System for the determination of retroreflectivity of road signs and other reflective objects
First Claim
1. A method of automated determination of retroreflectivity values for reflective surfaces disposed along a roadway comprising:
- activating a light source on a capture vehicle, while the capture vehicle is moving along the roadway, to illuminate an area that includes at least one reflective surface, the at least one reflective surface including a foreground surface and a background surface;
determining a plurality of light intensity values with at least one intensity sensor directed to cover a field of view which includes at least a portion of the area illuminated by the light source;
while the capture vehicle is moving, capturing a color image with a camera mounted on the capture vehicle and directed to cover a field of view which includes at least a portion of the area illuminated by the light source, the camera being distinct from the at least one intensity sensor; and
using a computer processing system to;
identify a portion of the plurality of light intensity values, the portion of the plurality of light intensity values being associated with one of the at least one reflective surfaces;
analyze the portion of the plurality of light intensity values; and
determine at least one retroreflectivity value for the one of the at least one reflective surfaces using the portion of the plurality of light intensity values, the captured color image, and at least one of;
a sheeting color of the background surface of the one of the at least one reflective surfaces and a sheeting color of the foreground surface of the one of the at least one reflective surfaces.
3 Assignments
0 Petitions
Accused Products
Abstract
A system for the determination of retroreflectivity values for reflective surfaces disposed along a roadway repeatedly illuminates an area along the roadway that includes at least one reflective surface using a light source. Multiple light intensity values are measured over a field of view which includes at least a portion of the area illuminated by the light source. A computer processing system is used to identifying a portion of the light intensity values associated with a reflective surface and analyze the portion of the light intensity values to determine at least one retroreflectivity value for that reflective surface.
162 Citations
52 Claims
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1. A method of automated determination of retroreflectivity values for reflective surfaces disposed along a roadway comprising:
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activating a light source on a capture vehicle, while the capture vehicle is moving along the roadway, to illuminate an area that includes at least one reflective surface, the at least one reflective surface including a foreground surface and a background surface; determining a plurality of light intensity values with at least one intensity sensor directed to cover a field of view which includes at least a portion of the area illuminated by the light source; while the capture vehicle is moving, capturing a color image with a camera mounted on the capture vehicle and directed to cover a field of view which includes at least a portion of the area illuminated by the light source, the camera being distinct from the at least one intensity sensor; and using a computer processing system to; identify a portion of the plurality of light intensity values, the portion of the plurality of light intensity values being associated with one of the at least one reflective surfaces; analyze the portion of the plurality of light intensity values; and determine at least one retroreflectivity value for the one of the at least one reflective surfaces using the portion of the plurality of light intensity values, the captured color image, and at least one of;
a sheeting color of the background surface of the one of the at least one reflective surfaces and a sheeting color of the foreground surface of the one of the at least one reflective surfaces. - View Dependent Claims (2, 3)
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4. A System for acquiring information to assess reflective surfaces disposed along a roadway comprising;
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a capture vehicle having;
.a light source, on the capture vehicle; a light sensor; a camera, mounted on the capture vehicle, the camera being distinct from the light sensor; and a control system operably connected to the light source, the camera and the light sensor such that i) the light sensor records light intensity information associated with an area that includes at least one reflective surface and ii) the camera captures a color image that includes color image information associated with an area that includes the at least one reflective surface, while the capture vehicle is moving along the roadway, in response to repeated illumination of the area by the light source while the capture vehicle is moving, the at least one reflective surface including a foreground surface and a background surface; and a computer processing system that; identifies a portion of the plurality of light intensity values from the recorded light intensity information, the portion of the plurality of light intensity values being associated with the at least one reflective surface, analyzes the portion of the plurality of light intensity values, and determines at least one retroreflectivity value for the at least one reflective surface using the portion of the plurality of light intensity values, the captured color image, and at least one of;
a sheeting color of the background surface of the at least one reflective surface and a sheeting color of the foreground surface of the at least one reflective surface. - View Dependent Claims (5, 6)
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7. A method of automated determination of retroreflectivity values for reflective surfaces comprising:
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activating a light source on a capture vehicle, while the capture vehicle is moving along a roadway, to illuminate an area that includes at least one reflective surface without targeting the light source on the at least one reflective surface, the at least one reflective surface including a foreground surface and a background surface; determining a plurality of light intensity values with at least one intensity sensor directed to cover a field of view which includes at least a portion of the area illuminated by the light source; while the capture vehicle is moving, capturing a color image with a camera mounted on the capture vehicle and directed to cover a field of view which includes at least a portion of the area illuminated by the light source, the camera being distinct from the at least one intensity sensor; and using a computer processing system to; identify a portion of the plurality of light intensity values associated with one of the at least one reflective surface; analyze the portion of the plurality of light intensity values; and determine at least one retroreflectivity value for the one of the at least one reflective surface using the portion of the plurality of light intensity values, the captured color image, and at least one of;
a sheeting color of the background surface of the at least one reflective surface and a sheeting color of the foreground surface of the at least one reflective surface;wherein the portion of the plurality of light intensity values comprises a frame of pixel intensity values and a plurality of reflective surfaces are present in the portion of the plurality of light intensity values. - View Dependent Claims (8, 9)
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10. A method of automated determination of retroreflectivity values for reflective surfaces comprising:
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activating a light source on a capture vehicle, while the capture vehicle is moving along a roadway, to illuminate an area that includes at least one reflective surface without targeting the light source on the at least one reflective surface, the at least one reflective surface including a foreground surface and a background surface; determining a plurality of light intensity values with at least one intensity sensor directed to cover a field of view which includes at least a portion of the area illuminated by the light source; while the capture vehicle is moving, capturing a color image with a camera mounted on the capture vehicle and directed to cover a field of view which includes at least a portion of the area illuminated by the light source, the camera being distinct from the at least one intensity sensor; and using a computer processing system to; identify a portion of the plurality of light intensity values associated with one of the at least one reflective surface; analyze the portion of the plurality of light intensity values; and determine at least one retroreflectivity value for the one of the at least one reflective surface using the portion of the plurality of light intensity values, the captured color image, and at least one of;
a sheeting color of the background surface of the at least one reflective surface and a sheeting color of the foreground surface of the at least one reflective surface;wherein the step of activating the light source is synchronized to the step of determining the plurality of light intensity values. - View Dependent Claims (11, 12)
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13. A. method of automated determination of retroreflectivity values for reflective surfaces comprising:
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creating a characterization profile for a light source, the characterization profile including an array of known luminance values associated with reflections of the light source;
creating a characterization profile for an intensity sensor, the characterization profile including an array of intensity values measured for reflections of a known light source;
activating the light source on a capture vehicle, while the capture vehicle is moving along a roadway, to illuminate an area that includes at least one reflective surface, the at least one reflective surface including a foreground surface and a background surface;determining a plurality of light intensity values with at least one intensity sensor without targeting a particular reflective surface; while the capture vehicle is moving, capturing a color image with a color camera mounted on the capture vehicle and directed to cover a field of view which includes at least a portion of the area illuminated by the light source, the color camera being distinct from the at least one intensity sensor; using a computer processing system to determine at least one retroreflectivity value for one of the at least one reflective surface, including; identifying a portion of at least one light intensity value associated with one of the at least one reflective surfaces; utilizing the characterization profile of the light source and the characterization profile for the intensity sensor to determine a luminance value associated with the portion of that light intensity value associated with that reflective surface based on the at least one color associated with that reflective surface; and converting the luminance value to determine a retroreflectivity value for the one of the at least one reflective surfaces using the portion of the at least one light intensity value, the captured color image, and at least one of;
a sheeting color of the hacks and surface of the one of the at least one reflective surfaces and a sheeting color of the foreground surface of the one of the one of the at least one reflective surfaces. - View Dependent Claims (14, 15)
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16. A method of automated determination of retroreflectivity values for reflective surfaces comprising:
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activating a light source on a capture vehicle, while the capture vehicle is moving along a roadway, to illuminate an area that includes at least one reflective surface without targeting the light source on the at least one reflective surface, the at least one reflective surface including a foreground surface and a background surface; determining a plurality of light intensity values with at least one intensity sensor directed to cover a field of view which includes at least a portion of the area illuminated by the light source; while the capture vehicle is moving, capturing a color image with a camera iz mounted on the capture vehicle and directed to cover a field of view which includes at least a portion of the area illuminated by the light source, the camera being distinct from the at least one intensity sensor; and using a computer processing system to; identify a portion of the plurality of light intensity values associated with one of the at least one reflective surface; and analyze the portion of the plurality of light intensity values; and determine at least one retroreflectivity value for the one of the at least one reflective surface using the portion of the plurality of light intensity values, the captured color image, and at least one of;
a sheeting color of the background surface of the at least one reflective surface and a sheeting color of the foreground surface of the at least one reflective surface. - View Dependent Claims (17, 18)
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19. A method of automated determination of retroreflectivity values for reflective surfaces disposed along a roadway comprising:
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activating a light source to emit light on a capture vehicle, while the capture vehicle is moving along the roadway, to illuminate an area that includes a reflective surface, the reflective surface including a foreground surface and a background surface; determining a plurality of light intensity values with a light sensor directed to cover a field of view which includes at least a portion of the area illuminated by the light source; while the capture vehicle is moving, capturing a color image with a camera mounted on the capture vehicle and directed to cover a field of view which includes at least a portion of the area illuminated by the light source, the camera being distinct from the light sensor; and using a computer processing system to; identify a portion of the plurality of light intensity values, the portion of the plurality of light intensity values being associated with the reflective surface; analyze the portion of the plurality of light intensity values; and determine a retroreflectivity value for the reflective surface using the portion of the plurality of light intensity values, the captured color image, and at least one of;
a sheeting color of the background surface of the reflective surface and a sheeting color of the foreground surface of the reflective surface. - View Dependent Claims (20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35)
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36. A system for automated determination of a retroreflectivity value of a reflective surface dispose along a roadway, the system comprising:
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a control system operably coupled to a light source, a camera and a light sensor, the camera being distinct from the light sensor, the control system configured to; activate the light source to emit light on a capture vehicle, while the capture vehicle is moving along the roadway, to illuminate an area that includes a reflective surface, the reflective surface including a foreground surface and a background surface, activate the light sensor to determine a plurality of light intensity values directed to cover a field of view which includes at least a portion of the area illuminated by the light source; and while the capturing vehicle is moving, capture a color image with a camera mounted on the capture vehicle and directed to cover a field of view which includes at least a portion of the area illuminated by the light source; a computer processing system configured to; identify a portion of the of plurality of light intensity values, the portion of the plurality of light intensity values being associated with the reflective surface; analyze the portion of the plurality of light intensity values; and determine a retroreflectivity value for the reflective surface using the portion of the plurality of the light intensity values, the captured color image, and at least one of;
a sheeting color of the background surface of the reflective surface and a sheeting color of the foreground surface of the reflective surface. - View Dependent Claims (37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52)
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Specification