Article location management system, method and program

Abstract

To provide an article location management system usable in environment which has restriction in installation of an RFID tag in a management region.SOLUTION: A system processing device which configures an article location management system is configured to: process article position management measurement data; calculate the time tp at which the maximum radio wave intensity of a reply RF signal is measured, for each article RF tag; total the reply RF signals from a plurality of address RF tags included in a totaling section which is a range of each predetermined time before and after the time tp; order and record the address RF tags on the basis of the reply RF signal from the address RF tag totaled for each article RF tag; and display article location information which displays a plurality of pieces of information on the address RF tag, with the information indicating the order, on the basis of the order of the address RF tag recorded for each article RF tag.SELECTED DRAWING: Figure 10

Description

[Technical Field]

[0001] The present disclosure relates to a system for grasping and managing the approximate location of an item to be detected, and in particular to a system, method, and program that can display the approximate location of an item in an environment where it is not possible to install a large number of address tags required to identify the location of the item within an area where the location of the item is managed. [Background technology]

[0002] A conventional method for managing items using RFID tags involves attaching an RFID tag to an item to identify it, placing an RFID tag to identify its location within a management area, and using an RFID reader (RFID: Radio Frequency Identification) to receive RF signals from each RFID tag to determine the location of the item.

[0003] For example, in the system described in Patent Document 1, multiple location RFID tags that provide location identification information are placed in appropriate locations on the ceiling of a factory building, and item RFID tags that provide individual identification information for each item are affixed to items to be detected. An RFID reader is then used to read the location RFID tags and item RFID tags, and the location indicated by the location identification information of the location RFID tag that is most sensitively read when reading the item RFID tag of a certain item is displayed as the location of the item. This makes it possible to appropriately manage the locations of items within a factory building. This system requires that location RFID tags be placed in a grid pattern within the building to detect the zones in which items are located within the zone.

[0004] In addition, in the system of Patent Document 2, a position detection RFID tag is placed in each placement area such as a shelf in a store, and an RFID tag for the item is attached to the item placed in the placement area. Then, by reading the signal of each tag with an RFID reader, the placement area is identified from the signal of the position detection RFID tag, and when the RFID tag for the item is measured at that time, the placement area in which the item is placed is identified. This system requires that a position detection RFID tag be placed in each placement area such as a shelf.

[0005] As described above, conventional location management systems using RFID tags require that a location RFID tag for identifying a location within an area be placed in each identification target area. Furthermore, this location management system requires that the location RFID tag placed within the identification target area and the item tag placed within the identification target area be placed in close proximity to each other.

[0006] Patent Document 3 discloses a location management system that can manage the location of an item even when the location of the item and the location RFID tag are some distance apart. This system tallies the number of measurements of the managed item RF tag and the managed location RF tag per unit time, and estimates the location of the location RFID tag that is detected most frequently while the signal of the managed item RF tag is being detected as the location of the item.

[0007] However, since the system of Patent Document 3 estimates the location of an item as the location of a single location RFID tag, it also assumes that location RFID tags are evenly distributed in the area where the items are placed. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Japanese Patent Application Publication No. 2023-94320 [Patent Document 2] Patent No. 6803089 [Patent Document 3] Japanese Patent Application Publication No. 2023-9899 Summary of the Invention [Problem to be solved by the invention]

[0009] The conventional location management systems using RFID tags disclosed in the above Patent Documents 1 and 3 were both based on the premise that location RFID tags would be placed in each partitioned area within the location management area.

[0010] While it would be ideal if location RFID tags could be installed in appropriate locations such as on ceilings or shelves, as in conventional technology, in reality, it is not easy to install RFID tags on ceilings, and it has been difficult to install location RFID tags in a grid pattern within a location management area so that address management can be performed. Therefore, it was not anticipated that this technology would be used in environments where there are restrictions on the installation locations and number of location RFID tags that identify partitioned areas within a location management area.

[0011] For example, in an environment where location RFID tags can only be installed on walls and pillars within a warehouse, it is not possible to place location RFID tags in each partitioned area. Also, items stored away from walls or pillars may not be in close proximity to any location RFID tags. In such an environment, it is not possible to identify the location of an item based on a one-to-one correspondence between the item and the partitioned area. As a result, conventional location management systems using RFID tags are unable to properly manage the location of items. [Means for solving the problem]

[0012] The present disclosure is intended to solve the above-mentioned problems and aims to provide an item location management system, method, and program that enables location management of managed items even in an environment where there are restrictions on the installation of location RFID tags within a managed area.

[0013] The item location management system according to the present disclosure includes at least one item RF tag attached to an item placed within a specified management area, a plurality of address RF tags placed at different locations within the management area, an RFID reader, and a system processing device. The RFID reader is configured to transmit item location management measurement data obtained by measuring return RF signals from the item RF tags and address RF tags within the specified management area to the system processing device. The system processing device is configured to receive the item location management measurement data, process the item location management measurement data, calculate the time tp at which the maximum radio wave strength of the return RF signal was measured for each item RF tag, collect return RF signals from the plurality of address RF tags included in a collection period that is a range of a certain time before and after the time tp, rank and record the address RF tags based on the return RF signals from the address RF tags collected for each item RF tag, and display item location information that displays multiple pieces of information from the address RF tags together with information indicating the rank based on the rank of the address RF tags recorded for each item RF tag. [Effects of the Invention]

[0014] The item location management system of the present disclosure enables item location management even in an environment where there are restrictions on the installation locations and number of location RFID tags that identify partitioned areas within a location management area. Furthermore, in a situation where location address RFID tags cannot be arranged in a grid pattern, the item location management system of the present disclosure allows a user to estimate the location of an item by displaying multiple addresses that serve as a guide for the item location and ranking them. [Brief explanation of the drawings]

[0015] [Figure 1] 1 is a schematic diagram of an item location management system according to an embodiment of the present invention; [Figure 2] FIG. 2 is a block diagram of an RFID reader and a block diagram of a system processing unit. [Figure 3] FIG. 1 is a diagram showing an example of the placement of RF tags in an assumed environment in which an article location management system is used. [Figure 4] 1 is a flowchart outlining the procedure of the first phase. [Figure 5] 10 is a flowchart of a measurement processing procedure for item location management data. [Figure 6] FIG. 10 is a diagram showing time-series data of each RF tag, which is the measurement result of the item location management data. [Figure 7] 10 is a flowchart of an item location management data process. [Figure 8] FIG. 7 is a diagram showing data extracted from the time series data of FIG. 6 around time tp. [Figure 9] 10 is a flowchart showing the procedure of an item location search process in the item location management system as a second phase. [Figure 10] 10 is a display example of item location information. [Figure 11] FIG. 1 is a schematic diagram of an RF tag used in the examples. [Figure 12] FIG. 1 is a diagram illustrating a usage environment of an embodiment. [Figure 13] FIG. 10 is a diagram showing item location management measurement data measured in the example. [Figure 14] 10 is a diagram showing time-series data of radio field intensity of return RF signals from the item RF tag 20 and each of the address RF tags 60 to 66 of the item location management measurement data in the embodiment. FIG. [Figure 15] 10 is a diagram showing time-series data of radio field intensity of return RF signals from the item RF tag 21 and each of the address RF tags 60 to 66 of the item location management measurement data in the embodiment. FIG. [Figure 16] 10 is a diagram showing time-series data of radio field intensity of return RF signals from the item RF tag 22 and each of the address RF tags 60 to 66 of the item location management measurement data in the embodiment. FIG. [Figure 17] 10 is a diagram showing time-series data of radio field intensity of return RF signals from the item RF tag 23 and each of the address RF tags 60 to 66 of the item location management measurement data in the embodiment. FIG. [Figure 18] FIG. 10 is a diagram showing a first display mode of the item location information of each item RF tag. [Figure 19]FIG. 10 is a diagram showing a second display mode of the item location information of each item RF tag. [Figure 20] FIG. 10 is a diagram showing a third display mode of the item location information of each item RF tag. DETAILED DESCRIPTION OF THE INVENTION

[0016] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. Note that the following description is an example, and some configurations may be changed without departing from the gist of the present disclosure. The same or similar reference numerals indicate the same or similar elements, and repeated explanations may be omitted. Numerical values ​​in the following description are examples, and other numerical values ​​may be used in the present disclosure without departing from the gist of the present disclosure.

[0017] First, an overview of the item location management system according to the present disclosure will be described. Fig. 1 is a schematic diagram of the item location management system according to the present disclosure. The item location management system 100 according to the present disclosure comprises a plurality of RFID tags 110, an RFID reader 120, and a system processing device 130. The RFID tags 110 are used as address RF tags for location and as item RF tags for affixing to items.

[0018] (RFID tag) The RFID tag 110 includes an antenna and an IC chip, and is configured to be able to communicate with an RFID reader through non-contact communication using RF signals.

[0019] In this embodiment, a passive RFID tag that does not have a power source for communication is used as an RFID tag that utilizes radio waves in the vicinity of 920 MHz included in the UHF (Ultra High Frequency) band.

[0020] The IC chip of an RFID tag contains memory and pre-recorded unique identification information for individually identifying the RFID tag. When the antenna receives a call signal from an RFID reader, the RFID tag responds to the call signal by encoding the unique identification information and transmitting it as an RF signal.

[0021] In this embodiment, the RFID tag 110 is used as an address RF tag for location and an item RF tag attached to an item, but the address RF tag and item RF tag may be tags with different specifications.

[0022] In this embodiment, the RF signal used for communication between the RFID reader 120 and the RFID tag 110 has a frequency of, for example, about 920 MHz included in the UHF (Ultra High Frequency) band. The RF signal used for communication between the RFID tag and the RFID reader may have a frequency other than the UHF band, for example, a frequency of about 2.45 GHz included in the microwave band.

[0023] The RFID tag may be an active type equipped with a power source for communication, or may be a semi-active type.

[0024] (RFID reader) The RFID reader 120 performs wireless communication using RF signals with each RFID tag 110 used as an address RF tag and an item RF tag. Specifically, the RFID reader transmits a call RF signal and receives a return RF signal from an RFID tag that responds to the call RF signal within a predetermined distance from the RFID reader. The RFID reader can also communicate with the system processing device 130 wirelessly or via a wired connection to exchange data.

[0025] The RFID reader 120 used in this embodiment measures the RFID tag when the operator operates the operation trigger 121 to turn it on.

[0026] FIG. 2 is a block diagram showing a schematic configuration of the RFID reader 120 and the system processing device 130. As shown in FIG.

[0027] The RFID reader 120 includes an antenna 210 , a control unit 211 , a communication unit 212 , an operation unit 213 , a display unit 214 , and a storage unit 215 .

[0028] The antenna 210 transmits an interrogating RF signal to the RFID tag 110 and receives a transmitted return RF signal from the RFID tag 110 .

[0029] The operation unit 213 is a part for performing operations such as starting and ending radio wave transmission and reception of the RFID reader 120, and includes the operation trigger 121 of the RFID reader 120 in this embodiment.

[0030] The display unit 214 is a liquid crystal screen that displays information about the radio wave transmission / reception status of the RFID reader 120. This display unit may be an image display means other than a liquid crystal screen, or may be an information display means such as an LED lamp. It may also be one that presents information using an audio signal such as a buzzer.

[0031] The control unit 211 is configured to control the RFID reader. For example, the control unit 211 controls the communication unit 212 to transmit and receive radio waves via the antenna 210, performs control in response to operation instructions from the operation unit 213, and displays on the display unit 214 in response to the status of radio wave transmission and reception. The control unit 211 also controls the communication unit 212 to control the RFID reader based on a signal transmitted from the system processing device 130. Note that the RFID reader can also be controlled based on a signal transmitted from an external device other than the system processing device 130.

[0032] The communication unit 212 is controlled by the control unit 211, and can transmit and receive signals to and from the RFID tag 110 via an antenna using a predetermined frequency, for example, an RF signal in the UHF band. The communication unit 212 can also transmit and receive signals to and from the system processing device 130.

[0033] The communication unit 212 transmits a call RF signal via the antenna in response to a measurement instruction from the operation unit 213, and receives a reply RF signal containing unique identification information from the RFID tag that received the call RF signal. The communication unit 212 decodes the unique identification information contained in the reply RF signal from the RFID tag 110 and writes it to the storage unit 215.

[0034] The storage unit 215 stores programs executed by the processor included in the control unit 211. In addition to the programs, various types of information used by the RFID reader are also stored. For example, the storage unit 215 temporarily stores information such as the signal reception time and decoded unique identification information as return RF reception information from the RFID reader.

[0035] The communication unit 212 also communicates with the system processing device 130. For example, the communication unit 212 transmits item location management measurement data including the return RF reception information temporarily stored in the storage unit 214 to the system processing device. The communication with the system processing device 130 can use existing wireless communication, but it is desirable to adopt a communication method using a frequency band different from the frequency used with the RFID tag. For example, the communication can be performed using a short-range wireless communication standard such as WiFi (registered trademark) or Bluetooth (registered trademark). It can also be performed using other communication standards or wired communication. The communication unit 212 may be configured as a first communication unit that communicates with the RFID tag and a second communication unit that communicates with the system processing device.

[0036] (System Processing Unit) The system processing device 130 is an information processing device configured to be able to communicate with the RFID reader 120. The system processing device 130 may be, for example, a smartphone with an item location management application installed. Alternatively, the system processing device 130 may be a personal computer, a tablet terminal, or other device.

[0037] The system processing device 130 executes processes such as data generation processing for estimating the location of the item RF tag, and database creation processing for the placement position of each address RF tag and item information corresponding to each item RF tag.

[0038] 2 shows a schematic configuration of the system processing device 130. The system processing device 130 includes an information processing unit 220, a communication unit 221, a display unit 222, an operation unit 223, and a storage unit 224.

[0039] The information processing unit 220 controls the system processing device and performs various information processing.

[0040] The information processing unit 220 performs processes such as item location management data processing, which processes item location management measurement data received from the RFID reader to generate item location management information, and item location search processing based on the item location management information. It also performs operation result feedback processing to the user who operates the system processing device for item location management.

[0041] The communication unit 221 communicates with the RFID reader 120. The communication unit 221 receives item location management measurement data including return RF reception information transmitted from the RFID reader. The communication unit 221 also transmits operation instructions to the RFID reader. As described above, existing wireless communication can be used for communication between the RFID reader 120 and the system processing device 130, but it is desirable to employ a communication method using a frequency band different from the frequency used with the RFID tag.

[0042] The display unit 222 is a screen display means such as an LCD screen that displays various information. For example, it is configured to display the measurement status and operation status of RFID tags by the RFID reader 120, item location information, etc. This display unit may be an image display means other than an LCD screen, or an information display means such as an LED lamp. It may also present information using an audio signal such as a buzzer. When a personal computer, smartphone, tablet, etc. is used as the system processing device, the LCD monitor portion of such a device may be used.

[0043] The operation unit 223 is, for example, a device such as a keyboard, buttons, a touch panel, or a mouse, and receives user operations and provides the information processing unit 220 with information about the received user operations.

[0044] The storage unit 224 stores programs executed by the processor included in the information processing unit. For example, it stores programs for executing item location management data processing and item location search processing, as well as programs for controlling the operation unit, display unit, communication unit, etc. In addition to the programs, it also stores various information used by the system processing device. For example, the storage unit stores reply RF reception data transmitted from RFID, information associating the identification number of an address RF tag with the address where the address RF tag is installed, and information associating the identification number of an item RF tag with the name of the item, etc. In addition, item location management information generated using this information is registered as an item location management database.

[0045] (RFID tag placement) Figure 3 is a diagram showing the arrangement of RFID tags in an assumed usage environment of an item location management system. The arrangement shown in Figure 3(a) assumes a management area for managing items, such as a warehouse, as the usage environment of the item location management system. Items to be managed are stored in the management area 300, and each item has an item RF tag affixed to it, which is an RFID tag for identifying the item.

[0046] In addition, address RF tags, which are location RFID tags, are installed on the boundaries of the managed area, such as on walls and pillars, to indicate specific locations within the managed area.

[0047] In this example, for simplicity of explanation, the usage environment is such that only one item with an item RF tag 1 affixed thereto is placed at position 320, and five address RF tags 1 to 5 are placed at positions shown as 331 to 335 in the figure. In this embodiment, it is assumed that the usage environment of the item location management system has restrictions on the number and installation positions of address RF tags, and that the item RF tag and the address RF tag are not necessarily close to each other.

[0048] As described above, each RFID tag includes an IC chip equipped with storage means, and the storage means stores unique identification information. In the system processing device, each RFID tag is stored in association with its unique identification information, as shown in Table 1. Information on the item RF tag 1, information on the item to which the item RF tag 1 is attached (item name and item management number), each address RF tag, and location information where those address RF tags are located (such as address numbers) are input and stored in the system processing device according to the location of the address RF tags in the management area and the items being managed.

[0049] The information shown in Table 1 is merely an example, and the tag name and item management number may be any number. For example, the item management number may be the item name or item ID. The tag's unique identification number does not have to be a number, as long as it is information that allows each tag to be identified. Furthermore, the placement location of the address RF tag may use location information such as latitude and longitude in addition to a predetermined address number, or a unique name assigned to the management area may be used.

[0050] [Table 1]

[0051] Next, a procedure for managing the location of items using the item location management system in the example arrangement of FIG. 3 will be described. The procedure of this embodiment can be broadly divided into two phases: "item location management data acquisition processing" and "item location search processing." In the following description, the two phases are performed separately, but the two phases can also be performed simultaneously.

[0052] In the item location management system of this embodiment, the first phase is an "item location management data acquisition process." In this process, item location management data is measured in advance, and the item location management measurement data is processed to create an item location management database used to identify the location of items to which item RF tags are affixed that are placed in a management area where address RF tags are installed. Then, in the second phase, an "item location search process" is performed using the item location management database that has been created in advance.

[0053] FIG. 4 is a flowchart showing the procedure of the item location management data acquisition process in the first phase.

[0054] In the first phase, first, an RFID reader is used to measure the item location management data (step 401), and then the system processing device processes the item location management measurement data (step 402).

[0055] (Measurement of item location management data) In order to estimate the location of an item, it is necessary to measure the item location management data in advance using an RFID reader and obtain the item location management measurement data.

[0056] This measurement of item location management data (step 401) is performed by a measurer holding an RFID reader 120 and moving along the measurement route shown in the figure from the measurement start point 341 to the measurement end point 342 within the management area 300 where the address RF tags are placed, while measuring signals from each RFID tag.

[0057] FIG. 5 is a flowchart showing the procedure for measuring this item location management data.

[0058] The measurer stands at the measurement start point, holds the RFID reader 120 over the management area 300 where the address RF tags and item RF tags are located, pulls the operation trigger 121 of the RFID reader 120, and starts measuring the item location management data (step 501).

[0059] Next, with the RFID reader pointed at the controlled area, the person walks along the measurement route and measures the return RF signals from each RFID tag.

[0060] From the time the measurer issues a measurement start instruction operation until the time the measurer issues a measurement end instruction operation, the RFID reader repeatedly transmits a call RF signal (step 502), receives a reply RF signal from the RF tag (step 503), and records the received RF signal (step 504). At this time, the measurement time of each received RF signal is also recorded as a timestamp.

[0061] Then, at the measurement end point, the operation trigger of the RFID reader is released, and the measurement ends (step 505).

[0062] The received data of the return RF signal obtained by this measurement is transmitted to the system processing device as item location management measurement data (step 506).

[0063] When measuring the item location management data, it is possible that the user's measurement route is far from the address RF tag, and the RFID reader's call RF signal may not reach it.

[0064] To prepare for such cases, for example, a function may be provided in which measurement thresholds are set for the number of measurements of the address RF tag when measurements are performed normally, the radio wave strength, the maximum radio wave strength, etc., and if the measurement result falls below these thresholds, the person taking the measurement may be notified that the measurement is inappropriate.If the measurement is inappropriate, a message may be displayed on the display unit of the RFID reader or the display unit of the system processing device to urge the person taking the measurement to take it again.

[0065] Furthermore, as measurements of item location management data are repeated in a specific usage environment, the measurement route and walking direction become more or less fixed, and in that case, the order in which the maximum radio wave strength of the return RF signal from the address RF tag is obtained also becomes more or less fixed. Therefore, it is possible to determine whether the measurement is being performed along the fixed measurement route based on the order in which the maximum radio wave strength, etc. of the address RF tag is received, and if the measurement route is different, to notify the person taking the measurement.

[0066] (Item location management data processing) As described above, information on the item RF tags and address RF tags is registered in advance in the system processing device. Using this registration information, the system processing device identifies and records which RF tag each reply RF signal comes from, based on the unique identification information included in the received data of each reply RF signal of the item location management measurement data.

[0067] An example of a reply RF signal recorded in this way is shown in Figure 6. Figure 6 is a graph in which the horizontal axis represents the time from the start to the end of item location management data measurement, and the vertical axis represents the radio wave strength of the reply RF signal from each RFID tag.

[0068] The graph in Fig. 6 is a plot of the radio wave strength of the reply RF signal from each RF tag at each time, based on the reply RF signal returned by each RF tag included in the item location management measurement data transmitted from the RFID reader and the time recorded as a timestamp. Note that in the graph in Fig. 6, the transition of each radio wave strength is depicted with a continuous line, but in reality, the timing at which the reply RF signal is received from each RF tag is irregular, so the data is not acquired at equal intervals on the horizontal time axis, resulting in uneven data.

[0069] FIG. 6 shows the received strength of the reply RF signal from the article RF tag 1 and the reply RF signals from the address RF tags 1 to 5 in chronological order.

[0070] For simplicity of explanation, Figure 3 shows an example of an arrangement in which one item with an item RF tag attached is placed, but multiple item RF tags (i.e., items whose locations are managed) may be placed, in which case time series data of the return RF signal strength of each item RF tag will be added to the data in Figure 6.

[0071] 3, for example, the measurement start point 341 is closest to the location 331 of the address RF tag 1, and as the measurer carrying the RFID reader moves along the measurement route, he or she gradually moves away from location 331. Therefore, the radio wave strength of the reply RF signal from the address RF tag 1 is high at the start of measurement and gradually decreases over time.

[0072] FIG. 7 is a flowchart showing the procedure of the item location management data processing 402.

[0073] 3, which is the assumed usage environment of the item location management system of this embodiment, there are limitations on the number and installation locations of address RF tags, and it is assumed that there will be situations in which the item RF tags and address RF tags are not necessarily close to each other. In such an environment, if the location of an item is determined using the data of FIG. 6 by the conventional method, for example, the location of address RF tag 3, which has the strongest return RF signal at the time when the return RF signal strength of item RF tag 1 is strongest, will be determined to be the item location.

[0074] The item location management data processing of this embodiment creates an item location management database that enables the appropriate display of item locations even in usage environments where there are limitations on the number and installation locations of address RF tags, and where the item RF tags and address RF tags are not necessarily close to each other.

[0075] This item location management data processing is based on the idea that an address RF tag whose return RF signal is measured around the time when the return RF signal from the item RF tag reaches its maximum radio wave strength is located in the vicinity of the item RF tag and can serve as an index for locating the item RF tag.

[0076] Based on this concept, the system ranks address RF tags in order of their proximity to the item, and displays multiple addresses that can serve as indicators for locating the item.

[0077] The specific steps of processing the item location management data will be described below with reference to the flowchart of FIG.

[0078] Step 701 is a process for generating time-series data for each item RF tag and address RF tag based on the timestamp included in the received data of the return RF signal for each item location management measurement data obtained by the item location management data measurement process using an RFID reader. This step 701 generates the data shown in FIG.

[0079] In step 702, the time tp of maximum radio wave intensity is calculated from the time series data of the radio wave intensity of the reply RF signal from the article RF tag 1 in FIG.

[0080] In step 703, a certain period of time before and after the time tp is set as a counting period for the address RF tag, and the return RF signals from the address RF tag measured during the counting period are counted.

[0081] Fig. 8 shows the time series data of Fig. 6, taken around time tp. In Fig. 8, time tp-α, which is α hours before time tp, and time tp+β, which is β hours after time tp, are set as fixed periods before and after time tp, and the interval from time tp-α to time tp+β is set as the counting window. In step 703, information on the reply RF signals from address RF tags present within the counting window is tallied for each address RF tag. In this embodiment, the counting results include the number of times the reply RF signal from each address RF tag was measured during the counting window, and the maximum radio wave intensity (dBm: decibel milliwatts) of the reply RF signals measured during the counting window.

[0082] Note that Figure 6 shows an example in which only one time tp, the time at which the maximum radio wave strength is detected, is calculated. Depending on the measurement conditions, the reply RF signal from the item RF tag may be measured at the maximum radio wave strength multiple times at different times. In this case, a certain period of time before and after the time at which each maximum radio wave strength is detected is set as the counting period.

[0083] Step 704 is a process performed when multiple times tp at which the reply RF signal from the item RF tag reaches its maximum radio wave intensity are calculated. As described above, in this case, multiple counting windows are set. If these multiple counting windows overlap on the time axis, RF tag information with the same address will be counted multiple times in each counting window. To prevent duplicate counting, step 704 deletes the received reply RF signal data that has been counted multiple times so that data with overlapping measurement times in the timestamps of reply RF signals counted in each counting window is counted only once.

[0084] In step 705, the counted RF tags for each address are ranked. In this embodiment, the maximum radio wave strength of the reply RF signals detected within the counting time period for each address RF tag is compared, and the tags are sorted in descending order to rank them. Note that if the maximum radio wave strengths are the same, the tag with the greater number of measurements may be ranked higher. Also, if the maximum radio wave strengths and the number of measurements are the same, the tags may be ranked the same.

[0085] Table 2 is an example of the results of ranking the address RF tags generated by the item location management data processing. By using the ranking of the results of the aggregation in Table 2, it can be determined that the address RF tag 3, address RF tag 2, address RF tag 1, and address RF tag 4 are located near the location of item RF tag 1, in order of proximity.

[0086] [Table 2] In step 706, the tabulation results of Table 2 generated by steps 702 to 705 are stored in the memory unit of the system processing device together with a representative timestamp of this time-series data as item location management data for the item to which the item RF tag 1 is attached, thereby forming an item location management database. In this embodiment, the representative timestamp is the measurement start time of the location management data used for tabulation (the earliest timestamp attached to the reply RF signal included in the location management data), but the measurement end time may also be used as the representative timestamp. Since the representative timestamp only needs to distinguish which of the time-series data obtained for each location management data measurement process represents the tabulation result, it may be any time between the measurement start time and the measurement end time as long as the location management data measurement process is not performed at the same time. Furthermore, if the location management data measurement process is used in a form where it is performed only once a day, the representative timestamp may be the measurement date.

[0087] In this embodiment, for simplicity of explanation, there is only one item RF tag, and therefore the flowchart in Fig. 7 is executed only once. In contrast, in actual use of the item location management system, it is assumed that there will be multiple items to which item RF tags are affixed. When there are multiple items, the above steps 702 to 706 are repeated for each item RF tag, and multiple item location management data for each item RF tag are registered in the item location management database.

[0088] By registering the item location management data in the item location management database, the item location management data processing 402 is completed, and the first phase of the advance item location management data acquisition work is completed.

[0089] (Search for the location of items) Next, a method for searching for the location of an item will be described. Fig. 9 is a flowchart of an item location search process when a user searches for the location of an item using the item location management system of the present disclosure as the second phase.

[0090] The user inputs the identification information of the item whose location he / she wishes to know, for example, the item control number in Table 1 in this embodiment, into the system processing device (step 901).

[0091] In step 902, the item location management data for the item RF tag corresponding to the input item identification information is read from the item location management database.

[0092] In step 903, the system processing device presents information on multiple address RF tags near the items as item location information based on the ranking of the address RF tag counting results. As will be described later, this item location information may be presented by displaying the address numbers of the locations where the address RF tags are located, or by displaying a map showing the locations of the address RF tags in the management area and distinguishing the address locations on the map display with the highest rankings.

[0093] FIG. 10 shows an example of a display mode in which item location information is displayed on the display unit of the system processing device when the user performs a location search for item 1.

[0094] As shown in Table 2, the item location management data for item 1 is ranked in the order of Address RF tag 3, Address RF tag 2, and Address RF tag 1. Therefore, in the display example of Fig. 10, multiple addresses of Address RF tags located near the location of item 1 are displayed, with Address 3, Address 2, and Address 1 being the highest ranked.

[0095] 10, address 4, which was ranked fourth in the item location management data in Table 2, is not displayed. However, the number of addresses to be displayed may be set appropriately depending on the size of the management area 300 and the number of address RF tags placed. Address RF tags whose maximum radio wave intensity of the reply RF signal is below a predetermined threshold may be excluded from the display.

[0096] 10, an example of the display of item location information shows a diagram of the placement of RFID tags in the management area 300, along with the address numbers indicating the locations where the RF tags are placed. In this example, the content of the information (ranking, maximum radio wave strength, etc.) of the tabulation results in Table 2 for the displayed address numbers is visualized and displayed as a circle.

[0097] In the display example of Figure 10, the radius of the circle shown at each address is proportional to the maximum radio wave strength, based on the information in Table 2. The color density within the circle is drawn to become darker in proportion to the number of measurements. (Note that details of this display mode will be described later.) In other words, the size of the circle centered on the address position and the color density within the circle are used to display information about the ranking of the address.

[0098] Therefore, the largest and darkest circle within the management area is drawn for Address 3, which corresponds to Address RF Tag 3, and is represented as being closest to the location of Item 1. Additionally, Address 2, which is ranked second in the evaluation ranking, is drawn with a lighter circle with a slightly smaller radius than Address 3.

[0099] The user searches for item 1 in the management area 300 in Figure 3, referring to the display of item location information in Figure 10. At this time, the user does not know the exact location of item 1, but since the user predicts that the item's location is closest to Address 3, followed by Address 2 and Address 1, the user can guess that they should search around Address 2 and Address 1, centering on Address 3.

[0100] In this way, the item location management system of this embodiment makes it possible to present information that can serve as a guide for the user to find the location of item 1 in a usage environment where there are limitations on the number and installation locations of address RF tags and where the item RF tag and the address RF tag are not necessarily close to each other.

[0101] In the location management data processing in the first phase of this embodiment, as described above, in the ranking of address RF tags in step 705, the maximum radio wave strength of the reply RF signal from each address RF tag and the number of measurements are used as factors for determining the ranking, but this is not limiting. For example, factors that can be extracted from time-series data, such as the minimum radio wave strength, average and variance of the radio wave strength of the reply RF signal from each address RF tag, or the density of measurement points within the counting time period, may also be used as factors for determining the ranking.

[0102] Specifically, for example, if the maximum radio wave strengths of the address RF tags of a certain item RF tag are the same in the aggregation results, the ranking may take into account the high number of weak radio wave strength measurements, the average value and variance of the measured radio wave strengths, etc. Another possible approach is to compare the minimum radio wave strengths and rank the tag with the higher value higher. Furthermore, if the density of measurement points within the aggregation period is extremely lower than that of other address RF tags, there is a possibility of false detection (environmental reflection), so the tag may be excluded from the candidate address RF tags.

[0103] In this embodiment, the presentation of item location information based on the results of a single location management data measurement has been described as an example. The item location management using the item location management system of the present disclosure is used, for example, to manage the location of wooden molds and dies in a warehouse where these are stored in a factory. In such a usage scenario, wooden molds and dies are routinely transported in and out of the warehouse, so the location of the items changes daily. Therefore, when used in such an environment, location management data is measured daily, and the aggregated results of processing this location management data are accumulated and updated in an item location management database along with timestamps such as the measurement start time and measurement date.

[0104] In this way, by accumulating the counting results daily, it becomes possible to search and check not only the latest location information of the managed item, but also past location information. Therefore, if the presented location information of the item is incorrect due to an error during measurement, etc., item location information based on past counting results can be presented, and the location of the item can be estimated and found based on that. [Example]

[0105] Next, an example in which the item location management system of the present disclosure is applied to an environment that simulates an actual usage environment will be described.

[0106] In this example, the item RF tags were not actual items, but rather a number of RF tags shown in Fig. 11 attached at a height of 90 cm from the floor were prepared. Similarly, the address RF tags used were those shown in Fig. 10. In this example, the same type of RF tags were used for the item RF tags and address RF tags, and they were arranged as shown in Fig. 12.

[0107] The usage environment of this embodiment is shown in FIG. 12. The management area 1200 of this embodiment is a rectangular area measuring 200 cm x 600 cm. Address RF tags (60, 61, 62, 63, 64, 65, 66) are placed at seven locations, namely, addresses A60, A61, A62, 63, A64, A65, and A66, along area boundaries 1210 to 1230, which serve as the wall positions of the management area 1200. It is also assumed that there is no wall on one long side of this management area 1200, making it impossible to install address RF tags. In this embodiment, if A60 is set as the origin in the upper left corner of the figure, adjacent address RF tags are placed 150 cm apart. Furthermore, as articles, article RF tags (20, 21, 22, 23) are placed at four locations as shown in the figure.

[0108] Item 20 (item RF tag 20) is placed 75 cm to the right and 75 cm to the left of address RF tag 60 of address A60. Items 21, 22, and 23 (item RF tags 21, 22, and 23) are placed at 150 cm intervals from item 20. The item RF tags and address RF tags are placed so that the person taking the measurements is facing forward.

[0109] The measurement start point 1241 was set at a position 200 cm away from A60, and the measurement end point 1242 was set at a position 200 cm away from A64.

[0110] In this example, the RFID reader 120, the system processing device 130, and the RF tags are the same as those described in the embodiment.

[0111] When measuring the location management data, the measurer held the RFID reader 120 in his / her hand and maintained the center of the RFID reader antenna at a height of approximately 90 cm from the floor. In this example, to minimize measurement errors, the RFID reader 120 was held perpendicular to the line connecting the address RF tag 60 and the address RF tag 64 while measuring the location management data. In this example, as with the measurement of location management data in the above-described embodiment, the measurer starts measuring the location management data by pressing the operation trigger 121 of the RFID reader. After starting the measurement, the measurer moves the RFID reader while maintaining its orientation until the measurement end point, at which point the measurer releases the trigger to end the measurement.

[0112] Fig. 13 is a diagram of the location management measurement data measured in this embodiment. As described above, the system processing device 130 processes the location management measurement data transmitted from the RFID reader, and generates time-series data of the radio wave strength of the return RF signal for each RFID tag. Fig. 13 shows the time-series data of the radio wave strength of the return RF signal for all RF tags (four item tags and seven address tags).

[0113] In Figure 13, as in Figure 6, the horizontal axis of each graph represents the measurement time, and the vertical axis represents the radio wave strength [dBm] of the received RF signal. Note that in Figure 13, the origin of the horizontal axis is set to 0, which is the time when the RF tag's radio wave was first received after the start of measurement, and the elapsed time measured thereafter is displayed.

[0114] Figures 14 to 17 show graphs of time-series data of the radio wave intensity of the reply RF signals from a specific item RF tag and seven address RF tags, among the data in Figure 13. Figure 14 shows the time-series data for item RF tag 20, Figure 15 shows the time-series data for item RF tag 21, Figure 16 shows the time-series data for item RF tag 22, and Figure 17 shows the time-series data for item RF tag 23.

[0115] The system processing device 130 executes the item location management data processing described in FIG. 7 for each piece of time-series data to calculate the reception time tp of the maximum radio wave strength for each item RF tag. A certain period of time before and after the calculated time tp is then set as a counting block, and the reply RF signals from the address RF tags within that counting block are tallied for each address RF tag. In this embodiment, the address RF tags are ranked based on the maximum radio wave strength and the number of measurements in the counting results. As described above, the ranking of the address RF tags may incorporate factors that can be extracted from the time-series data, such as the minimum radio wave strength, average and variance of the radio wave strength of the reply RF signals from each address RF tag, or the density of measurement points within the counting block.

[0116] Using FIG. 14 as an example, the article location management data processing based on the time-series data of the article RF tag 20 in the embodiment will be described.

[0117] 7 is executed to calculate the maximum radio wave intensity of the RF tag 20 from the time series data. In the time series data of FIG. 14, the maximum radio wave intensity is −46 [dBm].

[0118] In this embodiment, the time when the maximum radio wave strength is -46 [dBm] is used as the base time, and a period of 1 second (α=β=1 second) before and after that time is set as the counting period for the address RF tag.

[0119] In Fig. 14, the maximum radio wave strength of the article RF tag 20 was measured at three locations, 1401, 1402, and 1403, so three time windows (1411, 1412, and 1413 in Fig. 14) of one second each before and after the times tp1, tp2, and tp3 at which the maximum radio wave strength was detected at these three locations are set as three time windows. In Fig. 14, these three time windows overlap with each other, so step 704 in Fig. 7 is executed, and data from address RF tags with overlapping times collected within each window is deleted before being counted so that only one data item is counted.

[0120] Next, step 705 in FIG. 7 is executed to rank the address RF tags based on the maximum radio wave intensity and the number of measurements of the counted results.

[0121] Similar data processing is performed for the item RF tags 21 to 23 shown in Figures 15 to 17. Also in Figure 15, there are three points (1501 to 1503) where the radio wave strength of the item RF tag 21 is maximum, so three time windows (1511 to 1513) are set. In Figure 16, there are two points (1601, 1602) where the radio wave strength of the item RF tag 22 is maximum, and in Figure 17, there are two points (1701, 1702) where the radio wave strength of the item RF tag 23 is maximum, so two time windows (1611, 1612 or 1711, 1712) are set for each.

[0122] Tables 3 to 6 show the results of tallying the address RF tags for each item RF tag generated by the item location management data processing.

[0123] [Table 3]

[0124] [Table 4]

[0125] [Table 5]

[0126] [Table 6] As described above, in the item location management system of the present disclosure, the counting results are registered as item location management data for each item RF tag in the item location management database in the storage unit of the system processing device.

[0127] (First display mode of item location information) Figure 18 shows a first display mode of item location information displayed on the display screen of the system processing device, which is the result of executing the above-mentioned second phase of item location search processing using the item location management data registered in the item location management database of Example 1.

[0128] In this first display mode, the locations of the address RF tags in the management area 1200 shown in FIG. 12 are displayed on a map.

[0129] In Figure 18, the numbers written above each address indicate "ranking: (maximum radio wave strength, number of measurements)." Addresses with no rank displayed above them indicate that no return RF signal was measured from the RF tag at that address within the counting period set for the item RF tag. As described above, the item location management system disclosed herein is characterized by displaying multiple addresses that are assumed to be close to the item, ranked according to their proximity.

[0130] For ease of explanation, Fig. 18 shows the location of each item RF tag, as well as the maximum radio wave strength of the reply RF signal from the item RF tag in parentheses above the item. In an actual display of item location information, the location of the item RF tag is not clear, so the location of the item RF tag is not displayed. Also, in the example display of Fig. 18, demarcation lines including the management area are displayed, as in Fig. 12, to make it easier to understand the correspondence with the RF tag placement diagram of the usage environment in Fig. 12. However, the demarcation lines may be omitted, or only the management area may be displayed.

[0131] FIG. 18(a) shows the tabulation results for the article RF tags 20 in Table 3 displayed on a layout diagram showing the addresses where the RF tags are located in the management area, and will be described using this as an example.

[0132] The address A65 in the management area is marked with "1:(-49,17)," which indicates that the address RF tag 65 placed at address A65 is ranked first, that the maximum radio wave strength of the reply RF signal from address RF tag 65 measured in the counting section for item RF tag 20 was "-49 dBm," and that the number of measurements was 17. The ranking and maximum radio wave strength of each address RF tag are also displayed at the other addresses A60 to A63 based on Table 3. As shown in Table 3, reply RF signals were not received from address RF tags 64 and 66 in the counting section for item RF tag 20, so no display is made for addresses A64 and A66.

[0133] 18(a), the user can guess that the location of the item 20 is near the address A65, the address A61, or the address A60. In other words, when searching for the item 20, the user can understand that they should search around A65, which is ranked first, A61, which is ranked second, and A60, which is ranked third.

[0134] Similarly, in FIG. 18(b), it can be determined that the location of the item 21 is near the addresses A61, A62, and A63.

[0135] Note that by taking into consideration not only the ranking of maximum radio wave strength but also the magnitude of the radio wave strength itself as a determining factor, it is possible to more accurately determine the approximate location of an item. For example, in Fig. 18(b), the maximum radio wave strength of the first-ranked address RF tag 61 and the second-ranked address RF tag 62 is approximately the same as the maximum radio wave strength of the address RF tag 63 and the address RF tag 60, and the maximum radio wave strength of the address RF tag 61 and the address RF tag 62 is greater than that of the address RF tag 63 and the address RF tag 60.

[0136] Based on this information, the user can estimate that the location of the item 21 is near the address A61 and the address A62, in the area between them. Furthermore, the number of measurements can also be used as a reference for determining the location of the item 21.

[0137] Similarly, in Figure 18(c), based on the ranking of the address RF tags, it can be inferred that the location of item 22 is near the first-ranked address 62 and the second-ranked address 63. Also, in Figure 18(c), since the maximum radio wave strength of the first-ranked and second-ranked address RF tags is the same, it can be inferred that the item is likely to be somewhere between the two. Similarly, in Figure 18(d), based on the ranking of the address RF tags, it can be inferred that the item is near the first-ranked address 66, the second-ranked address 64, and the third-ranked address 63.

[0138] (Second display mode of item location information) Next, we will explain a second display mode of item location information, which allows users to intuitively identify the location of an item by visually displaying the maximum radio wave strength and number of receptions of each address RF tag rather than text information.

[0139] Fig. 19 is a diagram for explaining a second display mode, and Fig. 19(a) to (d) correspond to Fig. 18(a) to Fig. 18(d). In this display mode, the information displayed at each address position in Fig. 18 is displayed by a circle with the address position as its center. The item RF tags and their positions in Fig. 19(a) to (d) are the same as those in the corresponding Fig. 18(a) to (d), but the positions of the item RF tags are omitted in Fig. 19.

[0140] The radius r of the circle displayed with each address at its center is determined by r[pixel]=(D+x)×K.

[0141] Here, D is a predetermined constant, K is a predetermined positive constant, and the value of D is set so that D+x>0, taking into account the radio wave strength range of the return RF signal to be measured. Also, x is the maximum radio wave strength of the address RF tag corresponding to each address.

[0142] In this embodiment, the measured radio wave intensity of the return RF signal from each RF tag is within the range of -30 [dBm] to -80 [dBm], so D=100 and K=1.

[0143] The opacity O of the circle at each address is determined by O = number of detections x T.

[0144] Here, T is a predetermined positive constant. In this example of the display mode, the maximum opacity during drawing is 255, and T=5.

[0145] Using this determination method, the circle displayed with each address location at its center has a larger radius the greater the maximum radio wave intensity, and a darker color the more times the measurement is performed.

[0146] In this manner, in this display mode, the information displayed at each address in Figure 18 is displayed using the radius and opacity of a circle, so that not only can the ranking of the maximum radio wave strength of the address RF tags placed at each address be visually grasped, but also the difference in the magnitude of maximum radio wave strength between each address and the number of measurements.

[0147] Therefore, this display mode allows the user to identify the location of the item 21 more easily and intuitively.

[0148] 19(a) to 19(d), as another display mode, an area formed by connecting a predetermined number of the highest ranked addresses from the addresses ranked in the counting results with straight lines is also displayed as a guide to the location of the item. In the following explanation, an example is given in which an area is displayed by connecting three points of the top three addresses with straight lines, but the number of addresses forming an area may be set appropriately depending on the number of address RF tags to be placed in the management area.

[0149] In Figures 19(a) and 19(d), a triangular area formed by connecting the top three points is also displayed. The user identifies the displayed triangular area as the location of item 21 and searches for the item. When a straight line connecting the three points is displayed as in Figures 19(b) and 19(c), the user can identify the area near the wall of the straight line as the location of item 21 and search for the item. Note that the area formed by connecting the top three points does not need to be displayed, or a mode in which only the area formed by connecting the top three points is displayed alone may be used.

[0150] (Third display mode of item location information) Next, another display mode in which the display of the item location information is made by a circle with the address position as the center will be described with reference to FIG.

[0151] Fig. 20 shows the item location information using the item location management database of Example 1. Fig. 20(a) to Fig. 20(d) correspond to Fig. 18(a) to Fig. 18(d), and the positions of the item RF tags in Fig. 20 are the same as those in the corresponding Fig. 18(a) to (d), but the positions of the item RF tags are omitted.

[0152] The difference between the third display mode and the second display mode of FIG. 19 is as follows.

[0153] The radius of the circle indicating the magnitude of the return RF received signal from each address RF tag is determined by the value obtained by converting the radio wave intensity of the return RF signal from the address RF tag into power.

[0154] The conversion of radio wave strength x [dBm] to power P [mW] is P [mW] = 10 x / 10 The radius r [pixel] of the circle is determined by r = P × S, where S is a positive predetermined constant, and in this case, S = 10 7 was used.

[0155] In addition, the circle centered on each address RF tag displays not only the maximum radio wave strength, but also the radio wave strength of each reply RF signal from the address RF tag measured within the counting period set for the item RF tag.

[0156] The opacity of the lines (circumferences) that draw the circles indicating the radio wave strength of each return RF signal was kept constant. (The opacity was set to L, which was set to 15 in the experiment, but other levels of opacity were also acceptable.) ) The overlapping of the circles creates shading, which allows information about the radio wave intensity density of the address tag to be displayed.

[0157] This display format determines the radius based on power [mW] rather than radio wave strength [dBm], making it possible to more clearly visualize the magnitude of each return RF signal received at each address. Furthermore, since the display shows not only the maximum radio wave strength but also the magnitude of each return RF signal, it is possible to visualize the power distribution of return RF signals measured from item RF tags during the counting period for each item.

[0158] This third display mode allows the user to more easily and intuitively identify the location of the item 21. In this third display mode, an area formed by connecting the top three addresses ranked in the counting results with straight lines is also displayed as a guide to the location of the item, but the area display does not have to be displayed.

[0159] In the above example, the article RF tags and address RF tags are installed at the same height, but the article RF tags and address RF tags may be installed at different heights. Furthermore, if it is not possible to set the address RF tags at the same height at the locations set as each address, the address RF tags do not necessarily have to be set at the same height. Furthermore, articles to which article RF tags are affixed may not only be placed on the floor at the same height, but may also be placed at different heights, such as on a shelf with multiple tiers. In this case, multiple address RF tags may be placed on walls or pillars at different heights per location depending on the height of the shelf on which the articles are placed, thereby taking height information into account. [Industrial Applicability]

[0160] The item location management system of the present disclosure is capable of managing the location of items even in an environment where there are restrictions on the installation locations and number of location RFID tags that identify partitioned areas within a location management area.The present disclosure can provide an item location management system, method, and program that allows a user to estimate the location of an item by ranking and displaying multiple addresses that serve as a guide for the location of an item in a situation where location address RFID tags cannot be arranged in a grid pattern. [Explanation of symbols]

[0161] 100···············Item location management system 110 RFID tag 120 RFID reader 121 Operation trigger 130 System processing unit 210 Antenna 211, Control unit 212,221··········Communications Department 213,223......Operation section 214,222········Display section 215, 224... Storage section 220 Information Processing Unit 300, 1200... Management area 341, 1241... Measurement start point 342, 1242... Measurement end point 1210,1220,1230...Area boundary line 1401, 1402, 1403: The time when the maximum signal strength was measured 1501, 1502, 1503: The times when the maximum signal strength was measured 1601, 1602: The time when the maximum signal strength was measured 1701, 1702: The time when the maximum radio wave strength was measured 1411, 1412, 1413... Aggregation interval 1511,1512,1513... Aggregation interval 1611,1612... Aggregation interval 1711,1712... Aggregation interval

Claims

1. The system includes at least one or more item RF tags attached to each of the items placed within a predetermined management area, a plurality of address RF tags placed at different positions within the predetermined management area, an RFID reader, and a system processing device, the RFID reader is configured to transmit to a system processing device item location management measurement data obtained by measuring return RF signals from the item RF tags and the address RF tags within the predetermined management area; the system processing device receives the item location management measurement data; The item location management measurement data is processed to calculate the time tp at which the maximum radio wave intensity of the reply RF signal was measured for each of the item RF tags, and the reply RF signals from the plurality of address RF tags included in a counting period that is a range of a certain time before and after the time tp are counted, The address RF tags are ranked and recorded based on the returned RF signals from the address RF tags that have been counted for each of the article RF tags; An item location management system configured to display item location information that displays multiple pieces of information about the address RF tag along with information indicating the ranking based on the ranking of the address RF tag recorded for each item RF tag.

2. 2. The item location management system according to claim 1, wherein the ranking of the address RF tags is based on the maximum radio wave intensity of the return RF signal from each of the address RF tags, which is calculated for each item RF tag.

3. An item location management system as described in claim 2, characterized in that when there are multiple address RF tags with the same maximum radio wave strength, the number of times the return RF signal from the address RF tag is measured is used to rank the address RF tags.

4. 4. The goods location management system according to claim 1, wherein the display of the goods location information displays only a predetermined number of the address RF tags in descending order of the ranking.

5. The item location management system according to claim 4, characterized in that the display of the item location information excludes address RF tags whose maximum radio wave intensity of the reply RF signal from each of the address RF tags, calculated for each item RF tag, is below a predetermined threshold.

6. An item location management system as described in any one of claims 1 to 3, characterized in that the display of the item location information includes a diagram of the location of the address RF tags in the specified management area, and the maximum radio wave intensity of each address RF tag at the location of that address RF tag.

7. An item location management system as described in any one of claims 1 to 3, characterized in that the display of the item location information includes a diagram of the location of the address RF tags in the specified management area, and at the location of each address RF tag, a circle is displayed with the location of the address RF tag as its center and with a radius determined based on the maximum radio wave intensity of the address RF tag.

8. An item location management system as described in any one of claims 1 to 3, characterized in that the display of the item location information includes a diagram of the location of the address RF tags in the specified management area, and at the location of each address RF tag, a circle is displayed with the location of the address RF tag as its center and with a radius determined based on the power of the maximum radio wave strength of the address RF tag.

9. An item location management system according to any one of claims 1 to 3, characterized in that the display of the item location information includes a diagram of the location of the address RF tags in the specified management area, and an area in which the positions of a specified number of address RF tags in descending order of rank are connected by straight lines.

10. a communication unit that receives item location management measurement data that is obtained by measuring return RF signals from at least one item RF tag attached to each of the items placed within a predetermined management area and a plurality of address RF tags placed at different positions within the predetermined management area; an information processing unit that processes the received item location management measurement data, calculates the time tp at which the maximum radio wave intensity of the reply RF signal was measured for each of the item RF tags, and tallies the reply RF signals from the plurality of address RF tags included in a counting period that is a range of a certain time before and after the time tp; a memory unit that ranks and records the address RF tags based on the return RF signals from the address RF tags that are tallied for each of the article RF tags; a display unit that displays multiple pieces of item location information, each of which includes information on the address RF tag along with information indicating the ranking, based on the ranking of the address RF tag recorded for each of the item RF tags; An article location management system processing device comprising:

11. receiving item location management measurement data obtained by measuring return RF signals from at least one item RF tag attached to each of the items placed within a predetermined management area and from a plurality of address RF tags placed at different positions within the predetermined management area; The received item location management measurement data is processed, and the time tp at which the maximum radio wave intensity of the reply RF signal was measured is calculated for each of the item RF tags, and the reply RF signals from the plurality of address RF tags included in a counting period that is a range of a certain time before and after the time tp are counted. The address RF tags are ranked and recorded based on the returned RF signals from the address RF tags that have been counted for each of the article RF tags; An item location management method executed by a computer, in which item location information is displayed in multiple displays, along with information indicating the ranking of the address RF tag, based on the ranking of the address RF tag recorded for each item RF tag.

12. receiving item location management measurement data obtained by measuring return RF signals from at least one item RF tag attached to each of the items placed within a predetermined management area and from a plurality of address RF tags placed at different positions within the predetermined management area; The received item location management measurement data is processed, and the time tp at which the maximum radio wave intensity of the reply RF signal was measured is calculated for each of the item RF tags, and the reply RF signals from the plurality of address RF tags included in a counting period that is a range of a certain time before and after the time tp are counted. The address RF tags are ranked and recorded based on the returned RF signals from the address RF tags that have been counted for each of the article RF tags; An item location management program that causes a computer to display multiple item location information displays of the information of the address RF tag along with information indicating the ranking based on the ranking of the address RF tag recorded for each item RF tag.

Images