JP2010258846A - Rfid reader/writer antenna apparatus, and antenna adjusting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To identify an RFID tag without missing by solving the problem of communication inability with the RFID tag stuck on an article moving on a conveying path. <P>SOLUTION: In an RFID tag reader/writer antenna apparatus, a plurality of sets of antenna groups are provided, above an article conveying path, in the direction intersecting the article conveying path across the conveying path. The RFID reader/writer antenna apparatus includes an adjustment means for adjusting an interval between the plurality of sets of antenna groups, a direction of a communication enabled area, or the both in such a way that an RFID tag stuck on an article is passed through a portion where at least two communication enabled areas formed from the plurality of sets of antenna groups are overlapped with each other. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an RFID reader / writer antenna device connected to an RFID reader / writer for communication between an RFID (Radio Frequency Identification) tag and an RFID reader / writer, and an antenna adjusting device for adjusting the RFID reader / writer.

  In many cases, RFID tags that can communicate wirelessly are used for goods management at distribution centers and factories. In particular, passive tags that can be expected to lower the price because they do not have a built-in battery can secure a maximum communication distance of about 10 meters by using the UHF (Ultra-High Frequency) band, and therefore have a wider range of use than before. It is expected to expand.

  By the way, in many RFID systems conventionally used for article management etc., a gate with an antenna for receiving a signal from an RFID tag is installed in the middle of the movement path of the article, and the article passes through the gate. In this case, a gate method is employed in which communication with the RFID tag is performed.

  However, if only a single gate is used because the signal from the RFID tag has directivity, communication may not be possible even if it passes close to the gate antenna, depending on the attitude of the RFID tag. There was a problem that the article could not be identified. In particular, passive tags are driven by the energy of electromagnetic waves radiated from an antenna and have a weak output. Therefore, it is difficult to extend the communication distance unless directivity is provided to some extent, and this problem is likely to occur. is doing.

  As a conventional technique, Patent Document 1 discloses a technique for avoiding the problem of inability to communicate due to the influence of a shielding object by installing antennas not only on both sides of a gate but also on the top and bottom. Patent Document 2 discloses a technique for expanding a communicable region by adding antennas obliquely directed to both sides of an entrance and an exit of a gate.

JP 2008-112227 A JP 2007-88937 A

  However, even with the technique disclosed in Patent Document 1, for example, the gate of the antenna built in the sheet-like RFID tag (hereinafter referred to as “tag antenna”) remains facing the conveyance direction of the article. If you cross it, you will still be unable to communicate. Similarly, even with the technique disclosed in Patent Document 2, if the antenna surface of the tag antenna passes through the gate in a state parallel to the ground, communication is still impossible.

  The present invention has been made to solve the above-described problems of the prior art, solves the problem of inability to communicate with an RFID tag attached to an article moving on a conveyance path, and can identify the RFID tag without omission. The purpose is to do so.

  In order to achieve the above object, the present invention provides an antenna device for an RFID reader / writer that receives an electromagnetic wave signal radiated from an RFID tag and relays it to an RFID reader / writer. A portion (hereinafter referred to as “bi-communicable region”) in which at least two communicable areas formed by the plural antenna groups overlap each other (hereinafter referred to as “bi-communicable area”) is provided on the conveyance path. Adjusting means for adjusting the interval between the plurality of sets of antenna groups and / or the direction of the communicable region so that the RFID tag attached to the article to be conveyed passes.

  Moreover, the height adjustment means which adjusts the height from the ceiling surface of the said multiple groups of antenna group was provided.

  In addition, a swing control means for swinging the plurality of antenna groups as a whole from upstream to downstream of the transport path, or a third antenna group having directivity in the upstream direction of the transport path is provided. It was.

  Further, the plurality of sets of antenna groups are set so that the designated passing range is included in the dual communication possible area only by designating the passing range of the RFID tag immediately below the antenna device to the antenna adjustment device. Control means for controlling at least one of the interval between, the direction of the communicable area, and the height from the ceiling surface is provided.

  According to the present invention, the problem of inability to communicate with an RFID tag attached to an article moving on a conveyance path can be solved, and the RFID tag can be identified without omission.

It is a schematic diagram of the antenna device which concerns on 1st embodiment. It is explanatory drawing about the swing operation | movement of the antenna apparatus which concerns on 1st embodiment. It is a block diagram which shows the equipment configuration of the antenna device which concerns on 1st embodiment, and the connection form with another apparatus. It is explanatory drawing which shows the relationship between the attitude | position of a tag and the appearance from an antenna apparatus. It is explanatory drawing which shows the appearance from an antenna apparatus when a tag moves. It is a flowchart which shows the flow of a process of an antenna adjustment program. It is a display example of the parameter input screen for antenna adjustment. It is explanatory drawing about the parameter for antenna adjustment, and adjustment operation. This is an example of a test pole that is a tool for antenna adjustment. It is an example of the guidance message displayed at the time of antenna adjustment. It is a schematic diagram of the antenna device which concerns on 2nd embodiment. It is a block diagram which shows the equipment configuration of the antenna device which concerns on 2nd embodiment, and the connection form with another apparatus.

  Hereinafter, two modes for carrying out the present invention will be described in order with reference to the drawings.

<First embodiment>
FIG. 1 shows a state when an RFID reader / writer antenna device (hereinafter abbreviated as “antenna device”) 1 according to a first embodiment of the present invention is installed on a ceiling surface C in a form straddling a conveyance path. FIG. 5 is a schematic view seen from the upstream side of the conveyance path, and a communicable area A1 and the like have a cross-sectional shape immediately below the antenna device 1;

  In FIG. 1, a conveyance path (not shown) is provided on the floor surface F immediately below the antenna device 1 in the direction from the front to the back of the figure. In addition, an article (not shown) to which an RFID tag (hereinafter also abbreviated as “tag”) 2 is affixed irregularly on a cart (not shown) and conveyed on a conveyance path. The tag 2 is shown in FIG. As illustrated, the tag passing range A3 (inside the rectangle drawn with a broken line) is moved in parallel from the front to the back of the figure in various postures and heights. The antenna device 1 is required to be able to communicate with all these tags 2 passing through the tag passage range A3 without omission.

  In the antenna device 1, a telescopic and rotatable horizontal arm 12 having two antenna groups 16 on the left and right sides can be suspended from a ceiling surface C by a telescopic vertical arm 13 and a ceiling fixing part 11. It has a structure that can be done. A telescopic cable may be used instead of the vertical arm 13.

  In FIG. 1, each of the left and right antenna groups 16 has two planar antennas 15 connected in the longitudinal direction of the horizontal arm 12 by an antenna mounting shaft 14, but the number and connection means of the planar antennas 15 are not limited thereto. It is only necessary that the angle of each planar antenna 15 can be changed so that there is no gap between the communicable areas A1 of the two adjacent planar antennas 15 (inside the trapezoid drawn with a one-dot chain line). As a result, the beam widths of the left and right antenna groups 16 can be appropriately adjusted.

  That is, as shown in FIG. 1, if the communicable area A1 of each planar antenna 15 has a predetermined beam width (for example, 30 degrees), two planar antennas 15 are connected to form a beam as an antenna group 16. The width can be adjusted within a range of about 1 to 2 times the predetermined beam width (for example, a range of about 30 to 60 degrees). In order to increase the directivity to extend the communication distance, for example, if four planar antennas 15 having a beam width of 15 degrees are connected, the beam as the antenna group 16 is within a range of approximately 15 degrees to 60 degrees. The width can be adjusted.

  When adjusting the beam width of the antenna group 16, first, the outermost planar antenna 15 (the side far from the conveyance path) is set so that the outer end portion of the communicable area A1 faces almost directly below. Then, the angle of the inner planar antenna 15 may be set sequentially with reference to that.

  A portion A2 where the communicable areas A1 formed by the two left and right antenna groups 16 capable of adjusting the beam width overlap each other (a hatched portion in FIG. 1) A2 is a communication with both the left and right antenna groups 16. Therefore, this is referred to as a “bi-communication enabled area”.

  When the antenna device 1 according to the present embodiment is installed, the horizontal arm 12 and the vertical arm 12 are arranged so that the given tag passing range A3 (inside the rectangle drawn with a broken line) is included in the dual communication possible area A2. The length of the arm 13 and the angle of each planar antenna 15 are adjusted. This adjustment method will be described in detail later.

  Next, the swinging operation of the antenna device 1 according to this embodiment will be described. FIG. 2 is a schematic diagram showing the swinging operation of the antenna device 1, and an article (not shown) to which the tag 2 is attached is stacked on a cart or the like from the left to the right in the figure and spaced at a predetermined interval or more. Shall be transported.

  The antenna device 1 rotates the horizontal arm 12 about its axis to move the antenna group 16 from the left position P1 (denoted 16 (P1) in the figure) to the right position so as to automatically track the article being conveyed. A swing motion is performed to move to P2 (labeled 16 (P2) in the figure). As a result, a state in which the tag 2 that translates from the left to the right in the tag passage range A3 indicated by the upper and lower broken lines is in the dual communication possible area A2 (the hatched portion) is kept for a long time. Maintain over.

As a control method of the swing motion, for example, the number of tags 2 that can be communicated is monitored from the initial state where the antenna group 16 is at the left position P1, and the number of tags 2 that can be communicated increases or does not change. A method of rotating the antenna group 16 in the direction of the right position P2 so as to increase the number of tags 2 that can maintain communication and increase the number of tags 2 that can communicate, that is, to maximize the number of tags 2 that can communicate. Alternatively, there is a method of rotating the antenna group 16 in conjunction with the output of an infrared sensor or an image sensor for detecting the position of the article on the conveyance path. Also, when an article is transported at a constant speed, such as a belt conveyor, a switch for detecting the arrival of the article is provided, and the head is swung in a predetermined pattern from the time when the arrival of the article is detected. May be. Conversely, the movement of the article may be synchronized with the pattern of the swing motion.

  Next, the device configuration of the antenna device 1 will be described with reference to FIG. FIG. 3 is a block diagram illustrating a configuration of the antenna device 1 and a connection form with other devices.

  The antenna device 1 is connected to an RFID reader / writer 3 that communicates with the tag 2, radiates data transmission electromagnetic waves from the planar antenna 15 in accordance with a command from the RFID reader / writer 3, and transmits a signal transmitted from the tag 2. Catch and relay to the RFID reader / writer 3. At this time, each planar antenna 15 is time-division controlled by the antenna changeover switch 5 so as to operate cyclically at regular time intervals (for example, every 100 milliseconds). Thereby, since only one planar antenna 15 operates at the same time, mutual interference of electromagnetic waves between the plurality of planar antennas 15 does not occur.

  Note that it is desirable for the tag 2 to have a known anti-coregion function, so that mutual interference between electromagnetic waves radiated from the adjacent tag 2 can be avoided, so it is assumed that the tags 2 overlap each other. In addition, it is possible to sequentially communicate with each tag 2.

  The antenna device 1 also includes arm length control motors 7 and 8 and an antenna angle control motor 9 for adjusting the position and angle of each planar antenna 15, and the horizontal arm 12 according to a command from the antenna adjustment device 4. The length of the vertical arm 13 and the angle of the planar antenna 15 with respect to the antenna mounting shaft 14 are controlled. The antenna device 1 further includes a swing control motor 6, and controls the swing operation of rotating the horizontal arm 12 in accordance with a command from the RFID reader / writer 3.

  Next, with reference to FIG. 4 and FIG. 5, the principle of the problem that communication with the antenna device 1 becomes impossible due to the change of the posture of the tag 2 and the solution thereof according to the present invention will be described.

  FIG. 4 is a schematic diagram (simplified FIG. 1) of the dual communication possible area A2 in a state where the antenna device 1 is facing down, as viewed from the upstream in the conveyance direction of the article, and the center of the left antenna group at that time The relationship with the appearance of the tag 2 seen from the right antenna group center is shown.

  FIG. 5 is a schematic diagram (a simplified view of FIG. 2) of the trajectory of the two-communicable area A2 that moves in accordance with the swinging motion of the antenna device 1 as viewed from the right side in the article conveyance direction. It shows the relationship with the appearance of the tag 2 viewed from the center of the left antenna group and the center of the right antenna group.

  The left and right antenna group centers represented by black circles in FIGS. 4 and 5 are the communicable areas of the beam width θ formed by the left and right antenna groups 16 (the triangles drawn by the one-dot chain line in FIG. 4). The appearance of the tag 2 viewed from the planar antennas 15 can be approximated by the appearance of the tag 2 viewed from the center of the antenna group.

  In general, the tag 2 has directivity. For example, a sheet-like tag used for article management or the like has a tag antenna on the sheet surface, and therefore has directivity in a direction perpendicular to the sheet surface. Will eventually weaken and will be almost impossible to communicate.

  Therefore, for example, the tag 2a in FIG. 4 cannot communicate with the right antenna group 16 because the sheet surface looks right sideways from the center of the right antenna group. However, since the sheet surface looks almost right from the center of the left antenna group, communication with the left antenna group 16 is possible. Further, the tag 2b has substantially the same angle of the sheet surface viewed from the center of the right antenna group and the center of the left antenna group, and can communicate with both antenna groups 16.

  However, when the sheet surface is perpendicular to the conveying direction of the article as in the tag 2c, as shown at the bottom of the table in FIG. Even if it sees, since a sheet | seat surface turns to right side, it will become impossible to communicate with the antenna group 16 on either side.

  As in the case of the tag 2c, the above-described swinging operation is effective as a countermeasure when communication with both the left and right antenna groups 16 is disabled immediately below the antenna device 1.

  In FIG. 5, in the state of FIG. 4, the article with the tag 2c that cannot communicate with either the left or right antenna group 16 is conveyed from the left to the right as it is. It is assumed that the head is controlled so as to face the direction of the article. At this time, the position of the tag 2c changes in the order of 2c-1, 2c-2, and 2c-3 in FIG. When this is viewed from the center of the left antenna group and the center of the right antenna group of the antenna device 1 performing the swinging operation, it is as shown in the table of FIG.

  In other words, even when the sheet surface is oriented to the side at the position 2c-2, the sheet surface can be seen at a certain angle or more at the positions 2c-1 and 2c-3. Are in the bi-communication possible area A2, both of which can communicate.

As described above, according to the antenna device 1 according to the first embodiment, it is possible to solve the problem of inability to communicate due to the posture of the tag, and between all the tags attached to the articles conveyed on the conveyance path. Can reliably communicate.
Furthermore, the conventional gate method has a disadvantage that a transported article, a carriage, or the like may collide with the gate, or the facility layout is restricted by the installation of the gate. According to the antenna device 1 according to the embodiment, it is not necessary to install a gate that becomes an obstacle when conveying an article on the floor surface, so that these disadvantages can also be eliminated.

  Next, an adjustment method of the antenna device 1 using the antenna adjustment device 4 (see FIG. 3) will be described with reference to FIGS. The antenna adjustment device 4 is a portable computer that executes an antenna adjustment program (not shown), and an input / output interface for controlling an input unit such as a keyboard, a display unit such as a liquid crystal display, and an external device such as a motor. And have.

  FIG. 6 is a flowchart showing a process flow of the antenna adjustment program executed by the antenna adjustment device 4. FIG. 7 is a display example of a parameter input screen for antenna adjustment. FIG. 8 is an explanatory diagram of antenna adjustment parameters and adjustment operations.

  When the antenna adjustment program is started, first, in step S1, an antenna adjustment parameter input screen illustrated in FIG. 7 is displayed on a display unit (not shown). In this parameter input screen, the width w (mm) of the tag passage range A3, the height hu (mm) of the upper end, the height hl (mm) of the lower end, the height hc (mm) of the ceiling, and the beam width θ (degrees). ) Is input (see FIG. 8). For the beam width θ (degrees), an adjustable range (“30 to 90” in the example of FIG. 7) determined in accordance with the beam width and the number of connections of the planar antenna 15 is displayed. Accept only values.

  Next, in step S2, each of these parameter values input from a keyboard (not shown) is fetched. In step S3, the value of the height ha (mm) of the center of the antenna group is determined from the values of w, hu, hl, and θ. Is calculated (see FIG. 8).

  Next, in step S4, the required horizontal arm length and vertical arm length are calculated from the values of w, ha, and hc. In step S5, the validity of the calculation result is determined. Specifically, the obtained horizontal arm length and vertical arm length are both within a predetermined adjustable range, and the tag passing range A3 is included in the dual communication possible area A2, that is, d in FIG. Is determined to be appropriate if it is less than or equal to a predetermined value determined corresponding to the maximum communication distance of the planar antenna 15, and otherwise determined to be inappropriate.

  If it is determined that the calculation result is not valid (No in step S5), the process branches to step S7, and an error message prompting re-input of the parameter value is displayed on the display unit (not shown), and then the process goes to step S1. Return and repeat the above process.

  If it is determined that the calculation result is valid (Yes in step S5), the process proceeds to step S6 to control the control motors 7, 8, and 9 in FIG. 3 via an input / output interface (not shown). To adjust the horizontal arm length, the vertical arm length, and each antenna angle, and the process ends.

  The above-described antenna adjustment program has a parameter value input on the parameter input screen. By using an antenna adjustment tool, the size of the tag passing range A3 is designated on the actual conveyance path. You may do it.

  FIG. 9 illustrates a test pole as a tool for antenna adjustment. FIG. 10 is an example of a guidance message displayed on a display unit (not shown).

  A test pole 10a shown in FIG. 9A is a telescopic pole having a predetermined position detection tag 2d attached to the tip. Further, the stand type test pole 10b shown in FIG. 9B has a position detection tag 2e attached to the upper end of the extendable pole, and another position detection tag 2f can be moved up and down. Attached and can be moved on the floor by a stand with casters.

  FIG. 10A shows an example of guidance displayed when the test pole 10a is used. According to such guidance, a person supports the test pole 10a and sequentially passes through the tag passage range A3-4. The position detection tag 2d is arranged at the corner boundary point, and the antenna adjustment device 4 determines whether or not the position detection tag 2d can be read while changing the angle of the planar antenna 15, thereby grasping the tag passage range A3. be able to.

  FIG. 10B shows an example of guidance displayed when the size of the tag passage range A3 is specified using the stand-type test pole 10b. According to the guidance, a person can follow the tag passage range A3. The position detection tags 2e and 2f are aligned with the heights of the upper end and the lower end, respectively, and test poles 10b are installed at two locations on the left boundary line and the right boundary line of the tag passage range A3. However, it may be determined whether or not the position detection tags 2e and 2f can be read while changing the angle of the planar antenna 15.

  As described above, according to the antenna adjustment device according to the present embodiment, it is possible to correspond to the installation conditions of individual antenna devices only by specifying the tag passage range according to the size of the article to be conveyed and the conveyance form. Since the adjustment is performed automatically, the efficiency of installation and adjustment work of the antenna device can be greatly improved.

<Second embodiment>
FIG. 11 is a schematic view of the antenna device 1a according to the second embodiment of the present invention when installed on the ceiling surface C so as to straddle the conveyance path, and an article conveyance, as viewed from the upstream side of the conveyance path. It is the schematic diagram seen from the right side of the direction. FIG. 12 is a block diagram showing a configuration of the antenna device 1a according to the second embodiment and a connection form with other devices.

  As shown in FIGS. 11 and 12, the antenna device 1 a according to the second embodiment is arranged on the upstream side of the conveyance path as an alternative to the swinging operation of the antenna device 1 according to the first embodiment shown in FIGS. 1 to 3. A third antenna group 17 having directivity in the direction, and an antenna group depression angle control motor 18 that controls the depression angle of the antenna group 17 by rotating the antenna group attachment hinge 19 instead of the swing control motor 6. It is a thing. Since other components are the same as those in the first embodiment, common elements are denoted by the same reference numerals, description thereof is omitted, and differences from the first embodiment will be mainly described.

  The antenna group 17 is attached to the horizontal arm 12a by the antenna group attachment hinge 19 so that the communicable area A4 faces the upstream direction of the conveyance path and the depression angle γ with respect to the article conveyance direction can be adjusted. The planar antenna 15a constituting the antenna group 17 has higher directivity than the planar antenna 15 constituting the antenna group 16, and increases the communicable distance. As a result, the robot moves in a posture similar to the tag 2c in FIG. 4, so that even if communication is impossible at the position 2c-2 in FIG. 11, the same as described above with reference to FIG. According to the principle, communication can be performed via the antenna group 17 at the position 2c-1 in FIG. If only one planar antenna 15a has a communicable area A4 that includes a tag passing range A3a (see FIG. 11) that is equal to or smaller than a certain depression angle upstream of the transport path, the antenna group 17 has one planar antenna. You may comprise by 15a.

  According to the antenna device 1a according to the second embodiment described above, since it is not necessary to perform a swinging motion, even if an article is frequently or continuously conveyed, communication caused by the posture of the tag The problem of impossibility can be solved, and communication can be reliably performed with all the tags attached to the articles conveyed on the conveyance path.

  Although description of the form for implementing this invention is finished above, embodiment of this invention is not limited to these, You may change the shape of an antenna apparatus, a structure, etc. suitably, and an antenna adjustment apparatus This function may be provided to the RFID reader / writer. For example, the mounting position of the antenna device on the ceiling surface may be adjustable by rails, or the left and right antenna groups may be separated and each mounted on the ceiling surface. When the width of the transport path is wide, the communication range is divided by a configuration in which a plurality of pairs of left and right antenna groups are combined or an additional antenna group having a large beam width is added between the left and right antenna groups. You may do it.

  Further, the shape of the RFID tag is not limited to a sheet shape, and may be a passive tag or an active tag. The antenna to be used may not be a planar antenna as long as it has a certain directivity. Other components can be appropriately changed without departing from the spirit of the present invention.

1,1a Antenna device (RFID reader / writer antenna device)
2, 2a, 2b, 2c, 2d, 2e, 2f RFID tag 3 RFID reader / writer 4 Antenna adjustment device 5 Antenna switch 6 Swing control motor (swing control means)
7, 8 Arm length control motor (arm length control means)
9 Antenna angle control motor (angle control means)
10a Test pole 10b Stand type test pole 11 Ceiling fixing part 12, 12a Horizontal arm 13 Vertical arm 14 Antenna mounting shaft 15, 15a Planar antenna (antenna)
16 Antenna group 17 Antenna group (third antenna group)
18 Antenna group depression angle control motor 19 Antenna group mounting hinge A1, A4 Communication area A2 Dual communication area A3 Tag passage area

Claims (10)

An RFID reader / writer antenna device that receives an electromagnetic wave signal radiated from an RFID tag and relays it to an RFID reader / writer,
A dual communicable area provided with a plurality of antenna groups in a direction crossing the transport path above the article transport path, wherein at least two communicable areas formed by the plurality of antenna groups overlap each other. Adjusting means for adjusting the interval between the plurality of antenna groups and / or the direction of the communicable area so that the RFID tag attached to the article conveyed on the conveyance path passes. An antenna device for an RFID reader / writer. The adjusting means for adjusting the interval between the plurality of sets of antenna groups,
2. The RFID reader / writer antenna device according to claim 1, wherein the antenna device is an arm length control means for controlling a length of a telescopic horizontal arm to which the plurality of sets of antenna groups are attached. In the antenna group, two or more antennas having directivity are connected in the longitudinal direction of the horizontal arm,
The adjusting means for adjusting the direction of the communicable area includes:
2. The angle control means for controlling an angle of each antenna so that a part of a communicable range of each antenna overlaps a part of a communicable range of the adjacent antenna. An antenna device for an RFID reader / writer according to claim 2. The RFID reader / writer antenna device according to any one of claims 1 to 3, further comprising a height adjusting unit that adjusts a height of the plurality of antenna groups from a ceiling surface. . 5. The RFID reader / writer antenna device according to claim 4, wherein the height adjusting means is a means for controlling a length of a telescopic vertical arm or cable that suspends the plurality of antenna groups. 2. The apparatus according to claim 1, further comprising a swing control unit that swings the plurality of antenna groups from upstream to downstream of the transport path so that the number of detected RFID tags is maximized. The antenna device for RFID reader / writer according to claim 5. The RFID according to any one of claims 1 to 5, further comprising a third antenna group having directivity in an upstream direction of the transport path and capable of adjusting a depression angle thereof. Antenna device for reader / writer. It is connected to the antenna device for RFID reader / writer according to any one of claims 1 to 7,
A passing range specifying means for specifying a passing range of the RFID tag immediately below the antenna device is provided, and an interval between the plurality of sets of antenna groups is included so that the specified passing range is included in the dual communication possible region. An antenna adjustment apparatus comprising: control means for controlling at least one of an angle of the antenna and a height from the ceiling surface. 9. The antenna adjustment apparatus according to claim 8, wherein the passing range designating unit is an input unit that inputs a width and a height of the passing range. 9. The antenna adjustment device according to claim 8, wherein the passing range specifying means is configured such that a person places predetermined RFID tags at a plurality of positions indicating boundaries of the passing range in accordance with guidance.

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