Remote crane bar code system

• US 8,146,814 B2
• Filed: 04/07/2010
• Issued: 04/03/2012
• Est. Priority Date: 08/13/2004
• Status: Expired due to Fees

• Current Assignee: Arcelormittal Dofasco Incorporated (Mittal Steel)
• Original Assignee: Arcelormittal Dofasco Incorporated (Mittal Steel)
• Inventors: Mueller, Robert Eric, Shivji, Aly, Li, Kan
• Primary Examiner(s): Vo, Tuyen K
• Application Number:
  US12/756,156
• Publication Number:
  US 20100282842A1
• Time in Patent Office: 727 Days
• Field of Search: 235/383, 235/385, 235/462.08, 235/462.14, 235/462.25, 235/470, 235/472.01, 235/494, 235/375, 235/451, 235/462.01, 235/462
• US Class Current: 235/385
• CPC Class Codes: G06K 7/10811 Focalisation
• CPC Class Codes: G06Q 10/087 Inventory or stock management, e.g. order filling, procurement or balancing against orders
• CPC Class Codes: G06T 2207/30164 Workpiece; Machine component
• CPC Class Codes: G06T 7/0004 Industrial image inspection

Abstract

In general terms, the present invention provides a method of automatically scanning an inventory field to allow the selection of a desired item for retrieval. A camera is positioned in the crane trolley located above the field. The camera continuously performs a scan of the field displaying an image to the operator of the items being scanned. This real-time image allows the operator to distinguish between items scanned in the field. The operator can subsequently choose the desired item triggering the camera system to automatically capture desired information from the item which is in turn communicated to an inventory control system. The camera system mitigates the requirement of a second individual to communicate information between the field and the operator.

Claims

1. A method for retrieving an item from a field of inventory using an overhead crane system, comprising:

receiving an identifier for an item to be retrieved from the field of inventory;

using the identifier to obtain, from an inventory control database, an item location, within the field of inventory, for the item to be retrieved;

positioning a trolley of the overhead crane system above the item location to target a picker on the trolley to retrieve a target item in the item location;

using an adjustable imaging system on an underside of the trolley to obtain an image of an identification tag attached to the target item;

reading information identifying characteristics of the target item provided by the identification tag to confirm that the target item is the item to be retrieved; and

responsive to confirmation that the target item is the item to be retrieved, using the picker to retrieve the item to be retrieved from the field of inventory;

wherein using the imaging system carried by the trolley to obtain the image of the identification tag attached to the target item comprises;

obtaining an image having at least a portion of the identification tag visible in the image; and

aligning the identification tag within the image to obtain the image of the identification tag; and

wherein aligning the identification tag within the image to obtain the image of the identification tag comprises;

arranging an array of two-dimensional sensors on the image;

identifying markings in each of said sensors, the at least one marking indicative of the presence of a particular feature of the identification tag;

computing an average position of said markings to determine a deviation of said average position from a preferred position; and

aligning the identification tag in the image according to the deviation.

2. A method according to claim 1, wherein the method is fully automated.

3. A method for retrieving an item from a field of inventory using an overhead crane system, comprising:

receiving an identifier for an item to be retrieved from the field of inventory;

using the identifier to obtain, from an inventory control database, an item location, within the field of inventory, for the item to be retrieved;

positioning a trolley of the overhead crane system above the item location to target a picker on the trolley to retrieve a target item in the item location;

using an adjustable imaging system on an underside of the trolley to obtain an image of an identification tag attached to the target item;

reading information identifying characteristics of the target item provided by the identification tag to confirm that the target item is the item to be retrieved; and

responsive to confirmation that the target item is the item to be retrieved, using the picker to retrieve the item to be retrieved from the field of inventory;

wherein using the imaging system carried by the trolley to obtain the image of the identification tag attached to the target item comprises;

obtaining an image having at least a portion of the identification tag visible in the image; and

aligning the identification tag within the image to obtain the image of the identification tag; and

wherein aligning the identification tag within the image to obtain the image of the identification tag comprises;

identifying at least one marking on the identification tag indicative of the position of the identification tag in the image;

comparing the position of the at least one marking to a preferred position;

determining a deviation of the position from the preferred position; and

aligning the tag in the image by adjusting the orientation of the imaging system according to the deviation.

4. A method according to claim 3 wherein the at least one marking is a set of alignment markings disposed about the periphery of an identifier providing the information, an average of the position of each of the alignment markers being compared to the preferred position to determine the deviation, and the orientation of the imaging system being adjusted based on the deviation such that the average is located within a predetermined portion of the image.

5. A method according to claim 4 wherein one marking of the set of alignment markings is unique from the others, the location of the unique marker being used to determine the orientation of the tag.

6. A method according to claim 5 wherein the information identifying characteristics of the target item is a barcode displayed on the tag, and the orientation of the tag determines a scan direction for reading the barcode.

7. A method according to claim 3 wherein each of the at least one marking is identified using at least one sensor arranged on the image, each of the at least one marking indicative of a respective region of interest in the image corresponding to at least a portion of indicia on the identification tag, an average position of the at least one marking being compared to the preferred position to determine the deviation, and the orientation of the imaging system being adjusted based on the deviation such that the average position is located within a predetermined portion of the image.

8. A method according to claim 7 wherein the regions of interest are segments indicative of regions of similar intensity that are differentiated from other regions using an intensity gradient.

9. A method according to claim 7 comprising three oval shaped sensors arranged on the image concentrically around a center position in the image.

10. A method according to claim 9 wherein each of the oval sensors is analysed to determine the regions of interest, and an average position of the regions is determined from the avenge position of segments identified by respective ones of the sensors, the segments being indicative of regions of similar intensity that are differentiated from other regions by an intensity gradient.

11. A method according to claim 10 wherein the step of determining the deviation further includes the step of determining a second average position using horizontally and vertically arranged sensors passing through the average position, the second average position being determined from an average position of segments identified by one of the horizontally and vertically arranged sensors, the identification tag being aligned based on the second average position.

12. A method according to claim 11 wherein the one of the horizontally and vertically arranged sensors is chosen based on the orientation of the indicia.

13. A method according to claim 7 wherein the indicia comprises a barcode and the regions of interest correspond to respective barcode bars.

14. A method according to claim 3, wherein the method is fully automated.

15. An overhead crane system for retrieving items from a field of inventory, comprising:

a bridge;

a trolley movably mounted on the bridge;

at least one trolley motor to facilitate translation of the trolley along the bridge;

the bridge being mounted on rails transverse to the bridge, allowing the bridge to translate fore and aft along the rails;

at least one bridge motor to facilitate translation of the bridge along the rails;

the trolley having a picker for vertically hoisting items from the field of inventory;

a range finder system for locating the trolley'"'"'s position along each of an x-axis and a y-axis of the field of inventory;

an adjustable imaging system mounted to an underside of the trolley to obtain an image of an identification tag attached to an item disposed underneath the trolley; and

a processor coupled to the imaging system for reading information identifying characteristics of the item provided by the identification tag;

wherein the imaging system has;

an adjustable lens for magnifying said image;

an interface for displaying an item image of the item disposed underneath the trolley and adapted for receiving a location input for the identification tag attached to the item disposed underneath the trolley based on a location in the item image;

wherein the processor uses the location input to orient the imaging system towards the identification tag and commands the adjustable lens to magnify the identification tag; and

wherein the imaging system includes a first camera having a fixed magnification and a second camera having an adjustable magnification for magnifying the identification tag.

16. The overhead crane system of claim 15, further including an inventory control system coupled to the processor, the inventory control system being used to receive the information identifying characteristics of the item disposed underneath the trolley from the processor, for identification thereof;

wherein said inventory control system updates an inventory record according to the information identifying characteristics of the item disposed underneath the trolley from the processor when the item is moved by the overhead crane system.

17. The overhead crane system of claim 15, wherein the overhead crane system is fully automated.

18. An overhead crane system for retrieving items from a field of inventory, comprising:

a bridge;

a trolley movably mounted on the bridge;

at least one trolley motor to facilitate translation of the trolley along the bridge;

the bridge being mounted on rails transverse to the bridge, allowing the bridge to translate fore and aft along the rails;

at least one bridge motor to facilitate translation of the bridge along the rails;

the trolley having a picker for vertically hoisting items from the field of inventory;

a range finder system for locating the trolley'"'"'s position along each of an x-axis and a y-axis of the field of inventory;

an adjustable imaging system carried by the trolley to obtain an image of an identification tag attached to an item disposed underneath the trolley; and

a processor coupled to the imaging system for reading information identifying characteristics of the item provided by the identification tag;

wherein the imaging system has;

an adjustable lens for magnifying said image;

an interface for displaying an item image of the item disposed underneath the trolley and adapted for receiving a location input for the identification tag attached to the item disposed underneath the trolley based on a location in the item image;

wherein the processor uses the location input to orient the imaging system towards the identification tag and commands the adjustable lens to magnify the identification tag; and

wherein the imaging system includes a first camera having a fixed magnification and a second camera having an adjustable magnification for magnifying the identification tag.