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

• US 7,000,839 B2
• Filed: 09/02/2003
• Issued: 02/21/2006
• 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: Zhu, Xiaoxun, Good, Timothy A., Au, Ka Man, Wilz, David M. Sr., Ghosh, Sankar, Scott, Ian A., Kolis, George, Blake, Robert E., Germaine, Gennady, Colavito, Stephen J., Dickson, LeRoy, Amundsen, Thomas, Dehennis, Andrew D., Rockstein, George B., Knowles, Carl Harry
• Primary Examiner(s): Frech, Karl D.
• Assistant Examiner(s): WALSH, DANIEL I
• Application Number:
  US10/364,656
• Publication Number:
  US 20030234290A1
• Time in Patent Office: 903 Days
• Field of Search: 235/462.14, 235/462.01, 235/472.01, 235/435, 235/462.18, 235/462.24, 359/216, 356/2, 356/3
• US Class Current: 235/462.14
• 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: 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 system for automatically identifying and measuring packages moving along a conveyor structure in a singulated or non-singulated manner, said automated system comprising:

a package conveyor system having a conveyor structure to support one or more package transport lanes along the conveyor structure;

a scanning tunnel including bar code symbol reading subsystems supported overhead, alongside, and/or below the conveyor structure by a support frame, for generating a scanning volume thereabove, for scanning bar codes on packages transported therethrough;

a first multiple-package detection and dimensioning subsystem arranged on the input side of said scanning tunnel,

a master clock for generating a global time reference used in connection with the time stamping of data elements generated within the system;

a package velocity measurement subsystem;

an input/output subsystem for managing the data inputs to and data outputs from said system; and

a data management computer, with a graphical user interface (GUI), for realizing a data element queuing, handling and processing subsystem as well as other data and system management functions,

wherein a second multiple package detection and dimensioning subsystem arranged on the output side of said scanning tunnel comprises a laser-based scanning mechanism for (i) generating an amplitude modulated laser beam that is repeatedly scanned across the width-wise dimension of the scanning tunnel while oriented in direction substantially perpendicular to the surface of the conveyor structure, and (ii) producing data representative of the height profile of packages exiting the scanning tunnel and processing the same to automatically detect the presence of each package moving along said conveyor structure and out of said scanning tunnel, and generate a data element indicative thereof.

2. The system of claim 1, wherein said first multiple-package detection and dimensioning subsystem comprises a laser-based scanning mechanism for generating an amplitude modulated laser beam that is repeatedly scanned across the width-wise dimension of the scanning tunnel while oriented in direction substantially perpendicular to the surface of the conveyor structure and producing data representative of the height profile of packages entering the scanning tunnel, and processing the same to automatically detect the presence of each package moving along the conveyor structure and into said scanning tunnel, and generate a data element indicative thereof.

3. The automated system of claim 1, wherein said package velocity measurement subsystem comprises a roller wheel engaged against the undersurface of said conveyor structure, optical shaft incremental encoder connected to the axle of the roller wheel and producing and electrical pulse output stream per revolution of the roller wheel, and a programmed microprocessor for processing the output pulse stream and producing digital data representative of the velocity of the conveyor structure and thus package transported thereby at any instant in time.

4. The automated system of claim 1, which further comprises a weighing-in-motion subsystem, installed beneath said first simultaneous multiple-package detection and dimensioning subsystem, along the conveyor structure, for weighing packages as they are transported therealong.

5. The automated system of claim 1, wherein said first multiple package detection and dimensioning subsystem comprises a stereoscopic camera subsystem in which stereoscopic-image pairs are captured from packages along the conveyor structure, and processed to determine the vertices of the imaged packages as well as the length, height and width dimensions thereof measured relative to a local coordinate referenced symbolically embedded in the stereoscopic camera subsystem.

6. The system of claim 1, wherein each said bar code reading subsystem employs a laser scanning mechanism.

7. An automated system for automatically identifying and measuring packages moving along a conveyor structure in a singulated or non-singulated manner, said automated system comprising:

a package conveyor system having a conveyor structure to support one or more package transport lanes along the conveyor structure;

a scanning tunnel including bar code symbol reading subsystems supported overhead, alongside, and/or below the conveyor structure by a support frame, for generating a scanning volume thereabove, for scanning bar codes on packages transported therethrough;

a first multiple-package detection and dimensioning subsystem arranged on the input side of said scanning tunnel,

a master clock for generating a global time reference used in connection with the time stamping of data elements generated within the system;

a package velocity measurement subsystem;

an input/output subsystem for managing the data inputs to and data outputs from said system; and

a data management computer, with a graphical user interface (GUI), for realizing a data element queuing, handling and processing subsystem as well as other data and system management functions,

wherein said first multiple-package detection and dimensioning subsystem located on said input side of said scanning tunnel comprises;

a package height/run-length difference engine for processing, as input, each height profile data array {H<sub>n;

i</sub>} of length N provided to its data input ports at sampling time T_i, and producing as output a height/width profile difference data array {Δ

H<sub>n;

n−

1;

i</sub>} of length N−

1 indicative of package height profile changes between position n and n−

1 at sampling time T_i with respect to the widthwise dimension of said conveyor structure;

a package height/width difference engine for processing, as input, time-consecutive height profile data arrays {H<sub>n;

i</sub>} and {H<sub>n;

i+1</sub>} each of length N, and producing as output a height profile difference data array {Δ

H<sub>n;

i;

i−

1</sub>} of length N−

1, indicative of package height profile changes at sampling position n over sampling times T_i and T<sub>i−

1</sub> with respect to the run-lengthwise dimension of said conveyor structure; and

a height profile data analyzer for processing, as input, each height/width profile difference data array {Δ

H<sub>n;

n−

1;

i</sub>} and height/run-length difference data array {Δ

H<sub>n;

n−

1;

i</sub>} produced by the difference engines, and producing as output, time-stamped PIT data elements as well as time-stamped Package Dimension Data Elements (PDEs) for buffering in moving package tracking queues.

8. The system of claim 7, wherein said package height/run-length difference engine comprises:

a first data array buffering unit having N input data ports and N output data ports, and adapted for buffering the height profile data array {H<sub>n;

i</sub>} captured from the conveyor structure at sampling time T_i, where n=0,1,2, . . . N−

2,N−

1;

a second data array buffering unit having N input data ports and N output data ports, and adapted for buffering the height profile data array {H<sub>n;

i</sub>} captured from the conveyor structure at sampling time T<sub>i−

1</sub>, where n=0,1,2, . . . N−

2,N−

1;

a height data array differentiator unit for comparing time-consecutive height profile data arrays {H<sub>n;

i</sub>} and {H<sub>n;

i+1</sub>} captured at sampling times T_i and T<sub>i−

1</sub> at sampling position n along the run-lengthwise dimension of the conveyor structure, and producing as output a height profile difference data array {Δ

H<sub>n;

i;

i−

1</sub>} of length N−

1, indicative of package height profile changes at sampling position n over sampling times T_i and T<sub>i−

1</sub> with respect to the run-lengthwise dimension of said conveyor structure; and

a third data array buffering unit having N−

1 input data ports and N−

1 output data ports, and adapted for buffering the height profile difference data array {Δ

H<sub>n;

i;

i−

1</sub>} of length N−

1 produced from the height data array differentiator unit, prior to transfer as input to said height profile data analyzer.

9. The system of claim 7, wherein said package height/width difference engine comprises:

a first data array buffering unit having N input data ports and N output data ports, and adapted for buffering the height profile data array {H<sub>n;

i</sub>} captured from said conveyor structure at sampling time T_i, where n=0,1,2, . . . ,N−

2,N−

1;

an array of N−

1 height data differentiation units for comparing spatially-contiguous height profile data samples H<sub>n;

i</sub> and H<sub>n−

1;

i</sub> captured at sampling time T_i over sampling positions n and n−

1, respectively, along the widthwise dimension of said conveyor structure, and producing as output a height profile difference data array {Δ

H<sub>n,n−

1;

i</sub>} of length N−

1, indicative of package height profile changes between sampling positions n and n−

1 at sampling time T_i with respect to the widthwise dimension of said conveyor structure; and

a second data array buffering unit having N−

1 input data ports and N−

1 output data ports, and adapted for buffering the height profile difference data array {Δ

H<sub>n,n−

1;

i</sub>} produced from the array of height sample differentiator units, prior to transfer as input to said height profile data analyzer.

10. The system of claim 7, wherein said height profile data analyzer receives, as input, height profile difference data arrays {Δ

H<sub>n;

n−

1;

i</sub>} and {Δ

H<sub>n;

i;

i−

1</sub>} which are buffered and analyzed in order to automatically carry out the following functions in a programmed manner, namely;

(1) detecting singulated, stacked and/or side-by-side configurations of packages on the conveyor structure about the enter the scanning tunnel and, for each detected package thereabout, generating one package-in-the-tunnel (PIT) data element (or token) and attaching thereto, a time-stamp (T_i) obtained from the underlying height profile data utilized in the package detection process;

(2) obtaining (i,e, computing) accurate height, width and/or length dimension measurements for each detected package, and attaching thereto, a time-stamped obtained from the underlying height profile data utilized in the package measurement process;

(3) (3) loading each time-stamped PIT data element into the spatially correct moving package tracking queue, based on dimensional data obtained for the corresponding package, so as to create a unique trackable data object therefor within the multiple-package detection and dimensioning subsystem; and

(4) loading time-stamped package dimension data elements (PDEs) into the spatially correct moving package tracking queue in order to link the same with and becoming an attribute of the corresponding package in the moving package tracking queue; and

(5) transferring each data object in each moving package queue into its corresponding moving package queues maintained in the data element queuing, handling and processing subsystem; and

(6) resetting the moving package tracking queues each time the height data profile analyzer determines that one or more packages on the conveyor structure, arranged in a stacked and/or side-by-side configuration, appear in a singulated configuration with respect to a downstream arrangement of packages.

11. An automated sysem for automatically identifying and measuring packages moving along a conveyor structure in a singulated or non-singulated manner, said automated system comprising:

a package conveyor system having a conveyor structure to support one or more package transport lanes along the conveyor structure;

a scanning tunnel including a bar code symbol reading subsystems supported overhead, alongside, and/or below the conveyor structure by a support frame, for generating a scanning volume thereabove, for scanning bar codes on packages transported therethrough;

a first multiple-package detection and dimensioning subsystem arranged on the input side of said scanning tunnel,

a master clock for generating a global time reference used in connection with the time stamping of data elements generated within the system;

a package velocity measurement subsystem;

an input/output system for managing the data inputs to and data outputs from said system; and

a data management computer, with a graphical user interface (GUI), for realizing a data element queuing, handling and processing subsystem as well as other data and system management functions,

wherein a second simultaneous multiple-package detection and dimensioning subsystem located on said input side of laser scanning tunnel subsystem comprises;

a package height/run-length difference engine for processing, as input, each height profile data array {H<sub>n;

i</sub>} of length N provided to its data input ports at sampling time T_i, and producing as output a height/width profile difference data array {Δ

H<sub>n,n−

1;

i</sub>} of length N−

1 indicative of package height profile changes between position n and n−

1 at sampling time T_i with respect to the widthwise dimension of said conveyor structure;

a package height/width difference engine for processing, as input, time-consecutive height profile data arrays {H<sub>n;

i</sub>} and {H<sub>n;

i+1</sub>} each of length N, and producing as output a height profile difference data array {Δ

H<sub>n;

i,i−

1</sub>} of length N-1, indicative of package height profile changes at sampling position n over sampling times T_i and T<sub>i−

1</sub> with respect to the run-lengthwise dimension of said conveyor structure; and

a height profile data analyzer for processing, as input, each height/width profile difference data array {Δ

H<sub>n,n−

1;

i</sub>} and height/run-length difference data array {Δ

H<sub>n,n−

1;

i</sub>} produced by the difference engines, and producing as output, time-stamped PIT data elments as well as time-stamped Package Dimension Data Elements (PDEs) for buffering in moving package tracking queues.

12. The system of claim 11, wherein said package height/run-length difference engine comprises;

a first data array buffering unit having N input data ports and N output data ports, and adapted for buffering the height profile data array {H<sub>n;

i</sub>} captured from said conveyor structure at sampling time T_i, where n=0,1,2, . . . ,N−

2,N−

1;

a second data array buffering unit having N input data ports and N output data ports, and adapted for buffering the height profile data array {H<sub>n;

i</sub>} captured from said conveyor structure at sampling time T<sub>i−

1</sub>, where n=0,1,2, . . . , N−

2,N−

1;

a height data array differentiator unit for comparing time-consecutive height profile data arrays {H<sub>n;

i</sub>} and {H<sub>n;

i+1</sub>} captured at sampling times T_i and T<sub>i−

1</sub> at sampling position n along the run-lengthwise dimension of the conveyor structure, and producing as output a height profile difference data array {H<sub>n;

i,i−

1</sub>} of length N−

1, indicative of package height profile changes at sampling position n over sampling times T_i and T<sub>i−

1</sub> with respect to the run-lengthwise dimension of the conveyor structure;

a third data array buffering unit having N−

1 input data ports and N−

1 output data ports, and adapted for buffering the height profile difference data array {Δ

H<sub>n;

i,i−

1</sub>} of length N−

1 produced from the height data array differentiator unit, prior to transfer as input to the height profile data analyzer.

13. The system of claim 11, wherein said package height/width difference engine comprises:

a first data array buffering unit having N input data ports and N output data ports, and adapted for buffering the height profile data array {H<sub>n;

i</sub>} captured from said conveyor structure at sampling time T_i, where n=0,1,2, . . ., N−

2,N−

1;

an array of N−

1 height data differentiation units for comparing spatially-contiguous height profile data samples H<sub>n;

i</sub> and H<sub>n−

1;

i</sub> captured at sampling time T_i over sampling positions n and n−

1, respectively, along the widthwise dimension of said conveyor structure, and producing as output a height profile difference data array {Δ

H<sub>n,n−

1;

i</sub>} of length N−

1, indicative of package height profile changes between sampling positions n and n−

1 at sampling time T₁ with respect to the widthwise dimension of said conveyor structure; and

a second data array buffering unit having N−

1 input data ports and N−

1 output data ports, and adapted for buffering the height profile difference data array {Δ

H<sub>n,n−

1</sub>} produced from the array of height sample differentiator units, prior to transfer as input to the height profile data analyzer.

14. The system of claim 11, wherein said height profile data analyzer receives, as input, height profile difference data arrays {Δ

H<sub>n,n−

1;

i</sub>} and {Δ

H<sub>n;

i,i−

1</sub>} which are buffered and analyzed in order to automatically carry out the following functions in a programmed manner, namely;

(1) detecting singulated, stacked and/or side-by-side configurations of packages on the conveyor structure about the enter the scanning tunnel and, for each detected package thereabout, generating one package-in-the-tunnel (PIT) data element (or token) and attaching thereto, a time-stamp (T_i) obtained from the underlying height profile data utilized in the package detection process;

(2) obtaining (i.e. computing) accurate height, width and/or length dimension measurements for each detected package, and attaching thereto, a time-stamped obtained from the underlying height profile data utilized in the package measurement process;

(3) loading each time-stamped PIT data element into the spatially correct moving package tracking queue, based on dimensional data obtained for the corresponding package, so as to create a unique trackable data object therefor within the multiple-package detection and dimensioning subsystem; and

(3) loading time-stamped package dimension data elements (PDEs) into the spatially correct moving package tracking queue in order to link the same with and becoming an attribute of the corresponding package in the moving package tracking queue;

(4) transferring each data object in each moving package queue into its corresponding moving package queues maintained in the data element queuing, handling and processing subsystem; and

(5) resetting the moving package tracking queues each time the height data profile analyzer determines that one or more packages on the conveyor structure, arranged in a stacked and/or side-by-side configuration, appear in a singulated configuration with respect to a downstream arrangement of packages.