of the platform and a synchronization signal for time or distance synchronized image capture with accurate GPS positioning. One or more computers process the synchronized images captured stamps the images with one or more of time and distance data, GPS location and calculated 3D elevation for each point on the pavement surface using stereoscopic principles, and assesses the quality of the pavement surface to determine the level of pavement surface deterioration.

Claims

1. A mobile pavement surface scanning system, comprising:

one or more light sources for illuminating a pavement surface at a selected wavelength;

one or more stereoscopic image capturing devices for capturing sequential images of the illuminated pavement surface, the sequential images comprising intensity image pairs;

a plurality of positioning sensors adapted to encode movement of the system and provide a synchronization signal for the intensity image pairs captured by the one or more stereoscopic image capture devices; and

one or more computer processors adapted to;

synchronize the intensity image pairs captured by each camera in the one or more stereoscopic image capturing devices;

normalize the contrast of the intensity image pairs;

rectify the intensity image pairs;

calculate 3D elevation data for each point on the pavement surface using stereoscopic principles; and

combine the contrast normalized intensity image pairs with the calculated 3D elevation data to create a stereoscopic 3D image for assessing the quality of the pavement surface using the 3D elevation data to determine the level of deterioration.

2. The system of claim 1, wherein the one or more light sources are light emitting diodes.

3. The system of claim 1, wherein the one or more light sources are lasers with line generating optics.

4. The system of claim 1, wherein the one or more stereoscopic image capturing devices comprise line scan cameras with frame grabbers.

5. The system of claim 1, further comprising a synchronization module adapted to receive a signal from the plurality of positioning sensors, and provide a sequence of triggers to the line scan cameras for time synchronized image capturing.

6. The system of claim 5, wherein the synchronization module is further adapted to provide a sequence of triggers to the one or more light sources for time synchronized illumination of the pavement surface for image capturing.

7. The system of claim 1, wherein the one or more computer processors is further adapted to correlate the 3D elevation data with image intensity data to identify distressed regions of pavement in the stereoscopic 3D image.

8. The system of claim 7, wherein the one or more computer processors is further adapted to color-code the identified distressed regions of pavement in different colors to indicate the level of severity.

9. The system of claim 1, further comprising optical filters matched to the selected wavelength of the one or more light sources for filtering the images of the illuminated pavement surface.

10. The system of claim 1, further comprising polarizing filters for filtering the images of the illuminated pavement surface.

11. A mobile pavement surface scanning method, comprising:

illuminating a pavement surface at a selected wavelength utilizing one or more light sources;

capturing sequential images of the illuminated pavement surface utilizing one or more stereoscopic image capturing devices, the sequential images comprising intensity image pairs;

utilizing a plurality of positioning sensors, encoding movement and providing a synchronization signal for the intensity image pairs captured by the one or more stereoscopic image capture devices; and

utilizing one or more computer processors to;

synchronize the intensity image pairs captured by each camera in the one or more stereoscopic image capturing devices;

normalize the contrast of the intensity image pairs;

rectify the intensity image pairs;

calculate 3D elevation data for each point on the pavement surface using stereoscopic principles; and

combine the contrast normalized intensity image pairs with the calculated 3D elevation data to create a stereoscopic 3D image for assessing the quality of the pavement surface using the 3D elevation data to determine the level of deterioration.

12. The method of claim 11, wherein the one or more light sources are light emitting diodes.

13. The method of claim 11, wherein the one or more light sources are lasers with line generating optics.

14. The method of claim 11, wherein the one or more stereoscopic image capturing devices comprise line scan cameras with frame grabbers.

15. The method of claim 11, further comprising receiving at a synchronization module a signal from the plurality of positioning sensors, and providing a sequence of triggers to the line scan cameras for time synchronized image capturing.

16. The method of claim 15, further comprising adapting the synchronization module to provide a sequence of triggers to the one or more light sources for time synchronized illumination of the pavement surface for image capturing.

17. The method of claim 11, further comprising correlating the 3D range data with image intensity data to identify distressed regions of pavement.

18. The method of claim 17, further comprising color-coding the identified distressed regions of pavement in different colors to indicate the level of severity.

19. The method of claim 11, further comprising providing optical filters matched to the selected wavelength of the one or more light sources for filtering the images of the illuminated pavement surface.

20. The method of claim 11, further comprising providing polarizing filters for filtering the images of the illuminated pavement surface.