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

• US 7,084,769 B2
• Filed: 01/09/2003
• Issued: 08/01/2006
• Est. Priority Date: 01/09/2002
• Status: Active Grant

• Current Assignee: Sensormatic Electronics LLC (Johnson Controls International plc)
• Original Assignee: Vue Technology, Inc. (Johnson Controls International plc)
• Inventors: Metzler, Steven Paul, Campero, Richard John, Buiel, Edward Raymond, Taylor, Mark Albert, Carpenter, William Joseph, Rasband, Paul Brent, Bauer, Donald George, Nordgren, Richard Eric, Wood, Howard E. Jr.
• Primary Examiner(s): Zimmerman, Brian
• Application Number:
  US10/338,892
• Publication Number:
  US 20030174099A1
• Time in Patent Office: 1,300 Days
• Field of Search: 340/539.22, 340/10.1, 340/10.2, 340/10.31, 340/10.4, 340/572.1, 340/572.7, 235/472.02, 342/51, 342/357.11, 455/193.1
• US Class Current: 340/572.7
• 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 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 switches of non-selected antennae alter their associated tuning thus causing them to have a resonant frequency substantially different from the RF signal, and 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.

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

a reader unit that transmits and receives RF signals;

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; and

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;

wherein the first intelligent station further comprises a self-test RFID tag within range of each of the RF antennae;

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; and

wherein the adjacency information is used to determine which other RF antennae are to be detuned when an RF antenna is selected for reading.

3. 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;

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; and

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.

4. 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; and

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;

wherein the data storage means comprise a look-up table.

5. 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;

wherein two RF antennae are orthogonally disposed in two vertical planes within the center of the circular rack.

6. The intelligent shelf system according to claim 5, 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 ¼

of the RF wavelength.

7. The intelligent shelf system according to claim 5, wherein the two RF antennae are connected through a two-way 90 degree power splitter.

8. 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;

wherein the RF antennae are designed as hangers and are arranged or provided on different portions of the circular rack.