Automated system and method for identifying and measuring packages transported through a laser scanning tunnel

• US 6,382,515 B1
• Filed: 03/22/1999
• Issued: 05/07/2002
• Est. Priority Date: 12/18/1995
• Status: Expired due to Fees

• Current Assignee: Metrologic Instruments Incorporated (Honeywell International Inc.)
• Original Assignee: Metrologic Instruments Incorporated (Honeywell International Inc.)
• Inventors: Colavito, Stephen J., Zhu, Xiaoxun, Good, Timothy A., Au, Ka Man, Ghosh, Sankar, Scott, Ian A., Kolis, George, Blake, Robert E., Dickson, LeRoy, Amundsen, Thomas, Dehennis, Andrew D., Rockstein, George B., Knowles, Carl Harry, Wilz, David M.
• Primary Examiner(s): LE, THIEN MINH
• Application Number:
  US09/274,265
• Time in Patent Office: 1,142 Days
• Field of Search: 235/462-1-4, 235/472.01, 235/472.02, 177/2, 177/25.14, 177/25.15, 177/1, 177/3, 177/4, 177/5
• US Class Current: 235/472.01
• CPC Class Codes: G02B 26/106 having diffraction gratings as scanning elements, e.g. holographic scanners holographic optical elements G02B5/32, holography G03H
• CPC Class Codes: G06K 17/0022 arrangements or provisions for transferring data to distant stations, e.g. from a sensing device "transfer between computer elements G06F13/00 "; data-transmission H04L
• CPC Class Codes: G06K 2207/1013 Multi-focal
• CPC Class Codes: G06K 7/10 by electromagnetic radiation, e.g. optical sensing; by corpuscular radiation
• CPC Class Codes: G06K 7/10564 Light sources
• CPC Class Codes: G06K 7/10584 Source control
• CPC Class Codes: G06K 7/10594 Beam path
• CPC Class Codes: G06K 7/10603 Basic scanning using moving elements
• CPC Class Codes: G06K 7/10663 using hologram
• CPC Class Codes: G06K 7/10673 Parallel lines
• CPC Class Codes: G06K 7/10693 for omnidirectional scanning
• CPC Class Codes: G06K 7/10702 Particularities of propagating elements, e.g. lenses, mirrors G06K7/10831 takes precedence
• CPC Class Codes: G06K 7/10792 Special measures in relation to the object to be scanned
• CPC Class Codes: G06K 7/10801 Multidistance reading
• CPC Class Codes: G06K 7/10811 Focalisation
• CPC Class Codes: G06K 7/10851 Circuits for pulse shaping, amplifying, eliminating noise signals, checking the function of the sensing device basic electronic circuitry H03
• CPC Class Codes: G06K 7/10861 sensing of data fields affixed to objects or articles, e.g. coded labels postal sorting B07C3/14, conveying articles B65G47/48
• CPC Class Codes: G06K 7/10871 randomly oriented data-fields, code-marks therefore, e.g. concentric circles-code
• CPC Class Codes: G06K 7/10881 constructional details of hand-held scanners
• CPC Class Codes: G06K 7/10891 the scanner to be worn on a finger or on a wrist
• CPC Class Codes: G06K 7/109 : adaptations to make the hand-held scanner useable as a fixed scanner
• CPC Class Codes: G06K 7/14 : using light without selection of wavelength, e.g. sensing reflected white light G06K7/10831 - G06K7/1097 take precedence
• CPC Class Codes: G07F 9/002 : Vending machines being part of a centrally controlled network of vending machines
• CPC Class Codes: G07G 1/0054 : with control of supplementary check-parameters, e.g. weight or number of articles

Abstract

A fully automated package identification and measuring system, in which an omni-directional holographic scanning tunnel is used to read bar codes on packages entering the tunnel, while a package dimensioning subsystem is used to capture information about the package prior to entry into the tunnel. Mathematical models are created on a real-time basis for the geometry of the package and the position of the laser scanning beam used to read the bar code symbol thereon. The mathematical models are analyzed to determine if collected and queued package identification data is spatially and/or temporally correlated with package measurement data using vector-based ray-tracing methods, homogeneous transformations, and object-oriented decision logic so as to enable simultaneous tracking of multiple packages being transported through the scanning tunnel.

Claims

1. An automated package identification and dimensioning system capable of (i) identifying packages bearing bar code symbols, and (ii) measuring dimensional characteristics of said packages during package transport operations, said automated package identification and dimensioning system comprising:

a conveyor belt structure for transporting packages along a predetermined direction of travel;

a support framework arranged above said conveyor belt structure, for supporting a package identification subsystem providing a tunnel-like arrangement above said conveyor belt structure through which said conveyor belt structure extends and along which said packages are transported in an automated manner, wherein said tunnel-like arrangement has an entry port and an exit port;

said package identification subsystem being mounted from said support framework and projecting a plurality of laser scanning beams that produce a laser scanning pattern confined substantially within a three-dimensional laser scanning volume disposed above said conveyor belt structure, so that when each said package is transported through said three-dimensional laser scanning volume, the bar code symbol on said package is automatically read by at least one laser scanning beam and a scan beam data element is automatically generated,

wherein said scan beam data element includes (i) symbol character data representative of the bar code symbol read by at least one said laser scanning beam and thus the identity of said package, and (ii) laser scanning beam index data indicative of said at least one laser scanning beam used to read said bar code symbol;

a package dimensioning subsystem, mounted above said conveyor belt structure and before said entry port of said tunnel-like arrangement, for optically scanning each said package as said package is transported through said three-dimensional laser scanning volume, and automatically generating a package dimension data element for each optically scanned package, wherein each said package dimension data element contains package dimension-related data representative of one or more dimension-related characteristics of said optically scanned package;

a data element handling and processing subsystem including;

a time-stamping module for time-stamping each scan beam data element produced from said package identification subsystem and each package dimension data element produced from said package dimensioning subsystem so as to produce a time-stamped scan beam data element for each time-stamped scan beam data element, and a time-stamped package dimension data element for each time-stamped package dimension data element;

a data element combining module for selectively combining (i) said time-stamped package dimension data elements with (ii) each time-stamped scan beam data element so as to produce a plurality of package data element pairs, wherein each said package data element pair includes a time-stamped package dimension data element containing package dimension-related data, and a time-stamped scan beam data element containing symbol character data and laser scanning beam index data;

a package surface modeling module for generating a surface geometry model of the package represented by the package dimension related data contained within each said package data element pair;

a scan beam modeling module for generating a ray tracing model of the laser scanning beam represented by the laser scanning beam index data contained within each said package data element pair; and

a scan beam and package surface intersection determination module for determining the occurrence of an intersection between the surface geometry model and the ray tracing model associated with each package data element pair, so as to determine that the package dimension data element within said package data element pair is correlated with the corresponding scan beam data element within said package data element pair, and if so, generating an output data element containing the scan beam data element correlated with the package dimension data element,

thereby identifying each said package transported through said three-dimensional laser scanning volume while providing a measure of the dimension-related characteristics of said package in an automated manner.

2. The automated package identification and dimensioning system of claim 1, wherein said package identification subsystem comprises one or more laser scanning subsystems, and wherein the laser scanning pattern produced by each said laser scanning subsystem has multiple focal planes and a highly confined geometry extending about a projection axis extending from a scanning window provided within said laser scanning subsystem and above said conveyor belt structure.

3. The automated package identification and dimensioning system of claim 1, wherein said three-dimensional laser scanning volume has a widthwise dimension of at least about 1 meter extending along the width dimension of said conveyor belt structure, a lengthwise dimension of at least 1 meter extending along said predetermined direction of travel, and a heightwise dimension of at least 1 meter extending above said conveyor belt structure.

4. The automated package identification and dimensioning system of claim 2, wherein said one or more laser scanning subsystems are mounted within the corners of said support framework, on the top and sides of said support framework, and on the front and back of said support framework.

5. The automated package identification and dimensioning system of claim 2, which further comprises a computer system interfaced with said one or more laser scanning subsystems through an input/output port multiplexer, said computer system supporting functions carried out by said data element handling and processing subsystem.

6. The automated package identification and dimensioning system of claim 2, wherein each said laser scanning subsystem is a holographic laser scanning system.

7. The automated package identification and dimensioning system of claim 1, wherein said data element handling and processing subsystem further comprises a homogeneous transformation module for transforming each said surface geometry model and each said ray tracing model to a common coordinate reference frame, within which said scan beam and package surface intersection determination module can determine the occurrence of an intersection between said surface geometry model and said ray tracing model.

8. The automated package identification and dimensioning system of claim 7, which further comprises a package velocity determination subsystem for automatically determining the velocity of each said package being transported along said conveyor belt structure, generating a velocity data element representative of said package velocity, and providing said velocity data element to said data element handling and processing subsystem.

9. The automated package identification and dimensioning system of claim 8, wherein said homogeneous transformation module analyzes the time-stamp values contained within each said package data element pair to determine a time of travel between the point of dimensioning and the point of laser scanning, wherein the package velocity is used in conjunction with said time of travel to compute the distance between said the point of dimensioning and the point of laser scanning the package, and wherein said distance is used by said homogeneous transformation module to transform said surface geometry model and said ray tracing model to said common coordinate reference frame.

10. The automated package identification and dimensioning system of claim 1, wherein said package dimensioning subsystem comprises a pair of light transmitting and receiving structures mounted about said conveyor belt structure.

11. The automated package identification and dimensioning system of claim 1, wherein said dimension-related characteristics include one or more dimensions of said package.

12. The automated package identification and dimensioning system of claim 2, wherein each said laser scanning subsystem is a holographic laser scanning subsystem having a holographic scanning disc with a plurality of scanning facets, and each said scanning facet consists of a plurality of scanning sectors, and wherein said laser scanning beam index data is representative of the scanning sector(s) used to produce the laser scanning beam that read said package.

13. The automated package identification and dimensioning system of claim 2, wherein each said laser scanning subsystem is a polygonal laser scanning subsystem having a polygonal scanning disc with a plurality of scanning facets, and each said scanning facet consists of a plurality of scanning sectors, and wherein said laser scanning beam index data is representative of the scanning sector(s) used to produce the laser scanning beam that read said package.