US 7,995,796 B2Granted

System for road sign sheeting classification

AssigneeFacet Technology Corp.

InventorsJames E. Retterath, Robert A. Laumeyer

Life of this patent

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Abstract

A system for classifying different types of sheeting materials of road signs depicted in a videostream compares estimated retroreflectivity values against known minimum retroreflectivity values for each of a plurality of colors. Once a road sign has been identified in the videostream, the frames associated with that road sign are analyzed to determine each of a plurality of colors present on the road sign. An estimated retroreflectivity for each of the plurality of colors present on the road sign is then determined. By comparing the estimated retroreflectivity for each of the plurality of colors against known minimum retroreflectivity values for the corresponding color for different types of sheeting materials, an accurate determination of the classification of the sheeting material of the road sign is established. Preferably, certain conditions of gross failure of the sheeting material are filtered out before classification of the sheeting material is determined.

Claims3

Dependent claims

A method for determining sheeting type of a reflective sheeting material covering a road sign comprising:

means for illuminating at least a portion of the reflective sheeting material covering the road sign from a plurality of distances along the roadway;
means for collecting a plurality of light intensity measurements reflected from the at least a portion of the reflective sheeting material;
means for generating an as-measured retroreflectivity profile using the light intensity measurements corresponding to exemplary angular displacements of incident light from a reference position;
means for providing a database of retroreflectivity profiles with each retroreflectivity profile having an associated known sheeting type;
means for comparing the as-measured profile to each retroreflectivity profile from the database of retroreflectivity profiles;
means for selecting the retroreflectivity profile that best correlates to the as-measured retroreflectivity profile;
and
means for determining sheeting type of the reflective sheeting material based on the known sheeting type associated with the selected retroreflectivity profile.

5 more elements

Dependencies are inferred from the claim text.

Facts

Application: 12/419,843Filed 7 Apr 2009 · continuation
Priority: 12 Aug 2000
Published: US 2009/0252376 A18 Oct 2009
Granted: 9 Aug 2011
Term ends: Not estimatedThe source records don’t support an estimate.

Classification15 codes

G08G 1/096758
Where a selection of the information might take place: where no selection takes place on the transmitted or the received information
G01N 21/251
Colour; Spectral properties, i.e. comparison of effect of material on the light at two or more different wavelengths or wavelength bands:…
G01N 21/55
Systems in which incident light is modified in accordance with the properties of the material investigated: specular reflectivity
G01N 21/84
Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light: systems…

Family

Application60/224,761Us provisional application · filed 12 Aug 2000
Application60/296,596Us provisional application · filed 7 Jun 2001
Application09/928,218Parent of this continuation · filed 10 Aug 2001
Application11/056,926Parent of this continuation · filed 11 Feb 2005
US 6,891,960 B2Parent of this continuation · filed 10 May 2005
US 2009/0252376 A1Pre-grant publication · published 8 Oct 2009
US 7,515,736 B2Parent of this continuation
US 2002/0106109 A1Published application
US 2005/0249378 A1Published application
US 7,995,796 B2This patent

From the US filing history. Foreign family members aren’t listed.