JP4613634B2 - Radio tag communication apparatus and radio tag management system - Google Patents

Description

  The present invention relates to a wireless tag communication device that performs non-contact communication of information with a predetermined wireless tag, and an improvement of a wireless tag management system using the wireless tag communication device. The present invention relates to a technology for performing wireless tag management.

  2. Description of the Related Art An RFID (Radio Frequency Identification) system is known in which information is read out in a non-contact manner by a predetermined wireless tag communication device (interrogator) from a small wireless tag (responder) in which predetermined information is stored. This RFID system is capable of reading information stored in a wireless tag by communication with the wireless tag communication device even when the wireless tag is dirty or disposed at an invisible position. Therefore, practical use is expected in various fields such as merchandise management and inspection processes.

  As one usage form of such an RFID system, practical use for article management and the like is considered. For example, the rental storage management system described in Patent Document 1 is that. According to this technique, the wireless tag is attached to each of the management items for rent that are the articles to be managed, and information is communicated with the wireless tags by the wireless tag communication device, thereby suitably It can be searched or managed.

JP-A-11-79328

  However, in the conventional technology, since the RFID tag communication device always transmits radio waves (question waves), there is a possibility that it becomes a noise source of other devices, and there is a disadvantage that power consumption increases. there were. For this reason, development of a wireless tag communication device and a wireless tag management system that perform efficient wireless tag management while suppressing power consumption has been demanded.

  The present invention has been made in the background of the above circumstances, and an object of the present invention is to provide a wireless tag communication apparatus and a wireless tag management system that perform efficient wireless tag management while suppressing power consumption. It is in.

In order to achieve such an object, the gist of the first aspect of the present invention is to transmit a predetermined transmission signal from the transmission antenna toward the wireless tag, and return from the wireless tag according to the transmission signal. A wireless tag communication device that communicates information with a wireless tag by receiving a return signal by a receiving antenna . First, communication directivity with the wireless tag is set as an initial setting, and the wireless tag Is out of the detectable range, at least one of the transmitting antenna and the receiving antenna is controlled as a phased array antenna or an adaptive array antenna so that the communication directivity with the wireless tag is switched to a predetermined direction. Compare the directivity control unit and the return signal from the wireless tag for each communication directivity switched by the directivity control unit , And determining the wireless tag movement determination unit movement of the wireless tags based on the comparison result, characterized in that comprises.

  In order to achieve the above object, the gist of the second invention is that at least one wireless tag communication device of the first invention is provided and information is communicated with the wireless tag. The wireless tag management system manages the wireless tag.

Thus, according to the first invention, first, communication directivity with the wireless tag is set as an initial setting, and when the wireless tag is out of the detectable range, A directivity control unit that controls at least one of the transmission antenna and the reception antenna as a phased array antenna or an adaptive array antenna so that the communication directivity is switched in a predetermined direction, and each communication directivity that is switched by the directivity control unit. A wireless tag movement determination unit that compares return signals from the wireless tag in terms of performance and determines the movement of the wireless tag based on the comparison result, so that the wireless tag can be controlled by practical communication directivity control. It is possible to determine the movement of the wireless tag by performing necessary and sufficient communication with. That is, it is possible to provide a wireless tag communication device that performs efficient wireless tag management while reducing power consumption.

Here, in the first invention, preferably, information is communicated with the wireless tag by a plurality of antennas fixedly provided at predetermined positions. In this way, the movement of the wireless tag can be determined in a practical manner.

  According to the second aspect of the invention, at least one wireless tag communication device of the first aspect of the invention is provided, and the position where the wireless tag exists is managed by communicating information with the wireless tag. Therefore, movement of the wireless tag can be determined by performing necessary and sufficient communication with the wireless tag. That is, it is possible to provide a wireless tag management system that performs efficient wireless tag management while suppressing power consumption.

  Here, the second invention preferably includes a plurality of the RFID tag communication devices arranged along a predetermined first direction. In this way, it is possible to suitably manage the wireless tag that moves along the first direction.

  Preferably, the RFID tag management system manages RFID tags in a predetermined area, and the first RFID tag communication apparatus that determines the passage of the RFID tag between the inside and outside of the area; And a plurality of second RFID tag communication devices arranged along the first direction in the region. If it does in this way, the said radio | wireless tag which moves along the said 1st direction within the said area | region can be managed suitably.

  Preferably, at a time when a reply signal from the wireless tag is not received, the transmission signal is transmitted from at least one wireless tag communication device with a directivity direction as an initial setting. In this way, the movement of the wireless tag can be determined in a practical manner.

  Preferably, when it is determined by the predetermined RFID tag communication device that the RFID tag has moved in the first direction, another RFID tag communication device disposed adjacent to the first direction. To determine the movement of the wireless tag. In this way, the movement of the wireless tag can be determined in a practical manner.

  Preferably, when a predetermined wireless tag communication device determines that the wireless tag has moved in a predetermined second direction different from the first direction, a result of moving the wireless tag is determined. It is. In this way, the movement result of the wireless tag can be determined in a practical manner.

  Preferably, the wireless tag has a predetermined database for registering the movement result of the wireless tag, and the wireless tag is moved in a predetermined second direction different from the first direction by a predetermined wireless tag communication device. When it is determined that the data has been moved, the registered contents of the database are updated. In this way, the movement result of the wireless tag can be reflected in the database in a practical manner.

  Preferably, when the predetermined RFID tag communication device determines that the RFID tag has moved out of the area, the registered content of the database is updated. In this way, the movement of the wireless tag outside the area can be reflected in the database in a practical manner.

  Preferably, the wireless tag communication device includes a third wireless tag communication device that determines movement of the wireless tag within the region. In this way, the movement of the wireless tag within the area can be more suitably managed.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a diagram schematically illustrating a wireless tag management system 10 according to an embodiment of the present invention, in which the upper side from the broken line is a plan view of the detection area A1, and the lower side is a network diagram. As shown in FIG. 1, the RFID tag management system 10 according to the present embodiment includes a plurality of RFID tag communication devices 12 installed in a plurality (two in FIG. 1) of detection areas A1 and A2, respectively. This is a so-called RFID (Radio Frequency Identification) system that detects the wireless tag 14 by communicating information with the wireless tag 14 in a non-contact manner. The wireless tag 14 is attached to each of the objects 22 and is suitably used for searching or managing the managed objects 22.

The detection area A1 is, for example, a space inside the chamber 16 having the entrance _16ex at at least one location (only one location in FIG. 1). One or more (n + 2 in FIG. 1) stationary RFID tag communication ₁₂ w1, · · ·, a _{12 wn-2, 12 wn-} 1, 12 wn, 12 ex, 12 bp ( hereinafter, simply referred to as radio-frequency tag communication device 12 when not particularly distinguished), a plurality (Fig. 1 3) wireless tags 14a, 14b, 14c (hereinafter simply referred to as wireless tags 14 unless otherwise distinguished) and a control device 18 _A1 (in the detection area A2) for controlling the plurality of wireless tag communication devices 12. Corresponds to the control device _18A2 , and hereinafter referred to simply as the control device 18 unless otherwise distinguished). The wireless tag 14c is disposed outside the detection area A1. The wireless tag management system 10 includes a database server 24 that stores information related to the wireless tag 14 in each detection region, and a plurality (k units in FIG. 1) that are video display devices connected to the database server 24. ) 26 _{m 1} , 26 _{m 2} ,..., 26 _mk (hereinafter simply referred to as the monitor 26 unless otherwise distinguished), and the above-described RFID tag communication apparatus is connected by a LAN 20 or the like. 12 and the control device 18 can communicate information. Since the detection area A2 shown in FIG. 1 is configured in the same manner as the detection area A1 described above, the description thereof will be omitted, and in the following embodiments, only the detection area A1 will be described.

FIG. 2 is a schematic plan view for explaining in detail the storage area of the wireless tag 14 in the detection area A1 and the wireless tag communication device 12 installed in the detection area A1. As shown in this Figure 2, the the detection area A1, the wireless tag 14 is attached was management objects 22 to bonding is sandwiched between the passage 16 _w a person can traffic with it, their administration was 22 , Storage areas a1, a2,..., An-2, an-1, an, b1, b2,..., Bn-2 divided into a plurality (2n in FIG. 2). , Bn-1, bn (hereinafter simply referred to as storage area a unless otherwise distinguished), and the management object 22 to which the wireless tag 14 is attached is placed in any of the storage areas a. Stored and stored.

The RFID tag communication device 12 can be classified into three types according to the role in the RFID tag management system 10. That is, the RFID tag communication device 12 _ex which is a first scanner (entrance / exit scanner) installed near the entrance / exit 16 _{ex of the} chamber 16 and a predetermined first direction, that is, the passage 16 _w in the detection area A1. RFID communication devices 12 _w1 ,..., 12 _wn-2 , 12 _wn-1 , 12 _wn , which are second scanners (passage scanners) arranged in the above-mentioned _manner , the storage area an-2 and the storage area an The RFID tag communication device 12 _bp, which is a third scanner (bypass scanner) installed at the boundary of −1, plays a different role as will be described later in response to a command from the control device 18.

  FIG. 3 is a diagram for explaining an electrical configuration of the RFID tag communication apparatus 12. As shown in FIG. 3, the RFID tag communication apparatus 12 includes a main carrier generation unit 28 for generating a main carrier of a transmission signal, and a main carrier generated by the main carrier generation unit 28, which will be described later. A transmission signal modulation unit 30 that modulates the transmission information signal (transmission data) generated by the data generation unit 52 to generate the transmission signal, and transmits the transmission signal modulated by the transmission signal modulation unit 30 to the wireless tag. A plurality of (three in FIG. 2) transmission / reception antenna elements 32a, 32b, 32c (hereinafter, in particular, for receiving a reply signal returned from the wireless tag 14 in response to the transmission signal) When not distinguished, it is simply referred to as a transmission / reception antenna element 32), and when the transmission directivity of transmission signals transmitted from the plurality of transmission / reception antenna elements 32 is controlled. Furthermore, the directivity control unit 34 for controlling the reception directivity of the reception signals received by the plurality of transmission / reception antenna elements 32, and the transmission signal supplied from the directivity control unit 34 to each transmission / reception antenna element 32. A plurality of (three in FIG. 2) transmission / reception separation units 36a, 36b, and 36c (in the following, unless otherwise specified) that supply the received signals received by the transmission / reception antenna elements 32 to the directivity control unit 34 Is simply referred to as a transmission / reception separating unit 36), a local oscillator 38 for generating a local oscillation signal of a predetermined frequency, and a local oscillation generated by the local oscillator 38 for each received signal supplied from the directivity control unit 34. A plurality of (three in FIG. 2) down-converters 40a, 40b, and 40c (hereinafter referred to as “particularly”) If not, it is simply referred to as a down converter 40) and a DSP 42 for controlling the operation of the RFID tag communication apparatus 12 including the demodulation processing of the received signal down-converted by the down converter 40. ing. Here, as the transmission / reception separator 36, a circulator or a directional coupler is preferably used.

  The directivity control unit 34 includes a plurality (three in FIG. 2) of transmission signal phase control units 44a, 44b, and 44c (hereinafter, particularly distinguished) that control the phase of each transmission signal supplied from the transmission signal modulation unit 30. If not, it is simply referred to as a transmission signal phase control unit 44) and a plurality of (three in FIG. 2) transmission signal amplitude control units 46a, 46b, 46c (hereinafter, unless otherwise distinguished). Simply referred to as a transmission signal amplitude control unit 46), and the phases of the transmission signals transmitted from the plurality of transmission / reception antenna elements 32 via the transmission signal phase control unit 44 and the transmission signal amplitude control unit 46, respectively. And the transmission directivity of the transmission signal is controlled by controlling the amplitude. Also, a plurality (three in FIG. 2) of received signal phase control units 48a, 48b, 48c for controlling the phase of each of the received signals supplied from the plurality of transmission / reception separating units 36 (hereinafter, unless otherwise distinguished, simply And a plurality of (three in FIG. 2) reception signal amplitude control units 50a, 50b, and 50c (hereinafter simply referred to as reception signal amplitude control unless otherwise specified). And control the phase and amplitude of each of the received signals received by the plurality of transmission / reception antenna elements 32 via the received signal phase control unit 48 and the received signal amplitude control unit 50. Thus, the reception directivity of the received signal is controlled.

  The DSP 42 includes a CPU, a ROM, a RAM, and the like, and is a so-called microcomputer that performs signal processing according to a program stored in advance in the ROM while using a temporary storage function of the RAM, and generates and transmits transmission data. Determination of control amounts of the signal phase control unit 44 and the transmission signal amplitude control unit 46, determination of control amounts of the reception signal phase control unit 48 and the reception signal amplitude control unit 50, and transmission of the transmission signal toward the wireless tag 14 Transmission control, reception control for receiving a reply signal returned from the wireless tag 14 according to the transmission signal, demodulation control for demodulating the received reception signal, the control device 18 or database server via the LAN 20 Communication control with 24 etc., movement determination control of the wireless tag 14, etc. are performed. In order to execute such control, a transmission data generation unit 52, a transmission control unit 54, a reception control unit 56, a reception signal synthesis unit 58, a reception signal demodulation unit 60, a wireless tag position detection unit 62, a wireless tag movement determination unit 64, And a communication interface 66 functionally.

  The transmission data generation unit 52 generates transmission data that is a predetermined transmission information signal for modulating the transmission signal and supplies the transmission data to the transmission signal modulation unit 30. The transmission control unit 54 performs transmission control for transmitting a transmission signal to the wireless tag 14 in accordance with a command from the control device 18. Also, transmission phased array control is performed to control the phase (and amplitude if necessary) of the transmission signals transmitted from the plurality of transmission / reception antenna elements 32 and to control the transmission directivity of the transmission signals. That is, by controlling the phase of each transmission signal via the directivity control unit 34, the transmission antenna composed of the plurality of transmission / reception antenna elements 32 is controlled as a phased array antenna for transmission (Phased Array Antenna). Alternatively, by controlling the phase and amplitude of each transmission signal through the directivity control unit 34 so that the quality of the reception signal is improved, a transmission antenna composed of the plurality of transmission / reception antenna elements 32 is changed to an adaptive array antenna for transmission ( Control as Adaptive Array Antenna).

  The reception control unit 56 controls the reception directivity of the reception signal by controlling the phase (and amplitude if necessary) of each reception signal received by the plurality of transmission / reception antenna elements 32. That is, by controlling the phase of each reception signal via the directivity control unit 34, the reception antenna composed of the plurality of transmission / reception antenna elements 32 is controlled as a reception phased array antenna. Alternatively, the reception antenna composed of the plurality of transmission / reception antenna elements 32 is set as a reception adaptive array antenna by controlling the phase and amplitude of each reception signal through the directivity control unit 34 so as to improve the quality of the reception signal. Control. Preferably, the reception directivity of the reception signal is determined so that the amount of the reception signal combined in the reception signal combining unit 58 described later is as large as possible.

  The reception signal combining unit 58 combines reception signals respectively received by the plurality of transmission / reception antenna elements 32. The reception signals whose phases and amplitudes are respectively controlled by the reception control unit 56 via the directivity control unit 34 are combined by the reception signal combining unit 58, so that a reception antenna including the plurality of transmission / reception antenna elements 32 is obtained. Receive directivity is determined.

  The received signal demodulator 60 demodulates the received signals from the plurality of transmission / reception antenna elements 32 synthesized by the received signal synthesizer 58. Preferably, after the received signal is AM demodulated by the AM method, the demodulated signal is FM-decoded and the information signal returned by the wireless tag 14 is read.

  The wireless tag position detection unit 62 detects the position of the wireless tag 14 existing in the detection area A1. Preferably, according to the reception directivity determined by the reception control unit 56 so that the received signal synthesis amount in the received signal synthesis unit 58 is as large as possible, and the strength of the received signal at that time The position of the wireless tag 14 that is the communication target is detected.

  The wireless tag movement determination unit 64 compares return signals from the wireless tag 14 in each communication directivity switched by the directivity control unit 34, and determines the movement of the wireless tag 14 based on the comparison result. . For example, when the strength of the reply signal from the wireless tag 14 becomes weak or becomes unreceivable at a predetermined communication directivity, the directivity control unit 34 switches the communication directivity, and the new communication directivity. If a sufficiently strong response signal is obtained from the wireless tag 14, the wireless tag 14 is determined to have moved in the direction corresponding to the new communication directivity.

  The communication interface 66 communicates information with the control device 18 and the like via the LAN 20. For example, control such as receiving a command from the control device 18 and transmitting a result (movement determination result) of information communication with the wireless tag 14 to the control device 18 or the database server 24. I do.

  FIG. 4 is a diagram for explaining the configuration of the wireless tag 14. As shown in FIG. 4, the wireless tag 14 includes an antenna unit 68 for transmitting and receiving signals to and from the wireless tag communication device 12, and a signal received by the antenna unit 68. The IC circuit unit 70 is provided. The IC circuit unit 70 rectifies the interrogation wave (transmission signal) from the RFID tag communication apparatus 12 received by the antenna unit 68 and the energy of the interrogation wave rectified by the rectification unit 72. Functions as a power supply unit 74 for storing, a clock extraction unit 76 that extracts a clock signal from the carrier wave received by the antenna unit 68 and supplies the clock signal to the control unit 82, and an information storage unit that can store a predetermined information signal The radio tag 14 via the memory unit 78, the modem unit 80 connected to the antenna unit 68 for modulating and demodulating the signal, the rectifier unit 72, the clock extracting unit 76, the modem unit 80, and the like. And a control unit 82 for controlling the function. The control unit 82 performs control to store the predetermined information in the memory unit 78 by communicating with the wireless tag communication device 12, and transmits the interrogation wave received by the antenna unit 68 in the modulation / demodulation unit 80. After performing modulation based on the information signal stored in the memory unit 78, basic control such as control of reflecting and returning from the antenna unit 68 as a response wave is executed. For example, the wireless tag 14 stores information on the managed object 22 to be managed in the memory unit 78 and is attached to the managed object 22 as shown in FIG. Used to manage movement.

Here, the first wireless tag communication device 12 _ex determines the passage of the wireless tag 14 between the inside and the outside of the detection area A1. The detection area A1 is inside the chamber 16, and the chamber 16 is provided with only one entrance / exit _16ex . Therefore, the detection area A1 is detected by detecting the wireless tag 14 passing through the entrance / exit _16ex. The passage of the wireless tag 14 between A1 and outside, that is, whether the detection area A1 is taken out to the outside or brought into the inside can be determined. Preferably, when no reply signal is received from the wireless tag 14, no transmission signal is transmitted from the other wireless tag communication device 12, and the directivity direction is initialized only from the wireless tag communication device _12ex. A transmission signal is transmitted as a setting. The control device 18 is preferably activates first other radio-frequency tag communication device 12 passage of the RFID tag 14 is determined in the detection area A1 between the inner and outer by the first wireless tag communication device 12 _ex. Thus, since the RFID tag communication device _12ex does not necessarily switch the communication directivity with the RFID tag 14, the directivity control unit 34 and the like may not have a configuration related to directivity control. Conceivable.

Further, the second RFID tag communication devices 12 _w1 ,..., 12 _wn-2 , 12 _wn−1 , 12 _wn (hereinafter simply referred to as the RFID tag communication device 12 _w unless otherwise distinguished) It is determined whether the wireless tag 14 attached to the management object 22 transported along the passage _16w is moved, and in which storage area a the wireless tag 14 is stored. Wherein in these radio-frequency tag communication device 12 _w transceiver antenna element 32 is, for example, a plate-shaped patch antennas, are arranged in the manner such as is fixed to the ceiling portion of the said passage 16 _w.

Figure 15 is a diagram for explaining the wireless tag communication device 12 _w by switching of the communication directivity. As shown in FIG. 15, the wireless tag communication device 12 _w preferably first sets the communication directivity with the wireless tag 14 in the first direction, that is, the direction along the passage 16 _w (see FIG. 15). 15 in the first direction and the second direction), and when the wireless tag 14 is out of the detectable range, the communication directivity with the wireless tag 14 is set to the second direction, that is, the storage area a. The direction is switched (the third direction and the fourth direction shown in FIG. 15). When it is determined that the wireless tag 14 has moved in the second direction, the movement result of the wireless tag 14 is determined. For example, when the wireless tag communication device 12 _wn-2 determines that the wireless tag 14 has moved in the direction of the storage area an-2, the wireless tag 14 is stored (stored) in the storage area an-2. The result of the movement is determined. Further, the off the radio tag 14 is detectable range, if not even be detected communication directivity as the second direction, the radio-frequency tag 14 is moved in the first direction along the path 16 _w and determination To do. When it is determined by the predetermined wireless tag communication device _12w that the wireless tag 14 has moved in the first direction, the control device 18 uses another wireless device disposed adjacent to the first direction. The tag communication device 12 _w is caused to determine the movement of the wireless tag 14. For example, the wireless tag said by the communication device 12 _wn-2 when the wireless tag 14 is determined to have moved in the first direction, the radio tag communication apparatus disposed adjacent along the path 16 _{w Let} 12 _wn-1 (or the wireless tag communication device 12 _wn-3 ) determine the movement of the wireless tag 14. Further, in detecting the wireless tag 14 in the second direction, the direction and distance of the wireless tag 14 can be detected in detail by switching the reception directivity so that the reception sensitivity is maximized.

The third wireless tag communication device 12 _bp determines movement of the wireless tag 14 between the plurality of storage areas a. For example, the position where the wireless tag 14 exists in the storage area an-2 and the storage area an-1 is detected, and if there is a movement from one to the other, it is determined. Alternatively, even if the communication directivity is switched in two directions corresponding to the storage area a to be detected, such as switching the communication directivity between the direction of the storage area an-2 and the direction of the storage area an-1. Good. Thus, since the RFID tag communication device _12ex does not necessarily switch the communication directivity with the RFID tag 14, the directivity control unit 34 and the like may not have a configuration related to directivity control. Conceivable.

FIG. 7 is a diagram illustrating the movement result of the wireless tag 14 stored in the database server 24 and the information of the managed object 22 corresponding to the wireless tag 14. As shown in FIG. 7, in the database server 24, the ID of the wireless tag 14 (RFID tag ID) stored in each storage area (storage block) and the wireless tag 14 are pasted. The contents (pallet contents), warehousing time, and scheduled shipping time of the item 22 are stored. Preferably, in the database server 24, the contents of the management object 22 corresponding to the ID of each of the wireless tags 14 are registered in advance, and the management target is managed by reading the ID of the wireless tag 14. The contents of the object 22 can be inquired. The estimated shipping time is input by an input device (not shown) provided in the monitor 26. When the first wireless tag communication device 12 _ex determines that the wireless tag 14 is taken out of the detection area A1, the control device 18 updates the registered content of the database server 24 and takes it out. Reflect. When the movement result of the wireless tag 14 is determined by the second wireless tag communication device _12w , the registered contents of the database server 24 are updated to reflect the movement result. Further, when the movement of the wireless tag 14 between the storage areas a is determined by the third wireless tag communication apparatus 12 _bp , the registered content of the database server 24 is updated to reflect the movement result. .

  FIG. 8 is a flowchart illustrating wireless tag management control in the detection area A1 by the control device 18, and is repeatedly executed at a predetermined cycle.

First, step (hereinafter, omitting step) in S1, one of the radio-frequency tag communication device 12 detects the wireless tag 14 in the passage 16 _w at omnidirectional (communication directivity initialization) Therefore, a transmission signal is transmitted. Next, in SA, the reading process shown in FIG. 9 is executed. Next, in S2, it is determined whether or not the wireless tag 14 is detected, that is, whether or not a reply signal returned from the wireless tag 14 is received according to the transmission signal transmitted in S1. When the determination at S2 is negative, the processing after S1 is executed again. However, when the determination at S2 is affirmative, at S3, the wireless tag 14 is detected by the scanner at the entrance / exit. It is determined whether or not the first wireless tag communication device 12 _ex is used. If the determination at S3 is affirmative, this routine is terminated after the entrance / exit scanner processing shown in FIG. 10 is executed at SB. If the determination at S3 is negative, at S4, It is determined whether or not the wireless tag 14 is detected by a passage scanner, that is, the second wireless tag communication device _12w . If the determination in S4 is affirmative, the routine is terminated after the passage scanner processing shown in FIGS. 11a to 11c is executed in the SC. If the determination in S4 is negative, In SD, after the bypass scanner process shown in FIG. 12 is executed, this routine is terminated.

  FIG. 9 is a flowchart for explaining reading processing of the wireless tag 14 by the wireless tag communication device 12. In this control, first, in SA1, a transmission signal for inquiring ID is sent to the wireless tag 14. Next, a reply signal from the wireless tag 14 corresponding to the transmission signal transmitted at SA1 waits for a predetermined time. Next, in SA3, a reply signal from the wireless tag 14 is received, the received signal is demodulated, and the ID of the wireless tag 14 is read, and then the process returns to the main routine.

In the entrance / exit scanner processing of FIG. 10, first, in SB1, it is determined whether or not the wireless tag 14 is detected by the wireless tag communication device _12ex even after a predetermined time has elapsed. Among the determination at SB1 is positive, but is caused to wait by the determination of SB1 is repeated, if the determination of SB1 is negative, then, at SB2, the second direction along said path 16 _w operating a second radio-frequency tag communication device 12 _w disposed adjacently. Next, in the above-described SA, the reading process shown in FIG. 9 is executed. Next, at SB3, whether the by the passage 16 radio tag communication apparatus is disposed adjacent to the second direction along the _w 12 _w radio tag 14 is detected or not. If the determination at SB3 is negative, the process returns to the main routine. If the determination at SB3 is affirmative, the passage scanner process shown in FIGS. 11a to 11c is executed at the SC. Thereafter, the process returns to the main routine.

11a to 11c, first, in SC1 of FIG. 11a, the received signal from the wireless tag 14 is demodulated, the ID of the wireless tag 14 is read, and the database server 24 is accessed. Is called. Next, in SC2, it is determined whether or not the ID of the wireless tag 14 read in SC1 is stored in the database server 24. If the determination at SC2 is affirmative, the processing below SC4 is executed. If the determination at SC2 is negative, the ID of the new wireless tag 14 read at SC1 is read at SC3. and after the information such as the storage area a has been registered in the database server 24, in SC4, whether the wireless tag 14 by the RFID tag communicating apparatus 12 _w even after the predetermined time has elapsed is detected is determined The While the determination of SC4 is affirmed, the process waits by repeating the determination of SC4. However, when the determination of SC4 is negative, in SC5, adjacent to the first direction shown in FIG. Whether or not the RFID tag communication device 12 is disposed is determined. If the determination at SC5 is negative, SC8 but the following process is performed, if the determination of SC5 is yes, SC6, adjacent to the first direction along the path 16 _w The arranged RFID tag communication device _12w is operated. Next, at SC7, that was operated at SC6 whether a doorway scanner i.e. the radio-frequency tag communication device 12 _ex is determined. When the determination of SC7 is affirmed, the processing after SC9 is executed, but when the determination of SC7 is negative, after the reading processing shown in FIG. In SC8, it is determined whether or not the wireless tag 14 is detected. If the determination at SC8 is affirmative, the processing after SC4 is executed again. If the determination at SC8 is negative, the processing after SC13 in FIG. 11b is executed. In SC9, whether the wireless tag 14 also by the radio tag communication apparatus 12 _ex after a predetermined time has elapsed is detected is determined. While the determination of SC9 is affirmed, the process waits by repeating the determination of SC9. However, when the determination of SC9 is negative, in SC10, adjacent to the second direction shown in FIG. disposed Te wireless tag communication device 12 _w is operated. Next, in the above-described SA, the reading process shown in FIG. 9 is executed. Next, in SC11, it is determined whether or not the wireless tag 14 has been detected. When the determination of SC11 is affirmed, the processing after SC4 is executed again. However, when the determination of SC11 is negative, in SC12, the wireless tag 14 stored in the database server 24 is stored. After the information is updated, that is, the information that the predetermined wireless tag 14 has been taken out from the detection area A1 is registered, the process returns to the main routine.

In SC13 of FIG. 11b, whether the radio tag communication apparatus 12 adjacent a second direction along said path 16 _w is disposed it is determined. If the determination at SC13 is negative, SC16 but the following process is performed, if the determination of the SC13 is yes, SC14, adjacent in a second direction along said path 16 _w The arranged RFID tag communication device _12w is operated. Next, in SC15, it is determined whether or not it is the entrance / exit scanner, that is, the RFID tag communication device _12ex, that is operated in SC14. When the determination of SC15 is affirmed, the processing after SC17 is executed. However, when the determination of SC15 is negative, after the reading processing shown in FIG. In SC16, it is determined whether or not the wireless tag 14 is detected. If the determination at SC16 is affirmative, the processing after SC4 in FIG. 11a is executed again. If the determination at SC16 is negative, the processing after SC21 in FIG. 11c is executed. In SC17, it is determined whether or not the wireless tag 14 has been detected by the wireless tag communication device _12ex even after a predetermined time has elapsed. Among the determination at SC17 is positive, but is caused to wait by the determination of the SC17 is repeated, if the determination of the SC17 is negative, then, at SC18, adjacent to the first direction along the path 16 _w radio-frequency tag communication device 12 _w is operated which is disposed in. Next, in the above-described SA, the reading process shown in FIG. 9 is executed. Next, in SC19, it is determined whether or not the wireless tag 14 has been detected. If the determination at SC19 is affirmative, the processing from SC4 onward in FIG. 11a is executed again. If the determination at SC19 is negative, the radio stored in the database server 24 is stored at SC20. After the information of the tag 14 is updated, that is, the information that the predetermined wireless tag 14 has been taken out from the detection area A1 is registered, the process returns to the main routine.

In SC21 of FIG. 11c, the communication directivity of the radio tag communication apparatus 12 _w is switched to the direction of the second direction, i.e. the storage area a. Then, the SC22, the communication directivity of the radio tag communication apparatus 12 _w is directed in a third direction shown in FIG. 15 described above. Next, in the above-described SA, the reading process shown in FIG. 9 is executed. Next, in SC23, it is determined whether or not the wireless tag 14 has been detected. If the determination at SC23 is affirmative, the direction and distance of the wireless tag 14 are detected at SC27. Next, in SC28, the information of the wireless tag 14 stored in the database server 24 is updated, that is, information that a predetermined wireless tag 14 is stored in the direction and distance detected in SC27 is registered. After that, it is returned to the main routine. In SC24, communication directivity of the radio tag communication apparatus 12 _w is directed in the fourth direction shown in FIG. 15 described above. Next, in the above-described SA, the reading process shown in FIG. 9 is executed. Next, in SC25, it is determined whether or not the wireless tag 14 has been detected. If the determination at SC25 is affirmative, the processing from SC27 is executed, but if the determination at SC25 is negative, it is determined at SC26 that a communication error has occurred, and then the process returns to the main routine. Be made.

In the bypass scanner processing shown in FIG. 12, first, in SD1, the communication directivity of the RFID tag communication device 12 _bp is switched from one to the other. Next, in SD2, the direction and distance of the wireless tag 14 are detected. Next, in SD3, information on the wireless tag 14 stored in the database server 24 is updated, that is, information that the wireless tag 14 has moved from one of the storage areas a to be detected to the other is registered. After that, it is returned to the main routine. In the above control, SA, SB, SC, and SD correspond to the operation of the RFID tag movement determination unit 64.

  As described above, according to the present embodiment, the directivity control unit 34 for controlling the communication directivity with the wireless tag 14 to be sequentially switched, and the respective communication directivities switched by the directivity control unit 34. And a wireless tag movement determination unit 64 (SA, SB, SC, and SD) that compares return signals from the wireless tag 14 and determines the movement of the wireless tag 14 based on the comparison result. The movement of the wireless tag 14 can be determined by performing necessary and sufficient communication with the wireless tag 14. That is, it is possible to provide the wireless tag communication device 12 that performs efficient wireless tag management while suppressing power consumption.

  The directivity control unit 34 first sets the communication directivity with the wireless tag 14 as an initial setting. When the wireless tag 14 is out of the detectable range, Therefore, the movement of the wireless tag 14 can be determined in a practical manner.

  In addition, since a plurality of transmission / reception antenna elements 32 fixed at predetermined positions are used to communicate information with the wireless tag 14, the movement of the wireless tag 14 is determined in a practical manner. can do.

  In addition, since at least one wireless tag communication device 12 is provided and information is communicated with the wireless tag 14, the position where the wireless tag 14 is present is managed. It is possible to determine the movement of the wireless tag 14 by performing necessary and sufficient communication with. That is, it is possible to provide the wireless tag management system 10 that performs efficient wireless tag management while suppressing power consumption.

  In addition, since the wireless tag communication device 12 is provided along a predetermined first direction, the wireless tag 14 that moves along the first direction can be suitably managed. it can.

The wireless tag management system 10 manages the wireless tag 14 in a predetermined detection area A1, and determines the passage of the wireless tag 14 between the inside and outside of the detection area A1. Since the apparatus 12 _ex includes a plurality of second RFID tag communication apparatuses 12 _w arranged along the first direction in the detection area A1, the detection area A1 includes The wireless tag 14 that moves along the first direction can be suitably managed.

  In addition, when the reply signal from the wireless tag 14 is not received, the transmission signal is transmitted from at least one wireless tag communication device 12 with the directivity direction as an initial setting. The movement of the wireless tag 14 can be determined.

When it is determined by the predetermined RFID tag communication device 12 _w that the RFID tag 14 has moved in the first direction, another RFID tag communication device 12 disposed adjacent to the first direction. _{Since w} is used to determine the movement of the wireless tag 14, the movement of the wireless tag 14 can be determined in a practical manner.

Further, when it is determined by the predetermined wireless tag communication device 12 _w that the wireless tag 14 has moved in a predetermined second direction different from the first direction, the movement result of the wireless tag 14 is determined. Therefore, the movement result of the wireless tag 14 can be determined in a practical manner.

The wireless tag 14 includes a predetermined database server 24 for registering the movement result of the wireless tag 14, and the wireless tag 14 is different from the first direction by the predetermined wireless tag communication device 12 _w . When it is determined that the movement has been made in the direction, the registration contents of the database server 24 are updated, and therefore the movement result of the wireless tag 14 can be reflected in the database server 24 in a practical manner. .

In addition, when the wireless tag communication device 12 _ex determines that the wireless tag 14 has moved out of the detection area A1, the registration content of the database server 24 is updated. Thus, the movement of the wireless tag 14 outside the detection area A1 can be reflected in the database server 24.

Further, since the third wireless tag communication device 12 _bp for determining the movement of the wireless tag 14 in the detection area A1 is provided, the movement of the wireless tag 14 in the detection area A1 is further preferably performed. Can be managed.

  The preferred embodiments of the present invention have been described in detail with reference to the drawings. However, the present invention is not limited to these embodiments, and may be implemented in other modes.

  For example, in the above-described embodiment, the wireless tag communication device 12 includes a plurality of transmission / reception antenna elements 34 that are patch antennas in order to communicate information with the wireless tag 14 that is a communication target. However, the present invention is not limited to this, and another antenna including a dipole antenna and a Yagi antenna may be provided. 13 and 14 exemplify Esper Antennas 86 preferably used in the RFID tag communication apparatus of the present invention, FIG. 13 shows a transmission mode, and FIG. 14 shows a reception mode. As shown in these figures, the ESPAR antenna 86 is composed of a main element 86a and a subelement 86b, and the main element 86 functions as a reflector or a director by controlling the capacitance of the capacitor. Directivity can be realized. Even if the wireless tag communication device switches communication directivity with the wireless tag 14 using the ESPAR antenna 86, the effects of the invention described above can be obtained. That is, in the RFID tag communication apparatus of the present invention, various antennas are appropriately selected and used depending on the usage mode and the like.

  In the above-described embodiment, the wireless tag position detection unit 62 and the like are functionally provided in the DSP 42 of the wireless tag communication device 12, but are provided as a control device separate from the DSP 42. It may be a thing.

In the above-described embodiment, the second wireless tag communication device 12 _ex is disposed along the straight path 16 _w as shown in FIG. 2, but the wireless tag communication apparatuses 12 _ex are arranged along the curved path. The effect of this embodiment can also be obtained in the aspect in which the tag communication device 12 _ex is provided. That is, the one direction is not necessarily a linear direction.

  In the above-described embodiment, the control device 18 and the database server 24 are connected by the LAN 20 and can exchange information with each other. However, the movement result of the wireless tag 14 is registered in the control device 18. The database server 24 may not necessarily be provided. Further, the predetermined RFID tag communication device 12 may have the function of the control device 18.

In the above-described embodiment, the transmission / reception antenna element 32 is composed of a planar patch antenna and is arranged on the ceiling. However, other antennas such as a dipole antenna may be used. Further, as shown in the partial cross-sectional view of FIG. 6, it may be provided by being fixed to the bottom surface of the dug-down passage 16 _w and filled with a resin 84.

  In addition, although not illustrated one by one, the present invention is implemented with various modifications within a range not departing from the gist thereof.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which illustrates schematically the RFID tag management system which is one Example of this invention, The upper side from the broken line has shown the top view of the detection area, and the lower side has each shown the network diagram. FIG. 2 is a schematic plan view illustrating in detail a wireless tag storage region and a wireless tag communication device installed in the detection region in the detection region of FIG. 1. It is a figure explaining the electric constitution of the RFID tag communication apparatus with which the RFID tag management system of Drawing 1 was equipped. It is a figure explaining the electric structure of the radio | wireless tag which is a management object of the radio | wireless tag management system of FIG. It is a perspective view which illustrates the management thing to which the wireless tag of FIG. 4 is affixed. It is a fragmentary sectional view which shows a mode that the antenna element in the radio | wireless tag communication apparatus of FIG. 3 is arrange | positioned. It is a figure which illustrates the movement result of the wireless tag memorize | stored in the database server with which the wireless tag management system of FIG. 1 was equipped, and the information of the management thing corresponding to these wireless tags. 2 is a flowchart for explaining RFID tag management control in a detection area by a control device provided in the RFID tag management system of FIG. 1, and is repeatedly executed at a predetermined cycle. 9 is a flowchart for explaining a reading process by the RFID tag communication apparatus of FIG. 3 executed as part of the control of FIG. It is a flowchart explaining the entrance / exit scanner process performed as a part of control of FIG. FIG. 9 is a part of a flowchart illustrating passage scanner processing that is executed as part of the control of FIG. 8. FIG. 9 is a part of a flowchart illustrating passage scanner processing that is executed as part of the control of FIG. 8. FIG. 9 is a part of a flowchart illustrating passage scanner processing that is executed as part of the control of FIG. 8. It is a flowchart explaining the bypass scanner process performed as a part of control of FIG. The ESPAR antenna suitably used for the RFID tag communication apparatus of the present invention is illustrated and shows a transmission mode. The ESPAR antenna suitably used for the RFID tag communication apparatus of the present invention is illustrated, and the reception mode is shown. It is a figure explaining switching of the communication directivity by the radio | wireless tag communication apparatus of FIG.

Explanation of symbols

10: RFID tag management system 12: RFID tag communication device 12 _ex : first RFID tag communication device 12 _w : second RFID tag communication device 12 _bp : third RFID tag communication device 14: RFID tag 24: database server 32: Transmission / reception antenna element 34: Directivity control unit 64: Radio tag movement determination unit 86a: Main element (antenna element)
86b: Slave element (antenna element)
A1, A2: Detection area

Claims (11)

Communication of information with the wireless tag by transmitting a predetermined transmission signal from the transmission antenna toward the wireless tag and receiving a return signal returned from the wireless tag according to the transmission signal by the reception antenna A wireless tag communication device for performing
First, the communication directivity with the wireless tag is set as an initial setting, and when the wireless tag is out of the detectable range, the communication directivity with the wireless tag is switched to a predetermined direction. A directivity control unit that controls at least one of the transmission antenna and the reception antenna as a phased array antenna or an adaptive array antenna ;
A wireless tag movement determination unit that compares return signals from the wireless tags in the respective communication directivities switched by the directivity control unit and determines the movement of the wireless tag based on the comparison result. A wireless tag communication device. 2. The wireless tag communication device according to claim 1 , wherein information is communicated with the wireless tag by a plurality of antennas fixedly provided at predetermined positions. A wireless tag management system comprising at least one wireless tag communication device according to claim 1 or 2 and managing the location of the wireless tag by communicating information with the wireless tag. The wireless tag management system according to claim 3 , comprising a plurality of the wireless tag communication devices arranged along a predetermined first direction. The wireless tag management system manages wireless tags in a predetermined area, and includes a first wireless tag communication apparatus that determines passage of the wireless tag between the inside and outside of the area, and the first in the area. The wireless tag management system according to claim 4 , further comprising a plurality of second wireless tag communication devices arranged along one direction. Wherein at the time the reply signal is not received from the wireless tag, the one of the radio-tag management of the transmission signal from claim 3 is to send the 5 directivity direction from at least one radio tag communication apparatus as an initial setting system. When it is determined by the predetermined RFID tag communication device that the RFID tag has moved in the first direction, the RFID tag is moved to another RFID tag communication device disposed adjacent to the first direction. The RFID tag management system according to any one of claims 4 to 6 , wherein: If it is determined to have moved to a different predetermined second direction from said wireless tag the first direction by a predetermined radio-frequency tag communication device, of claims 4 to is what determines the movement result of the radio tag The wireless tag management system according to any one of 7 . It has a predetermined database for registering the movement result of the wireless tag, and it is determined by the predetermined wireless tag communication device that the wireless tag has moved in a predetermined second direction different from the first direction. In the case, the wireless tag management system according to any one of claims 4 to 8 , wherein the registered content of the database is updated. The wireless tag management system according to claim 9 , wherein when a predetermined wireless tag communication device determines that the wireless tag has moved out of the area, the registered content of the database is updated. The wireless tag third the one of the wireless tag management system according to claim 4 to 10 are those having a wireless tag communication device determines the movement of the said area.