Automated method of and system for dimensioning objects over a conveyor belt structure by applying contouring tracing, vertice detection, corner point detection, and corner point reduction methods to two-dimensional range data maps of the space above the conveyor belt captured by an amplitude modulated laser scanning beam

An automated object dimensioning system for measuring the dimensions of a scanned object transported along a conveyor belt structure, comprising:

• a system housing having a light transmission aperture, supportable above a conveyor belt structure;
• an optical bench, disposed within said system housing;
• a laser beam production module disposed within said system housing, for generating an amplitude modulated laser beam;
• a scanning mechanism, mounted on said optical bench, for projecting and said amplitude modulated laser beam through said light transmission aperture, and repeatedly scanning said amplitude modulated laser beam across the width of said conveyor belt structure;
• a light collecting mechanism, mounted within said system housing, for collecting laser light reflected off said scanned object and focusing said reflected laser light;
• a photodetector, mounted on said optical bench, for detecting said focused laser light and producing an electrical signal corresponding thereto;
• signal processing circuitry, disposed within said system housing, for processing said produced electrical signal and, during each scan of said amplitude modulated laser beam across said scanned object, generating a row of raw digital range data representative of the distance from said scanning element to sampled points along said scanned object, measured with respect to a polar-type coordinate system symbolically-embedded within said automatic object dimensioning system;
• a preprocessing data buffer, disposed within said system housing, for storing rows of raw range data produced by said signal processing circuitry;
• and
• a programmed digital image processor, disposed within said system housing, for receiving rows of raw range data from said preprocessing data buffer, and processing data, including raw range data buffered in said preprocessing data buffer,
• wherein said programmed digital image processor includes
• a first data processing stage for automatically processing said rows of raw range data in said preprocessing data buffer so as to produce a range data map representative of the space above said conveyor belt structure, and
• a second data processing stage for automatically tracing contours within said buffered range data map, said traced contours being represented by a first set of indices (m,n) indicative of objects being transported along said conveyor belt structure;
• a third data processing stage for automatically processing said first set of indices (m,n) associated with said traced contours so as to detect vertices associated with polygonal-shaped objects extracted from said range data map, said detected vertices being represented by a second set of indices (m,n) and indicative of polygonal-shaped objects corresponding to objects being transported along said conveyor belt structure;
• a fourth data processing stage for automatically processing said second set of indices (m,n) associated with said detected vertices so as to detect a set of candidate corner points associated with the corners of a particular object being transported along said conveyor belt structure, said candidate corner points being represented by a third set of indices (m,n) and indicative of the corners of a particular object being transported along said conveyor belt structure;
• a fifth data processing stage for automatically processing said third set of indices (m,n) associated with detected corner point candidates so as to reduce said set of candidate corner points down to a set of corner points most likely to correspond to the corner points of a regular-shaped polygonal object, said most likely set of candidate corner points being represented by a fourth set of indices (m,n) and indicative of the corners of a regular-shaped polygonal object which most likely corresponds to the particular object being transported along said conveyor belt structure;
• a sixth data processing stage for automatically processing said fourth set of indices (m,n) associated with the corner points of a regular-shaped polygonal object so as to compute dimension-related parameters of the object represented by said image contours traced within said buffered range data map.