Inventory Management System

Abstract

This system provides a configuration that allows for accurate management of the entry and exit status of items using wireless tags attached to items, without restricting the storage location of the items on the management shelves. [Solution] Each item G to be managed is fitted with a wireless tag T on which a tag ID that can identify the item G is recorded in a way that can be read via contactless communication. The management terminal 32 of the management device 30 uses the information read from the wireless tag T via the antenna 20 by the wireless tag reader 31 to manage the entry and exit of items G through the entrance / exit 11 of the management shelf 10. The antenna 20 is installed on the management shelf 10 so that the entrance / exit 11 is within the reading range S.

Description

Technical Field

[0001] The present invention relates to an article management system that manages articles to be stored and retrieved in a storage shelf as management targets.

Background Art

[0002] Conventionally, when storing articles in a storage shelf or retrieving articles from a storage shelf, an operator reads information codes such as barcodes displayed on the articles, the storage shelf, work instructions, etc. sequentially using a portable reader device, thereby operating a system that manages the inventory status of articles in the storage shelf to be managed. In a system premised on the operation of an operator reading information codes for each article, there are problems such as a decrease in inventory management accuracy due to human errors and high management costs due to complicated reading operations.

[0003] For this reason, a system that manages the inventory status of articles using the reading results of wireless tags such as RF tags that can be read by non-contact communication has been proposed. As a technology related to such a system, for example, an article management system disclosed in Patent Document 1 below is known. In this article management system, an RFID reader is connected to one end of a reader antenna composed of an open transmission line terminated in a matching manner, and a plurality of RF tags are installed at positions where they are each electromagnetically coupled to the reader antenna. With such a configuration, by distinguishing between RF tags on which management target articles are arranged and RF tags on which management target articles are not arranged according to the signal intensity of each RF tag detected by the RFID reader, the storage and retrieval of management target articles are managed.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, with the system configuration described above, the location where managed items are placed (the storage location on the management shelf) is restricted to the RF tag. Therefore, if the placement of managed items is misaligned with the placement of the RF tag, depending on the degree of the misalignment, the RF tag's signal strength may not weaken, potentially leading to the misinterpretation that the managed item is not placed on that RF tag.

[0006] The present invention was made to solve the above-mentioned problems, and its objective is to provide a configuration that allows for accurate management of the entry and exit status of items using wireless tags attached to items, without restricting the storage location of the items in the management shelves. [Means for solving the problem]

[0007] To achieve the above objective, the present invention An item management system (1) that manages items (G) that are moved in and out of a storage shelf (10), The aforementioned article is fitted with a wireless tag (T) on which information that can identify the article is recorded in a readable format via contactless communication. The antenna (20) installed on the aforementioned management shelf, A management device (30, 31, 32) manages the entry and exit of the items through the entrance (11) of the management shelf using information read from the wireless tag via the antenna, Equipped with, The antenna is characterized in that it is installed on the management shelf such that the entrance / exit area is within the reading range (S). The symbols within the parentheses above indicate the correspondence with the specific means described in the embodiments described later. [Effects of the Invention]

[0008] In this invention, each item to be managed is fitted with a wireless tag on which information that can identify the item is recorded in a readable format via contactless communication. The information read from the wireless tag via an antenna is used by a management device to manage the entry and exit of items through the entrance / exit of the management shelf, and the antenna is installed on the management shelf so that the entrance / exit is within the reading range.

[0009] As a result, when items are brought in, information is read from the wireless tags attached to the items via an antenna as they pass through the entrance / exit, allowing the storage status of items to be managed using the reading results, regardless of their storage location on the management shelves. Similarly, when items are taken out, information is read from the wireless tags attached to the items via an antenna as they pass through the entrance / exit, allowing the storage status of items to be managed using the reading results. Therefore, a system can be realized that accurately manages the storage status of items using wireless tags attached to items, without restricting the storage location of the items to be managed on the management shelves.

[0010] The antenna may be installed on the upper wall of the control shelf above the entrance, so that the reading range covers the entrance. For example, when metal items are brought in and placed on the control shelf, the items may be located near the antenna, potentially affecting the reading process via the antenna. Therefore, by installing the antenna on the upper wall of the control shelf above the entrance, it becomes easier to ensure a sufficient distance between the antenna and the items compared to installing the antenna on the bottom or side wall of the control shelf, thereby reducing the impact on the reading process and improving the accuracy of management regarding the entry and exit of items.

[0011] The management device may determine the entry and exit of goods based on the time change in the radio wave intensity of the wireless tag read via the antenna. [Brief explanation of the drawing]

[0012] [Figure 1] This is an explanatory diagram illustrating the article management system according to the first embodiment. [Figure 2] Figure 1 is a perspective view of the storage shelves from the entrance side. [Figure 3] This is an explanatory diagram illustrating the schematic configuration of the antenna shown in Figure 1. [Figure 4] This block diagram shows the schematic configuration of the wireless tag reader shown in Figure 1. [Figure 5] Figure 5(A) is an explanatory diagram illustrating the storage state in which items are placed into a storage rack, and Figure 5(B) is an explanatory diagram illustrating the storage state in which items are placed further into the storage state from the state in Figure 5(A). [Figure 6] This is an explanatory diagram illustrating the main parts of an item management system according to a first modified example of the first embodiment. Figure 6(A) shows an example in which the antenna is installed on the bottom wall of the management shelf, and Figure 6(B) shows an example in which the antenna is installed on the back wall of the management shelf. [Figure 7] This is an explanatory diagram illustrating the structure of the management shelf and the installation locations of each antenna in the item management system according to a second modified example of the first embodiment. [Figure 8] This is an explanatory diagram illustrating the relationship between the radio wave intensity of a wireless tag received via an antenna, which is a key component of the item management system according to the second embodiment, and the receiving position relative to the antenna. [Figure 9] Figure 9(A) is an explanatory diagram illustrating the case of storing goods, Figure 9(B) is an explanatory diagram illustrating the case of placing goods on a storage shelf, and Figure 9(C) is an explanatory diagram illustrating the case of carrying goods that have been brought close to the entrance / exit without storing them. [Figure 10] Figure 10(A) is an explanatory diagram illustrating the time change in the radio wave intensity of the received wireless tag in the case of Figure 9(A), Figure 10(B) is an explanatory diagram illustrating the time change in the radio wave intensity of the received wireless tag in the case of Figure 9(B), and Figure 10(C) is an explanatory diagram illustrating the time change in the radio wave intensity of the received wireless tag in the case of Figure 9(C). [Figure 11] Figure 11(A) is an explanatory diagram illustrating the case of retrieving an item from storage, and Figure 11(B) is an explanatory diagram illustrating the case of returning an item that was about to be retrieved back into storage. [Figure 12]FIG. 12(A) is an explanatory diagram for explaining the temporal change in the radio wave intensity of the wireless tag received in the case of FIG. 11(A), and FIG. 12(B) is an explanatory diagram for explaining the temporal change in the radio wave intensity of the wireless tag received in the case of FIG. 11(B). [Figure 13] It is a flowchart illustrating the flow of the inventory management process performed by the management terminal in the second embodiment.

Mode for Carrying Out the Invention

[0013] [First Embodiment] Hereinafter, a first embodiment embodying the article management system according to the present invention will be described with reference to the drawings. The article management system 1 according to the present embodiment is a system for managing articles G that are received and shipped in and out of the management shelf 10. As shown in FIGS. 1 and 2, the article management system 1 is configured to include an antenna 20 installed on the management shelf 10 and a management device 30 that manages the receipt and shipment of the article G through the entrance / exit 11 of the management shelf 10.

[0014] The article G to be managed is, for example, a packing box in which predetermined parts are stored and packed, and a wireless tag T such as an RF tag having a unique tag ID recorded so as to be readable by non-contact communication is attached to the side surface or the like. In the present embodiment, the tag ID functions as information capable of specifying the article G, and is registered in a server or the like so as to be associated with the article G itself to which the wireless tag T recording the tag ID is attached and the type and number of the stored parts of the article G. Therefore, by inquiring the server or the like about the tag ID or the like read from the wireless tag T, the article G to which the wireless tag T recording the tag ID is attached can be specified.

[0015] As shown in Figures 1 and 2, the storage shelf 10 in this embodiment has a roughly rectangular box shape, with a rectangular opening at the front entrance 11, and the space enclosed by the upper wall 12, bottom wall 13, side walls 14, 15, and back wall 16 is configured to be the storage space for the stored items G. In this embodiment, each wall of the storage shelf 10 is made of resin material, but it is not limited to this, and at least a part of it may be made of metal material, glass material, wooden material, etc. Note that in Figure 1 and Figure 5, which will be described later, the side wall 15 is omitted from the illustration for convenience.

[0016] In this embodiment, the antenna 20 is configured as a planar antenna such as a microstrip line type antenna and is installed on the inner surface of the upper wall 12 of the management shelf 10 that constitutes the upper part of the entrance / exit 11, connected to the wireless tag reader 31 of the management device 30 via a coaxial cable or the like. More specifically, as illustrated in Figure 3, the antenna 20 has a GND size with a ground conductor width W2 that is wider than the conductor width (microstrip line width) W1 of the surface pattern, and is installed on the front inner surface of the upper wall 12 such that one end in the longitudinal direction is close to the side wall 14 and the other end in the longitudinal direction is close to the side wall 15. For convenience, in Figure 3, one end of the surface pattern with conductor width W1 and one end of the ground pattern (GND) with ground conductor width W2 are schematically shown, and the approximate outer shape of the dielectric substrate, etc. is shown by a dashed line.

[0017] With this configuration, the antenna 20 operates using predetermined power supplied from the wireless tag reader 31 to make the entrance / exit 11 of the management shelf 10 the reading range S. The antenna 20 is not limited to being configured as a microstrip line type antenna; any antenna capable of operating to make the entrance / exit 11 the reading range S may be configured, such as a planar antenna like a patch antenna, a flexible antenna like a leaky coaxial type, or a multi-stage antenna like a collinear array.

[0018] The management device 30 is configured to include a wireless tag reader 31 and a management terminal 32. The wireless tag reader 31 is a so-called RFID reader and is configured to output the tag ID etc. read from the wireless tag T via the antenna 20 to the management terminal 32. As shown in Figure 4, the wireless tag reader 31 includes a control unit 41, a storage unit 42, a communication processing unit 43, an antenna 44, and an external interface 45, etc. The control unit 41 is mainly composed of a microcontroller and has a CPU, a system bus, an input / output interface, etc., and together with the storage unit 42 which consists of semiconductor memory etc., it constitutes an information processing device.

[0019] As shown in Figure 4, the communication processing unit 43 includes a transmitting circuit 43a, a receiving circuit 43b, and the like. The transmitting circuit 43a is composed of, for example, a carrier oscillator, an encoding unit, a modulation unit, and an amplifier. The carrier oscillator outputs a carrier wave of a predetermined frequency, and the encoding unit is connected to the control unit 41. The encoding unit encodes the transmission data output from the control unit 41 and outputs it to the modulation unit. The modulation unit receives the carrier wave from the carrier oscillator and the transmission data from the encoding unit. It generates a modulated signal that is ASK (Amplitude Shift Keying) modulated with the carrier wave output from the carrier oscillator by the encoded transmission code (modulation signal) output from the encoding unit when a command is transmitted to the communication target, and outputs this to the amplifier. The amplifier amplifies the input signal (the modulated signal modulated by the modulation unit) at a set amplification factor, and this amplified signal is output to the antenna 44 as a transmission signal.

[0020] The input terminal of the receiving circuit 43b is connected to the antenna 44, and the radio signal (received signal) corresponding to the response wave from the wireless tag T received by the antenna 44 is input to the receiving circuit 43b. The receiving circuit 43b is composed of, for example, an amplifier and a demodulator, and the received signal received by the antenna 44 is amplified by the amplifier, and the amplified signal is demodulated by the demodulator. Furthermore, the signal corresponding to the demodulated signal waveform is output to the control unit 41 as received data.

[0021] The external interface 45 is configured as an interface for data communication with external devices such as the management terminal 32, and is configured to perform communication processing in cooperation with the control unit 41.

[0022] The management terminal 32 is a personal computer or the like, and is configured to perform inventory management processing, such as managing the entry and exit of items G through the entrance and exit 11 of the management shelf 10, using the tag ID read via the antenna 20 from the wireless tag T that passes through the entrance and exit 11 by the wireless tag reader 31.

[0023] In the item management system 1 configured in this way, as illustrated in Figure 5(A), when an item G1 is placed in the storage shelf 10 via the entrance / exit 11, the wireless tag T1 attached to the item G1 passes through the reading range S of the antenna 20. Therefore, the item G1 placed in the storage shelf 10 can be identified by using the tag ID read from the wireless tag T1 via the antenna 20 by the wireless tag reader 31 during the inventory management process performed at the management terminal 32. Furthermore, as illustrated in Figure 5(B), even when another item G2 is placed in the storage shelf 10, the item G2 with the wireless tag T2 attached can be identified by reading the tag ID from the wireless tag T2 that has passed through the reading range S.

[0024] In the inventory management process, when a tag ID without an inventory flag set to indicate its inventory status is read, the inventory flag is set for that tag ID and it is registered as an inventory item in a predetermined database built in the storage unit of the management terminal 32, along with the inventory time, etc. Also, in the inventory management process, when a tag ID with an inventory flag set is read, the inventory flag is removed for that tag ID and an outgoing flag is set and it is registered as an outgoing item in the predetermined database, along with the outgoing time, etc. Therefore, in the inventory management process, it is possible to determine whether an item G is being received or outgoing based on whether or not an inventory flag is set for the read tag ID.

[0025] As described above, in the item management system 1 according to this embodiment, each item G to be managed is attached to a wireless tag T on which a tag ID that can identify the item G is recorded in a way that can be read by contactless communication. The management terminal 32 of the management device 30 manages the entry and exit of items G through the entrance / exit 11 of the management shelf 10 using information read from the wireless tag T via the antenna 20 by the wireless tag reader 31. The antenna 20 is installed on the management shelf 10 so that the entrance / exit 11 is within the reading range S.

[0026] As a result, when an item G is brought in and passes through the entrance / exit 11, the tag ID is read from the wireless tag T of the item G via the antenna 20. Therefore, regardless of its storage location on the management shelf 10, the storage status of the item G can be managed using the reading result. Similarly, when an item G is brought out and passes through the entrance / exit 11, the tag ID is read from the wireless tag T of the item G via the antenna 20. Therefore, the storage status of the item G can be managed using the reading result. Thus, a system can be realized that accurately manages the storage status of items G using the wireless tag T attached to the item G, without restricting the storage location of the item G on the management shelf 10.

[0027] In particular, in this embodiment, the antenna 20 is installed on the upper wall 12 of the management shelf 10 that constitutes the area above the entrance 11, so that the entrance 11 is the reading range S. For example, when a metal item is brought in and stored in the management shelf 10, the stored item may be located near the antenna 20, which could affect the reading process via the antenna 20. In such a case, for example, if the antenna 20 were installed on the bottom wall 13, in order to eliminate the above-mentioned effect on the reading process, an attempt would be made to secure a distance between the antenna 20 and the stored item, which would narrow the range in which items can be stored within the management shelf 10 and restrict the storage location.

[0028] Therefore, as in this embodiment, by installing the antenna 20 on the upper wall 12 of the management shelf 10 that constitutes the upper part of the entrance / exit 11, the distance between the antenna 20 and the stored items can be more easily secured compared to when the antenna 20 is installed on the bottom wall 13, side walls 14, 15, or back wall 16 of the management shelf 10, thus suppressing the impact on the reading process. In particular, even when the stored items are stacked from bottom to top within the management shelf 10, the reading of the wireless tags T of newly stacked items will not be obstructed by the already stored items. Thus, it is possible to improve the management accuracy regarding the entry and exit of items while suppressing restrictions on the storage location.

[0029] As a first modification of this embodiment, in cases such as managing the inbound and outbound movement of items that do not affect the reading process via the antenna 20, the antenna 20 may be installed in a location different from the upper wall 12. For example, the antenna 20 may be installed on the front side of the bottom wall 13 of the management shelf 10, as illustrated in Figure 6(A), or it may be installed in the center of the back wall 16 of the management shelf 10, as illustrated in Figure 6(B).

[0030] As a second modification of this embodiment, the management shelf 10 is not limited to being configured to have one entrance / exit 11, but may be configured to have multiple entrances / exits 11. For example, even when configured to have two entrances / exits 11a and 11b, as illustrated in Figure 7, antennas 20a and 20b are installed on the upper wall 12, etc., for each entrance / exit 11a and 11b, so that each entrance / exit 11a and 11b has a reading range Sa and Sb, respectively. By installing each antenna 20a and 20b in this way, the inbound and outbound status of items G can be managed for each entrance / exit 11a and 11b using the reading results of the wireless tags T attached to the items G.

[0031] As a third modification of this embodiment, the storage shelf 10 may be configured as a metal shelf in which at least some of the walls (top wall 12, bottom wall 13, side walls 14, 15, back wall 16) are made of metal. For example, if the item G is a pharmaceutical product or an item containing a pharmaceutical product, it is preferable to use a metal material for the storage shelf 10 from a hygienic standpoint. By configuring the storage shelf 10 as a metal shelf in this way, even if some of the radio waves radiated from the antenna 20 installed on the top wall 12 are reflected by the bottom wall 13, the entrance 11 is always open, which suppresses the formation of areas (null areas) where the wireless tag T is difficult to read.

[0032] [Second Embodiment] Next, the article management system according to this second embodiment will be described with reference to the drawings. In this second embodiment, the main difference from the first embodiment is that the entry and exit of goods are determined based on the time change in the radio wave intensity of the wireless tag. Therefore, components that are substantially the same as those in the first embodiment are denoted by the same reference numerals, and their descriptions are omitted.

[0033] For example, if item G is temporarily placed on top of the storage shelf 10 (on the outer surface of the upper wall 12) without being placed in the storage shelf 10, or if item G is brought close to the entrance / exit 11 with the intention of being placed in storage but is carried away without being placed in storage, the wireless tag T of item G may be read via the antenna 20, potentially leading to the misconception that item G has been placed in storage. Also, for example, if item G is returned to its stored state without being placed out, the wireless tag T of item G may be read via the antenna 20, potentially leading to the misconception that item G has been placed out.

[0034] Therefore, in this embodiment, in order to suppress the misidentification described above, the receiving and shipping management process performed at the management terminal 32 determines whether an item G is receiving or shipping based on the time change in the radio wave intensity (reading power) of the wireless tag T received via the antenna 20.

[0035] As illustrated in Figure 8, the radio wave intensity P of the wireless tag T received via antenna 20 decreases with increasing distance from antenna 20. However, the rate of decrease in radio wave intensity P differs depending on whether the distance from antenna 20 is towards the inside of the storage shelf 10 (towards the back wall 16) or towards the outside of the storage shelf 10. The decrease is smaller on the outside of the storage shelf 10 than on the inside. This is because the measurement takes place in a closed space surrounded by the walls on the inside of the storage shelf 10. Figure 8 shows the relationship between the radio wave intensity P of the wireless tag T received via antenna 20 at a predetermined frequency and the receiving position relative to antenna 20. On the horizontal axis of Figure 8, the center position of antenna 20 in the front-to-back direction (left-to-right direction in Figure 1) is set to "0 mm," with the inside of the shelf being positive and the outside of the shelf being negative.

[0036] When item G is brought into storage (see Figure 9(A)), the radio wave strength P of the wireless tag T received via antenna 20 changes over time to a constant value P1 greater than "0" after peaking when it is closest to antenna 20, as illustrated in Figure 10(A). When item G is placed on the storage shelf 10 (see Figure 9(B)), the radio wave strength P of the wireless tag T received via antenna 20 changes over time to a constant value P2 greater than "0" without forming a clear peak, as illustrated in Figure 10(B). Furthermore, when item G is brought close to the entrance / exit 11 and carried away without being brought into storage (see Figure 9(C)), the radio wave strength P of the wireless tag T received via antenna 20 changes over time to a peak when it is closest to antenna 20, as illustrated in Figure 10(C), after gradually decreasing to "0".

[0037] Therefore, when the first threshold Pth1 is set to a radio wave intensity value slightly smaller than the radio wave intensity P of the wireless tag T expected to pass through the reading range S, and the second threshold Pth2 is set to a radio wave intensity value slightly smaller than the radio wave intensity P of the wireless tag T expected to be in storage at the position furthest from the antenna 20, it is possible to determine whether or not an item G with the wireless tag T attached has been stored based on the relationship between the time change of radio wave intensity P and the first threshold Pth1 and the second threshold Pth2. Specifically, as illustrated in Figure 10(A), if the detected value of radio wave intensity P (hereinafter also referred to as the detected value Pb) after the peak detected value of radio wave intensity P (hereinafter also referred to as the peak detected value Pa) exceeds the first threshold Pth1 (after a predetermined time has elapsed since radio wave detection) is almost stably above the second threshold Pth2, it can be determined that an item G with the wireless tag T attached has been stored.

[0038] Furthermore, when item G is to be released (see Figure 11(A)), the radio wave intensity P of the wireless tag T received via antenna 20 changes over time, starting from a constant value P3 greater than "0", gradually increasing until it peaks when it is closest to antenna 20, and then gradually decreasing until it becomes "0", as illustrated in Figure 12(A). Also, when item G is returned to the stored state without being released (see Figure 11(B)), the radio wave intensity P of the wireless tag T received via antenna 20 changes over time, gradually decreasing but not becoming "0", as illustrated in Figure 12(B).

[0039] Therefore, for a wireless tag T with a tag ID that has an incoming flag set, as illustrated in Figure 12(A), when the detected value Pb of the radio wave intensity P becomes approximately "0" after the peak detected value Pa of the radio wave intensity P exceeds the first threshold Pth1, it can be determined that the item G to which the wireless tag T is attached has been released.

[0040] Therefore, in the inventory management process performed at the management terminal 32 in this embodiment, the inbound and outbound status of items G is determined based on the time change in the radio wave intensity P of the wireless tag T read by the wireless tag reader 31 via the antenna 20.

[0041] The inventory management process performed on the management terminal 32 will be explained below with reference to the flowchart in Figure 13. When a predetermined operation is performed on the control unit of the management terminal 32, the control unit of the management terminal 32 starts the inventory management process. In the determination process of step S101 in Figure 13, it is determined whether or not a wireless tag T with fluctuating radio wave strength P has been detected, based on the premise of reading a wireless tag on which a tag ID that may be subject to management has been recorded. If a wireless tag T with fluctuating radio wave strength P received via the antenna 20 is detected (Yes in S101), the time change of the radio wave strength P of that wireless tag T is acquired and stored in the memory unit of the management terminal 32 (S102).

[0042] If the received flag is not set for the read tag ID (No in S103), a process is performed to determine whether or not the item G with the wireless tag T attached has been received, based on the acquired radio wave intensity P. That is, if the peak detection value Pa of the acquired radio wave intensity P is greater than Pth1 (Yes in S104), and the detection value Pb of the acquired radio wave intensity P is almost stably above the second threshold Pth2 (Yes in S105), it is determined that the item G with the wireless tag T attached has been received, and the received flag is set, etc. (S106). After that, if no termination instruction is received (No in S112), the process from step S101 above is performed.

[0043] On the other hand, if the peak detection value Pa of the acquired radio wave intensity P is less than or equal to Pth1 (No in S104), the item G with the wireless tag T attached is determined to be outside the shelf, as it is assumed that it was not stored but placed on the outer surface of the upper wall 12 of the management shelf 10 (S107). Also, even if the peak detection value Pa of the acquired radio wave intensity P is greater than Pth1 (Yes in S104), if the detected value Pb of the acquired radio wave intensity P is "0" and less than or equal to the second threshold Pth2 (No in S105), the item G with the wireless tag T attached is determined to be outside the shelf, as it was brought close to the entrance / exit 11 but was carried away without being stored (S107). In the case of an outside-the-shelf determination as described above, if the storage flag is not set and no termination instruction has been received (No in S112), the processing from step S101 above is performed.

[0044] Furthermore, since the stored item G is being moved, if the stored flag is set for the read tag ID (Yes in S103), a process is performed to determine whether the item G with the wireless tag T attached has been released, based on the acquired radio wave intensity P. Specifically, if the peak detection value Pa of the acquired radio wave intensity P is greater than Pth1 (Yes in S108), and the detection value Pb of the acquired radio wave intensity P is "0" and less than or equal to the second threshold Pth2 (No in S109), it is determined that the item G with the wireless tag T attached has been released, and the stored flag is cleared and the released flag is set (S110). Subsequently, if no termination instruction is received (No in S112), the process from step S101 above is performed.

[0045] On the other hand, if the peak detection value Pa of the acquired radio wave intensity P is less than or equal to Pth1 (No in S108), or if the detection value Pb of the acquired radio wave intensity P is almost stably above the second threshold Pth2 (Yes in S109), then it is determined that item G is moving within the management shelf 10, and it is judged to maintain its status as an incoming item (S111). In the event of such a determination to maintain its status as an incoming item, if the incoming flag is not cleared and the outgoing flag is not set, and no termination instruction has been received (No in S112), the processing from step S101 above is carried out.

[0046] As described above, in the item management system 1 according to this embodiment, the entry and exit of items G is determined based on the time change in the radio wave intensity P of the wireless tag T. This suppresses misjudgments of the entry and exit of items G, even when items G are placed on the management shelf 10, when items G brought close to the entrance / exit 11 are carried without being stored, or when stored items G move within the management shelf 10, thereby further improving the management accuracy regarding the entry and exit of items G.

[0047] In addition, in the inventory management process performed on the management terminal 32, the first threshold Pth1 and second threshold Pth2 used for inventory determination and the first threshold Pth1 and second threshold Pth2 used for inventory determination may be set differently depending on the operating environment.

[0048] The present invention is not limited to the embodiments described above, and may be further embodied as follows, for example. (1) The storage shelf 10 is not limited to being configured as a box shape such that the entrance 11 opens in a rectangular shape, but the entrance 11 may be configured to open in a shape other than a rectangle, for example, a polygon, an ellipse, or a curved shape. Even when the entrance 11 is formed in a shape other than a rectangle, the above effect can be achieved by installing the antenna 20 near the entrance 11 so that the entrance 11 is within the reading range S. Furthermore, the storage shelf 10 is not limited to being formed so that each wall section does not have an opening except for the entrance 11 as described above, but may be formed so that at least a part of each wall section is provided with an opening or the like where items G cannot be put in or taken out.

[0049] (2) In order to limit the reading range S to only the vicinity of the entrance / exit 11, radio wave shielding shields or the like may be installed on the outside of each wall surrounding the entrance / exit 11 to block radio waves.

[0050] (3) In order to prevent the wireless tag T of an item G placed on the outer surface of the upper wall 12 of the management shelf 10 from being read, a radio wave shield or the like may be installed on the outer surface of the upper wall 12 where the item G may be placed. By installing a radio wave shield or the like on the outer surface of the upper wall 12 in this way, even if the item G is brought so close to the entrance 11 that the peak detection value Pa of the radio wave intensity P exceeds the first threshold Pth1, and then placed on the outer surface of the upper wall 12 without being stored, the detected value Pb of the radio wave intensity P will not exceed the second threshold Pth2 (No in S105), thus preventing a false determination that the item G with the wireless tag T attached has been stored. [Explanation of symbols]

[0051] 1. Inventory Management System 10 Management shelf 11 Entrance / exit 12 Upper wall 20 antennas 30 Management device 31 Wireless tag reader 32 Management terminals G Goods S Reading range T Wireless Tag

Claims

1. An item management system that manages items that are moved in and out of storage shelves, The aforementioned article is fitted with a wireless tag on which information that can identify the article is recorded in a way that can be read via contactless communication. The antenna installed on the aforementioned management shelf, A management device that manages the entry and exit of items through the entrance and exit of the management shelf using information read from the wireless tag via the antenna, Equipped with, The item management system is characterized in that the antenna is installed on the management shelf so as to have the entrance / exit as its reading range.

2. The article management system according to claim 1, characterized in that the antenna is installed on the upper wall of the management shelf that constitutes the area above the entrance, such that the entrance is within the reading range.

3. The item management system according to claim 1, characterized in that the management device determines the entry and exit of the item based on the time change in the radio wave intensity of the wireless tag read via the antenna.

Images