Scrap sorting system

A computer-implemented method for sorting randomly-shaped scrap particles as they are conveyed in random locations on a moving conveyor through a pre-defined viewing area, including the steps of:

• acquiring data corresponding to an image of the viewing area;
• dividing the viewing area into a matrix of cells, each cell including a plurality of pixels, defining a resultant array of memory locations corresponding to the total number of pixels in the image;
• defining a discriminator signal array of memory locations corresponding to the total number of cells in the matrix;
• determining for each pixel, independently of the presence or absence of particles in the viewing area, whether the data in that pixel satisfies a predetermined color criteria and setting a value in the location in the resultant array corresponding to that pixel as a function of the color criteria determination;
• determining for each cell whether the values in the resultant array corresponding to pixels in that cell satisfies a predetermined separation criteria;
• setting a value in the location in the discriminator signal array corresponding to the cell as a function of the separator criteria determination;
• and
• sending a control signal to activate a separator located downstream from the image detector as a function of the discriminator signal to selectively actuate the separator to separate desired from undesired particles.

A method for sorting scrap particles based upon color as the particles are conveyed on a moving conveyor;

• the method comprising:
• determining the position of the conveyor;
• periodically acquiring an image of a defined viewing area on the conveyor;
• employing a computer image processor for receiving from the image detector the data corresponding to an image of the viewing area, dividing the viewing area into a matrix of cells, wherein each cell includes a plurality of pixels, determining for each cell in the viewing area, independently of the presence or absence of particles in the viewing area, whether the pixels in that cell satisfy a predetermined separation criteria, and transmitting a discriminator signal corresponding to each cell;
• employing a first computer controller for receiving a signal from the position sensor, determining whether the conveyor has moved a distance equal to the length of the viewing area, and as a function of that determination, sending an activation signal to acquire an image;
• and
• employing a second controller for receiving a signal from the position sensor, determining whether the conveyor has moved a distance equal to the length of a cell, and sending a control signal to activate a separator located downstream from the image detector as a function of the discriminator signal received from the image processor to separate desired from undesired objects.

A method for sorting scrap particles based upon color including the steps of:

• conveying the scrap particles on an opaque belt conveyor having a surface providing a uniformly contrasting background for the particles;
• determining the position of the conveyor;
• providing constant, controlled illumination of different preselected wavelengths at a pre-defined viewing area along which the particles are conveyed by the conveyor;
• removing heat, dust and debris from the viewing area;
• acquiring data corresponding to a color image of the viewing area at timed intervals based upon the location of the conveyor;
• employing an image processor computer to divide the viewing area into an imaginary matrix of cells and analyze the data corresponding to the image of the viewing area, independently of the presence or absence of particles in the viewing area, to determine for each cell in the matrix whether the color of the image in that cell satisfies a predetermined color criteria, and generate a discriminator signal for each cell of the matrix as a function of the comparison of each cell of the matrix with the predetermined color criteria;
• and
• sending a control signal to activate a separator located downstream from the image detector as a function of the discriminator signal to selectively actuate the separator to separate desired from undesired particles.