Item management system and item management method

Abstract

This invention provides an item management system that enables stable and accurate wireless communication between RFID tags attached to metal items being managed. [Solution] When managing a metal key bundle 8 with an RFID tag 11 attached in a storage container 1, the RFID tag 11 is inserted into the storage container 1 from which radio waves are emitted from the antenna 9, and the key bundle 8 is placed outside the storage container 1, thereby avoiding reflection and diffusion of radio waves by the key bundle 8. This reliably prevents the key bundle 8 from reducing the performance of reading information from the RFID tag 11 or writing information to the RFID tag 11.

Description

Technical Field

[0001] The present invention relates to an article management system and an article management method for managing the state of an article by wireless communication using an RFID tag.

Background Art

[0002] Systems that attach RFID (Radio Frequency Identification) tags to articles and manage the location, destination, etc. of the articles based on the information stored in the RFID tags have been conventionally used in fields such as manufacturing, sales, and logistics. Since an RFID reader that transmits and receives information to and from an RFID tag can receive data transmitted from a plurality of RFID tags in a batch, in an industry where there are many types and a large number of articles to be managed, by reading the management status of those articles with an RFID reader, efficient article management becomes possible.

[0003] On the other hand, since a system using an RFID tag performs information writing and reading by wireless communication, there is a problem that reliable information exchange cannot be performed in an environment where radio waves are reflected and diffused. In particular, in the case of a security company, since the keys received from customers are metallic bodies, in an environment where keys are managed, a metallic body exists in the vicinity of the RFID tag, and due to its influence, radio wave reflection, penetration, and attenuation occur, and the communication performance with the RFID tag may deteriorate. When such metallic bodies exist in large quantities and at high density, a significant deterioration in communication performance occurs.

[0004] For example, Patent Document 1 discloses a configuration in which an antenna is arranged on the back side of the storage surface of a key box in which a keyholder incorporating an RFID tag is stored, in order to address the problem that the keyholder incorporating the RFID tag and the metallic key physically interfere with each other and stable wireless communication cannot be performed between the RFID tag and the RFID reader, and wireless communication is performed between the RFID tag of the keyholder within the key box.

Prior Art Documents

Patent Documents

[0005] [Patent Document 1] Japanese Patent Publication No. 2012-67467 [Disclosure of the Invention] [Problems that the invention aims to solve]

[0006] The UHF band radio waves used for transmitting and receiving data using the aforementioned RFID tags have good diffraction characteristics and can easily penetrate behind radio wave obstacles. In addition, it is known that metal reflects and diffuses the radio waves, resulting in constructive or destructive interference. When managing metal items by attaching RFID tags, simply reviewing the selection of RFID tags and the method of attaching them will not eliminate the possibility of misreading or missing tag information.

[0007] In the configuration described in Patent Document 1 above, the RFID tag on the keychain attached to the key is placed within the communication range of the antenna, and the key is placed outside that range to prevent radio waves from reaching the key. However, the key and the RFID tag on the keychain are installed in the same space with no shielding between them.

[0008] Considering the linearity and scalability of radio wave propagation, it is difficult to limit the communication range of an antenna within the same space, as described in Patent Document 1, that is, to create areas where radio waves arrive and areas where they do not. Therefore, the configuration in Patent Document 1 has the problem that radio waves from the antenna are reflected and diffused by the key that is close to the RFID tag, and mutual interference between the RFID tag and the key in the electromagnetic environment of the same space cannot be completely eliminated.

[0009] In other words, RFID tags used in RFID systems that communicate using radio waves are susceptible to interference from metal objects such as keys. Therefore, if an RFID tag and metal are placed in the same space without electromagnetic shielding, the direct waves that should reach the RFID tag from the antenna are reflected by the metal, resulting in poor information reading on the RFID tag. Furthermore, when a composite wave is generated from the direct waves from the antenna to the RFID tag and the reflected waves that reach the RFID tag after being reflected by the metal, reinforcement or cancellation of radio waves occurs (fading), and poor information reading on the RFID tag occurs at the point where cancellation occurs. In either case, stable wireless communication between the antenna and the RFID tag becomes impossible.

[0010] The present invention has been made in view of the above-mentioned problems, and its objective is to provide an item management system that can perform stable and accurate wireless communication with an RFID tag even when a metal item to be managed is located near the RFID tag. [Means for solving the problem]

[0011] To achieve the above objectives and as a means of solving the above-mentioned problems, the present invention provides an article management system for which articles with RFID tags attached are managed articles, comprising: a storage container having an insertion opening configured to hold the managed articles; an antenna provided inside the storage container; an acquisition unit that acquires identification information unique to the managed articles through communication between the antenna and the RFID tag; and a management unit that grasps the current status of the managed articles based on the identification information, wherein the insertion opening is configured to allow the RFID tag to be inserted inside the storage container and to hold the managed parts and the RFID tag with the managed articles exposed to the outside of the storage container, and the storage container functions as a shielding unit that electromagnetically blocks the RFID tag and the managed articles held through the insertion opening, so that radio waves radiated from the antenna do not irradiate the RFID tag and reach the managed articles.

[0012] For example, the insertion openings are formed at predetermined intervals in the circumferential direction of the wall surface of the storage container and are arranged in multiple rows in the vertical direction of the wall surface. For example, the insertion openings are arranged such that the odd-numbered and even-numbered rows of the multiple rows are staggered. For example, the insertion openings have horizontally elongated rectangular openings. These insertion openings are arranged so as to be parallel to each other in the vertical direction of the wall surface of the storage container. Furthermore, for example, the insertion openings have vertically elongated rectangular openings. These insertion openings are arranged so as to be parallel to each other in the circumferential direction of the wall surface of the storage container. Also, for example, the storage container has a cylindrical or prismatic shape with a central axis in the vertical direction, or a cylindrical or rectangular tube shape, and is configured so that radio waves can pass through the inside of the storage container. For example, the storage container is configured so as to be rotatable horizontally with the central axis as the axis of rotation.

[0013] As another means of solving the above-mentioned problems, the item management method according to the present invention is characterized by using the item management system described above to grasp the status of items being taken out and returned. [Effects of the Invention]

[0014] According to the present invention, even in environments where it is difficult to maintain a large distance between the RFID tag and the metal object to be managed, and where they must be kept in close proximity, information can be reliably read from the RFID tag and information can be written to the RFID tag. [Brief explanation of the drawing]

[0015] [Figure 1] External perspective view of a storage container used in an article management system according to one embodiment of the present invention. [Figure 2] This diagram shows the configuration of items managed by the item management system. [Figure 3] This is a plan view of a storage container holding a bunch of keys, located on the outside of a wall, as seen from the vertical upper side. [Figure 4]This diagram shows an example of the overall configuration of an inventory management system. [Modes for carrying out the invention]

[0016] Embodiments of the present invention will be described below with reference to the drawings. Figure 1 is an external perspective view of a storage container 1 used in an article management system according to one embodiment of the present invention. In Figure 1, a part of the storage container 1 is cut away to show its internal structure. The storage container 1 is a cylindrical hollow body made of a metal such as copper, iron, aluminum, or brass, and is supported by a central axis 2 that extends vertically inside it.

[0017] Furthermore, the shape of the storage container 1 is not limited to a cylindrical shape; for example, it may be a hollow rectangular prism, a cylindrical shape, or a rectangular tube shape. The storage container 1 is not limited to being made entirely of metal; for example, it may be made of a container made of resin or the like, with only the outer surface covered with metal.

[0018] Furthermore, the storage container 1 is not limited to a hollow body; the inside of the storage container 1 may be filled with a material that does not affect the propagation of radio waves emitted from the antenna 9, which will be described later. This increases the mechanical strength of the storage container 1, and the RFID tag 11, which will be described later, can be held using the filling material. As the filling material, plastic resins such as acrylic, polystyrene foam, wood, etc., can be used.

[0019] The wall surface 4 of the storage container 1 has multiple insertion slots 5 for inserting and removing the RFID tags, which are used to hold the managed items in the article management system according to this embodiment (a bunch of keys 8 to which RFID tags 11, described later, are attached). Here, a bunch of keys is used as an example of a managed item, but the managed items are not limited to this and broadly include other articles made of metal (articles that are conductive).

[0020] The storage container 1 is placed on the upper surface of the pedestal 7 and is configured to be rotatable horizontally about the central axis 2 as a rotation axis. That is, the administrator / user applies an external force in the circumferential direction perpendicular to the normal direction of the wall surface 4 to rotate the storage container 1, and positions the desired insertion port 5 on the administrator / user side, so that the management target items held at the insertion port 5 can be taken out arbitrarily.

[0021] The insertion port 5 has a horizontally long rectangular opening and functions as an opening for inserting and removing the RFID tag 11 into the storage container 1. The insertion ports 5 are arranged at regular intervals in the circumferential direction of the wall surface 4 of the storage container 1, and they are arranged in a row while maintaining a constant interval in the vertical direction of the wall surface 4, that is, parallel to each other in the vertical direction.

[0022] In the example shown in FIG. 1, 30 insertion ports 5 are arranged in a single row in the circumferential direction of the wall surface 4 of the storage container 1, and further, 20 rows are arranged in the vertical direction of the wall surface 4 of the storage container 1. As a result, the storage container 1 can hold and manage a total of 600 key bundles.

[0023] The number of insertion ports 5 arranged on the wall surface 4 of the storage container 1 may be further increased and made denser within the range where the reading sensitivity of the RFID tag 11 attached to the key bundle 8 can be maintained.

[0024] At the lower end inside the storage container 1, an antenna 9 for transmitting and receiving the unique information (identification information) etc. of each key bundle 8 to and from the RFID tag 11 inserted into the storage container 1 is arranged. The antenna 9 emits electromagnetic waves with a specific frequency (here, 920 MHz) and a specific output power (here, 1 W) from the lower end side to the upper direction of the storage container 1. With this configuration, the storage container 1 functions as a circular waveguide, and the radio waves radiated from the antenna 9 are coupled with the storage container 1 and propagate inside the storage container 1 in a predetermined propagation mode.

[0025] Furthermore, if the number of items to be managed collectively (key bundle 8) becomes large, and the height of the storage container 1 (indicated by H in Figure 1) is increased accordingly, it is conceivable that problems may arise, such as the radio waves radiated from the antenna 9 installed at the lower end of the storage container 1 being attenuated at the vertical upper part of the storage container 1. In such cases, an additional antenna that transmits and receives radio waves, similar to antenna 9, may be added to the upper end inside the storage container 1.

[0026] Furthermore, the output power of the antenna 9 may be adjusted as needed, such as by increasing or decreasing it according to the quantity of managed items (key bundles 8) being centrally controlled.

[0027] Figure 2 shows the configuration of the managed items in the item management system according to this embodiment. The key bundle 8, which is a managed item, is bound to the RFID tag 11 via the ring portion 10 as shown in Figure 2, and they are handled as a single unit when the key bundle 8 is stored or used.

[0028] The RFID tag 11 includes an inlay portion 15 consisting of an RFIC chip (integrated circuit), an antenna, etc., housed in a flat plate-shaped case made of an insulating material (for example, resin). One end of the RFID tag 11 (the side to which the key bundle 8 is attached) is provided with a stopper portion 13 with an outer diameter larger than the diameter of the insertion opening 5.

[0029] As shown in Figure 2, the other end of the RFID tag 11 (the side to which the key bundle 8 is not attached) is inserted into the insertion opening 5 in the direction of the arrow, and pushed in until the stopper part 13 contacts the wall surface of the storage container (not shown). This causes the receiving part 6a on the stopper part 13, which has an outer diameter approximately the same as the diameter of the insertion opening 5, to connect with the receiving part 6b on the insertion opening 5, thereby fitting the RFID tag 11 into the insertion opening 5. As a result, the key bundle 8 remains attached to the RFID tag 11 and is held outside the wall surface 4 of the storage container 1 (see Figure 3), preventing it from falling out of the insertion opening 5.

[0030] The radio waves emitted from the antenna 9 are reflected upon contact with the inner wall of the storage container 1, and as a result, the radio waves with opposite phases cancel each other out, which may create areas (null points) inside the storage container 1 where the RFID tag 11 cannot receive radio waves. Therefore, as shown in Figure 2, a gap d (for example, about 10 to 20 mm) is provided between one end of the inlay portion 15 and the receiving portion 6a of the stopper portion 13 in the RFID tag 11. This separates the inlay portion 15 from the inner wall of the storage container 1, thereby avoiding the null points.

[0031] Furthermore, even if reinforcement or destructive interference (fading) of radio waves occurs between the RFID tag 11 and the inner wall (metal wall) of the storage container 1, reading of the RFID tag 11 is possible by separating the RFID tag 11 and the metal wall by approximately the aforementioned distance d.

[0032] Figure 3 is a plan view of the storage container 1, which holds the key bundle 8 on the outside of the wall surface 4, as seen from the vertical upper side. From Figure 3, it can be seen that the RFID tag 11, which is attached to the key bundle 8, is held adjacent to the wall surface 4, protruding horizontally from the wall surface 4 toward the central axis 2 and toward the inside of the container.

[0033] Inside the storage container 1, adjacent RFID tags 11 are arranged so that they do not overlap with each other. This prevents interference between adjacent RFID tags in transmitting and receiving radio waves.

[0034] As described above, considering the storage container 1 as a circular waveguide, the cutoff wavelength λc of the radio waves (frequency fc = 920 MHz) propagating inside it can be determined from λc = C / fc (where C is the speed of light). From this, the inner diameter of the storage container 1 (D in Figure 3) can be calculated from the equation λc = πD / x (x = 1.841184), resulting in D = 191 mm. Therefore, the inner diameter D of the storage container 1 shown in Figures 1, 3, etc., must be 191 mm or more.

[0035] Figure 4 shows an example of the overall configuration of the item management system according to this embodiment. The item management system 20 according to this embodiment comprises a management server 31 that controls the entire system and a storage container 1 that houses the items to be managed, and the management server 31 and the storage container 1 are connected by a communication line 21.

[0036] The management server 31 consists of a control unit 32, a key management unit 34, an input unit 36, and a display unit 37. The control unit 32 has a storage unit 33 and a communication unit 35. The control unit 32 is equipped with a central processing unit (CPU) consisting of a microprocessor or the like, and controls the entire management server 31.

[0037] The storage unit 33 stores the control operation program, control data, etc. of the control unit 32 and consists of, for example, ROM (Read Only Memory), non-volatile memory, etc. The communication unit 35 functions as a communication interface (I / F) for data communication, etc., between the management server 31 and the storage container 1.

[0038] The key management unit 34 manages and stores management information related to the key bundle 8, which is a managed item in the item management system 20, such as the name of the key bundle, the management number of the key bundle, and the history of the key bundle's retrieval / return. For this purpose, the key management unit 34 is equipped with, for example, an HDD (hard disk drive) and a large-capacity semiconductor memory. This management information is associated with ID information recorded in the inlay portion 15 provided on the RFID tag 11 attached to each key bundle 8.

[0039] The input unit 36 ​​receives data necessary for managing the key bundle 8 from the administrator or user of the item management system 20, and the display unit 37 displays the aforementioned management information for the key bundle 8 in a format that can be viewed by the administrator or user.

[0040] Alternatively, instead of the management server 31, a personal computer (PC), mobile terminal, or the like, equipped with a predetermined management program, may be used.

[0041] <Explanation of Verification Results> A simple prototype of the aforementioned key bundle storage environment, specifically a configuration where the key bundle and RFID tags are not placed adjacent to each other, was created to verify the effect of the key bundle on the RFID tag reading sensitivity. In this prototype, 30 RFID tag insertion slots were provided on the side of a disc made of polystyrene foam that transmits radio waves, and a cylinder was created by stacking 20 of these discs. Aluminum sheets were attached to the sides of the cylinder, except for the RFID tag insertion slots. This cylinder was then placed inside a cabinet, and planar antennas were installed at the top and bottom of the cylinder in the axial direction.

[0042] 600 RFID tags with key bundles attached were inserted into all the slots, and all RFID tags were read within 20 seconds of the start of communication between the antenna and the RFID tags. The RSSI (received signal strength) at that time was -35.9 dBm at its maximum, -67.9 dBm at its minimum, and -54.0 dBm at its average.

[0043] Regarding the relationship between received signal strength and readability, if we evaluate the readability as follows: -30 dBm is considered "very good," -67 dBm as "good," -70 dBm as "readable," -80 dBm as "poor," and -90 dBm as "unreadable," then the average received signal strength of the RFID tags with key bundles attached, obtained from the verification in the above storage environment, can be evaluated as having "good" readability and no decrease in sensitivity.

[0044] On the other hand, for the purpose of obtaining comparative data, 600 RFID tags without key bundles were inserted into all input slots, and communication between the antenna and the RFID tags was performed. In this case as well, all RFID tags could be read within 20 seconds from the start. The RSSI (received signal strength) at that time was -38.2 dBm at its maximum, -63.6 dBm at its minimum, and -51.8 dBm at its average.

[0045] The average RSSI of RFID tags with key bundles was lower than that of RFID tags without key bundles, but a "good" reading condition was obtained. Furthermore, the minimum RSSI of RFID tags with key bundles also indicated a "good" reading condition, indicating that the storage container used in the item management system according to this embodiment has a structure that is robust against information loss when reading RFID tags with key bundles attached.

[0046] In a conventional storage environment, where a bunch of keys and RFID tags are placed next to each other in a cabinet, and a total of four antennas are installed on the cabinet door, it was found that the minimum RSSI value of the RFID tags was around -76.0 dBm. From this, it can be concluded that the cylindrical structure used in this verification, which has a minimum RSSI of -67.9 dBm, is an effective structure for avoiding a decrease in the reception sensitivity of RFID tags when a bunch of keys is present.

[0047] Furthermore, the RSSI of the RFID tag with the key bundle, as mentioned above, had a median value of -54.5 dBm, which is higher than the maximum value and lower than the minimum value of the RFID tag without the key bundle, which had a median value of -52.1 dBm. This is thought to be because the insertion opening of the cylinder used in this verification was not completely sealed by the RFID tag, and there was slight reflection of radio waves from the key bundle near the insertion opening, causing fluctuations in the strength of the composite wave reaching the RFID tag.

[0048] In this verification, for both RFID tags with and without key bundles, the maximum, median, and minimum values ​​mentioned above were calculated from the average of the most recent three RSSI values ​​for 600 RFID tags 180 seconds after the start of measurement.

[0049] As described above, the item management system according to this embodiment, when managing a key bundle to which an RFID tag is attached, removes the metal key bundle from the environment where radio waves are emitted, and electromagnetically isolates the RFID tag and the key bundle, thereby reliably avoiding the reflection and diffusion of radio waves caused by the key bundle. Therefore, when managing items such as an RFID tag and a key bundle attached to it, which cannot be kept far apart, it is possible to reliably prevent a decrease in the information reading performance from the RFID tag or the information writing performance to the RFID tag due to the influence of the key bundle, and to ensure stable information exchange.

[0050] Therefore, even in environments where a large number of metal items such as keychains with RFID tags attached are stored at high density, there is no reflection or diffusion of radio waves by the keychains, etc., and the reading sensitivity of the RFID tags is not reduced, allowing for reliable information reading, and the management status of the keychains, etc., can be accurately grasped and confirmed by external devices.

[0051] <Variation> The embodiments of the present invention are not limited to the examples described above, and various modifications are possible. For example, the storage container 1 is not limited to a hollow body, and as long as radio waves can pass through the inside of the storage container 1, it may be made into a cylindrical shape by stacking disc-shaped members made of polystyrene foam or the like, as in the storage container used in the verification described above. Also, the storage container 1 may not have a rotating shaft 2, and for example, the base 7 may be used as a turntable to make the storage container 1 rotatable in the horizontal direction.

[0052] As an antenna for sending and receiving information with RFID tags, for example, a leaky coaxial cable (LCX), which is a cable-type antenna for short-range communication, may be used. Alternatively, a planar antenna may be used. Since the cable-type antenna has an elongated shape suitable for installation in a narrow space such as the inside of the storage container 1, by laying it along the central axis 2 of the storage container 1, the cable-type antenna and the RFID tags will face each other in close proximity inside the storage container 1, enabling reliable wireless communication at close range between the cable-type antenna and multiple RFID tags.

[0053] Furthermore, when using a cable-type antenna, the antenna output can be set so that radio waves reach only the RFID tag facing the antenna, and not the key bundle 8 located on the outer wall of the storage container 1, thereby preventing radio wave scattering within the storage container 1. In this case, since the range of radio waves is limited, the storage container 1 and the central axis 2 can be constructed from materials other than metal (for example, resin), which can lead to weight reduction, cost reduction, and improved processability of the storage container 1.

[0054] Furthermore, when a cable-type antenna is laid along the central axis 2 as described above, an actuator such as a motor may be provided to move the cable-type antenna up and down along the central axis 2. This allows the relative position of the antenna and the RFID tag to be changed, which is an effective measure to avoid the occurrence of null points inside the storage container 1. In addition, since the cable-type antenna itself is lightweight, the actuator can also be small.

[0055] In this case, for example, if the control unit 32 determines that reading the RFID tag has failed for a certain period of time, it may drive the cable-type antenna up and down. If the cause of the reading failure is a null point, the system can transition to a normal reading state by driving the antenna up and down.

[0056] In the embodiment described above, the opening shape of the insertion port 5 was a horizontally elongated rectangle, but the opening shape of the insertion port 5 may be a vertically elongated rectangle, and these insertion ports may be arranged so that they are parallel to each other in the circumferential direction of the wall surface of the storage container. This allows the RFID tag to be matched to the polarization direction of the antenna used, and can accommodate variations in RFID tag reading performance depending on the surrounding environment, such as the mounting direction of the RFID tag.

[0057] Furthermore, to provide greater flexibility in responding to variations in reading performance depending on the mounting direction of the RFID tag, the opening shape of the insertion slot 5 may be a cross shape formed by combining a vertically elongated rectangle and a horizontally elongated rectangle.

[0058] Furthermore, if the number of items to be managed is less than the number of insertion slots 5 provided on the wall surface 4 of the storage container 1, or if it is desired to store the items sparsely to avoid adjacent placement, empty insertion slots 5 will remain. In this case, it is possible that radio waves emitted inside the storage container 1 may leak to the outside through the empty insertion slots 5. Therefore, a metal sealing plug that matches the opening shape of the insertion slot 5 may be prepared to seal the insertion slot 5 and prevent radio wave leakage.

[0059] In the embodiment described above, as shown in Figure 1, the insertion slots 5 are arranged at regular intervals in the circumferential direction of the wall surface 4 of the storage container 1, and are also arranged in a stepped manner at the same position in the vertical direction while maintaining a regular interval in the vertical direction of the wall surface 4. However, the arrangement is not limited to this. For example, considering the attenuation of radio waves due to the overlap of RFID tags in the vertical direction within the storage container 1, the insertion slots 5 may be arranged so that odd-numbered and even-numbered rows alternate in the vertical direction.

[0060] For storage container 1, several types of storage containers with different heights (indicated by H in Figure 1) may be prepared according to the quantity of items to be managed. Alternatively, a storage container of a basic height may be prepared, and if the quantity of items to be managed increases, storage containers of the basic height may be stacked to form a longer storage container. This makes it possible to provide a flexible item management system equipped with storage containers of heights that correspond to the management status of the items to be managed. [Explanation of Symbols]

[0061] 1. Storage container 2 center axis 4 Wall surface 5 Insertion slot 6a, 6b Receiving part 7 Pedestal 8 Keys 9 Antennas 10 Ring section 11 RFID tags 13 Stopper section 15 Inlay section 20. Inventory Management System 21 Communication lines 31 Management Server 33 Storage section 34 Key Management Department 35 Communications Department 36 Input section 37 Display section

Claims

1. An item management system that treats items to be managed as items to which RFID tags are attached, A storage container having an insertion opening configured to hold the items to be managed, An antenna provided inside the aforementioned storage container, An acquisition unit that acquires identification information unique to the managed item through communication between the antenna and the RFID tag, A management unit that grasps the current status of the managed items based on the aforementioned identification information, Equipped with, The insertion opening is configured to allow the RFID tag to be inserted into the storage container, and to hold the managed component and the RFID tag while the managed item is exposed to the outside of the storage container. The storage container functions as a shielding unit that electromagnetically separates the RFID tag held through the insertion opening from the managed item, thereby preventing radio waves radiated from the antenna from reaching the RFID tag and the managed item.

2. The article management system according to claim 1, characterized in that the insertion openings are formed at predetermined intervals in the circumferential direction of the wall surface of the storage container and are arranged in multiple rows in the vertical direction of the wall surface.

3. The article management system according to claim 2, characterized in that the insertion slots are arranged in alternating positions in the odd-numbered and even-numbered rows of the multiple rows.

4. The article management system according to claim 2 or 3, characterized in that the insertion port has a horizontally elongated rectangular opening.

5. The article management system according to claim 4, characterized in that the insertion openings are arranged to be parallel to each other in the vertical direction of the wall surface of the storage container.

6. The article management system according to claim 2 or 3, characterized in that the insertion port has a vertically elongated rectangular opening.

7. The article management system according to claim 6, characterized in that the insertion openings are arranged so as to be parallel to each other in the circumferential direction of the wall surface of the storage container.

8. The article management system according to claim 1, characterized in that the storage container has a cylindrical or prismatic shape with a central axis in the vertical direction, or a cylindrical or rectangular tube shape, and the inside of the storage container is configured to allow radio waves to pass through.

9. The article management system according to claim 8, characterized in that the storage container is configured to be rotatable horizontally with the central axis as the axis of rotation.

10. A method for managing items, characterized by using the item management system described in claim 1 to understand the status of items being taken out and returned.

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