Optical type granule sorting machine

摘要

An optical type granule sorting machine is provided which allows a sensitivity setting to be easily performed by effectively utilizing RGB three-dimensional color space information similar to information obtained via human eyes and which enables signal processing to be substantially simplified. Determination means includes a three-dimensional color distribution data creation section that creates data on wavelength components of R light, G light, and B light from the granules, on a three-dimensional color space, a Mahalanobis distance interface creation section that sets an interface calculated based on a Mahalanobis distance to partition the data into a conforming-granule cluster area and a nonconforming granule cluster area, a Euclidean distance interface creation section that determines a position of center of gravity of the conforming granule cluster area and a position of center of gravity of the nonconforming granule cluster area to set an interface calculated based on a Euclidean distance at which the positions of center of gravity lie at a longest distance from each other, and a threshold determination section that determines a line of intersection between the interface calculated based on the Mahalanobis distance and the interface calculated based on the Euclidean distance, to determine the line of intersection to be a determination threshold that allows determination of whether or not the granules are to be treated as a separation target.

主权项

1. An optical type granule sorting machine comprising transfer means for transferring granules including conforming granules, nonconforming granules, and foreign substances in such a manner that the granules form a continuous flow, inspection means for inspecting the granules transferred by the transfer means, determination means for determining whether or not the granules are to be treated as a separation target based on individual color information on the granules inspected by the inspection means, and exclusion means for excluding the separation target determined by the determination means from the continuous flow,
wherein the inspection means includes an illumination section that illuminates the granules with light and an optical detection section that detects light transmitted through the granules or reflected from the granules, and the determination means includes a three-dimensional color distribution data creation section that plots wavelength components of R light, G light, and B light from the granules detected by the optical detection section on a three-dimensional color space to create three-dimensional color distribution data for a granule sample; a Mahalanobis distance interface creation section that sets an interface calculated based on a Mahalanobis distance in the three-dimensional color distribution data created by the three-dimensional distribution data creation section to partition the data into a first conforming granule cluster area containing many conforming granules and a first nonconforming granule cluster area containing many nonconforming granules and foreign substances; a Euclidean distance interface creation section that determines a position of center of gravity of the first conforming granule cluster area created by the Mahalanobis distance interface creation section and a position of center of gravity of the first nonconforming granule cluster area created by the Mahalanobis distance interface creation section, the Euclidean distance interface creation section setting an interface calculated based on a Euclidean distance at which the positions of center of gravity lie at a longest distance from each other to partition the data into a second conforming granule cluster area and a second nonconforming granule cluster area; and a threshold determination section that determines a line of intersection between the interface calculated based on the Mahalanobis distance and the interface calculated based on the Euclidean distance, to determine the line of intersection to be a determination threshold that allows determination of whether or not the granules are to be treated as a separation target.