Institut National D'optique

Her Majesty the Queen in Right of Canada as Represented by the Minister of Natural Resources

Institut National D'optique/national Optics Institute

Systemes Pavemetrics Inc.

Daniel Lefebvre

Michel Doucet

Richard A Habel

Eric Samson

Éric Samson

Magella Bilodeau

Sebastien Roy

Richard Habel

Michel Robert

Andre Demers

Jean-François Hebert

Sébastien Roy

A method for controlling a laser profiler, the laser profiler being configured for generating a laser line on a surface to be inspected, the method comprising: receiving an image of the laser line; determining an actual intensity of the laser line; calculating an amplification factor for the laser line based on the actual intensity of the laser line, a target intensity for the laser line, a power of the laser, a camera gain of the camera and an exposure time of the laser line on the surface to be inspected, the amplification factor allowing the actual intensity of the laser line to reach the target intensity while minimizing the power of the laser; and based on the calculated amplification factor, adjusting at least one parameter of the laser profiler so that the actual intensity of the laser line corresponds to the target intensity.

Method and system for controlling a laser profiler

Provided herein is a method for measuring the size distribution and/or hardness of free falling rock pieces. The method comprises projecting at least one laser line on the falling rock pieces by a laser device; capturing images of the falling rock pieces at an angle from the at least one laser line by at least one camera; and obtaining size distribution data of the falling rock pieces based on data obtained from a topographical map generated from the captured images. Certain embodiments further comprise: obtaining at least one of the volume and area of individual rock pieces from the topographical map; conducting a data analysis on at least one of the volume and area measurements of the rock pieces to reduce at least one of sampling and measurement errors; determining the size distribution of the falling rock pieces based on the data analysis and, optionally, evaluating a rock hardness index for the rock. Further provided is a method comprising: producing two topographical maps of the pieces from captured images; and obtaining the volume of pieces from the topographical map by adding half-volumes from each of the topographical maps.

Methods for measuring properties of rock pieces

There is described an optical system for sensing the surface of an object. The system comprises: a light source for emitting at least one light beam centered on the optical axis of the system; a light reflector for reflecting the at least one incident light beam to generate at least two hollow conical light beams centered on the optical axis and having different opening angles, the at least two reflected hollow conical light beams for illuminating the surface; and an image capture device for imaging the illuminated surface.

Device for optical profilometry with conical light beams

A method for determining a centerline for a triangulation-based optical profilometry system, compensating for the spatial variations of the reflectance of an object's surface. The method comprises providing a luminous line on the object, the luminous line being a triangulation line superposed with a compensation line; capturing an image of the triangulation line and of the compensation line; for each position along the imaged triangulation line, determining a transverse triangulation profile from the imaged triangulation line and a transverse compensation profile from the imaged compensation line; determining a transverse correction profile given by the reciprocal of the transverse compensation profile; multiplying the transverse triangulation profile with the transverse correction profile to obtain a corrected transverse triangulation profile; computing a center of the corrected transverse triangulation profile. The centers determined at positions along the triangulation line form the centerline. Embodiments of a triangulation-based optical profilometry system integrating the method are disclosed.

Method and apparatus for triangulation-based 3D optical profilometry

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Daniel Lefebvre