System and Method for Detecting Features on a Laminated Veneer Lumber Billet

Abstract

The disclosure relates to systems and methods for detecting features on billets of laminated veneer lumber (LVL). In some embodiments, an LVL billet is provided and passed through a scanning assembly. The scanning assembly includes an x-ray generator and an x-ray detector. The x-ray generator generates a beam of x-ray radiation and the x-ray detector measures intensity of the beam of x-ray radiation after is passes through the LVL billet. The measured intensity is then processed to create an image. Images taken according to the disclosure may then be analyzed to detect features on the LVL billet.

1 . A system for detecting features on a laminated veneer lumber (LVL) billet, the LVL billet having a first planar surface and a second planar surface, the system comprising:
 a scanning assembly comprising:
 an x-ray generator positioned above the first planar surface, the x-ray generator being configured to project a beam of x-ray radiation onto the first planar surface; and 
 an x-ray detector positioned below the second planar surface, the x-ray detector being configured to measure intensity of the beam of x-ray radiation after is passes through the LVL billet; and 
   an image processor configured to generate an image from the measured intensity;   wherein the measured intensity is inversely proportionate to density of the LVL billet.   
     
     
         2 . The system of  claim 1 , further comprising a platform attached to the frame, the platform being configured for receiving the LVL billet. 
     
     
         3 . The system of  claim 1  wherein the features are substantially perpendicular to the beam of x-ray radiation. 
     
     
         4 . The system of  claim 1  wherein the features are selected from the group consisting of lap lengths and slip sheets. 
     
     
         5 . The system of  claim 1 , further comprising an x-ray collimator, the x-ray collimator being configured to narrow the beam of x-ray radiation generated by the x-ray generator. 
     
     
         6 . The system of  claim 1  wherein the x-ray generator, the x-ray detector, and the image processor are mounted on a frame, the frame comprising:
 one or more upper components arranged in a substantially parallel configuration; 
 one or more lower components located a distance from the one or more upper components, the one or more lower components being arranged in a substantially parallel configuration; and 
 four or more side components connecting the one or more upper components to the one or more lower components. 
 
     
     
         7 . The system of  claim 5  wherein the frame is positioned at an outfeed of a press in an LVL manufacturing line. 
     
     
         8 . The system of  claim 1  wherein the image is a 128 pixel scan line. 
     
     
         9 . A method for detecting features on laminated veneer lumber (LVL) comprising:
 providing a first group of veneers;   forming a first billet from the first group of veneers by:
 aligning the first group of veneers; and 
 pressing the first group of veneers; 
   exposing the first billet to a beam of x-ray radiation;   detecting information about one or more features on the first billet;   providing a second group of veneers; and   forming a second billet from the second group of veneers by:
 aligning the second group of veneers; and 
 pressing the second group of veneers; 
   and using the information about the one or more features on the first billet to optimize forming of the second billet.   
     
     
         10 . The method of  claim 9  wherein the step of forming a second billet from the second group of veneers using the information about the one or more features on the first billet to optimize forming of the second billet comprises:
 altering alignment of the second group of veneers based on the information about the one or more features on the first billet; or 
 altering pressing of the second group of veneers based on the information about the one or more features on the first billet. 
 
     
     
         11 . The method of  claim 9  wherein the information about the one or more features on the first billet is selected from the group consisting of information about lap length and information about existence of slip sheets. 
     
     
         12 . The method of  claim 9  wherein the step of forming a second billet from the second group of veneer using the information about the one or more features on the first billet to optimize formation of the second billet further comprises:
 generating an image of the information about the one or more features on the first billet, the image comprising one or more pixels arranged in a one or more columns; 
 calculating a mean intensity for each of the one or more columns; 
 creating a one dimensional array based on each mean intensity; 
 fitting a second order polynomial to the one dimensional array; 
 subtracting the second order polynomial from the one-dimensional array to create a difference array; 
 passing the difference array through a low pass filter to create a filtered array; 
 performing a peak and valley search on the filtered array to identify overlaps or gaps on the first billet. 
 
     
     
         13 . The method of  claim 9  wherein the step of exposing the first billet to a beam of x-ray radiation is performed by a scanning assembly, the scanning assembly comprising:
 an x-ray generator positioned above the first billet; and 
 an x-ray detector positioned below the first billet.