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JP-7855707-B2 - Method and system for locating the position of items in a storage system

JP7855707B2JP 7855707 B2JP7855707 B2JP 7855707B2JP-7855707-B2

Inventors

  • グレイ、ジェフ

Assignees

  • 株式会社サトー

Dates

Publication Date
20260508
Application Date
20220218

Claims (20)

  1. A method for locating multiple tagged articles in a storage system having multiple height levels , The first step involves scanning the tag at multiple power levels using a first antenna, The first antenna identifies each tag of interest found at each of the multiple power levels and records the first tag discovery data . The steps include scanning tags at multiple power levels using at least one additional antenna, The steps include: using each of the additional antennas to identify each tag of interest found at each of the multiple power levels and recording further tag discovery data ; The process includes the step of analyzing the first tag discovery data and the further tag discovery data, and determining the location of each tag of interest by applying a height level bias that favors lower shelves , The first antenna is associated with a first height level of the storage system, The at least one additional antenna is associated with each of the additional height levels of the storage system, A method characterized in that the location of each tag of interest determined includes the height level of the article .
  2. The step of scanning tags at multiple power levels using the first antenna includes the step of activating the antenna coil of the first antenna at each of the multiple power levels. The method according to claim 1, characterized in that the step of identifying each tag of interest found at each of the plurality of power levels using the first antenna includes the step of receiving response signals from at least some of the tags of interest at each of the plurality of power levels.
  3. The method according to 1 or 2, characterized in that the electric field strength radiated from each antenna changes by a predetermined amount according to each power level.
  4. The method according to any one of claims 1 to 3, characterized in that the power level is a logical power level corresponding to the actual power level required for a predetermined antenna range.
  5. The method according to any one of claims 1 to 4, further comprising the step of calibrating the antenna power level within the storage system.
  6. The step of calibrating the antenna power level in the storage system is: The steps include placing multiple calibration tags in the storage system, The steps include scanning calibration tags at multiple different power levels using the aforementioned antennas, The steps include: identifying the minimum power level at which each antenna discovers each calibration tag; The method according to 5, further comprising the step of setting one or more calibration values for each antenna from a specified minimum power level.
  7. The method according to 6, characterized in that the step of calibrating the antenna power level in the storage system is repeated with the calibration tags positioned at multiple different levels within the storage system.
  8. The method according to any one of 5 to 7, wherein the step of calibrating the antenna power levels in the storage system is characterized by compensating for differences in antenna coils so that each logic power level of each antenna corresponds to substantially the same antenna coil range.
  9. The method according to any one of 1 to 8, characterized by including the step of setting the tag to a low-power mode that reduces the number of activated tags in the storage system before scanning the tag.
  10. The aforementioned tag includes memory, The method according to any one of 1 to 9, further comprising the step of storing a value representing the power level that was first detected in the tag.
  11. The aforementioned memory is a timestamp field, The method according to the present invention, characterized in that the value representing the power level at which the tag was first discovered, stored in the timestamp field, is a power level ID.
  12. The step of analyzing the first tag discovery data and the further tag discovery data and determining the location of each tag of interest includes the step of applying a power level offset that offsets the antenna power level to a lower height level with respect to each height level of the storage system, The method according to claim 1 , characterized in that the power level offset increases as the height level increases .
  13. The method according to 12 , characterized in that the power level offset is applied to the logic power level of each of the antennas.
  14. The method according to any one of 11 to 13, wherein the step of estimating the location of each tag of interest using the identified antenna and the minimum power level that identified each tag of interest includes the step of determining the horizontal position of each tag of interest at the height level of the storage system in which the tag is identified.
  15. The method according to 14, characterized in that the horizontal position of each tag of interest is determined to be a position at a distance from the antenna having the minimum power level that identified the tag, and at a distance corresponding to the range of the antenna at the minimum power level.
  16. The method according to any one of 1 to 15 , characterized in that the first antenna and the at least one further antenna are located on or inside the storage system.
  17. The aforementioned storage system has a height level, The method according to 16 , characterized in that at least a portion of the height level has at least two overlapping antennas including overlapping coils.
  18. The method according to 17, characterized in that each of the at least two overlapping antennas including the overlapping coils has a first loop having a first current and a second loop having a second current rotating in the opposite direction to the first current.
  19. The method according to 18 , characterized in that the overlapping coils are arranged to overlap so that the loops are aligned along the axis, thereby generating a continuous reading zone along the axis.
  20. The method according to 19 , characterized in that the continuous reading zone corresponds to a section of the storage system.

Description

This disclosure relates, in general, to locating the location of tags placed within storage cabinets, and more specifically, to a system and method for locating radio frequency identification (RFID) tagged items within multi-shelf cabinets. Radio frequency identification (RFID) is a method of wireless identification. Here, data is stored electronically on a tag, and this data can be read by an RFID reader to identify, locate, and/or track the tagged item. RFID systems do not always provide the precise location of a tagged item; instead, they often provide a general location. For example, if a tagged item is placed inside a cabinet, an RFID reader will often only detect the presence of the tag within the cabinet. In this case, it does not necessarily determine which shelf or drawer the tagged item is located in within the cabinet. An RFID reader operates by generating electrical signals, creating an electromagnetic field that interacts with the antenna coil of an RFID tag to query the tag and retrieve identification information from it. These and other embodiments and features will become apparent to those skilled in the art by considering the following description relating to certain non-limiting embodiments in conjunction with the accompanying drawings. A detailed description of exemplary (non-limiting) embodiments will be better understood by considering them in conjunction with the accompanying drawings. This is a schematic diagram of a non-limiting embodiment of an RFID system. This is a schematic representation of the magnetic field coupling between an RFID antenna and an RFID tag. This is a perspective view of a storage system having multiple shelves and RFID antennas distributed throughout. Figure 1 shows an exemplary, non-limiting embodiment of a cabinet in which an RFID system may be used to locate RFID-tagged items within the cabinet. This is a schematic diagram of the antenna configuration of prior art. This is a flowchart of a non-limiting embodiment of a method for locating the position of items within a storage system. This is a schematic diagram of the multilevel antenna configuration used to detect tags. In drawings, similar reference numerals indicate similar parts. The drawings are not necessarily to scale and may be illustrated with phantom lines, perspective views, and fragmentary diagrams. In certain examples, details not necessary for understanding the non-limiting embodiments, or details that would make it difficult to perceive other details, may be omitted. Next, various non-limiting embodiments of methods and systems for locating articles within a storage system will be described in detail. Other non-limiting embodiments, modifications, and equivalents will be apparent to those skilled in the art in view of the non-limiting embodiments disclosed herein, and these variations should be considered within the scope of the appended claims. Furthermore, it will be recognized by those skilled in the art that certain structural and operational details of the non-limiting embodiments (one or more) described below may be modified or omitted entirely (i.e., are not essential). In other examples, well-known methods, procedures, and components are not described in detail. System Overview Figure 1 is a schematic diagram of a non-limiting embodiment of an RFID reader system 100 for locating items within a section of a storage system. The RFID reader system 100 has an array of antenna coils 102 that communicate with an RFID reader 104. The RFID reader 104 comprises an antenna controller 106 that selectively supplies power to each antenna coil 108 at multiple different power levels, and a processor 110. The processor 110 receives multiple response signals from the array of antenna coils 102. The response signals are generated in response to one or more query signals from the RFID reader 104. In some non-limiting embodiments, the controller and processor may be located in a single shared processing unit. In addition to the antenna controller 106 and processor 110, the RFID reader 104 may include various modules 120 that support the operation of the RFID reader 104. These modules may include one or more of the following: memory 112 (e.g., volatile memory, non-volatile memory, and/or other storage), a communication interface 114 that supports communication between the RFID reader 104 and other devices (e.g., in the form of a network interface controller or other interface hardware), and a user interface 116. The modules 120 of the RFID reader 104 cooperate with each other by exchanging data via the bus 118. The user interface 116 may include, for example, a display means such as a screen and/or touchscreen, along with a keyboard and/or other buttons/levers. The communication interface 114 can communicate with or support communication between the RFID reader 104 and user equipment (not shown). User equipment may include computers, laptops, handheld devices, tablets, smartphones, etc. The user equipment