# US 2025/0164631 A1 · Method and system for determining the location of an item in a storage system > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2025/0164631 A1 - Document ID: US20250164631A1 - Status: Published application - Kind: A1 - Application number: 18/839,186 - Filed: 2022-02-18 - Published: 2025-05-22 - Earliest claimed: 2022-02-18 - Assignees: Sato Holdings Kabushiki Kaisha - Applicants: Sato Holdings Kabushiki Kaisha - Inventors: Jeff Gray - Web page: https://patentgrep.com/patent/US20250164631A1 ## CPC - G01S 13/758: {using a signal generator powered by the interrogation signal} - G06K 7/10356: {using a plurality of antennas, e.g. configurations including means to resolve interference between the plurality of antennas} - G06K 7/10217: {parameter settings controlling the transmission power of the interrogator} - G06K 7/10297: {arrangements for handling protocols designed for non-contact record carriers such as RFIDs NFCs, e.g. ISO/IEC 14443 and 18092 (cryptographic protocols H04L9/00; network security protocols H04L63/00; real-time communication protocols in data switching networks H04L65/00; network protocols for data switching network services H04L67/00)} - G06K 7/10415: {the interrogation device being fixed in its position, such as an access control device for reading wireless access cards, or a wireless ATM (banking machines in general G07F19/00)} - G01S: RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES - G06K: GRAPHICAL DATA READING (image or video recognition or understanding G06V); PRESENTATION OF DATA; RECORD CARRIERS; HANDLING RECORD CARRIERS ## Abstract A method of determining the location of a plurality of tagged items in a storage system comprises scanning (540) for tags with a first antenna at a plurality of power levels, analysing (560) the scan to identify each tag of interest sighted by the first antenna at each power level of the plurality of power levels, and scanning (540) for tags with at least one further antenna at a plurality of power levels. The method further comprises analysing (560) the further scan to identify each tag of interest sighted by each further antenna at each power level of the plurality of power levels, further analysing (560) the scan to determine the antenna with the lowest power level that identified each tag of interest, and estimating a position (580) of each tag of interest using the determined antenna and the lowest power level that identified that tag. ## Claims ### Claim 1 A method of determining the location of a plurality of tagged items in a storage system, the method comprising: scanning for tags with a first antenna at a plurality of power levels; identifying each tag of interest sighted by the first antenna at each power level of the plurality of power levels; scanning for tags with at least one further antenna at a plurality of power levels; identifying each tag of interest sighted by each further antenna at each power level of the plurality of power levels; determining the antenna with the lowest power level that identified each tag of interest; and estimating a position of each tag of interest using the determined antenna and the lowest power level that identified that tag. ### Claim 2 (depends on 1) The method of determining the location of a plurality of tags in a storage system of claim 1, wherein the step of scanning for tags with a first antenna at a plurality of power levels comprises activating an antenna coil of the first antenna at each of the plurality of power levels and the step of identifying each tag sighted by the first antenna at each power level comprises receiving response signals from at least a portion of the plurality of tags at each power level. ### Claim 3 (depends on 1) The method of claim 1, wherein a field intensity emitted from each antenna varies a predetermined amount according to each power level. ### Claim 4 (depends on 1) The method of claim 1, wherein the power levels are logical power levels that correspond to actual power levels required for predetermined antenna ranges. ### Claim 5 (depends on 1) The method of claim 1, further comprising the step of calibrating the antenna power levels in the storage system. ### Claim 6 (depends on 5) The method of claim 5, wherein the step of calibrating the antenna power levels in the storage system comprises: placing a plurality of calibration tags into the storage system; scanning for the calibration tags with each antenna at a plurality of different power levels; identifying the minimum power level each antenna sights each calibration tag; and setting one or more calibration values for each antenna from the identified minimum power levels. ### Claim 7 (depends on 6) The method of claim 6, wherein the steps of calibrating the antenna power levels in the storage system are repeated with the calibration tags being located at a plurality of different levels within the storage system. ### Claim 8 (depends on 5) The method of claim 5, wherein the step of calibration compensates for antenna coil differences such that each logical power level of each antenna corresponds to substantially the same antenna coil range. ### Claim 9 (depends on 1) The method of claim 1, wherein the tags are set to a lower power mode, that reduces the number of tags in the storage system that are active, prior to scanning for the tags. ### Claim 10 (depends on 1) The method of claim 1, wherein the tags comprise memory and the method further comprises the step of storing a value representative of the power level at which the tag is first sighted. ### Claim 11 (depends on 10) The method of claim 10, wherein the memory is a time stamp field and the value representative of the power level at which the tag is first sighted being stored in the time stamp field is a power level ID. ### Claim 12 (depends on 1) The method of claim 1, wherein the step of estimating a position of each tag of interest using the determined antenna and the lowest power level that identified that tag comprises identifying a height level of the storage system at which the tag is located. ### Claim 13 (depends on 12) The method of claim 12, wherein the step of identifying a height level of the storage system at which the tag of interest is located comprises applying a power level offset that biases antenna power levels towards a lower height level for each height level of the storage system. ### Claim 14 (depends on 13) The method of claim 13, wherein the power level offset is applied to a logical power level for the antenna. ### Claim 15 (depends on 11) The method of claim 11, wherein the step of estimating a position of each tag of interest using the determined antenna and the lowest power level that identified that tag comprises identifying a horizontal position of the tag of interest at the height level of the storage system at which the tag is identified as being located. ### Claim 16 (depends on 15) The method of claim 15, wherein the horizontal position of the tag of interest is determined to be at a distance from the antenna with the lowest power level that identified that tag that corresponds to a range of that antenna at that power level. ### Claim 17 (depends on 1) The method of claim 1, wherein the first antenna and at least one further antennas are located on or in the storage system. ### Claim 18 (depends on 17) The method of claim 17, wherein the storage system comprises height levels and at least some of the height levels comprise at least two overlapping antennas with overlapping coils. ### Claim 19 (depends on 18) The method of claim 18, wherein each of the at least two antennas with overlapping coils comprises a first loop having a first current flow and a second loop having a second current flow in a rotationally opposite direction to the first current flow. ### Claim 20 (depends on 19) The method of claim 19, wherein the overlapping antenna coils of the overlapping antennas are arranged to overlap so that the loops are aligned along an axis, thereby generating a continuous reading zone along that axis. ### Claim 21 (depends on 20) The method of claim 20, wherein the continuous reading zone corresponds to a section of the storage system. ### Claim 22 A system for determining the location of an RFID tagged item located in a storage system configured to contain a plurality of RFID tagged items, the system comprising: a plurality of antenna coils configured to be associated with one or more height levels of the storage system; an antenna controller configured to energise the antenna coils at a power level that corresponds to a received power level signal; and a processor in communication with the antenna controller, the processor configured to: output a plurality of power level signals to the antenna controller to selectively activate each RFID antenna coil at a plurality of different power levels; receive response signals from each antenna coil at each power level; identify each RFID tag sighted in each received response signal; determine the antenna coil with the lowest power level that identified each RFID tag of interest; and estimate a position of at least one RFID tagged item of interest using the determined antenna coil and the lowest power level that identified its tag.