RFID conveyor system and method

• US 20060232423A1
• Filed: 03/22/2006
• Published: 10/19/2006
• Est. Priority Date: 03/29/2005
• Status: Active Grant

• Current Assignee: Datalogic Automation Incorporated (Datalogic S.p.A.)
• Original Assignee: Accu-Sort Systems Incorporated (Datalogic S.p.A.)
• Inventors: Cox, James N.
• Granted Patent: US 7,492,259 B2
• Time in Patent Office: Days
• US Class Current: 340/572.700
• CPC Class Codes: B07C 5/3412 according to a code applied to the object which indicates a property of the object, e.g. quality class, contents or incorrect indication sorting according to size measured by light-responsive means B07C5/10; sorting according to optical properties B07C5/342; for packages B65D79/02; for information carriers G06K7/00
• CPC Class Codes: B65G 2203/042 Sensors
• CPC Class Codes: G06K 17/00 Methods or arrangements for effecting co-operative working between equipments covered by two or more of main groups G06K1/00 - G06K15/00, e.g. automatic card files incorporating conveying and reading operations
• CPC Class Codes: G06K 2207/1012 Special detection of object
• CPC Class Codes: G06K 7/0008 General problems related to the reading of electronic memory record carriers, independent of its reading method, e.g. power transfer
• CPC Class Codes: G06K 7/10079 the collision being resolved in the spatial domain, e.g. temporary shields for blindfolding the interrogator in specific directions
• CPC Class Codes: G06K 7/10316 using at least one antenna particularly designed for interrogating the wireless record carriers antennas in general H01Q1/22
• CPC Class Codes: G06K 7/10336 the antenna being of the near field type, inductive coil
• CPC Class Codes: G06K 7/10346 the antenna being of the far field type, e.g. HF types or dipoles
• CPC Class Codes: G06K 7/10356 using a plurality of antennas, e.g. configurations including means to resolve interference between the plurality of antennas
• CPC Class Codes: G06K 7/10435 the interrogation device being positioned close to a conveyor belt or the like on which moving record carriers are passing conveying in accordance with bodily destination marks, see B65G47/46, sorting of objects carrying identity markings, see B07C5/34
• CPC Class Codes: G06Q 10/08 Logistics, e.g. warehousing, loading or distribution; Inventory or stock management
• CPC Class Codes: H01Q 1/2208 associated with components used in interrogation type services, i.e. in systems for information exchange between an interrogator/reader and a tag/transponder, e.g. in Radio Frequency Identification [RFID] systems methods or arrangements for sensing record carriers, e.g. for reading patterns G06K7/00; record carrier for use with machines and with at least a part designed to carry digital markings G06K19/00
• CPC Class Codes: H01Q 1/2216 used in interrogator/reader equipment
• CPC Class Codes: H01Q 1/2241 used in or for vehicle tyres
• CPC Class Codes: H01Q 17/001 for modifying the directional characteristic of an aerial
• CPC Class Codes: H01Q 21/065 Patch antenna array
• CPC Class Codes: H01Q 21/08 the units being spaced along or adjacent to a rectilinear path waveguide fed H01Q21/0037
• CPC Class Codes: H01Q 21/28 Combinations of substantially independent non-interacting antenna units or systems multiple beam H01Q25/00
• CPC Class Codes: H01Q 9/0407 Substantially flat resonant element parallel to ground plane, e.g. patch antenna dipole H01Q9/285; monopole H01Q9/40
• CPC Class Codes: H01Q 9/0428 : radiating a circular polarised wave

Abstract

A conveyor system for processing items on which radio frequency identification tags are disposed includes a frame, a conveyor disposed movably on the frame and that conveys items through a path of travel, each item having at least one respective radio frequency identification tag disposed thereon, at least one first antenna, at least one second antenna, a radio frequency receiver, and a processor. The processor is programmed to associate information included in a first signal corresponding to a response from a radio frequency identification tag with a first item if the processor receives the first signal while at least a portion of the first item is within a first area that includes at least part of a second area into which the first antenna radiates radio frequency signals. If the processor receives a predetermined number of first signals while at least a portion of the first item is within the first area, wherein the predetermined number of first signals includes information identifying the same radio frequency identification tag, the processor thereafter prohibits association of the information with a second item that is upstream from the first item.

Claims

1. A conveyor system for processing items on which radio frequency identification tags are disposed, said system comprising:

a frame;

a conveyor disposed movably on the frame and that conveys items through a path of travel, each item having at least one respective radio frequency identification tag disposed thereon;

at least one first antenna disposed proximate the path of travel so that the first antenna radiates radio frequency signals into a first area proximate path of travel and through which the items pass;

at least one second antenna disposed proximate the path of travel so that the second antenna receives responses to the radio frequency signals from the respective radio frequency identification tags on the items, wherein each response includes information that identifies the radio frequency identification tag from which said response is received;

a radio frequency receiver that receives signals from the second antenna corresponding to the responses received by the antenna from the radio frequency identification tags and outputs first signals corresponding to the responses and including the information; and

a processor that receives the first signals from the receiver,

wherein the processor is programmed to

associate said information included in a said first signal with a first said item if the processor receives the first signal from the receiver while at least a portion of the first item is within a second area that includes at least part of the first area, and

if the processor receives a predetermined number of said first signals while at least a portion of the first item is within the second area, wherein the predetermined number of first signals include first said information identifying the same radio frequency identification tag, thereafter prohibit association of the first information with any second said item that is upstream from the first item on the conveyor with respect to the path of travel.

2. The system as in claim 1, wherein a single antenna comprises a said first antenna and a said second antenna.

3. The system as in claim 2, including a plurality of said single antennas.

4. The system as in claim 3, wherein the plurality of single antennas are disposed with respect to the path of travel so that a plurality of respective said second areas corresponding to the single antennas coincide with each other.

5. A conveyor system for processing items on which radio frequency identification tags are disposed, said system comprising:

a frame;

a generally planar belt that is disposed movably on the frame and that conveys items through a path of travel, each item having at least one respective radio frequency identification tag disposed thereon;

at least one antenna disposed proximate the belt so that the antenna

radiates radio frequency signals into a first area proximate the belt and through which the items pass and

receives responses to the radio frequency signals from the respective radio frequency identification tags on the items on the belt, wherein each response includes information that identifies the radio frequency identification tag from which said response is received;

a radio frequency receiver that receives signals from the antenna corresponding to the responses received by the antenna from the radio frequency identification tags and outputs first signals corresponding to the responses and including the information; and

a processor that receives the first signals from the receiver,

wherein the processor is programmed to

associate said information included in a said first signal with a first said item if the processor receives the first signal from the receiver while at least a portion of the first item is within a second area that includes at least part of the first area, and

if the processor receives a predetermined number of said first signals while at least a portion of the first item is within the second area, wherein the predetermined number of first signals include first said information identifying the same radio frequency identification tag, thereafter prohibit association of the first information with any second said item that is upstream from the first item on the belt with respect to the path of travel.

6. The system as in claim 5, wherein

the processor is programmed so that

if the processor associates with the first item information that identifies a first said radio frequency identification tag based on reception of a first number of said first signals while at least a portion of the first item is within the second area, and

if the processor also associates with the second item information that identifies the first radio frequency tag based on reception of a second number of said first signals while at least a portion of the second item is in the second area,

the processor

disassociates the information identifying the first radio frequency identification tag from the first item if the second number is greater than the first number, or

disassociates the information identifying the first radio frequency identification tag from the second item if the first number is greater than the second number, and

thereafter prohibits association of the information identifying the first radio frequency identification tag with items that pass through the second area.

7. The system as in claim 6, wherein the second item next follows the first item in the second area with respect to the path of travel.

8. The system as in claim 5, including a tachometer that operatively engages the belt and outputs third signals corresponding to movement of the belt through the path of travel, wherein the processor tracks each said item with respect to the second area based on the third signals.

9. The system as in claim 5, wherein the predetermined number is two.

10. The system as in claim 6, wherein the processor is programmed compare the first number to the second number when the first item reaches a predetermined position in the path of travel of the belt downstream from the second area.

11. The conveyor system as in claim 10, wherein the second item follows the first item with respect to the path of travel.

12. The system as in claim 5, wherein the processor is programmed so that if the processor associates with the first item any said information from a said first signal received by the processor while at least a portion of the first item is within the second area, the processor does not associate any other said information with the first item where the processor receives the other information while the first item is entirely outside the second area.

13. The system as in claim 5, wherein the processor is programmed to associate information from a said first signal with the first item if the processor receives the first signal from the receiver while at least a portion of the first item is within a predetermined fourth area adjacent the second area and if the processor does not associate with the first item any other said information from a said first signal received while the first item is within the second area.

14. The system as in claim 13, wherein the fourth area is upstream from the second area, with respect to the path of travel.

15. The system as in claim 14, including a plurality of said antennas.

16. The system as in claim 15, wherein the plurality of antennas are disposed with respect to the path of travel so that a plurality of respective said second areas corresponding to the antennas coincide with each other.

17. A conveyor system for processing items on which radio frequency identification tags are disposed, said system comprising:

a frame;

a generally planar belt that is disposed movably on the frame and that conveys items through a path of travel, each item having at least one respective radio frequency identification tag disposed thereon;

at least one antenna disposed proximate the belt so that the antenna

radiates radio frequency signals into a first area proximate the belt and through which the items pass and

receives responses to the radio frequency signals from the respective radio frequency identification tags on the items on the belt, wherein each response includes information that identifies the radio frequency identification tag from which said response is received;

a radio frequency transmitter that drives the antenna to emit the radio frequency signals into the first area;

a radio frequency receiver that receives signals from the antenna corresponding to the responses received by the antenna from the radio frequency identification tags and outputs first signals corresponding to the responses and including the information;

a detector disposed with respect to the belt so that second signals output by the detector indicate presence of the items on the belt; and

a processor that controls the transmitter to drive the antenna and that receives the first signals from the receiver and the second signals from the detector,

wherein the processor is programmed to

responsive to the second signals, track each said item with respect to a second area that includes at least part of the first area, and

associate said information included in a said first signal with a first said item if the processor receives the first signal from the receiver while at least a portion of the first item is within the second area, and

if the processor receives a predetermined number of said first signals while at least a portion of the first item is within the second area, wherein the predetermined number of first signals include first said information identifying the same radio frequency identification tag, thereafter prohibit association of the first information with any second said item that is upstream from the first item on the belt with respect to the path of travel.

18. The system as in claim 17, including a plurality of said antennas that are disposed with respect to the path of travel so that the antennas radiate respective said radio frequency signals into a common area and wherein a common said second area is defined for all of the antennas.

19. The system as in claim 18, wherein the processor is programmed to prohibit association of the first information with the second item that is upstream from the first item with respect to the path of travel if the processor consecutively receives said predetermined number of first signals but to not prohibit association of the first information with the second item if the processor receives a said first signal with information identifying a radio frequency identification tag different from the radio frequency identification tag identified by the first information prior to receiving the predetermined number of first signals.

20. The system as in claim 19, wherein

the processor is programmed so that

if the processor associates with the first item information that identifies a first said radio frequency identification tag based on reception of a first number of first signals while at least a portion of the first item is within the second area, and

if the processor also associates with the second item information that identifies the first radio frequency identification tag based on reception of a second number of first signals while at least a portion of the second item is in the second area,

the processor

disassociates the information identifying the first radio frequency identification tag from the first item if the second number is greater than the first number, or

disassociates the information identifying the first radio frequency identification tag from the second item if the first number is greater than the second number, and

thereafter prohibits association of the information identifying the first radio frequency identification tag with items that pass through the second area.

21. A conveyor system for processing items on which radio frequency identification tags are disposed, said system comprising:

a frame;

a generally planar belt that is disposed movably on the frame and that conveys items through a path of travel, each item having at least one respective radio frequency identification tag disposed thereon;

a plurality of antennas disposed proximate the belt so that the antennas

radiate radio frequency signals into a common first area proximate the belt and through which the items pass and

receive responses to the radio frequency signals from the respective radio frequency identification tags on the items on the belt, wherein each response includes information that identifies the radio frequency identification tag from which said response is received,

wherein the plurality of antennas include

a said first antenna disposed on the frame on a first side of the belt opposite a second side of the belt on which the items are conveyed, so that a gain pattern from the first antenna radiates from the first antenna generally into an area between the frame and the belt to an area on the second side of the belt,

a second said antenna disposed on a third side of the belt laterally offset from the belt with respect to the path of travel,

a third said antenna disposed on a fourth side of the belt laterally offset from the belt opposite the third lateral side, and

a fourth antenna disposed on the frame on the second side of the belt, opposite the first antenna;

at least one radio frequency transmitter that drives the antennas to emit the radio frequency signals into the first area;

at least one radio frequency receiver that receives signals from the antennas corresponding to the responses received by the antennas from the respective radio frequency identification tags and outputs first signals corresponding to the responses and including the information;

a detector disposed with respect to the belt so that second signals output by the detector indicate presence of the items on the belt; and

a processor that controls the at least one transmitter to drive the antennas and that receives the first signals from the at least one receiver and the second signals from the detector,

wherein the processor is programmed to

responsive to the second signals, track each said item with respect to a second area that includes at least part of the first area, and

associate said information included in a said first signal with a first said item if the processor receives the first signal from the at least one receiver while at least a portion of the first item is within the second area, and

if the processor consecutively receives a predetermined number of first signals while at least a portion of the first item is within the second area, wherein the predetermined number of first signals include first said information identifying the same radio frequency identification tag, thereafter prohibit association of the first information with any second said item that is upstream from the first item on the belt with respect to the path of travel unless the processor receives a first signal with information identifying a different radio frequency identification tag prior to receiving the predetermined number of first signals.

22. The system as in claim 21, wherein

the processor is programmed so that

if the processor associates with the first item information that identifies a first radio frequency identification tag based on reception of a first number of said first signals while at least a portion of the first item is within the second area, and

if the processor also associates with a second said item information that identifies the first radio frequency tag based on reception of a second number of said first signals while at least a portion of the second item is in the second area,

the processor

disassociates the information identifying the first radio frequency identification tag from the first item if the second number is greater than the first number, or

disassociates the information identifying the first radio frequency identification tag from the second item if the first number is greater than the second number, and

thereafter prohibits association of the information identifying the first radio frequency identification tag with items that pass through the second area.

23. The system as in claim 21, including a plurality of said radio frequency transmitters, each said radio frequency transmitter driving a respective one of the antennas to emit the radio frequency signals into the first area.

24. The system as in claim 21, including a plurality of said radio frequency receivers, each said radio frequency receiver receiving signals from a respective one of the antennas corresponding to the responses received by the respective antenna from the radio frequency identification tags and outputting said first signals corresponding to the responses and including the information.

25. A method of processing items on each of which at least one respective radio frequency identification tag is disposed, where the items are conveyed through a path of travel by a generally planar belt that is disposed movably on a frame, said method comprising the steps of:

driving at least one antenna disposed proximate the belt so that the antenna

radiates radio frequency signals into a first area proximate the belt and through which the items pass and

receives responses to the radio frequency signals from radio frequency identification tags on the items on the belt, wherein each response includes information that identifies the radio frequency identification tag from which said response is received;

providing a radio frequency receiver that receives signals from the antenna corresponding to the responses received by the antenna from the respective radio frequency identification tags and outputs first signals corresponding to the responses and including the information;

associating said information included in a said first signal with a first said item if the receiver outputs the first signal while at least a portion of the first item is within a second area that includes at least part of the first area; and

if the receiver outputs a predetermined number of said first signals while at least a portion of the first item is within the second area, wherein the predetermined number of first signals include first information identifying the same radio frequency identification tag, thereafter prohibiting association of the first information with any second said item that is upstream from the first item on the belt with respect to the path of travel.

26. The method as in claim 25, including the steps of:

if information associated with the first item identifies a first said radio frequency identification tag based on reception of a first number of said first signals while at least a portion of the first item is within the second area, and

if information associated with a second said item also identifies the first radio frequency tag based on reception of a second number of said first signals while at least a portion of the second item is in the second area,

disassociating the information identifying the first radio frequency identification tag from the first item if the second number is greater than the first number, or

disassociating the information identifying the first radio frequency identification tag from the second item if the first number is greater than the second number, and

thereafter prohibiting association of the information identifying the first radio frequency identification tag with items that pass through the second area.

27. The method as in claim 26, wherein the second item next follows the first item in the second area.