JP4821117B2 - RFID tag communication system - Google Patents

Description

  The present invention relates to an improvement in a wireless tag communication system that performs information communication with a predetermined wireless tag in a contactless manner, and more particularly to a technique for detecting an accurate position of a wireless tag that is a communication target.

  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, there is an article search method using RFID described in Patent Document 1, and according to this technology, the above-mentioned wireless tag is attached to each article to be managed, and information is stored between the wireless tags. By communicating, it is said that the search or management of articles can be suitably performed.

JP 2002-271229 A

  However, since the conventional technique searches for a target wireless tag by changing the directivity of a radio wave (transmission signal) transmitted from the wireless tag communication device, for example, a wireless tag used for searching In the case where the communication device is a portable handy reader, the relative direction of the wireless tag that is a communication target is changed by the movement of the handy reader, and there is an adverse effect that the search becomes difficult. Further, when managing the arrangement position of the article, it may be necessary to perform manual registration or the like, which is cumbersome and not suitable for practical use. For this reason, there has been a demand for the development of a wireless tag communication system that can easily detect an accurate position of a wireless tag that is a communication target.

  The present invention has been made against the background of the above circumstances, and an object of the present invention is to provide a wireless tag communication system that can easily detect an accurate position of a wireless tag to be communicated. .

In order to achieve such an object, the gist of the present invention is a wireless tag communication system that performs non-contact communication of information with a predetermined wireless tag, with respect to a predetermined reference position. A first wireless tag provided at a fixed position, a wireless tag communication device that communicates information between the first wireless tag, and the wireless tag communication device that is movable with respect to the reference position; A second wireless tag that communicates information, and the wireless tag communication device includes a signal strength detection unit that detects a strength of a return signal from the wireless tag, and the second wireless tag communicates with the first wireless tag. The position of the RFID tag communication device with respect to the reference position is determined by performing communication of information with the second tag, and the position of the RFID tag communication device is determined by communicating information with the second wireless tag. Based on the reference position The position of the second wireless tag is determined. When searching for the second wireless tag, in the first process, when reply signals are received from the plurality of first wireless tags, A position of the wireless tag communication device with respect to the reference position is determined based on a signal intensity detected by the signal intensity detection unit corresponding to each of the plurality of first wireless tags, and a determination result of the first process In the second process, it is determined whether or not the position of the first RFID tag with respect to the reference position indicates the position of the RFID tag communication apparatus with respect to the reference position. In the third step, the wireless tag communication device is informed that the wireless tag communication device is located at the position of the first wireless tag, and after the notification in the third step, the fourth step In advance Based on the determined relationship, the second wireless tag between the plurality of first wireless tags based on the signal strength detected by the signal strength detection unit corresponding to each of the plurality of first wireless tags. The position of the second RFID tag with respect to the reference position indicates the position of the RFID tag communication apparatus with respect to the reference position in the fifth process based on the determination result of the fourth process. If the determination in the fifth step is affirmative, in the sixth step, the fact that the wireless tag communication device exists at the position of the second wireless tag is notified. It is characterized by.

According to this configuration, the first wireless tag that is fixed in position with respect to the predetermined reference position, the wireless tag communication device that performs communication of information between the first wireless tag, and the reference position And a second wireless tag that communicates information with the wireless tag communication device, the wireless tag communication device detecting the strength of a return signal from the wireless tag. And communicating information with the first wireless tag to determine the position of the wireless tag communication device with respect to the reference position , and communicating information with the second wireless tag. To determine the position of the second wireless tag with respect to the reference position based on the position of the wireless tag communication device. When searching for the second wireless tag, A plurality of the first When a reply signal is received from a line tag, the wireless tag communication device with respect to the reference position based on the signal strength detected by the signal strength detector corresponding to each of the plurality of first wireless tags The position of the first RFID tag with respect to the reference position indicates the position of the RFID tag communication apparatus with respect to the reference position in the second process based on the determination result of the first process. If the determination in the second process is affirmative, in the third process, the fact that the RFID tag communication device exists at the position of the first RFID tag is notified, After the notification of the third process, in the fourth process, based on the signal strength detected by the signal strength detection unit corresponding to each of the plurality of first wireless tags from a predetermined relationship. The position of the second wireless tag among the plurality of first wireless tags is determined, and the second wireless tag with respect to the reference position is determined in a fifth process based on the determination result of the fourth process. Is determined to indicate the position of the RFID tag communication device with respect to the reference position, and if the determination in the fifth step is affirmative, in the sixth step, the RFID tag communication is performed. Since the device informs that the device exists at the position of the second wireless tag, even if the wireless tag communication device moves with respect to the reference position, the relative positional relationship with the first wireless tag Thus, the position of the wireless tag communication device can be suitably detected , and the relative position of the second wireless tag can be suitably detected. Further, by registering the position of the first wireless tag with respect to the reference position in the wireless tag communication device in advance, a complicated operation such as manually registering the position of the detected second wireless tag is performed. You do n’t have to. That is, it is possible to provide a wireless tag communication system that can easily detect the accurate position of the wireless tag communication device and the wireless tag that is a communication target .

Here, it preferably includes a storage device for storing the position of the first wireless tag with respect to the reference position. In this way, the position of the first wireless tag with respect to the reference position can be managed in a practical manner.

  Preferably, the storage device stores a position of the second wireless tag with respect to the reference position. In this way, the position of the second wireless tag with respect to the reference position can be managed in a practical manner.

  Preferably, the storage device stores the position of the first wireless tag and the position of the second wireless tag with respect to the reference position in association with each other. In this way, the positions of the first wireless tag and the second wireless tag with respect to the reference position can be managed in a practical manner.

  Preferably, the wireless tag communication device includes a display unit that displays the position of the first wireless tag or the position of the second wireless tag with respect to the reference position. In this way, the position of the second wireless tag with respect to the reference position can be visually confirmed.

  Preferably, the wireless tag communication device alternately performs communication of information with the first wireless tag and communication of information with the second wireless tag. If it does in this way, superimposition of communication between the 1st wireless tag and the 2nd wireless tag can be prevented in a practical mode.

  Preferably, the strength of the transmission signal for communicating information with the first wireless tag is the strength of the transmission signal for communicating information with the second wireless tag. Is bigger than that. In this way, in addition to being able to distinguish the communication range between the first wireless tag and the second wireless tag, it is easy to communicate with a plurality of first wireless tags. .

  Preferably, the communicable distance of the first wireless tag is larger than the communicable distance of the second wireless tag. In this way, in addition to being able to distinguish the communication range between the first wireless tag and the second wireless tag, it is easy to communicate with a plurality of first wireless tags. .

  Preferably, in the first wireless tag and the second wireless tag, commands to which a reply signal is to be returned are separately determined in advance. If it does in this way, superimposition of communication between the 1st wireless tag and the 2nd wireless tag can be prevented in a practical mode.

  Preferably, the first wireless tag is an active tag having a power supply device. In this way, the communicable distance of the first wireless tag can be extended, and the number of installed first wireless tags can be reduced.

  Preferably, the second wireless tag is used by being affixed to an article in order to manage the prescribed article. If it does in this way, the arrangement | positioning position etc. of the said article | item can be managed in a practical aspect.

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

FIG. 1 is a diagram for explaining a radio tag communication system 10 (hereinafter referred to as a communication system 10) according to an embodiment of the present invention. The communication system 10 is a so-called RFID (Radio Frequency Identification) composed of a wireless tag communication device 12 and a plurality of types (two types in FIG. 1) of wireless tags 14 and 16 that are communication targets of the wireless tag communication device 12. The RFID tag communication device 12 functions as an interrogator of the RFID system, and the RFID tags 14 and 16 function as responders. That is, when the interrogation wave F _c that is a transmission signal is transmitted from the radio tag communication device 12 toward the radio tags 14 and 16, predetermined information is received in the radio tags 14 and 16 that have received the interrogation wave F _c. The interrogation wave F _c is modulated by the signal (data), and response waves F _ra and F _{rb as} response signals (hereinafter simply referred to as response waves F _r unless otherwise distinguished) are sent to the RFID tag communication apparatus 12. Information is communicated between the wireless tag communication device 12 and the wireless tags 14 and 16 by returning the response. Here, the wireless tag communication device 12 is a portable wireless tag communication device (handy reader) provided so as to be movable with respect to a predetermined reference position, and the user 18 carries the wireless tag communication device 12. The wireless tags 14 and 16 are detected while referring to the screen. Further, different IDs are assigned to the wireless tags 14 and 16, respectively, and each wireless tag can be identified based on the IDs.

  The communication system 10 includes a single or multiple (single in FIG. 1) first wireless tags 14 as communication targets of the wireless tag communication device 12, and a single or multiple (single in FIG. 1) first wireless tags. 2 wireless tags 16. The first wireless tag 14 is preferably provided with location information indicating a predetermined location by being fixed to a predetermined reference position (for example, a room to which the communication system 10 of the present embodiment is applied). In the following description, the tag is referred to as a place tag 14. The second wireless tag 16 is preferably a tag having management information for managing the article 20 that is used by being attached to the article 20 in order to manage the predetermined article 20. In the following description, it will be referred to as an article tag 16. In the place tag 14 and the article tag 16, commands to which a reply signal is to be returned are separately determined in advance. In addition, the communication system 10 is provided with a server 96 including a storage device 98 for storing information on the place tag 14 and the article tag 16 in association with each other, and the server 96 is connected via the network 13. Information can be exchanged with the wireless tag communication device 12.

  FIG. 2 is a plan view for explaining the external appearance of the RFID tag communication device 12, and FIG. 3 is a rear view of FIG. 2 viewed from the direction of arrow III. As shown in FIGS. 2 and 3, the wireless tag communication device 12 includes a main unit 22 and an antenna unit 24 that is detachably provided on the main unit 22. The main unit 22 includes a housing 26, a display unit 28 provided on a flat surface portion of the housing 26, an operation unit 30 provided on the side of the display unit 28 in the flat surface portion, a buzzer, an alarm, Alternatively, a sound generation device 32 such as a chime speaker is provided. The operation unit 30 includes input devices such as predetermined keys, buttons, switches, or pads, and the input devices can be used for various displays related to display on the display unit 28 and communication with the wireless tags 14 and 16. Can be operated.

The antenna unit 24 transmits a predetermined interrogation wave F _c toward the wireless tags 14 and 16 in order to communicate information with the wireless tags 14 and 16 in a contactless manner. antenna 34 both transmission and reception for receiving the response wave F _r returned from their wireless tag 14, 16 in response to the waves F _c are provided so as to protrude to the left and right from the unit base 36. The antenna 34 is, for example, a unimodal antenna having a relatively narrow directivity, and is capable of detecting the wireless tags 14 and 16 pinpointed by using a so-called pencil beam shape with a narrow directivity. It is configured.

FIG. 4 is a diagram illustrating the configuration of the wireless tag communication device 12. As shown in FIG. 4, the wireless tag communication device 12 is transmitted from the transmission unit (transmission circuit) 38 for transmitting a predetermined interrogation wave F _c to the wireless tags 14 and 16, and transmitted from the transmission unit 38. that receiver for processing a response wave F _r sent back from the radio tag 14, 16 in response to the interrogating wave F _c (the homodyne detection circuit) 40, the communication target via the transmission section 38 and reception section 40 A control unit 42 that controls information communication with the wireless tags 14 and 16, an image processing unit 44 that displays a predetermined image on the display unit 28 in accordance with a command from the control unit 42, and a predetermined network And a wireless LAN communication unit 46 for connecting the control unit 42 to the server 96 or the like via the network. The control unit 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.

The transmitter 38 generates a reference frequency generator 48 that generates a reference frequency of the main carrier wave of the interrogation wave F _c , a reference frequency generated by the reference frequency generator 48, and a control signal from the controller 42. A PLL (Phase Locked Loop) 50 for setting the frequency of the main carrier based on the frequency, a VCO (Voltage Controlled Oscillator) 52 for controlling the frequency of the main carrier according to a control voltage from the PLL 50, and a predetermined controlled by the VCO 52 A transmission signal modulation unit 54 that modulates a main carrier wave having a predetermined frequency based on a predetermined control signal TX-ASK supplied from the control unit 42, and an output signal from the transmission signal modulation unit 54 is a predetermined control signal TX-. A transmission signal amplifying unit 56 that amplifies based on the PWR and supplies the amplified signal to the antenna 34. Transmission signal that is transmitted to the wireless tag 14, 16 as the interrogating wave F _c from the antenna 34 via the transmitting and receiving separation unit 62. Here, as the transmission / reception separation unit 62, a circulator or a directional coupler is preferably used.

  The reception unit 40 receives an I-phase signal that is received by the antenna 34 and is supplied via the transmission / reception separation unit 62 from the wireless tags 14 and 16 into an I-phase signal and a Q-phase signal that are orthogonal to each other. From the conversion unit 58 and the Q-phase signal conversion unit 60, the I-phase signal BPF 64 that extracts only a signal in a predetermined frequency band from the I-phase signal output from the I-phase signal conversion unit 58, and the I-phase signal BPF 64 An I-phase signal amplifier 66 for amplifying the output I-phase signal, a Q-phase signal BPF 68 for extracting only a signal in a predetermined frequency band from the Q-phase signal output from the Q-phase signal converter 60, and A Q-phase signal amplifier 70 that amplifies the Q-phase signal output from the Q-phase signal BPF 68, and the intensities of the I-phase signal and the Q-phase signal output from the I-phase signal BPF 64 and the Q-phase signal BPF 68. An output signal strength detection unit RSSI (Received Signal Strength Indicator) circuit 72, and the signals output from the I-phase signal amplification unit 66, Q-phase signal amplification unit 70, and RSSI circuit 72 are: A predetermined information signal is read out by being processed in the control unit 42.

FIG. 5 is a plan view showing the appearance of the place tag 14, and FIG. 6 is a view for explaining the configuration of the place tag 14. As shown in FIGS. 5 and 6, the place tag 14 is received by the antenna unit 74 such as a dipole antenna for transmitting and receiving signals to and from the wireless tag communication device 12. And an IC circuit unit 76 for processing the processed signal. The IC circuit unit 76 rectifies the interrogation wave F _c received from the RFID tag communication device 12 received by the antenna unit 74, and the energy of the interrogation wave F _c rectified by the rectification unit 78. Functions as a power supply unit 80 for accumulation, a clock extraction unit 82 that extracts a clock signal from the carrier wave received by the antenna unit 74 and supplies the clock signal to the control unit 88, and an information storage unit that can store a predetermined information signal The location tag 14 via the memory unit 84, the modem unit 86 connected to the antenna unit 74 for modulating and demodulating the signal, the rectifier unit 78, the clock extracting unit 82, the modem unit 86, and the like. And a control unit 88 for controlling the function. The control unit 88 performs control to store the predetermined information in the memory unit 84 by communicating with the wireless tag communication device 12, and transmits the interrogation wave F _c received by the antenna unit 74 to the modulation / demodulation unit 86. in executing the basic control as a response wave F _r of the control or the like that reflects back from the antenna unit 74 in terms of modulated based on the information signal stored in the memory unit 84.

FIG. 7 is a plan view showing the appearance of the article tag 16, and FIG. 8 is a diagram for explaining the configuration of the article tag 16. As shown in FIGS. 7 and 8, the article tag 16 is received by the antenna unit 92 such as a dipole antenna for transmitting / receiving a signal to / from the RFID tag communication device 12. And an IC circuit unit 94 for processing the received signal. The IC circuit unit 94 functionally includes the rectification unit 78, the power supply unit 80, the clock extraction unit 82, the memory unit 84, the modulation / demodulation unit 86, and the control unit 88, and the IC circuit unit of the place tag 14 described above. Similarly to 76, the modem unit 86 controls the memory unit 84 to store the predetermined information by communicating with the RFID tag communication device 12, and the modulation / demodulation unit 86 receives the interrogation wave F _c received by the antenna unit 92. executes basic control such as control that reflects back from the antenna unit 92 as a response wave F _r in terms of modulated based on the information signal stored in the memory unit 84.

The location tag 14 preferably includes a predetermined power supply device 90 as shown in FIG. 6, and the IC circuit unit 76 is an electrode for receiving power supply from the power supply device 90. It has. The power supply unit 80 of the IC circuit part 76, in addition to the energy of the interrogation wave rectified F _c by the rectification unit 78 is configured to be used a energy supplied from the power supply 90 as a power supply . That is, the place tag 14 is preferably a semi-passive tag or an active tag that includes a predetermined power supply device 90 and operates by energy supplied from the power supply device 90. The antenna portion 74 provided in the place tag 14 is larger than the antenna portion 92 provided in the article tag 16. With these configurations, the communicable distance of the place tag 14 is larger than the communicable distance of the article tag 16. Incidentally, the article tag 16 is a passive tag using the interrogating wave F _c which is transmitted from the radio tag communication apparatus 12 as the energy for operation.

  FIG. 9 is a flowchart for explaining the detection control of the wireless tags 14 and 16 by the control unit 42 of the wireless tag communication device 12, and is repeatedly executed at a predetermined cycle. In this control, first, the reading control of the place tag 14 is executed in a step SA shown in detail in FIG. 11 (hereinafter, step is omitted) SA. Next, in SB shown in detail in FIG. 12, the reading control of the article tag 16 is executed. Next, in SC, after the association control of the information read in SA and SB is executed, this routine is terminated.

FIG. 10 is a diagram for explaining reading of information from the wireless tags 14 and 16 by the wireless tag communication device 12. As shown in FIG. 9 and FIG. 10 described above, the wireless tag communication device 12 alternately performs information communication with the place tag 14 and information communication with the article tag 16. Is. That is, first, in order to communicate information with the place tag 14, the tag type flag for extracting, for example, a location code as a command to be sent back by the place tag 14 is "1". After transmitting a question wave F _c including a command and communicating information with the place tag 14, the article tag 16 returns a reply to communicate information with the article tag 16. As a command to which a signal is to be returned, for example, a query wave F _c including a command whose tag type flag for extracting the article code is “0” is transmitted, and information is communicated with the article tag 16. By doing in this way, the place tag 14 and the article tag 16 can perform communication processing separately, and the data of the place tag 14 and the data of the article tag 16 can be associated with each other.

  In the reading control of the place tag 14 shown in FIG. 11, first, in SA1, “Ping (1)” processing for listing the ID of the place tag 14 is executed. This process uses a so-called “Ping” command that specifies a part of the tag ID and receives replies from all tags including the specified ID, specifying that the head of the tag ID is “1” To do. By using this processing, it is possible to list all the location tags 14 even when there are a plurality of location tags 14 within the communication range. Next, in SA2, it is determined whether or not the location tag 14 is listed in SA1. If the determination at SA2 is negative, the process returns to the main routine shown in FIG. 9. If the determination at SA2 is affirmative, the location tag received by the antenna 34 at SA3. 14 is processed by the receiver 40, and the location code stored in the place tag 14 is extracted. Next, in SA4, the location of the place tag 14 and the location of the RFID tag communication apparatus 12 itself with respect to the place tag 14 are determined based on the location code extracted in SA3, and then the main routine shown in FIG. Returned.

  In the reading control of the article tag 16 shown in FIG. 12, first, in SB1, “Ping (0)” processing for listing the ID of the article tag 16 is executed. This process uses the “Ping” command by designating that the head of the tag ID is “0”. By using this processing, it is possible to list all the article tags 16 even when there are a plurality of article tags 16 within the communication range. Next, in SB2, it is determined whether or not the article tag 16 is listed in SB1. If the determination at SB2 is negative, the process returns to the main routine shown in FIG. 9. If the determination at SB2 is affirmative, the article tag received by the antenna 34 at SB3. The reply signal from 16 is processed by the receiving unit 40, and the article code stored in the article tag 16 is extracted. Next, in SB4, after the article codes extracted in SB3 are listed, the process is returned to the main routine shown in FIG.

  The wireless tag communication device 12 determines the position of the place tag 14 with respect to a predetermined reference position by communicating information between the place tag 14 and the article tag 16, and the position of the place tag 14 The positions of the wireless tag communication device 12 and the article tag 16 with respect to the reference position are determined based on. The association control indicated by SC in FIG. 9 is a control for associating the position of the place tag 14 and the position of the article tag 16 with respect to the reference position, and the information associated with the position is stored in the wireless LAN communication unit 46. And stored in the storage device 98 of the server 96.

  FIG. 13 is a diagram exemplifying the relative positional relationship between the plurality of place tags 14 and the article tags 16 and describes an aspect of managing the articles 20m and 20n in a warehouse or a library. In this embodiment, the location tag 14a storing the location code “Loc A” for indicating the location A is stored in the location A, and the location tag 14b storing the location code “Loc B” indicating the location B is stored in the location A. A place tag 14c in which a location code “Loc C” for indicating the place C is stored is provided at the place B at a fixed position. Further, the article 20m to which the article tag 16m storing the article code “Mat M” for managing the article 20m is attached is installed in the place A, and the article code “for managing the article 20n” The article 20n to which the article tag 16n storing “Mat N” is attached is placed in the middle of the place B and the place C.

  In the detection control by the wireless tag communication device 12, preferably, first, the information reading control of the place tag 14 is performed, so that the position of the place tag 14 and the position of the wireless tag communication device 12 with respect to a predetermined reference position are performed. Then, information reading control of the article tag 16 is performed, and the position of the article tag 16 with respect to the reference position is determined based on the position of the place tag 14 detected immediately before. Here, preferably, when reply signals are received from a plurality of the location tags 14, the article tag 16 with respect to the reference position is based on the signal strength detected by the RSSI circuit 72 which is a signal strength detection unit. Is determined. For example, as shown in FIG. 14, after the location tag 14a in which the location code “Loc A” is stored by the information reading control of the location tag 14 returns a signal strength “10”, the information of the product tag is read. When the article code “Mat M” is read out by the control, the wireless tag communication device 12 is located near the location A, and the article tag 16m in which the article code “Mat M” is stored is also provided. It is determined that it is disposed at a position close to the place A. In addition, a signal strength “3” is returned from the location tag 14b in which the location code “Loc B” is stored by the information reading control of the location tag 14, and from the location tag 14c in which the location code “Loc C” is stored. When the article code “Mat N” is read out by the information reading control of the article tag after the signal strength “5” is returned, the wireless tag communication device 12 is located between the place B and the place C. It is determined that the item tag 16n that is present at a position close to C and in which the item code “Mat N” is stored is also disposed between the location B and the location C from the location C. Is done. This location determination will be described later with reference to FIG.

  FIG. 15 is a flowchart for explaining registration control in which the position of the place tag 14 and the position of the article tag 16 with respect to the reference position are stored in association with each other by the control unit 42 of the wireless tag communication device 12 and has a predetermined cycle. Is executed repeatedly. In this control, first, the reading control of the location tag 14 is executed in the SA shown in detail in FIG. Next, in the SB shown in detail in FIG. 12, the reading control of the article tag 16 is executed. Next, in the SC described above, association control of information read by SA and SB is executed. Next, in S1a, the number of tags listed in SB is substituted for n, and in subsequent S1b, it is determined whether or not n = 0. If the determination in S1b is affirmative, the routine is terminated accordingly. If the determination in S1b is negative, in S1, for the nth tag in the list, for example, FIG. As shown, the location code read by SA, the article code (tag ID) read by SB, the article name corresponding to the article code, the date and time read, and the like are correlated with the display unit 28. Displayed. Next, in S2, it is determined whether or not a scanning operation has been performed via the operation unit 30 or the like. If the determination in S2 is affirmed, the processing below SA is executed again to recreate the list. However, if the determination in S2 is negative, in S3 via the operation unit 30 or the like. It is determined whether or not a registration operation has been performed. If the determination in S3 is negative, the routine is terminated accordingly. If the determination in S3 is affirmative, in S4, the location relative to the reference position that is associated with the SC is determined. After the information such as the position of the tag 14 and the position of the article tag 16 is stored (registered) in the storage device 98 of the server 96 via the wireless LAN communication unit 46 or the like, an operation of selecting the next tag in S4a It is determined whether or not has been performed. If the determination in S4a is affirmative, 1 is subtracted from n in S4b, and then in S1b, a registration operation for the next tag listed is performed. If the determination in S4a is negative, the processes after S2 are executed again. By the above registration control, for example, the database 100 as shown in FIG. 17 is formed in the storage device 98 of the server 96.

  FIG. 18 is a flowchart illustrating search control of the wireless tags 14 and 16 by the control unit 42 of the wireless tag communication device 12 and display control of the search results on the display unit 28, and is repeated at a predetermined cycle. Is to be executed. In this control, first, in S5, articles (article names) to be searched are narrowed down from a predetermined list. Next, in S6, an article code (tag ID) corresponding to the article name narrowed down in S5 is determined. Next, in S7, the registration location where the search is performed is read via the operation unit 30 or the like. Next, in S8, a screen showing the registration location read in S7 is displayed on the display unit 28. FIG. 19 shows an example of an image displayed on the display unit 28 in S8. Next, in the SA shown in detail in FIG. 11 described above, the reading control of the place tag 14 is executed. Next, in S9, it is determined whether or not the location code read in SA indicates the registered location read in S7. If the determination in S9 is negative, the processing after SA is executed again. If the determination in S9 is positive, in S10, the RFID tag communication device 12 is read in S7. “Here is the notification” indicating that it is located at the registration location is displayed on the display unit 28. FIG. 20 shows an example of an image displayed on the display unit 28 in S10. On this screen, a column indicating a registration location such as “Loc A” is flashed and “Here” is displayed at the bottom of the screen. The character telop flashes! Next, in the SB shown in detail in FIG. 12, the reading control of the article tag 16 is executed. Next, in S11, it is determined whether or not the article code read in SB indicates the article to be searched determined in S6. If the determination in S11 is negative, the processing subsequent to SB is executed again. However, if the determination in S11 is positive, in S12, the RFID tag communication device 12 is determined in S6. After “this is a notification” indicating that the article to be searched is approached is displayed on the display unit 28, this routine is terminated. FIG. 21 shows an example of an image displayed on the display unit 28 in S11. On this screen, a column indicating the name of an article to be searched for such as “article 1” is flashed and at the bottom of the screen. The text telop “This is it!” Flashes.

FIG. 22 is a flowchart for explaining position detection control by the control unit 42 of the RFID tag communication apparatus 12, and is repeatedly executed at a predetermined cycle. In this control, first, in S13, the process of “Ping (1)” for listing IDs is executed as described above. Next, in S14, the location whether the tag 14 is found, i.e. whether there is a reply of the response wave F _r from the location tag 14 is judged. If the determination at S14 is negative, the routine is terminated accordingly, but if the determination at S14 is affirmative, whether or not there is one location tag 14 found at S15. That is, it is determined whether or not a response wave F _r is returned from one place tag 14. If the determination in S15 is affirmative, in S16, a return signal from the location tag 14 received by the antenna 34 is processed by the receiving unit 40, and information on the location tag 14 is stored in the server 96. After being stored in the storage device 98 or the like, this routine is terminated, but if the determination in S15 is negative, in S17, whether or not there are two location tags 14 found, that is, two It is determined whether or not a response wave _Fr is returned from the place tag 14. If the determination in S17 is negative, in S17a, two of the found place tags are selected from those having a large RSSI value, and then the SD process is executed. If the determination in S17 is affirmative, location determination control is performed in the SD shown in detail in FIG. In S18, the location information determined by the SD is stored in the storage device 98 of the server 96, and then this routine is terminated.

The location determination control shown in FIG. 23 is the location tag 14b in which the location code “Loc B” is stored and the location code “Loc C” in the control shown in FIG. The control when the tag 14c is selected is shown. In this control, first, in SD1, the received signal strength RSSI response wave _{F r} from the received signal strength RSSI (B) and the location tag 14c of the response wave _{F r} from the location tag 14b which is detected by the RSSI circuit 72 Based on (C), R (B) is calculated from the equation (1) and R (C) is calculated from the equation (2) shown in FIG. Next, in SD2, after the location is determined as “BR (B) CR (C)”, the process returns to the main routine shown in FIG. The location determined as described above represents a position between two place tags 14 as shown in FIG. 24, and a place tag 14b storing a location code “Loc B” is installed. The location between the location where the location tag 14c where the location code “Loc C” is stored is “B9C1,” “B8C2,” “B7C3”,..., “B3C7”, “B2C8” , "B1C9" is represented by the coordinates. In this way, the RFID tag communication apparatus 12 itself or the article tag 16 or the like is based on the signal strength of the two place tags 14 detected by the RSSI circuit 72 from a predetermined relationship. The detailed position (coordinates) can be detected.

  FIG. 25 shows the search control of the wireless tags 14 and 16 by the control unit 42 of the wireless tag communication device 12 when the target object (the target article tag 16) is specified, and the search result to the display unit 28. And a registration control for storing the position of the place tag 14 and the position of the article tag 16 with respect to the reference position in association with each other and is repeatedly executed at a predetermined cycle. In this control, the intensity of the transmission signal for communicating information with the place tag 14 is greater than the intensity of the transmission signal for communicating information with the article tag 16. The That is, first, in S19a, the object is specified, and in the subsequent S19b, the ID of the article tag attached to the object and the ID of the place tag registered as the place tag indicating the place of the object are read out. . Next, in S19, the setting “POWER = HIGH” is set so that the intensity of the transmission signal transmitted from the transmission unit 38 is relatively large. Next, in the SA shown in detail in FIG. 11 described above, the reading control of the place tag 14 is executed. Next, in S20, the setting “POWER = LOW” is set so that the intensity of the transmission signal transmitted from the transmission unit 38 is relatively small. Next, in the SB shown in detail in FIG. 12, the reading control of the article tag 16 is executed. Next, in S21, it is determined whether or not the target place tag 14 and the target article tag 16 have been found. If the determination in S21 is affirmative, in S22, “Here is the notification” as shown in FIG. 20 is displayed on the display unit 28. In S23, “This is shown in FIG. This routine is terminated after “notification” is displayed on the display unit 28, but if the determination in S21 is negative, it is determined in S24 whether or not the target place tag 14 has been found. The If the determination in S24 is affirmative, in S25, the “notice here” as shown in FIG. 20 described above is displayed on the display unit 28, and then the processing from S19 is executed again. If the determination in S24 is negative, it is determined in S26 whether or not the target article tag 16 has been found. If the determination in S26 is negative, the processing from S19 is executed again. If the determination in S26 is affirmative, a screen indicating a destination location error is displayed in S27 in S27. 28. FIG. 26 is a diagram illustrating a destination location error screen displayed on the display unit 28 in S27. Next, in S28, the contents of the database 100 stored in the storage device 98 of the server 96 are updated. Then, in S29, the “this is notification” as shown in FIG. 21 is displayed on the display unit 28, and then this routine is terminated.

  As described above, according to the present embodiment, the first wireless tag 14 provided in a fixed position with respect to a predetermined reference position and the wireless tag communication for communicating information between the first wireless tag 14. The wireless tag communication device 12 determines the position of the first wireless tag 14 relative to the reference position by communicating information with the first wireless tag 14. In addition, since the position of the wireless tag communication device 12 with respect to the reference position is determined based on the position of the first wireless tag 14, it is assumed that the wireless tag communication device 12 has moved relative to the reference position. In addition, the position of the wireless tag communication device 12 can be suitably detected from the relative positional relationship with the first wireless tag 14. That is, it is possible to provide the wireless tag communication system 10 that can easily detect the accurate position of the wireless tag 14 to be communicated.

  The wireless tag further includes a second wireless tag 16 that is movable with respect to the reference position and communicates information with the wireless tag communication device 12, and the reference position is based on the position of the wireless tag communication device 12. Therefore, the relative position of the second wireless tag 16 with respect to the first wireless tag 14 can be suitably detected. Further, by registering the position of the first wireless tag 14 with respect to the reference position in the wireless tag communication device 12 in advance, it is troublesome to manually register the position of the detected second wireless tag 16. No need to do work. That is, it is possible to provide a wireless tag communication system that can easily detect an accurate position of a wireless tag that is a communication target.

  Further, since the storage device 98 for storing the position of the first wireless tag 14 with respect to the reference position is included, the position of the first wireless tag 14 with respect to the reference position is managed in a practical manner. Can do.

  Further, since the storage device 98 stores the position of the second wireless tag 16 with respect to the reference position, the storage device 98 manages the position of the second wireless 16 tag with respect to the reference position in a practical manner. be able to.

  Further, since the storage device 98 stores the position of the first wireless tag 14 and the position of the second wireless tag 16 with respect to the reference position in association with each other, the storage device 98 stores the first wireless tag 14 with respect to the reference position. The positions of the wireless tag 14 and the second wireless tag 16 can be managed in a practical manner.

  The wireless tag communication device 12 includes a display unit 28 that displays the position of the first wireless tag 14 and the position of the second wireless tag 16 with respect to the reference position. The position of the second wireless tag 16 can be visually confirmed.

  In addition, since the wireless tag communication device 12 alternately performs communication of information with the first wireless tag 14 and communication of information with the second wireless tag 16, The first wireless tag 14 and the second wireless tag 16 can be associated with each other in a practical manner.

  The strength of the transmission signal for communicating information with the first wireless tag 14 is greater than the strength of the transmission signal for communicating information with the second wireless tag 16. Since it is large, it is possible to distinguish the communication range between the first wireless tag 14 and the second wireless tag 16.

  Further, since the communicable distance of the first wireless tag 14 is larger than the communicable distance of the second wireless tag 16, the distance between the first wireless tag 14 and the second wireless tag 16. Can distinguish the communication range.

  The wireless tag communication device 12 includes an RSSI circuit 72 that is a signal strength detection unit that detects the strength of a reply signal from the wireless tags 14 and 16, and includes a plurality of first wireless tags 14. When a reply signal is received, the position relative to the reference position is determined based on the signal strength detected by the RSSI circuit 72, so that the position relative to the reference position can be detected more reliably. .

  Further, the wireless tag communication device 12 has the plurality of first wirelesss based on the signal strength detected by the RSSI circuit 72 corresponding to each of the plurality of first wireless tags 14 from a predetermined relationship. Since the position of the second wireless tag 16 between the tags 14 is determined, the position relative to the reference position can be reliably detected in a practical manner.

  Further, since the first wireless tag 14 and the second wireless tag 16 each have a predetermined command to which a reply signal should be returned, the first wireless tag 14 and the first wireless tag 14 are practically used. And the superimposition of communication between the 2nd radio | wireless tags 16 can be prevented.

  In addition, since the first wireless tag 14 is an active tag having the power supply device 90, the communicable distance of the first wireless tag 14 is extended as compared with the communicable distance of the second wireless tag 16. Can do.

  Further, since the second wireless tag 16 is used by being attached to the article 20 in order to manage the predetermined article 20, the arrangement position of the article 20 is managed in a practical manner. can do.

  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 RFID tag communication device 12 may determine whether the location tags 14 are connected to each other based on the signal strength detected by the RSSI circuit 72 corresponding to each of the two location tags 14 from a predetermined relationship. However, the present invention is not limited to this, and for example, a planar (two-dimensional) position can be obtained by detecting three or more place tags 14. It may be determined. FIG. 27 is a diagram illustrating a state in which the location tags 14 are arranged in a plane, a location tag 14a1 storing a location code “Loc A1”, and a location tag storing a location code “Loc A2”. 14a2, a location tag 14a3 in which the location code “Loc A3” is stored, a location tag 14b1 in which the location code “Loc B1” is stored, a location tag 14b2 in which the location code “Loc B2” is stored, and a location code Location tag 14b3 storing “Loc B3”,... Location tag 14c1 storing location code “Loc C1”, Location tag 14c2 storing location code “Loc C2”, Location code “Loc C3” Is stored in a grid pattern in a fixed manner. In this embodiment, in order to detect the position of the article tag 16 attached to the article 1 disposed at the position shown in FIG. 28, the RSSI circuit 72 corresponds to each of the place tags 14a2, 14b1, and 14b2. Based on the detected signal strength, the position on the plane between the place tags 14 is determined from a predetermined relationship. For example, the received signal strength corresponding to the location tag 14a2 is A2 (3), the received signal strength corresponding to the location tag 14b1 is B1 (1), and the received signal strength corresponding to the location tag 14b2 is B2 (5). In some cases, the article tag 16 is located between the location tags 14a2, 14b1, and 14b2 relatively close to the location tag 14b2 and subsequently close to the location tag 14a2 and relatively far from the location tag 14b1. It is determined to be a thing. In this way, a planar position with respect to the reference position can be reliably detected in a practical manner. Further, a mode is also conceivable in which a spatial (three-dimensional) position between the location tags 14 is determined based on the signal intensity detected by the RSSI circuit 72 corresponding to each of the four or more location tags 14.

  In the above-described embodiment, the usage mode of the communication system 10 using the wireless tag communication device 12 which is a handy reader provided to be movable with respect to a predetermined reference position has been described. However, the present invention is not limited to this. However, the present invention is also preferably applied to a communication system using a stationary reader provided in a fixed position with respect to a predetermined place.

  In the above-described embodiment, the wireless tag communication device 12 is integrally provided with the display unit 28 for displaying information related to the wireless tags 14 and 16. A display device may be provided separately from the wireless tag communication device 12, and information regarding the wireless tags 14 and 16 may be displayed on the display device by exchanging information with the wireless tag communication device 12. .

  In the above-described embodiment, when the wireless tag communication device 12 discovers the wireless tags 14 and 16, the wireless tag communication device 12 notifies the discovery by changing the display of the display unit 28. You may alert | report discovery by an audio | voice etc. using the audio | voice generator 32 with which the said radio | wireless tag communication apparatus 12 was equipped.

The reception in the embodiment described above, the radio tag communication apparatus 12, but was equipped with an antenna 34 for both transmission and reception, a transmitting antenna for transmitting the carrier wave F _c, the response wave F _r It is also possible to provide a separate receiving antenna for the purpose. Further, an aspect in which a plurality of antenna elements are provided and the directivity of an antenna constituted by these antenna elements can be controlled by phased array processing or the like is also conceivable.

  In the above-described embodiment, the place tag 14 is an active tag having a predetermined power supply device 90, but may be a passive tag having no such power supply device 90. The article tag 16 may be an active tag having a power supply device.

  In the above-described embodiment, the database 100 is provided separately from the RFID tag communication device 12, but the database 100 is built in the RFID tag communication device 12. It does not matter. The database 100 is not necessarily provided.

  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.

It is a figure explaining the radio | wireless tag communication system which is one Example of this invention. It is a top view explaining the external appearance of the RFID tag communication apparatus which comprises the RFID tag communication system of FIG. FIG. 3 is a rear view of the wireless tag communication device of FIG. 2 as viewed from the direction of arrow III. It is a figure explaining the structure of the radio | wireless tag communication apparatus of FIG. It is a top view which shows the external appearance of the 1st wireless tag which comprises the wireless tag communication system of FIG. It is a figure explaining the structure of the radio | wireless tag of FIG. It is a top view which shows the external appearance of the 2nd radio | wireless tag which comprises the radio | wireless tag communication system of FIG. FIG. 8 illustrates a configuration of the wireless tag in FIG. 7. 9 is a flowchart for explaining detection control of the wireless tag in FIG. 6 and the wireless tag in FIG. 8 by the control unit of the wireless tag communication apparatus in FIG. 4. FIG. 9 is a diagram for describing reading of information from the wireless tag in FIG. 6 and the wireless tag in FIG. 8 by the wireless tag communication device in FIG. 4. 10 is a flowchart illustrating information reading control of the wireless tag in FIG. 6 that is a part of the control in FIG. 9. 10 is a flowchart illustrating information reading control of the wireless tag in FIG. 8 that is a part of the control in FIG. 9. FIG. 9 is a diagram illustrating a relative positional relationship between the wireless tags in FIG. 6 and a plurality of wireless tags in FIG. It is a figure which illustrates notionally location determination control by the radio | wireless tag communication apparatus of FIG. 9 is a flowchart for explaining registration control for storing the position of the wireless tag in FIG. 6 and the position of the wireless tag in FIG. 8 with respect to the reference position by the control unit of the wireless tag communication apparatus in FIG. 4 in association with each other. It is an example of the screen which shows the registration place displayed on the display part of the wireless tag communication apparatus of FIG. It is an example of the database memorize | stored in the memory | storage device of the server of FIG. 9 is a flowchart for explaining search control of the wireless tag of FIG. 6 and the wireless tag of FIG. 8 by the control unit of the wireless tag communication device of FIG. 4 and display control of the search result on the display unit. It is an example of the screen displayed on the display part of the wireless tag communication apparatus of FIG. FIG. 5 is an example of a “here is notification” screen displayed on the display unit of the RFID tag communication apparatus of FIG. 4. FIG. FIG. 5 is an example of a “this is notification” screen displayed on the display unit of the RFID tag communication apparatus in FIG. 4. FIG. 5 is a flowchart illustrating position detection control by a control unit of the RFID tag communication apparatus of FIG. It is a flowchart explaining the location determination control which is a part of control of FIG. It is a figure explaining the code | symbol expressing the linear relative position between the two radio | wireless tags of FIG. Search control of the wireless tag of FIG. 6 and the wireless tag of FIG. 8 by the control unit of the wireless tag communication apparatus of FIG. 4, display control of the search result on the display unit, and the position and diagram of the wireless tag of FIG. 8 is a flowchart illustrating registration control for storing the positions of 8 wireless tags in association with each other. 5 is an example of a “location error notification” screen displayed on the display unit of the RFID tag communication apparatus of FIG. 4. It is a figure which illustrates a mode that the radio | wireless tag of FIG. 6 was arrange | positioned planarly. FIG. 28 is a diagram conceptually illustrating determination of a planar location of the wireless tag of FIG. 8 disposed between the plurality of wireless tags of FIG. 6 in the embodiment of FIG.

Explanation of symbols

10: RFID tag communication system 12: RFID tag communication device 14: RFID tag (location tag)
16: Radio tag (article tag)
20: Article 28: Display unit 72: RSSI circuit (signal strength detection unit)
90: Power supply device 98: Storage device

Claims (11)

A wireless tag communication system for communicating information with a predetermined wireless tag in a contactless manner,
A first wireless tag provided in a fixed position with respect to a predetermined reference position;
A wireless tag communication device for communicating information with the first wireless tag ;
A second wireless tag that is movable relative to the reference position and communicates information with the wireless tag communication device ,
The wireless tag communication device
A signal strength detection unit for detecting the strength of a reply signal from the wireless tag;
Determining the position of the wireless tag communication device relative to the reference position by communicating information with the first wireless tag ;
By communicating information with the second wireless tag, the position of the second wireless tag with respect to the reference position is determined based on the position of the wireless tag communication device,
When searching for the second wireless tag,
In the first process, when reply signals are received from a plurality of the first wireless tags, the signal strength detected by the signal strength detection unit corresponding to each of the plurality of the first wireless tags is set. Determining the position of the RFID tag communication device relative to the reference position based on
Based on the determination result of the first step, whether or not the position of the first wireless tag with respect to the reference position indicates the position of the wireless tag communication device with respect to the reference position in the second step. Judgment
If the determination in the second process is affirmed, in the third process, the wireless tag communication device is informed that it exists at the position of the first wireless tag,
After the notification of the third process, in the fourth process, the plurality of the plurality of the plurality of the first wireless tags based on the signal strength detected by the signal strength detection unit corresponding to each of the plurality of the first wireless tags from a predetermined relationship. Determining the position of the second wireless tag between the first wireless tags,
Based on the determination result of the fourth process, whether or not the position of the second RFID tag with respect to the reference position indicates the position of the RFID tag communication apparatus with respect to the reference position in the fifth process. Judgment
If the determination in step 5 is affirmed, in step 6, the fact that the RFID tag communication apparatus is located at the position of the second RFID tag is notified.
RFID tag communication system, characterized in that. RFID tag communication system according to claim 1 is intended to include a storage device for storing the position of the first wireless tag with respect to the reference position. The wireless tag communication system according to claim 2 , wherein the storage device stores a position of the second wireless tag with respect to the reference position. 4. The wireless tag communication system according to claim 3 , wherein the storage device stores the position of the first wireless tag and the position of the second wireless tag with respect to the reference position in association with each other. The RFID tag communication system according to any one of claims 1 to 4 , wherein the RFID tag communication apparatus includes a display unit that displays the position of the first RFID tag or the position of the second RFID tag with respect to the reference position. . The radio tag communication apparatus, and communication of information between the first wireless tag, any of claims 1 to 5 and the communication of information between the second wireless tag is performed alternately Wireless tag communication system. The strength of the transmission signal for communicating information with the first wireless tag is greater than the strength of the transmission signal for communicating information with the second wireless tag. any of the wireless tag communication system of claims 1-6. The communicable distance of the first wireless tag, the second one of the wireless tag communication system of claims 1 is larger than the communicable distance of 7 of the radio tag. The wireless tag communication system according to any one of claims 1 to 8 , wherein the first wireless tag and the second wireless tag each have a predetermined command for returning a reply signal. It said first radio tag is one of a radio tag communication system of claims 1 to 9 which is active tag having a power supply. The wireless tag communication system according to any one of claims 1 to 10 , wherein the second wireless tag is used by being attached to the article in order to manage a predetermined article.

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