JP2009146104A - RFID system - Google Patents

Abstract

An RFID reading error may be overlooked in an RFID system in the physical distribution / distribution field.
A wireless tag system including a plurality of first wireless tags, a second wireless tag, a reading unit, a control unit, and a registration unit, wherein the registration unit includes the plurality of first wireless tags. The identifier of the tag and the identifier of the second wireless tag are held in association with each other, and each first wireless tag transmits a wireless signal including the identifier of each first wireless tag when receiving a predetermined signal, When the second wireless tag receives the predetermined signal, the second wireless tag transmits a wireless signal including an identifier of the second wireless tag, and the reading unit includes at least one of the plurality of first wireless tags and the second wireless tag. When receiving the radio signal from one, the control unit associates the radio signal received by the reading unit with the plurality of second signals held in the storage device in association with an identifier of one second radio tag. All the identifiers of one wireless tag It determines Murrell or not.
[Selection] Figure 1

Description

  The technology disclosed herein relates to an RFID system.

  An RFID system that reads and writes data stored in an RFID (Radio Frequency Identification) by wireless communication includes a terminal generally called a reader / writer 101 and a plurality of passive RFIDs 103 as shown in FIG. The reader / writer 101 includes an antenna 140 and a main body 190. The main body 109 includes an RF 110, a memory 130, and a CPU 120. The RF 110 is a transmission / reception device that transmits and receives electromagnetic waves. The CPU 120 is an arithmetic processing device that controls the memory 130 and the RF 110. The reader / writer 101 transmits an unmodulated wave or a modulated wave electromagnetic wave 102 to the passive RFID 103.

  Each passive RFID 103 is a wireless tag including an antenna 150 and an integrated circuit 160. The integrated circuit 160 includes a memory (not shown). In the memory, at least an identifier for uniquely identifying each passive RFID 103 is stored. The passive RFID 103 receives and demodulates the electromagnetic wave 102 emitted from the reader / writer 101, and reflects (transmits) the unmodulated wave electromagnetic wave 102 transmitted from the reader / writer 101 by the memory data in the integrated circuit 160 as necessary. To do. The electromagnetic wave 102 reflected from each passive RFID 103 includes information indicating the identifier of the passive RFID 103 stored in the integrated circuit 160.

  The reader / writer 101 can acquire the identifier of the passive RFID 103 by receiving and demodulating the electromagnetic wave 102 reflected from the passive RFID 103.

  The power source of the integrated circuit 160 is generated from the electromagnetic wave 102 transmitted from the reader / writer 101 by a rectifier circuit inside the integrated circuit 160. Therefore, when the distance between the reader / writer 101 and the passive RFID 103 is increased, the level of the electromagnetic wave 102 received by the passive RFID 103 is weakened due to the propagation loss of the electromagnetic wave 102, so that a power supply cannot be generated by the rectifier circuit in the integrated circuit 160. Assuming that electromagnetic waves in the UHF band (860 MHz to 960 MHz) generally used in the physical distribution / distribution field are used, the distance that the reader / writer 101 and the passive RFID 103 can communicate is about 3 m.

  An RFID system used in the physical distribution / distribution field is a gate type in which a plurality of boxes (hereinafter referred to as a set of boxes) on which a passive RFID 103 is attached are placed on a belt conveyor. The identifiers of the plurality of passive RFIDs 103 are read through the reader / writer antenna 140.

In this case, the propagation loss increases due to the change in the amplification degree and directivity of the antenna 150 due to the proximity of the passive RFIDs 103 and the influence of the material of the box and the contents of the box to which the passive RFID 103 is attached. For this reason, the passive RFID 103 cannot generate power by the rectifier circuit in the integrated circuit 160, and as a result, a reading error by the reader / writer 101 occurs. In this case, the distance between the reader / writer 101 where the reading error occurs and the passive RFID 103 is shorter than about 3 m described above. As described above, the distance at which the reader / writer 101 and the passive RFID 103 can communicate depends on the number of passive RFIDs 103 included in the box group, the box material, and the contents of the box.
JP 2005-316838 A

  The above-mentioned reading error in the RFID system in the physical distribution / distribution field may be overlooked because it is not known whether or not the reading can be actually performed during actual operation. For example, if only 99 RFIDs can be read while trying to read 100 RFIDs, it can be seen that one reading error has occurred. However, since it is not known how many RFIDs should be read in practice, it is unclear whether 99 is sufficient or 110, for example.

  An object of the present invention is to provide a technique capable of detecting this reading error.

  The representative invention disclosed in the present application includes a plurality of first wireless tags, a second wireless tag, a first reading unit, a control unit connected to the first reading unit, and a connection to the control unit. A first tag for transmitting and receiving a radio signal; and a first integrated circuit connected to the first antenna; and a first integrated circuit connected to the first antenna. One integrated circuit holds at least an identifier of each first wireless tag, and the second wireless tag includes a second antenna that transmits and receives a wireless signal; a second integrated circuit connected to the second antenna; A battery for supplying power to the second integrated circuit, wherein the second integrated circuit holds at least an identifier of the second wireless tag, and the first reading unit includes a third antenna, A first transmitting / receiving device connected to three antennas; The control unit includes a computing device and a memory connected to the computing device, and the registration unit associates the identifiers of the plurality of first wireless tags with the identifiers of the second wireless tags. The first reading unit transmits a reading start signal, and each of the first wireless tags receives the reading start signal, and then holds each of the holdings in the first integrated circuit. When the wireless signal including the identifier of the first wireless tag is transmitted and the second wireless tag receives the reading start signal, the wireless signal including the identifier of the second wireless tag held in the second integrated circuit is transmitted. And the first reading unit receives the wireless signal including the identifier from the plurality of first wireless tags and the second wireless tag, and the first reading unit includes the plurality of first wireless tags and The second wireless tag When the wireless signal including the identifier is received from at least one of the wireless communication device, the control unit associates the wireless signal received by the first reading unit with the identifier of one second wireless tag and stores the wireless signal. It is determined whether or not all of the identifiers of the plurality of first wireless tags held in the device are included.

  According to an embodiment of the present invention, it is possible to reliably grasp whether or not an RFID reading error has occurred.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Note that in all the drawings for explaining the embodiments, the same members are denoted by the same reference numerals, and the repeated explanation thereof is omitted.

(Embodiment 1)
FIG. 1 is a block diagram showing the configuration of the RFID system according to the first embodiment of the present invention.

  The RFID system of this embodiment includes a plurality of passive RFIDs 103, a semi-passive RFID 105, a reader / writer 101, a host device 106, a network 107, and a database 108.

  Each passive RFID 103 is a wireless tag similar to that shown in FIG. The plurality of passive RFIDs 103 are attached to the plurality of boxes 240, respectively. In the present embodiment, the passive RFID 103 only needs to be attached to an article managed by the RFID system. In other words, the passive RFID 103 may be attached to the box 240 containing the article to be managed as shown in FIG. 1 or may be attached to the article to be managed.

  The semi-passive RFID 105 is a wireless tag attached to the pallet 250 that is a base of the plurality of boxes 240. The configuration of the semi-passive RFID 105 will be described later (see FIG. 2).

  The reader / writer 101 is the same as that shown in FIG. However, the reader / writer 101 of the present embodiment is connected so as to be communicable with the host device 106. In the following description, processing executed by the reader / writer 101 is controlled by the arithmetic processing unit 120 executing a program (not shown) stored in the memory 130.

  Although only one reader / writer 101 is shown in FIG. 1, the RFID system of this embodiment may include a plurality of reader / writers 101. For example, one of the plurality of reader / writers 101 may be fixed in the vicinity of the conveyance path of the box 240, and the other one is a small one that is carried and used by an operator. Also good.

  The host device 106 is a computer including an arithmetic processing device 210 and a memory 220 and controls the reader / writer 101. In the following description, processing executed by the host device 106 is controlled by the arithmetic processing device 210 executing a program (not shown) stored in the memory 220. The host device 106 may be further connected to the output device 230. Alternatively, the upper device 106 may incorporate the output device 230. The output device 230 may be, for example, an image display device or a speaker. The host device 106 may be further connected to a transport device 401 that transports the box group 200 (see FIG. 4).

  The network 107 connects the host device 106 and the database 108 so that they can communicate with each other. The network 107 may be, for example, a so-called LAN (Local Area Network).

  The database 108 may be, for example, a computer including an arithmetic processing device 260, a memory 270, and a storage device 280. The storage device 280 stores data that is referred to by the host device 106. This data will be described later (see FIG. 3). The storage device 280 (for example, a hard disk drive or flash memory) needs to have a sufficient data capacity to store the data shown in FIG. When the memory 270 (for example, a dynamic random access memory) has a sufficient capacity, the memory 270 may also serve as the storage device 280.

  FIG. 2 is a block diagram illustrating a configuration of the semi-passive RFID 105 according to the first embodiment of this invention.

  The semi-passive RFID 105 includes an antenna 150, an integrated circuit 161, and a battery 170. The integrated circuit 161 includes a memory (not shown). In this memory, at least an identifier for uniquely identifying the semi-passive RFID 105 is stored. The battery 170 supplies power to the integrated circuit 161.

  The circuit operation of the semi-passive RFID 105 is the same as that of the passive RFID 103 except for the power supply described above. Therefore, since the semi-passive RFID 105 is in a state where power is always supplied regardless of the communication distance, it can be expected that the communicable distance will be increased by more than twice as compared with the passive RFID 103. In other words, the reader / writer 101 can more reliably execute reading from the semi-passive RFID 105 than reading from the passive RFID 103.

  FIG. 3 is an explanatory diagram of data stored in the database 108 according to the first embodiment of this invention.

  In the database 108, the RFID information of the semi-passive RFID 105 attached to the pallet 250 and the RFID information of the plurality of passive RFIDs 103 attached to the plurality of boxes 240 placed on the pallet 250 are registered in advance in association with each other. . The RFID information of the semi-passive RFID 105 includes at least a unique identifier of the semi-passive RFID 105. The RFID information of the passive RFID 103 includes at least a unique identifier of the passive RFID.

  For example, as shown in FIG. 3, the RFID information (SRFID1) of the semi-passive RFID 105 and the RFID information (PRFID1 to PRFID100) of 100 passive RFIDs 103 are registered in association with each other. This is because 100 boxes 240 are placed on a pallet 250, and the RFID information of the passive RFID 103 attached to the 100 boxes 240 is “PRFID1” to “PRFID100”, respectively. The RFID information of the semi-passive RFID 105 attached to the pallet 250 on which the box 240 is placed is “SRFID1”.

  FIG. 4 is an explanatory diagram of a physical distribution management system to which the RFID system according to the first embodiment of this invention is applied.

  FIG. 4 shows a system including a transport device 401 as an example of a physical distribution management system.

  FIG. 4 shows a belt conveyor that conveys the box group 200 as an example of the conveying device 401.

  Box group 200 includes a plurality of boxes 240 placed on pallet 250. A passive RFID 103 is attached to each of the plurality of boxes 240. On the other hand, the semi-passive RFID 105 is attached to the pallet 250. The box group 200 passes through the vicinity of at least one antenna 140 arranged in a gate shape by being transported in a predetermined direction (advancing direction shown in FIG. 4) along a predetermined path by the transport device 401. The at least one antenna 140 needs to be installed at a position where communication with the plurality of passive RFIDs 103 and semi-passive RFIDs 105 included in the box group 200 conveyed on the route by the electromagnetic wave 102 is possible.

  FIG. 4 shows an example in which the boxes 240 included in the box group 200 are stacked on the pallet 250, but the pallet 250 may be replaced by any kind of transportation means. For example, the boxes 240 included in the box group 200 may be packed in a cage or a larger box. In that case, the semi-passive RFID 105 is attached to a car or a larger box.

  The transport device 401 is communicably connected to the host device 106 (see FIG. 1), and transports the box group 200 according to the control signal received from the host device 106.

  FIG. 4 shows an example in which a belt conveyor is used as the conveying device 401. The RFID system of this embodiment is a physical distribution management system in which a conveying device other than the belt conveyor (for example, a forklift or an automatic operation cart) is used. It can also be applied to.

  FIG. 5 is a flowchart showing the operation of the RFID system according to the first embodiment of this invention.

  First, the reader / writer 101 reads the RFID information of the passive RFID 103 attached to each box 240 included in the box group 200 and the RFID information of the semi-passive RFID 105 attached to the pallet 250 on which the box group 200 is placed (step). S101). For example, the operator may read the semi-passive RFID 105 and the passive RFID 103 attached to each box 240 one by one using the small reader / writer 101 before assembling the box group 200.

  Next, the worker assembles the box group 200 (step S102). This assembly may be performed, for example, by an operator stacking boxes 240 on a pallet 250.

  Next, the database 108 registers the RFID information read by the reader / writer 101 (step S103). For example, the RFID information read by the reader / writer 101 is transmitted to the host device 106, the RFID information received by the host device 106 is transmitted to the database 108 via the network 107, and the RFID information received by the database 108 is registered in the storage device 280. May be. At this time, the database 108 registers the RFID information of the passive RFID 103 received from the host device 106 and the RFID information of the semi-passive RFID 105 in association with each other as shown in FIG.

  Note that the RFID information of the semi-passive RFID 105 and the plurality of passive RFIDs 103 may be associated and registered in the database 108 by a method other than the above.

  Next, the box group 200 including the 100 boxes 240 loaded on the pallet 250 is placed on the transfer device 401 and passes near the antenna 140 of the reader / writer 101 arranged in a gate shape. At this time, the reader / writer 101 reads RFID information from the box group 200. Specifically, when the box group 200 passes near the antenna 140 of the reader / writer 101, the reader / writer 101 detects RFID information (for example, SRFID1) of the semi-passive RFID 105 attached to the pallet 250 on which the box group 200 is placed, Then, the RFID information (for example, PRFID1 to PRFID100) of the passive RFID 103 attached to each box 240 included in the box group 200 is read, and the RFID information is sequentially transmitted to the host device 106 (step S104).

  When receiving the RFID information from the reader / writer 101, the host device 106 requests the database 108 to search for the received RFID information (step S105). The database 108 stores, for example, RFID information (SRFID1) of the semi-passive RFID 105 and RFID information (PRFID1 to PRFID100) of the passive RFID 103 in association with each other. The host device 106 collates the RFID information received from the reader / writer 101 with the retrieved RFID information.

  Next, the host device 106 determines whether or not the collation results match (step S106).

  For example, when the RFID information of one passive RFID 103 (for example, PRFID 15) is searched in the database 108, it is understood that PRFID1 to PRFID14, PRFID16 to PRFID100, and SRFID1 are registered in association with PRFID15. Alternatively, when RFID information (for example, SRFID1) of the semi-passive RFID 105 is searched in the database 108, it can be seen that PRFID1 to PRFID100 are registered in association with SRFID1.

  In this way, if the reader / writer 101 can read the RFID information of the semi-passive RFID 105, the number of passive RFIDs 103 included in the box group 200 on the pallet 250 to which the semi-passive RFID 105 is attached (that is, the box group 200 includes The number of boxes 240 included) is known. Alternatively, if the reader / writer 101 can read at least one RFID information among the plurality of passive RFIDs 103, the number of boxes 240 included in the box group 200 to which the box 240 to which the passive RFID 103 is attached belongs can be known.

  Therefore, when the reader / writer 101 cannot read the RFID information of the passive RFID 103 attached to all the boxes 240 included in the box group 200 (in other words, it is registered in association with the RFID information of one semi-passive RFID 105). If at least one of the RFID information of the plurality of passive RFIDs 103 is not included in the RFID information read by the reader / writer 101), it can be determined as a reading error.

  When the RFID information received from the reader / writer 101 matches the RFID information retrieved from the database 108, the host device 106 determines that the RFID information is normal from the passive RFIDs 103 attached to all the boxes 240 included in the box group 200. It is determined that it has been read, and the reading is terminated. In this case, the host device 106 sets “NO counter X” to “0”. The “NO count counter X” is a counter held in, for example, the memory 220 of the host device 106.

  On the other hand, if the RFID information received from the reader / writer 101 does not match the RFID information retrieved from the database 108, a reading error has occurred. That is, the RFID information of the passive RFID 103 attached to at least one of the boxes 240 included in the box group 200 is not read. In this case, the host device 106 increments “NO counter X” by 1 (step S107).

  In step S107, the host device 106 may notify the operator that a reading error has occurred. This notification is executed, for example, when the upper device 106 causes the output device 230 to output a warning. For example, when the output device 230 is an image display device, a warning screen may be displayed, and when the output device 230 is a speaker, a warning sound may be output.

  Next, the host device 106 compares the predetermined integer N with the “NO number counter X” (step S108). The integer N is a threshold value held in, for example, the memory 220 of the upper device 106. An operator, an administrator of the RFID system, or the like can set an arbitrary number as an integer N in advance.

  If the “NO number counter X” is less than N, the higher-level device 106 causes the reader / writer 101 to read the RFID information from the box group 200 again (step S104). For example, the host device 106 stops the transport device 401 and then reverses the transport direction of the transport device 401 to return the box group 200 to a predetermined position, and then instructs the transport device 401 to perform a normal operation. 401 may be transmitted. As a result, since the box group 200 passes again in the vicinity of the antenna 140, the reader / writer 101 can perform reading again.

  When the “NO number counter X” is N or more, the host device 106 controls the transport device 401 to move the box group 200 to a predetermined position. Thereafter, for example, the worker reads RFID information one by one from the passive RFID 103 attached to the box 240 using the small reader / writer 101 or the like (step S109). When the reading from all the passive RFIDs 103 is completed, the upper apparatus 106 sets the “NO counter X” to “0”.

  The reading error can be detected by the above processing. When a reading error is detected, it is possible to prevent a final reading omission by performing the reading again. As a result, the shortage or excess of the boxes 240 included in the box group 200 is reliably detected.

  Furthermore, in this embodiment, the semi-passive RFID 105 is attached to the pallet 250 on which the box group 200 is placed. Since the reader / writer 101 can reliably read the RFID information of the semi-passive RFID 105, even if it cannot read any RFID information of the passive RFID 103, it is registered in the database 108 from the RFID information (for example, SRFID1) of the semi-passive RFID 105. Related passive RFID information (for example, PRFID1 to PRFID100). For this reason, the reading error of the passive RFID 103 can be reliably detected.

  FIG. 6 is a sequence diagram illustrating processing executed by each device according to the first embodiment of this invention.

  Specifically, FIG. 6 is a diagram showing how each device exchanges in step S104 of FIG.

  The host device 106 transmits a reading start signal for the box group 200 to the reader / writer 101 (step S601). The reader / writer 101 that has received the reading start signal transmits an RFID information reading start signal to the box group 200. The passive RFID 103 and the semi-passive RFID 105 included in the box group 200 that has received the reading start signal transmit each RFID information (for example, PRFID57,..., SRFID1,... PRFID12) to the reader / writer 101 (step S603). Step S605).

  The reader / writer 101 transmits the received RFID information (eg, PRFID57,..., SRFID1,... PRFID12) to the higher-level device 106 (steps S606 to S608).

  The host device 106 transmits an inquiry signal to the database 108 using one of the received RFID information (for example, PRFID 57) (step S609).

  The database 108 stores other RFID information (PRFID1 to PRFID56, PRFID57 to PRFID100, and SRFID1 corresponding to PRFID57 in the example of FIG. 3) related to the RFID information (for example, PRFID57) included in the received inquiry signal as the upper device 106. (Step S610). Alternatively, the host device 106 itself may read related RFID information from the database 108.

  Thereafter, the host device 106 proceeds to the collation operation in step S105 in FIG.

  The above is the first embodiment of the present invention.

  Next, a modification of the first embodiment will be described.

  FIG. 7 is a block diagram showing a configuration of a first modification of the RFID system according to the first embodiment of the present invention.

  The reader / writer 101 of the RFID system shown in FIG. 7 has functions equivalent to those of the host device 106 shown in FIG. 1 in addition to the functions of the reader / writer 101 shown in FIG. For this reason, the RFID system shown in FIG.

  Also in the RFID system shown in FIG. 7, the same processing as that of the RFID system shown in FIGS. 1 to 6 is executed. However, the processing executed by the host device 106 among the processing shown in FIG. 5 is executed by the reader / writer 101 in the RFID system shown in FIG. Furthermore, communication (step S601, step S606 to step S608) between the reader / writer 101 and the host device 106 is not executed in the processing shown in FIG. The inquiry in step S609 is transmitted from the reader / writer 101, and the information in step S610 is received by the reader / writer 101.

  FIG. 8 is a block diagram showing a configuration of a second modification of the RFID system according to the first embodiment of the present invention.

  The RFID system shown in FIG. 8 is the same as the RFID system shown in FIG. 1 except that the semi-passive RFID 105 is replaced by an active RFID 109.

  FIG. 9 is a block diagram illustrating a configuration of the active RFID 109 according to the first embodiment of this invention.

  Similar to the semi-passive RFID 105, the active RFID 109 includes an antenna 150, an integrated circuit 162, and a battery 170, and the integrated circuit 162 includes a memory (not shown). Power to the integrated circuit 162 is supplied by a battery 170.

  Further, the active RFID 109 creates a carrier wave using the power of the battery 170 and transmits a modulated wave with built-in data, as in a general wireless device. For this reason, the communicable distance between the active RFID 109 and the reader / writer 101 is further extended as compared with the case of the semi-passive RFID 105. In other words, the reader / writer 101 can read RFID information from the active RFID 109 more reliably than when the semi-passive RFID 105 is used.

  FIG. 10 is a block diagram showing a configuration of a third modification of the RFID system according to the first embodiment of the present invention.

  The RFID system shown in FIG. 10 is the same as the RFID system shown in FIG. 7 except that the semi-passive RFID 105 is replaced by an active RFID 109.

  Also in the modification of the first embodiment described above, an RFID information reading error can be reliably detected as in the first embodiment shown in FIGS.

(Embodiment 2)
FIG. 11 is a block diagram showing a configuration of an RFID system according to the second embodiment of this invention.

  The RFID system according to the second embodiment of the present invention includes a plurality of passive RFIDs 103, a semi-passive RFID 105, a reader / writer 101, and a host device 106. The passive RFID 103, the reader / writer 101, the host device 106, and the semi-passive RFID 105 are the same as those in the first embodiment. In the following, the difference between the present embodiment and the first embodiment will be described.

  The host device 106 may be connected to the output device 230 and the transport device 401, but need not be connected to the network.

  The semi-passive RFID 105 includes an antenna 150, an integrated circuit 161, and a battery 170 as shown in FIG. The integrated circuit 161 includes a memory (not shown). In the memory of the integrated circuit 161, in addition to an identifier for uniquely identifying the semi-passive RFID 105, for example, the number of passive RFIDs 103 included in the box group 200 is stored.

  FIG. 12 is a flowchart showing the operation of the RFID system according to the second embodiment of this invention.

  Hereinafter, an example in which the box group 200 including the RFID information (SRFID1) of the semi-passive RFID 105 and the RFID information (PRFID1 to 100) of 100 passive RFIDs 103 is transported and read by the transport device 401 as shown in FIG. I will explain it.

  First, the operator reads the RFID information of the passive RFID 103 attached to the box 240 one by one using the small reader / writer 101 or the like (step S201), and assembles a group of boxes (step S202). These steps may be executed in the same manner as steps S101 and S102 in FIG.

  Next, the reader / writer 101 writes the number of read passive RFIDs 103 in the memory in the semi-passive RFID 105 (step S203). At this time, if the memory capacity in the semi-passive RFID 105 is sufficiently large, the reader / writer 101 may write not only the number of read passive RFIDs 103 but also all the RFID information read from those passive RFIDs 103. Information indicating the number of passive RFIDs 103 (and RFID information of each passive RFID if written) written in the memory in the semi-passive RFID 105 is also described as semi-passive memory information in the following description.

  Next, the box group 200 composed of 100 boxes 240 loaded on the pallet 250 is placed on the transport device 401 and passes near the antenna 140. At this time, the reader / writer 101 reads RFID information included in the box group 200 (step S204).

  Specifically, the reader / writer 101 reads RFID information (for example, SRFID1) and semipassive memory information (for example, 100 pieces) from the semi-passive RFID 105. Further, the reader / writer 101 reads RFID information (for example, PRFID1 to PRFID100) from the passive RFID 103. Then, the reader / writer 101 sequentially transmits the read information to the higher-level device 106.

  Upon receiving the RFID information and the semi-passive memory information from the reader / writer 101, the host device 106 collates the number of the received RFID information with the received semi-passive memory information (step S205), and the number of the received RFID information. Is equal to the number of passive RFIDs 103 indicated by the received semi-passive memory information (step S206). The received RFID information is counted by counting the RFID information received from one passive RFID 103 as one RFID information.

  When the number of RFID information received from the reader / writer 101 matches the number of passive RFIDs 103 indicated by the semi-passive memory information, the RFID information is correctly obtained from all the passive RFIDs 103 attached to all the boxes 240 included in the box group 200. Read. In this case, the host device 106 ends the reading. Furthermore, the host device 106 sets “NO counter X” to “0”. The “NO counter X” is the same as that used in the first embodiment.

  On the other hand, if the number of RFID information received from the reader / writer 101 and the number of passive RFIDs 103 indicated by the semi-passive memory information do not match, a reading error has occurred. In other words, at least one RFID information among the passive RFIDs 103 included in the box group 200 was not read. In this case, the host device 106 increments the “NO number counter X” by 1 (step S207), and compares the predetermined integer N with the “NO number counter X” (step S208).

  When the “NO number counter X” is less than N, the upper level device 106 reads the RFID information included in the box group 200 again (step S204).

  When the “NO number counter X” is N or more, the host device 106 controls the transport device 401 to move the box group 200 to a predetermined position. Thereafter, for example, an operator reads RFID information one by one from the passive RFID 103 attached to the box 240 using the small reader / writer 101 or the like (step S209). Thereafter, the host device 106 sets the “NO number counter X” to “0”.

  Note that steps S206 to S209 may be executed in the same manner as steps S106 to S109 of the first embodiment, respectively.

  The above is the second embodiment of the present invention.

  Next, a modification of the second embodiment will be described.

  FIG. 13 is a block diagram showing a configuration of a first modification of the RFID system according to the second embodiment of the present invention.

  The reader / writer 101 of the RFID system shown in FIG. 13 has functions equivalent to those of the host device 106 shown in FIG. 11 in addition to the functions of the reader / writer 101 shown in FIG. For this reason, the RFID system shown in FIG.

  Also in the RFID system shown in FIG. 13, the same processing as that of the RFID system shown in FIGS. 11 and 12 is executed. However, the processing executed by the host device 106 among the processing shown in FIG. 12 is executed by the reader / writer 101 in the RFID system shown in FIG.

  FIG. 14 is a block diagram illustrating a configuration of a second modification of the RFID system according to the second embodiment of this invention.

  The RFID system shown in FIG. 14 is the same as the RFID system shown in FIG. 11 except that the semi-passive RFID 105 is replaced by an active RFID 109.

  As shown in FIG. 9, the active RFID 109 includes an antenna 150, an integrated circuit 162, and a battery 170, and the integrated circuit 162 includes a memory (not shown). In this memory, in addition to the identifier for uniquely identifying the active RFID 109, information similar to the semi-passive information described in FIG. 12 is stored.

  FIG. 15 is a block diagram illustrating a configuration of a third modification of the RFID system according to the second embodiment of this invention.

  The RFID system shown in FIG. 15 is the same as the RFID system shown in FIG. 13 except that the semi-passive RFID 105 is replaced by an active RFID 109.

  According to the second embodiment of the present invention described above, as in the case of the first embodiment, it is possible to prevent a final reading omission by reliably detecting an RFID information reading error. Furthermore, according to the first embodiment of the present invention, it is possible to reliably detect reading errors based only on RFID information and semi-passive memory information read from the box group 200 without previously registering RFID information in a database or the like. can do.

It is a block diagram which shows the structure of the RFID system of the 1st Embodiment of this invention. It is a block diagram which shows the structure of the semi-passive RFID of the 1st Embodiment of this invention. It is explanatory drawing of the data stored in the database of the 1st Embodiment of this invention. It is explanatory drawing of the physical distribution management system to which the RFID system of the 1st Embodiment of this invention is applied. It is a flowchart which shows operation | movement of the RFID system of the 1st Embodiment of this invention. It is a sequence diagram explaining the process which each apparatus of the 1st Embodiment of this invention performs. It is a block diagram which shows the structure of the 1st modification of the RFID system of the 1st Embodiment of this invention. It is a block diagram which shows the structure of the 2nd modification of the RFID system of the 1st Embodiment of this invention. It is a block diagram which shows the structure of the active RFID of the 1st Embodiment of this invention. It is a block diagram which shows the structure of the 3rd modification of the RFID system of the 1st Embodiment of this invention. It is a block diagram which shows the structure of the RFID system of the 2nd Embodiment of this invention. It is a flowchart which shows operation | movement of the RFID system of the 2nd Embodiment of this invention. It is a block diagram which shows the structure of the 1st modification of the RFID system of the 2nd Embodiment of this invention. It is a block diagram which shows the structure of the 2nd modification of the RFID system of the 2nd Embodiment of this invention. It is a block diagram which shows the structure of the 3rd modification of the RFID system of the 2nd Embodiment of this invention. It is a block diagram which shows the structure of the conventional RFID system.

Explanation of symbols

101 Reader / Writer 102 Electromagnetic Wave 103 Passive RFID
105 Semi-passive RFID
106 Host device 107 Network 108 Database 109 Active RFID
110 Transceiver (RF)
120 arithmetic processing unit (CPU)
130, 220 Memory 140, 150 Antenna 160, 161, 162 Integrated circuit (IC)
170 Battery 230 Output device 240 Box 250 Pallet 401 Conveying device

Claims (12)

A wireless tag system comprising a plurality of first wireless tags, a second wireless tag, a first reading unit, a control unit connected to the first reading unit, and a registration unit connected to the control unit. There,
Each of the first wireless tags includes a first antenna that transmits and receives a wireless signal, and a first integrated circuit connected to the first antenna,
The first integrated circuit holds at least an identifier of each first wireless tag,
The second wireless tag includes a second antenna that transmits and receives a radio signal, a second integrated circuit connected to the second antenna, and a battery that supplies power to the second integrated circuit,
The second integrated circuit holds at least an identifier of the second wireless tag;
The first reading unit includes a third antenna and a first transmission / reception device connected to the third antenna,
The control unit includes an arithmetic device and a memory connected to the arithmetic device,
The registration unit includes a storage device that holds the identifiers of the plurality of first wireless tags and the identifiers of the second wireless tags in association with each other,
The first reading unit transmits a reading start signal,
When each of the first wireless tags receives the reading start signal, the first wireless tag transmits a wireless signal including an identifier of the first wireless tag held in the first integrated circuit,
When the second wireless tag receives the reading start signal, the second wireless tag transmits a wireless signal including an identifier of the second wireless tag held in the second integrated circuit,
The first reading unit receives the wireless signal including the identifier from the plurality of first wireless tags and the second wireless tag,
When the first reading unit receives the wireless signal including the identifier from at least one of the plurality of first wireless tags and the second wireless tag, the control unit receives the wireless signal received by the first reading unit. It is determined whether or not a wireless signal includes all of the identifiers of the plurality of first wireless tags held in the storage device in association with the identifier of one second wireless tag. Tag system. The control unit is connected to an output device that outputs information according to an instruction of the control unit,
When at least one of the identifiers of the plurality of first wireless tags held in the storage device in association with the identifier of one second wireless tag is not included in the wireless signal received by the first reading unit 2. The wireless tag system according to claim 1, wherein, when determined, the control unit causes the output device to output information indicating that the reading of the identifier of the first wireless tag has failed. Each of the plurality of first wireless tags is attached to a plurality of articles,
The second wireless tag is attached to a transportation means for loading the plurality of articles,
The control unit is connected to a transport device,
The transport device transports the plurality of articles loaded on the transport unit and the transport unit along a predetermined path based on a control signal received from the control unit,
The third antenna is installed at a position where it can communicate with the plurality of first wireless tags and the second wireless tag passing on the predetermined route;
When at least one of the identifiers of the plurality of first wireless tags held in the storage device in association with the identifier of one second wireless tag is not included in the wireless signal received by the first reading unit If determined, the control unit transmits a control signal for reversing the conveyance direction of the plurality of articles loaded on the conveyance unit and the conveyance unit to the conveyance device;
The wireless tag system according to claim 1, wherein the first reading unit transmits the reading start signal again. The wireless tag system further includes a second reading unit connected to the control unit and including a fourth antenna and a second transmitting / receiving device connected to the fourth antenna,
The second reading unit includes:
Before the first reading unit transmits the reading start signal, the reading start signal is transmitted;
Receiving the wireless signal including the identifier from the plurality of first wireless tags and the second wireless tag;
The control unit causes the registration unit to hold the identifiers of the plurality of first wireless tags and the identifiers of the second wireless tags included in the wireless signal received by the second reading unit in association with each other. The wireless tag system according to claim 1. A wireless tag system comprising a plurality of first wireless tags, a second wireless tag, a first reading unit, and a control unit connected to the first reading unit,
Each of the first wireless tags includes a first antenna that transmits and receives a wireless signal, and a first integrated circuit connected to the first antenna,
The first integrated circuit holds at least an identifier of each first wireless tag,
The second wireless tag includes a second antenna that transmits and receives a radio signal, a second integrated circuit connected to the second antenna, and a battery that supplies power to the second integrated circuit,
The second integrated circuit holds at least information indicating the identifier of the second wireless tag and the number of the plurality of first wireless tags,
The first reading unit includes a third antenna and a first transmission / reception device connected to the third antenna,
The control unit includes an arithmetic device and a memory connected to the arithmetic device,
The first reading unit transmits a reading start signal,
When each of the first wireless tags receives the reading start signal, the first wireless tag transmits a wireless signal including an identifier of the first wireless tag held in the first integrated circuit,
When the second wireless tag receives the reading start signal, the wireless signal includes an identifier of the second wireless tag held in the second integrated circuit and information indicating the number of the plurality of first wireless tags. Send
The first reading unit receives at least a radio signal including information indicating the identifier of the second radio tag and the number of the plurality of first radio tags from the second radio tag,
The control unit may include identifiers of the first radio tag, the number of which is equal to the number of the plurality of first radio tags indicated by the information included in the received radio signal, of the radio signal received by the first reading unit. A wireless tag system for determining whether or not to include a wireless tag system. The control unit is connected to an output device that outputs information according to an instruction of the control unit,
It is determined that the wireless signal received by the first reading unit does not include the same number of identifiers of the first wireless tag as the number of the plurality of first wireless tags indicated by the information included in the received wireless signal. 6. The wireless tag system according to claim 5, wherein the control unit causes the output device to output information indicating that reading of the identifier of the first wireless tag has failed. Each of the plurality of first wireless tags is attached to a plurality of articles,
The second wireless tag is attached to a transportation means for loading the plurality of articles,
The control unit is connected to a transport device,
The transport device transports the plurality of articles loaded on the transport unit and the transport unit along a predetermined path based on a control signal received from the control unit,
The third antenna is installed at a position where it can communicate with the plurality of first wireless tags and the second wireless tag passing on the predetermined route;
It is determined that the wireless signal received by the first reading unit does not include the same number of identifiers of the first wireless tag as the number of the plurality of first wireless tags indicated by the information included in the received wireless signal. The control unit transmits a control signal for reversing the transport direction of the plurality of articles loaded on the transport means and the transport means to the transport device;
The wireless tag system according to claim 5, wherein the first reading unit transmits the reading start signal again. The wireless tag system further includes a second reading unit connected to the control unit and including a fourth antenna and a second transmitting / receiving device connected to the fourth antenna,
The second reading unit includes:
The wireless signal for writing information indicating the number of the plurality of first wireless tags is transmitted to the second wireless tag before the first reading unit transmits the reading start signal. 5. The wireless tag system according to 5. A wireless tag system comprising: a plurality of first wireless tags; a second wireless tag; a first reading unit; a control unit connected to the first reading unit; and a registration unit connected to the control unit. A control method,
Each of the first wireless tags includes a first antenna that transmits and receives a wireless signal, and a first integrated circuit connected to the first antenna,
The first integrated circuit holds at least an identifier of each first wireless tag,
The second wireless tag includes a second antenna that transmits and receives a radio signal, a second integrated circuit connected to the second antenna, and a battery that supplies power to the second integrated circuit,
The second integrated circuit holds at least an identifier of the second wireless tag;
The first reading unit includes a third antenna and a first transmission / reception device connected to the third antenna,
The control unit includes an arithmetic device and a memory connected to the arithmetic device,
The registration unit includes a storage device that holds the identifiers of the plurality of first wireless tags and the identifiers of the second wireless tags in association with each other,
The method
A procedure in which the first reading unit transmits a reading start signal;
When each of the first wireless tags receives the reading start signal, a procedure of transmitting a wireless signal including an identifier of each of the first wireless tags held in the first integrated circuit;
When the second wireless tag receives the reading start signal, a procedure for transmitting a wireless signal including an identifier of the second wireless tag held in the second integrated circuit;
The first reading unit receives the wireless signal including the identifier from at least one of the plurality of first wireless tags and the second wireless tag;
All the identifiers of the plurality of first wireless tags held in the storage device are associated with the identifier of one second wireless tag in the wireless signal received by the first reading unit. And a procedure for determining whether or not it is included. The control unit is connected to an output device that outputs information according to an instruction of the control unit,
In the method, the wireless device further receives at least one of the identifiers of the plurality of first wireless tags held in the storage device in association with the identifier of the second wireless tag received by the first reading unit. 10. The method according to claim 9, further comprising: a step of causing the output device to output information indicating that reading of the identifier of the first wireless tag has failed when it is determined that the signal is not included in the signal. The method described in 1. Each of the plurality of first wireless tags is attached to a plurality of articles,
The second wireless tag is attached to a transportation means for loading the plurality of articles,
The control unit is connected to a transport device,
The transport device transports the plurality of articles loaded on the transport unit and the transport unit along a predetermined path based on a control signal received from the control unit,
The third antenna is installed at a position where it can communicate with the plurality of first wireless tags and the second wireless tag passing on the predetermined route;
In the method, the wireless device further receives at least one of the identifiers of the plurality of first wireless tags held in the storage device in association with the identifier of the second wireless tag received by the first reading unit. When it is determined that the signal is not included in the signal, the control unit includes a procedure of transmitting, to the transfer device, a control signal that reverses the transfer direction of the plurality of articles loaded on the transfer unit and the transfer unit. ,
The method according to claim 9, wherein the first reading unit transmits the reading start signal again. The wireless tag system further includes a second reading unit connected to the control unit and including a fourth antenna and a second transmitting / receiving device connected to the fourth antenna,
The method further comprises:
A procedure in which the second reading unit transmits the reading start signal before the first reading unit transmits the reading start signal;
The second reading unit receives the wireless signal including the identifier from the plurality of first wireless tags and the second wireless tag;
A procedure in which the control unit causes the registration unit to retain the identifiers of the plurality of first wireless tags and the identifiers of the second wireless tags included in the wireless signal received by the second reading unit; The method of claim 9, comprising: