Intelligent station using multiple RF antennae and inventory control system and method incorporating same

• US 20030174099A1
• Filed: 01/09/2003
• Published: 09/18/2003
• Est. Priority Date: 01/09/2002
• Status: Active Grant

• Current Assignee: Sensormatic Electronics LLC (Johnson Controls International plc)
• Original Assignee: Westvaco Corporation (Meadwestvaco Corporation)
• Inventors: Campero, Richard John, Metzler, Steven Paul, Buiel, Edward Raymond, Carpenter, William Joseph, Rasband, Paul Brent, Bauer, Donald George, Nordgren, Richard Eric
• Granted Patent: US 7,084,769 B2
• Time in Patent Office: Days
• US Class Current: 343/893
• 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 19/07767 the first and second communication means being two different antennas types, e.g. dipole and coil type, or two antennas of the same kind but operating at different frequencies
• 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 7/10178 including auxiliary means for focusing, repeating or boosting the electromagnetic interrogation field comparable booster antennas integrated on the record carrier itself G06K19/07794
• 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: G06Q 10/087 Inventory or stock management, e.g. order filling, procurement or balancing against orders
• CPC Class Codes: G07G 1/0045 with a code reader for reading of an identifying code of the article to be registered, e.g. barcode reader or radio-frequency identity [RFID] reader
• CPC Class Codes: G08B 13/2474 Antenna or antenna activator geometry, arrangement or layout loop antennae H01Q1/22
• CPC Class Codes: H01Q 1/2216 used in interrogator/reader equipment
• CPC Class Codes: H01Q 21/28 Combinations of substantially independent non-interacting antenna units or systems multiple beam H01Q25/00
• CPC Class Codes: H01Q 7/00 Loop antennas with a substantially uniform current distribution around the loop and having a directional radiation pattern in a plane perpendicular to the plane of the loop

Abstract

An inventory control system and method that tracks inventories of items with RFID tags, includes a reader unit and an intelligent station that tracks RFID tags to determine item information of items to be inventoried. The reader unit transmits and receives RF signals. The intelligent station includes a first RF antenna connected to the reader unit by a first transmission cable through a first switch, and one or more additional RF antennae connected to the reader unit by the same first transmission cable through additional switches. An inventory control processing unit receives item information from the intelligent stations to update inventory information regarding the items to be inventoried.

Claims

1. An intelligent station that tracks RFID tags, the intelligent station comprising:

a reader unit that transmits and receives RF signals;

a first RF antenna connected to the reader unit by a first transmission cable through a first switch; and

one or more additional RF antennae connected to the reader unit by the same first transmission cable through one or more respective additional switches.

2. The intelligent station according to claim 1, further comprising:

a control unit that is operatively connected to the reader unit and to the first and one or more additional switches, wherein the control unit generates a control signal that selectively operates the first and one or more additional switches.

3. The intelligent station according to claim 1, further comprising:

respective tuning circuits for the first and one or more additional RF antennae each tuning circuit operatively connected to a respective antennae through a switch in communication with the first transmission cable, and further operatively connected to the reader unit through the first transmission cable.

4. The intelligent station according to claim 3, further comprising:

a control unit that is operatively connected to the reader unit and to first and one or more additional switches, wherein the control unit is configured to selectively operate the first and one or more additional switches to connect the tuning circuits to the first and one or more additional RF antennae, respectively.

5. The intelligent station according to claim 1, further comprising:

a second transmission cable that connects the reader unit to one or more auxiliary RF antenna loops, arranged proximate to the first RF antenna and one or more additional RF antennae, respectively.

6. The intelligent station according to claim 1, wherein each of the first and one or more additional switches comprise one of a PIN type diode, a field effect transistor (FET) or a metal-semiconductor FET.

7. The intelligent station according to claim 2, wherein RF and control signals are transmitted along the same first transmission cable.

8. The intelligent station according to claim 2, wherein signals from the control unit to operate the first and one or more additional switches are sent along wiring other than the first transmission cable.

9. An intelligent station system that tracks RFID tags comprising:

a reader unit that transmits and receives RF signals; and

a first intelligent station that comprises;

a first RF antenna connected to the reader unit by a first transmission cable through a first switch; and

one or more additional RF antennae connected to the reader unit by the same first transmission cable through respective one or more additional switches.

10. The intelligent station system according to claim 9, further comprising a control unit that is operatively connected to the reader unit and to the first and one or more additional switches, wherein the control unit generates a control signal that selectively operates the first and one or more additional switches.

11. The intelligent station system according to claim 9, wherein the first intelligent station further comprises a control unit that is operatively connected to the reader unit and to the first and one or more additional switches, wherein the control unit generates a control signal that selectively operates the first and one or more additional switches.

12. The intelligent station system according to claim 11, further comprising:

a second or more additional intelligent stations, each of the second or more additional intelligent stations comprising a secondary control unit that communicates with and is controlled by said control unit.

13. The intelligent station system according to claim 9, wherein said reader unit is arranged on said first intelligent station.

14. The intelligent station system according to claim 9, further comprising:

a control unit that is operatively connected to the reader unit and to the first and one or more additional switches, wherein the control unit generates a control signal that selectively operates the first and one or more additional switches.

15. The intelligent station system according to claim 11, wherein signals from the control unit are routed to distributed secondary control units that in turn operate the first and one or more additional switches.

16. The intelligent station system according to claim 12, wherein the one or more additional associated antennae with associated selector switches are connected in a series arrangement.

17. The intelligent station system according to claim 12, wherein the one or more additional associated antennae with associated selector switches are connected in a parallel-series arrangement.

18. The intelligent station system according to claim 12, wherein the first transmission cable comprises an RF cable, and wherein a bypass switch is provided between the RF cable and an intelligent station to either allow an RF signal to enter the intelligent station, or to prevent an RF signal from the entering the intelligent station.

19. The intelligent station system according to claim 12, wherein the first transmission cable comprises an RF cable, and wherein an inline switch is provided in the RF cable to either allow an RF signal to continue along the RF cable or to prevent the RF signal from continuing along the RF cable.

20. The intelligent station system according to claim 15, wherein signals from the control unit to distributed secondary control units include address information to determine which switches are selected.

21. The intelligent station system according to claim 9, wherein the switches of non-selected antennae alter their associated tuning thus causing them to have a resonant frequency substantially different from the RF signal.

22. The intelligent station system according to claim 21, wherein the switches of non-selected antennae are only used to alter their tuning when the non-selected antennae are adjacent to a selected antenna.

23. The intelligent station system according to claim 9, wherein each antennae are associated with an adjustable tuning circuit that are arranged to be accessible for adjustment.

24. The intelligent station system according to claim 9, further comprising:

a tuning circuit associated with each antenna; and

a tuning adjustment system that automatically performs servo adjustments of variable tuning components, based on feedback information from an associated antenna, said feedback being provided through a conductive electrical connection to the antenna or through communication with the reader unit.

25. The intelligent station system according to claim 9, further comprising:

a tuning circuit associated with each antenna; and

a tuning adjustment system that automatically performs electronic adjustments of variable tuning components, based on feedback information from the associated antenna.

26. The intelligent station system according to claim 25, wherein the variable tuning components comprise one or more voltage controlled capacitors.

27. The intelligent station system according to claim 9, further comprising a tuning adjustment system that automatically performs servo adjustments of variable tuning components, based on feedback information from a reader unit attached to the associated antenna, the feedback information indicative of how the associated antenna is able to read a plurality of RFID tags each positioned uniquely in a predetermined spatial pattern proximate to the associated antenna.

28. The intelligent station system according to claim 9, further comprising:

one or more passive antennae associated with one or more of the RF antennae such that the passive antennae are powered through inductive coupling by the associated RF antennae when the associated RF antennae are powered.

29. The intelligent station system according to claim 28, wherein the passive antennae and the associated RF antennae are provided on a shelf.

30. The intelligent station system according to claim 29, wherein the passive antennae are provided at a back end of the shelf while the associated RF antennae are provided at a front end of the shelf.

31. The intelligent station system according to claim 10, wherein the first intelligent station further comprises a self-test RFID tag within range of each of the RF antennae.

32. The intelligent station system according to claim 31, wherein if any of the RF antennae do not detect the self-test RFID tag, the control unit performs a tuning process for that RF antennae,

wherein if the self-test RFID tag is still not detected after completing of the tuning process, the control unit generates a message to an electronic network.

33. The intelligent station system according to claim 31, wherein each intelligent station comprises at least one self-test RFID tag within range of each RF antenna, and an RF antenna during a testing step detects the self-test RFID tags within adjacent RF antennae and thus determines which other RF antennae or which other intelligent stations are adjacent.

34. The intelligent station system according to claim 33, wherein the adjacency information is used to determine which other RF antennae are to be detuned when an RF antenna is selected for reading.

35. The intelligent station system according to claim 31, wherein the self-test RFID tag is instructed to respond during a self-test and instructed not to respond during normal operation of the system.

36. The intelligent station system according to claim 9, wherein the first intelligent station further comprises:

one or more second RF antennae that operate at frequencies different from the first and one or more additional RF antennae, the one or more second RF antennae connected to the reader unit by the same first transmission cable through respective one or more second switches,

wherein the reader unit is configured to selectively operate at different frequencies.

37. The intelligent station system according to claim 9, wherein the intelligent stations internally contain signal processing circuits to perform at least a part of the signal processing otherwise performed by the reader unit.

38. The intelligent station system according to claim 9, wherein the first transmission cable comprises an RF cable having a RF amplifier device incorporated therein.

39. The intelligent station system according to claim 9, wherein the intelligent station and/or RF antennae are incorporated into doors, portals, floors, floor mats, or ceilings.

40. The intelligent station system according to claim 9, wherein the RF antennae is fabricated by running a conductor through thermoplastic tubing and heat-forming the tubing.

41. The intelligent station system according to claim 26, wherein the voltage controlled capacitors are used to tune or detune the antennae.

42. The intelligent station system according to claim 9, wherein the first transmission cable comprises an RF bus and the reader unit is connected to the RF bus, wherein the intelligent station system further comprises:

a plurality of RF antennae connected at spacings along the RF bus of approximately an integer sub-multiple of a quarter wavelength of the RF signal;

respective select switches that selectably connect each of the RF antennae to the RF bus;

respective shunting switches that selectably connect each of the RF antennae to the RF ground,

wherein each of the RF antennae can be activated on demand by closing its associated select switch to allow RF energy to enter the antenna while at the same time closing a shunting switch that is located a quarter-wavelength further along the RF bus.

43. The intelligent station system according to claim 42, wherein the select switches and the shunting switches comprise PIN diodes or MESFET diodes.

44. The intelligent station system according to claim 42, wherein the RF antennae are connected within the intelligent unit.

45. The intelligent station system according to claim 42, further comprising:

a quarter wavelength of end cable extending beyond the last antenna on the RF bus;

additional addressable shunt switches arranged along the end cable and spaced apart from each other by the same distance as the antennae are spaced apart on the RF bus.

46. The intelligent station system according to claim 42, further comprising:

electronic components, arranged beyond the last antenna on the RF bus, to simulate a quarter wavelength of the RF bus.

47. The intelligent station system according to claim 15, wherein signals from the control unit to distributed secondary control units include information to be output visually or by sound in the immediate vicinity of selected antennae.

48. An intelligent station system that tracks RFID tags comprising:

a reader unit that transmits and receives RF signals;

a first intelligent station comprising;

a first RF antenna connected to the reader unit by a first transmission cable through a first switch;

one or more additional RF antennae connected to the reader unit by the same first transmission cable through respective one or more additional switches,

wherein the antennae are incorporated into structure associated with the intelligent station.

49. The intelligent station system according to claim 48, wherein the intelligent station structure comprises a shelf or panel and an RF-blocking material is applied to an opposite face of the shelf or panel from the face proximate to the antennae.

50. The intelligent,station system according to claim 48, wherein the intelligent station structure further comprises individual shelf or panel units that are interconnected with connectors comprising an RF cable, a data cable, and a power cable.

51. The intelligent station system according to claim 48, wherein the intelligent station structure further comprises individual shelf or panel units that are interconnected with connectors comprising an RF cable carrying RF signals with superimposed direct current (DC) power.

52. The intelligent station system according to claim 48, wherein the intelligent station structure further comprises individual shelf or panel units that are interconnected with connectors comprising an RF cable carrying RF signals with superimposed data other than the RFID signals.

53. The intelligent station system according to claim 48, wherein the intelligent station structure comprises individual shelf or panel units that are interconnected with connectors comprising an RF cable carrying RF signals at the RFID reader frequency with superimposed data in a frequency range other than the RFID reader frequency.

54. The intelligent station system according to claim 52, wherein the superimposed non-RF digital communications are transmitted by varying a superimposed DC voltage.

55. The intelligent station system according to claim 52, wherein the superimposed non-RF digital communications are transmitted by varying a superimposed DC current drain.

56. The intelligent station system according to claim 48, wherein the intelligent station structure comprises a shelf or panel and a non-conductive layer having high magnetic permeability is provided between the antennae and the shelf or panel to increase the magnetic flux for detecting target RFID tags.

57. The intelligent station system according to claim 48, wherein the intelligent station structure comprises shelves, and wherein the intelligent station system further comprises passively coupled antennae that are located in a vertical plane at the end of the shelves or backs of the shelves.

58. The intelligent station system according to claim 48, wherein the intelligent station structure comprises shelves, and wherein the intelligent station system further comprises passively coupled antennae that are located in a horizontal plane at a distance above the shelf.

59. The intelligent station system according to claim 48, wherein the antennae are incorporated into or on a thin and/or flexible mat associated with the intelligent station structure.

60. An intelligent shelf system that tracks RFID tags comprising:

a reader unit that transmits and receives RF signals; and

a first intelligent station that comprises;

a first RF antenna connected to the reader unit by a first transmission cable through a first switch; and

one or more additional RF antennae connected to the reader unit by the same first transmission cable through respective one or more additional switches,

wherein the antennae are incorporated into decorative laminate materials associated with the shelf.

61. The intelligent shelf system according to claim 60, wherein the laminate materials containing antennae are applied to one face of a corrugated paperboard core to form the shelf or a panel for the shelf.

62. An inventory control system that tracks inventories of items with RFID tags, the inventory control system comprising:

a) one or more reader units;

b) one or more intelligent stations each of which is connected to at least one reader unit, each of the intelligent stations tracks RFID tags to determine item information of items to be inventoried, each intelligent station comprising;

a first RF antenna connected to the reader unit by a first transmission cable through a first switch; and

one or more additional RF antennae connected to the reader unit by the same first transmission cable through one or more additional switches, respectively, and

c) an inventory control processing unit, connected to a data store, that receives item information from the intelligent stations to update inventory information regarding the items to be inventoried.

63. The inventory control system according to claim 62, wherein at least one of the intelligent stations is attached on a horizontal surface of a shelf.

64. The inventory control system according to claim 62, wherein at least one of the intelligent stations is on a vertical or angular surface of a shelf.

65. The inventory control system according to claim 62, wherein the intelligent stations are provided on one or more of a shelf, a storage area, a chamber, a room, a warehouse, a trailer, a counter, a safe, a refrigerator, a freezer, or a rack.

66. The inventory control system according to claim 62, wherein the intelligent stations are provided with locking devices for access control, said locking devices controlled by the inventory control system.

67. The inventory control system according to claim 62, wherein the intelligent stations further comprise:

a plug-in bar code scanner to scan bar codes and provide bar coded item information that is correlated and stored with item information determined by the intelligent stations from RFID tags.

68. The inventory control system according to claim 62, wherein the intelligent stations further comprise:

a plug-in global positioning sensor (GPS) to provide information about the location of the intelligent station that is stored with information about items associated with the intelligent station.

69. The inventory control system according to claim 62, further comprising a proximity sensor to detect proximity of a person or an object,

wherein the intelligent stations determine item information or activate auxiliary displays or perform other actions in response to the proximity sensor detecting the presence of a person or an object.

70. The inventory control system according to claim 62, further comprising an environmental sensor to measure temperature, humidity, or light at the intelligent station,

wherein the inventory control system records with a merchandise item information comprising an environmental condition.

71. The inventory control system according to claim 62, wherein one or more antennae are selected in combination for reading.

72. The inventory control system according to claim 62, wherein the removal of a large number of items, when detected by the intelligent stations, causes the inventory control system to generate an alert.

73. The inventory control system according to claim 62, further comprising a customer RFID tag associated with a customer, wherein the inventory control system associates the customer RFID tag with the customer and when detecting the customer RFID tag generates an action responsive to detecting the customer RFID tag.

74. The inventory control system according to claim 62, wherein the inventory control processing unit processes RFID tag activity to generate an alert to adjust staffing levels based on the processed RFID tag activity.

75. The inventory control system according to claim 62, further comprising an employee RFID tag associated with an employee, wherein the inventory control processing unit associates the employee RFID tag with the employee, and when detecting the employee RFID tag generates an action responsive to detecting the employee RFID tag.

76. The inventory control system according to claim 62, wherein the inventory control processing unit processes RFID tag activity to determine an optimal stocking pattern based on the processed RFID tag activity.

77. A method of inventory control for items tagged with RFID tags, the method comprising the steps of:

providing one or more reader units and one or more intelligent stations each of which is connected to at least one reader unit, each of the intelligent stations tracks RFID tags to determine item information of items to be inventoried, each intelligent station comprising;

a first RF antenna connected to the reader unit by a first transmission cable through a first switch; and

one or more additional RF antennae connected to the reader unit by the same first transmission cable through one or more additional switches, respectively;

determining item information of items to be inventoried by selectively energizing the first and one or more additional RF antennae of each of the intelligent stations to determine item information of items that are located on the respective intelligent stations; and

processing the determined item information to update inventory information of the items to be inventoried.

78. The method of inventory control according to claim 77, wherein more than one intelligent station is connected to a reader unit.

79. The method of inventory control according to claim 77, wherein the step of determining item information comprises selectively controlling the first and one or more additional switches to energize the first and one or more additional RF antennae, respectively, and detect item information of items with RFID tags that are within range of the respective energized first and one or more additional RF antennae.

80. The method of inventory control according to claim 77, wherein the step of processing the determined item information comprises updating the determined item information in a data store.

81. The inventory control method according to claim 77, wherein the step of providing one or more intelligent stations further comprises, for each intelligent station, providing a second transmission cable that connects the reader unit to the first and one or more additional RF antennae through first and one or more additional switches, respectively,

wherein the reader unit transmits an unmodulated RF signal to the first and one or more additional RF antennae through the second transmission cable, and transmits a modulated RF signal to the first and one or more additional RF antennae through the first transmission cable.

82. The inventory control method according to claim 81, wherein the step of providing one or more intelligent stations comprises, for each intelligent station, configuring the first and one or more additional switches to operate in one of only three states, a first state that only transmits a modulated RF signal to a respective one of the first or one or more additional RF antennae, a second state that only transmits an unmodulated RF signal to the one of the respective first or one or more additional RF antennae, and a third state such that both the modulated RF signal and the unmodulated RF signal bypass the respective one of the first or one or more additional RF antennae.

83. An inventory control method according to claim 77, further comprising the steps of:

for each reader unit, determining optimal RF power to be provided to read RF antennae connected to that reader unit;

storing the determined optimal RF power for each reader unit in a data storage means; and

using the stored optimal RF power for a reader unit when selectively energizing the RF antennae connected to that reader unit to determine item information of items located on the intelligent stations connected to that reader unit.

84. The inventory control method according to claim 83, wherein the data storage means comprise a look-up table.

85. An intelligent shelf system that tracks RFID tags comprising:

a reader unit that transmits and receives RF signals; and

a first intelligent station that comprises;

a first RF antenna connected to the reader unit by a first transmission cable through a first switch; and

one or more additional RF antennae connected to the reader unit by the same first transmission cable through respective one or more additional switches,

wherein the intelligent station is arranged on a circular rack.

86. The intelligent shelf system according to claim 85, wherein two RF antennae are orthogonally disposed in two vertical planes within the center of the circular rack.

87. The intelligent shelf system according to claim 86, wherein the two RF antennae are connected to the reader unit with the length of the lead-in cables from the reader unit to the two RF antennae differing by {fraction (1/4)} of the RF wavelength.

88. The intelligent shelf system according to claim 86, wherein the two RF antennae are connected through a two-way 90 degree power splitter.

89. The intelligent shelf system according to claim 85, wherein the RF antennae are designed as hangers and are arranged or provided on different portions of the circular rack.

90. An intelligent station system that tracks RFID tags comprising:

two or more reader units that transmit and receive RF signals;

two or more intelligent stations each connected to one of the two or more reader units, the intelligent stations comprising;

a first RF antenna connected to the one of the two or more reader units by a first transmission cable through a first switch; and

one or more additional RF antennae connected to the reader unit by the same first transmission cable through respective one or more additional switches; and

a control unit connected to the two or more reader units,

wherein the control unit transmits command signals to the reader units in different formats that are recognizable by the respective reader units, and the control unit parses received data in different formats from the respective reader units.

91. The intelligent station system according to claim 90, wherein the control unit is connected to an electronic network, and wherein the control unit receives a command signal in common format from the electronic network and translates the received command signal to the different formats recognizable by the respective reader units, and

wherein the control unit translates the received data in different formats from the respective reader units into a common format for transmission to the electronic network.

92. A method of making a radio frequency antenna comprising the steps of:

providing a substrate with grooves for receiving conductors and holes for receiving the end of the conductors, wherein the grooves are formed by molding or stamping;

inserting wire conductors into some or all of the grooves to form loops, dipoles, or other antenna shapes; and

connecting the ends of the wire conductors to electronic circuits to form the radio frequency antenna.

93. The method of claim 92, wherein the grooves and holes are formed in a rectilinear grid pattern that allows a large variety of antenna patterns to be generated on the substrate.

94. The method of claim 92, wherein the grooves and holes are formed in a specific pattern that allows a specific antenna pattern to be generated on the antenna.

95. A method of making a radio frequency antenna comprising the steps of:

providing a fixture having a plurality of holes, said holes arranged to receive pins that define the corners or endpoints of one or more antenna patterns, or to receive the ends of antenna wires;

temporarily attaching a wire to the fixture by inserting wire ends into holes or attaching wire ends to devices that fit over the pins, and wrapping the wire between its ends around other pins to form an antenna shaped wire;

transferring the antenna shaped wire onto a substrate material; and

securing the antenna shaped wire on the substrate material.

96. An apparatus for depositing one or more conductive pathways onto a planar substrate to form foil antennas, comprising the steps of:

a supply source of conductive strip or ribbon material;

an applicator, connected to the supply source, that can be positioned and moved over the plane of the substrate and applies the conductive strip or ribbon material to the substrate; and

a controller that automatically moves and positions the applicator over the substrate and controls the feed of the conductive strip or ribbon material.