JP5030693B2 - Electronic tag management system, electronic tag management method, electronic tag management program - Google Patents

Description

  The present invention relates to an electronic tag management system, an electronic tag management method, an electronic tag management program, and an electronic tag. Specifically, the present invention relates to a technique for estimating the position and pasting status of an electronic tag.

In recent years, electronic tags have attracted attention for application to traceability. There is a position detection system as an application example of an electronic tag. As an electronic tag position detection method, a method has been proposed in which a position is confirmed by using a plurality of antennas, changing the transmission / reception level of a reader / writer, or changing the transmission / reception level of an electronic tag. For example, it is possible to detect the placement position of an ID tag, and it is possible to expand the usage of an application. It is an object to construct an ID tag system, and data related to each position is arranged at a plurality of positions. The present invention relates to wireless communication in which data is written and data is read and written, and the plurality of ID tags having a wireless communication distance variable function and wireless communication in which data written in each ID tag is collected, Including a data collection unit having a function of variable communication distance and capable of wireless communication having directivity, and capable of detecting an arrangement direction of an ID tag as a data collection partner based on the directivity. An ID tag system (see Patent Document 1) is proposed.
JP 2004-348559 A

  Currently, a wide variety of electronic tags are provided on the market by many manufacturers, but these electronic tags have different communication performances. Moreover, even if it is the same electronic tag, communication performance changes with sticking objects. Depending on the system, there are cases where it is necessary to cope with these electronic tags having different communication performances. In the case of dealing with such electronic tags having different communication performances, there is a possibility that the position of the electronic tag is misidentified in the related art and the like.

  Therefore, the present invention has been made in view of the above problems, and it is possible to easily and accurately estimate the communication distance even in a situation where there are various types of electronic tags and objects to be attached. The purpose is to provide technology that makes it possible to estimate the installation status of the target.

The electronic tag management device of the present invention is a device for managing the status of the electronic tag, and the reader / writer that performs wireless communication with the electronic tag, and the transmission power and antenna gain of the reader / writer of the electronic tag, which is its own communication characteristic data The characteristic acquisition is performed by reading the reflected power data of the electronic tag stored in the communication target electronic tag as communication characteristic data and storing it in the storage device when communicating with the storage device storing the data of the electronic tag. Processing, communication with an electronic tag at a predetermined antenna power transmission level by the reader / writer, and detection of received power at the reader / writer as actual communication status data during the communication, and the electronic tag The reflected power of the electronic tag as communication characteristic data relating to the transmission power of the reader / writer as the communication characteristic data of itself Subtracting the reader / writer's received power from the reader / writer's transmission power based on each data of the gain and the actual communication status data of the reader / writer, and subtracting the antenna gain and the antenna gain Each value of the reflected power of the electronic tag is summed, an exponential function is obtained by multiplying the sum by a predetermined value, and a value obtained by dividing the sum by the predetermined value is multiplied by the wavelength of the radio communication radio wave. And an arithmetic unit that performs an estimation process for calculating a distance between the tag and the reader / writer and an output process for outputting the calculated distance to an output interface.

  In the electronic tag management apparatus, the storage device stores a polarization characteristic of a communication radio wave as its own communication characteristic data, and the arithmetic unit is configured to communicate with the electronic tag in the characteristic acquisition process. In addition, as the communication characteristic data related to the electronic tag stored in the electronic tag to be communicated, the polarization characteristic of the communication radio wave in the electronic tag is read and stored in the storage device. It is detected whether or not a received power of a predetermined level or more has been obtained in actual communication with the electronic tag, and the polarization characteristics of the electronic tag and the own polarization characteristics in the storage device are collated. If the received power of a predetermined level or more is obtained during actual communication with the electronic tag, a notification warning the abnormal installation status of the electronic tag is output to the output interface. It may execute a tell process.

  In the electronic tag management apparatus, the arithmetic unit detects the actual communication status data for each antenna angle of the reader / writer of the electronic tag in the status acquisition process, and converts the communication status data into the communication status data in the estimation process. Based on the group of electronic tags that can communicate at the antenna angle A, the electronic tags except for the electronic tag that can communicate at the other antenna angle B, which should be unable to communicate due to the communication characteristics of the electronic tag and the reader / writer. The distance may be calculated for the identified electronic tag.

The electronic tag management method of the present invention, a reader writer that performs electronic tag and a wireless communication, that is an communication characteristic data, and a storage device that stores data of the transmission power and antenna gain of the reader-writer of the electronic tag computer provided is, when communicating with the electronic tag, stores the data of the reflected power of the electronic tag RFID communication target was stored in read by the storage device as the communication characteristic data, and the characteristic acquisition processing, the Communicating with the electronic tag at a predetermined antenna power transmission level by the reader / writer, and detecting the received power at the reader / writer as actual communication status data during the communication, and communication characteristic data regarding the electronic tag The reflected power of the electronic tag, the transmission power of the reader / writer as the communication characteristic data of itself, and the antenna gain And the received power of the reader / writer as the actual communication status data, the received power of the reader / writer is subtracted from the transmitted power of the reader / writer, and the antenna gain and the electronic tag are subtracted from the subtracted value. Each of the reflected power values of the electronic tag, an exponential function obtained by multiplying the total value by a predetermined value, and a value obtained by dividing the exponential function by the predetermined value is multiplied by the wavelength of the radio communication radio wave. An estimation process for calculating a distance to the writer and an output process for outputting the calculated distance to an output interface are executed.

The electronic tag management program of the present invention includes: a reader-writer that performs electronic tag and a wireless communication, that is an communication characteristic data, and a storage device that stores data of the transmission power and antenna gain of the reader-writer of the electronic tag the computer provided, when communicating with the electronic tag, stores the data of the reflected power of the electronic tag RFID communication target was stored in read by the storage device as the communication characteristic data, and the characteristic acquisition processing, the Communicating with the electronic tag at a predetermined antenna power transmission level by the reader / writer, and detecting the received power at the reader / writer as actual communication status data during the communication, and communication characteristic data regarding the electronic tag The reflected power of the electronic tag, the transmission power of the reader / writer, which is the communication characteristic data of the tag, and the antenna Based on the data of the gain and the reception power of the reader / writer as the actual communication status data, the reception power of the reader / writer is subtracted from the transmission power of the reader / writer, and the antenna gain and the The respective values of the reflected power of the electronic tag are summed, an exponential function is obtained by multiplying the sum by the predetermined value, and the value obtained by dividing the sum by the predetermined value is multiplied by the wavelength of the radio communication radio wave. An estimation process for calculating a distance between the reader / writer and an output process for outputting the calculated distance to an output interface is executed.

  The communication characteristics for each electronic tag may be stored not only in the electronic tag storage device but also in the electronic tag reader / writer and the storage device of another device with which the reader / writer can communicate. In this case, the reader / writer reads and uses information on communication characteristics necessary for the tag ID obtained by communicating with the electronic tag from its own storage device or a storage device of another device.

  In addition, the problems disclosed by the present application and the solutions thereof will be clarified by the embodiments of the present invention and the drawings.

  According to the present invention, the communication distance can be estimated easily and accurately even in a situation where there are various types of electronic tags and sticking targets, and the installation status of the electronic tag and sticking target can be estimated.

--- System configuration ---
Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a configuration diagram of an electronic tag management apparatus according to the present embodiment. An electronic tag management device 100 (hereinafter, device 100) in the present embodiment is a device that manages the status of the electronic tag 10. For example, the electronic tag management device 100 of the present invention integrates the reader / writer 150 of the electronic tag 10 together. The situation to be prepared can be assumed. Alternatively, it can be assumed that the apparatus 100 communicates with the reader / writer 150 of the electronic tag 10 through the network 140 and manages the electronic tag 10 through the reader / writer 150. In the present embodiment, an example in which the reader / writer 150 and the apparatus 100 are integrated as an example will be described below.

  The apparatus 100 reads out the program 102 stored in the storage device 101 such as a nonvolatile memory to the memory 103 in order to realize the function of executing the electronic tag management method of the present invention in cooperation with the electronic tag 10, It is executed by the CPU 104 as an arithmetic unit.

  Further, the device 100 is a reader / writer that is a communication device responsible for wireless communication with an input interface 105 such as various buttons generally provided in a computer device, an output interface 106 such as an LED or a display, and the electronic tag 10. 150 or the like. The reader / writer 150 includes an antenna 160 for wireless communication with the electronic tag 10.

  Next, functional units that are configured and held by the apparatus 100 based on the program 102 will be described. The device 100 can use the communication characteristic table 125 storing its own communication characteristic data (eg, transmission power and antenna gain of the reader / writer 150) in the storage device 101.

  When the device 100 communicates with the electronic tag 10, the device 100 reads communication characteristic data (for example, reflected power of the electronic tag) related to the electronic tag 10 stored in the communication target electronic tag 10 and stores it in the memory 103. The characteristic acquisition part 110 which performs is provided.

  In addition, the apparatus 100 includes a status acquisition unit 111 that detects actual communication status data (for example, received power in a reader / writer) when communicating with the electronic tag 10.

  In addition, the apparatus 100 includes an estimation unit 112 that calculates the distance from the electronic tag 10 based on the communication characteristic data of the electronic tag 10, the communication characteristic data of the storage unit 101, and the communication status data. Prepare. As the distance calculation here, for example, between the electronic tag 10 and the reader / writer 150 based on the respective data of the reflected power of the electronic tag, the transmission power and antenna gain of the reader / writer 150, and the reflected power of the electronic tag. A method for calculating the distance between them is assumed, and details thereof will be described later.

  In addition, the device 100 includes an output unit 113 that outputs the calculated distance to the output interface 106.

  In addition, it can be assumed that the polarization characteristic of the communication radio wave is stored as its own communication characteristic data in the communication characteristic table 125 of the storage device 101. In this case, when the characteristic acquisition unit 110 communicates with the electronic tag 10, communication characteristic data regarding the electronic tag 10 stored in the electronic tag 10 to be communicated is transmitted to the electronic tag 10. The wave characteristic is read and stored in the storage device. Then, the status acquisition unit 111 detects whether or not the received power of a predetermined level or more has been obtained in actual communication with the electronic tag 10.

  At this time, the device 100 collates the polarization characteristics of the electronic tag 10 with its own polarization characteristics in the storage device, the polarization characteristics of the two differ, and the electronic tag 10 When a reception power of a predetermined level or more is obtained in actual communication with the communication device, a warning unit 114 that outputs a notification that warns of an abnormal installation status of the electronic tag 10 to the output interface 106 can be provided.

  The status acquisition unit 111 can detect the actual communication status data for each antenna angle of the reader / writer 150 of the electronic tag 10. In this case, the estimation unit 112 determines, based on the communication status data, other antenna angles that should be unable to communicate from the electronic tag group that can communicate at the antenna angle A due to the communication characteristics of the electronic tag and the reader / writer. The electronic tag may be specified except for the electronic tag that can communicate with B, and the distance may be calculated for the specified electronic tag.

  Next, the electronic tag 10 that communicates with the device 100 will be described. The electronic tag 10 includes an IC chip 20 composed of a CPU 14, a RAM 13, a ROM 11 (stores a chip ID), an EEPROM 12 (stores communication characteristic data of the electronic tag 10), a mold 21 that accommodates the IC chip 20, and It consists of an antenna 22 arranged on the mold 21 and a wireless communication interface 23 (communication device). Then, the antenna 22 receives a radio wave transmitted from the reader / writer 150, and receives a power / clock signal and data from the received radio wave. Further, the circuit is activated by the power thus obtained, and the chip ID stored in the ROM 11 and the communication characteristic data stored in the EEPROM 18 are returned to the reader / writer 150 as radio waves.

  Therefore, when the electronic tag 10 communicates with the reader / writer 150, the electronic tag 10 has a characteristic transmission unit 15 that reads communication characteristic data related to the electronic tag stored in the EEPROM 12 as the storage device and transmits the communication characteristic data to the reader / writer 150. Prepare. For example, the characteristic transmission unit 15 can be assumed to be stored as a program in either the ROM 11 or the EEPROM 12. Therefore, the CPU 14 of the electronic tag 10 reads the characteristic transmission unit 15 as a program from either the ROM 11 or the EEPROM 12 into the RAM 13 and executes it.

  Note that each of the functional units 110 to 114 in the device 100 described so far may be realized as hardware, or may be realized as a program stored in an appropriate storage device such as a memory or an HDD (Hard Disk Drive). Good. In this case, the CPU 104 reads the corresponding program from the storage device 101 to the memory 103 and executes it in accordance with the program execution. The characteristic transmission unit 15 in the electronic tag 10 may be realized as hardware, or may be realized as a program stored in an appropriate storage device such as a memory. In this case, the CPU 14 reads the corresponding program from the storage device 11 to the memory 13 and executes it in accordance with the program execution.

  As for the network 140, a network in accordance with the communication protocol of the electronic tag is assumed.

--- Example of table structure ---
Next, the structure of the table used by the apparatus 100 and the electronic tag 10 in this embodiment will be described. FIG. 2 is a diagram showing examples of data structures of (a) the reader / writer communication characteristic table 125 and (b) the electronic tag communication characteristic table 126 in the present embodiment.

  The reader / writer communication characteristic table 125 is a table for storing communication characteristic data of the reader / writer 150 itself. The communication characteristic table 126 of the reader / writer 150 is a collection of records in which data such as transmission power, antenna gain, reception sensitivity, and polarization characteristics of the reader / writer 150 are associated.

  The electronic tag communication characteristic table 126 is a table storing communication characteristic data of the electronic tag 10. The communication characteristic table 126 of the electronic tag 10 includes, for example, an antenna gain, a matching loss (indicating whether the IC chip of the electronic tag is matched with the antenna part), a necessary reception power (minimum required for the electronic tag to operate) Limit power), reflected power, power half-width (the angle between the azimuths 3dB lower than the operating gain in the antenna's main axis direction) → When the angle is shifted from the direction of the strongest radio wave emission, Half the angle width), null angle (the direction in which radio waves are not radiated or the reception sensitivity is low), FB ratio (the maximum sensitivity direction of the antenna and the opposite direction (within 180 ° C ± 60 ° C)) Ratio), polarization characteristics, and the like.

--- Processing flow example 1 ---
Hereinafter, the actual procedure of the electronic tag management method in the present embodiment will be described with reference to the drawings. Of the various operations corresponding to the electronic tag management method described below, those related to the device 100 are realized by the program 102 that the device 100 reads into the memory 103 and executes, and those related to the electronic tag 10 The electronic tag 10 is realized by a program 12 that is read into the memory 13 and executed. And this program 12 is comprised from the code | cord | chord for performing the various operation | movement demonstrated below.

  FIG. 3 is a diagram illustrating a processing procedure example 1 of the electronic tag management method according to the present embodiment. Here, there are three types of electronic tags (A, B, C), and the same types of electronic tags have the same communication characteristics. In addition, regarding the three types of electronic tags, communication characteristics are measured in advance, and a spectrum analyzer, a signal generator, or the like may be used for this measurement. The measured communication characteristic data is stored in the storage device 101 of the device 100 or the like.

  Under such a premise, the device 100 writes the data related to the communication characteristics of the electronic tag described above in the nonvolatile memory of the electronic tag scheduled to be used for each type of electronic tag scheduled to be used. Therefore, if the communication characteristic data writing has not been completed for all of the electronic tags scheduled to be used (s100: NO), the apparatus 100 first determines whether or not the electronic tags that have not been written are A-type electronic tags. The tag ID and the like are read and determined (s101). If it can be determined that the tag is an A type electronic tag (s101: YES), the communication characteristic data for the A type electronic tag is read from the storage device 101 or the like and written into the EEPROM 12 of the corresponding electronic tag (s102). .

  If the writing of the communication characteristic data regarding the A type electronic tag is completed (s102 to s100 to s101: NO), then whether or not the unwritten electronic tag is the B type electronic tag is determined by the tag ID. Etc. are read and judged (s103). If it can be determined that the tag is a B-type electronic tag (s103: YES), the communication characteristic data for the B-type electronic tag is read from the storage device 101 or the like and written to the EEPROM 12 of the corresponding electronic tag (s104). .

  If the writing of the communication characteristic data for the B type electronic tag is completed (s104 to s100 to s101: NO to s103: NO), whether or not the unwritten electronic tag is a C type electronic tag. After reading the tag ID and the like, the communication characteristic data for the C type electronic tag is read from the storage device 101 and written in the EEPROM 12 of the corresponding electronic tag (s105). Thus, the writing of the communication characteristic data for each type of electronic tag is completed.

--- Processing flow example 2 ---
FIG. 4 is a diagram illustrating a processing procedure example 2 of the electronic tag management method of the present embodiment. In this flow example, processing for estimating the distance between the electronic tag 10 and the reader / writer 150 will be described. In this case, first, the reader / writer 150 starts communication with the electronic tag 10 at a transmission level of, for example, an antenna power of 36 dBm (s200). Next, when the communication with the electronic tag 10 can be started, the status acquisition unit 111 of the device 100 measures received power (communication status data) that is a response level of the electronic tag 10 (s201). The received power that can be measured here is, for example, -44 dBm.

  Further, the characteristic acquisition unit 110 of the device 100 communicates with the electronic tag 10 and transmits communication characteristic data (for example, reflected power of the electronic tag) related to the electronic tag 10 stored in the EEPROM 12 or the like by the electronic tag 10. The data is read and stored in the memory 103 (s202).

Next, the estimation unit 112 of the device 100 calculates the distance to the electronic tag 10 based on the communication characteristic data of the electronic tag 10, the own communication characteristic data in the storage device 101, and the communication status data. (S203). As the distance calculation here, for example, the reflected power of the electronic tag, the transmission power and antenna gain of the reader / writer 150, and the received power of the reader / writer are applied to the equation of FIG. A method for calculating the distance between the electronic tag 10 and the reader / writer 150 is assumed. With regard to this example, when these numerical values are substituted into the mathematical formula of FIG. 7, a communication distance value of 2 m (rounded off after the decimal point) can be calculated.

  The output unit 113 of the apparatus 100 outputs the calculated distance to the output interface 106 (s204), and ends the process.

  Based on the above method, even if different types of electronic tags are mixed, the communication characteristic data stored in the electronic tag in a predetermined data format is read from the electronic tag and the actual communication status etc. By considering it together, the communication distance can be estimated accurately for each electronic tag.

  In addition, even if the communication characteristics of the electronic tag change depending on the application target, etc., the communication characteristics in the applied state are measured and stored in the nonvolatile memory of the corresponding electronic tag for later use. Corresponding to the communication characteristics to be performed, the communication distance of each electronic tag can be accurately estimated.

  Note that this embodiment is merely an example, and the communication distance may be estimated by changing the transmission / reception level of the reader / writer 150 or the transmission / reception level of the electronic tag 10 (the method disclosed in Japanese Patent Application Laid-Open No. 2004-348559, etc.). Adopted).

--- Processing flow example 3 ---
FIG. 5 is a diagram showing a processing procedure example 3 of the electronic tag management method of the present embodiment. There is a case where it is desired to grasp the installation state of the object to which the electronic tag 10 is attached. For example, there is a case where there is a vertically-prohibited item such as a delivery item, but it is desired to confirm that it is not always placed vertically. In such a case, by applying the electronic tag management method of the present invention, it is possible to efficiently grasp the installation status of the object. Below, the example which performs the status management of the thing with which the electronic tag 10 was affixed through the installation status management of the electronic tag 10 is demonstrated. In the example described here, an example in which a situation where a vertically prohibited object is vertically placed is detected is employed.

  In this case, it is assumed that the polarization characteristic of the communication radio wave (eg, linearly polarized wave and ground level) is stored as its own communication characteristic data in the communication characteristic table 125 of the storage device 101. Further, the polarization characteristic is also displayed on the electronic tag label 80 so that the polarization characteristic of the communication radio wave can be visually recognized from the outside (FIG. 8). In this embodiment, in the sticking target object 85 that cannot be placed vertically, the electronic tag label 80 is stuck so that the arrow 81 is parallel to the ground level when the sticking target object 85 is in the horizontal position (FIG. 9).

  In addition, an antenna 160 of the reader / writer 150 for reading the electronic tag 10 attached to the attaching object 85 is prepared as a linearly polarized wave. The polarization direction of the antenna 160 of the reader / writer 150 is also illustrated as shown in FIG. 10 so that the polarization characteristics can be understood. The polarization direction of the antenna 160 can be visually confirmed by illustrating. In this embodiment, the vertically polarized antenna 160 is connected to the reader / writer 150. At this time, the electronic tag 10 and the reader / writer 150 in which the sticking object 85 is placed horizontally cannot communicate, but the electronic tag 10 and the reader / writer 150 in the vertically placed state can communicate (FIG. 11).

  In such a situation, when the characteristic acquisition unit 110 of the device 100 communicates with the electronic tag 10, the characteristic acquisition unit 110 stores the communication characteristic data regarding the electronic tag 10 stored in the electronic tag 10 as a communication target. The polarization characteristic of the communication radio wave is read and stored in the memory 103 (s300).

  Next, the status acquisition unit 111 detects whether or not a received power level equal to or higher than a predetermined level has been obtained in actual communication with the electronic tag 10 (s301). The fact that the received power of a predetermined level or higher can be obtained, that is, the polarization characteristics of the electronic tag 10 are matched, and the electronic tag 10 and the reader / writer 150 in the pasting object 85 can communicate with each other. It means that there is.

  At this time, the warning unit 114 of the device 100 collates the polarization characteristic of the electronic tag 10 with its own polarization characteristic in the storage device (s302). Further, when the polarization characteristics of the two are different in this collation (s303: YES), and when the received power of a predetermined level or more is obtained during actual communication with the electronic tag 10 (s304: YES). Then, a notification for warning of abnormal installation status of the electronic tag 10 is output to the output interface 106 (s305).

  That is, in this example, the polarization direction of the electronic tag 10 is horizontal polarization, and reading from the reader / writer 150 is permitted when the electronic tag 10 is in a horizontal state. Since the electronic tag 10 and the reader / writer 150 can communicate with each other under the condition that the vertical direction cannot be read in this example, an alarm is notified. On the other hand, when the polarization direction of the electronic tag 10 is the vertical direction, no alarm notification is made because the polarization direction of the reader / writer 150 is vertical.

  Based on the above method, it is possible to determine the installation status of the object to be attached 85 of the electronic tag 10, and it is possible to output an alarm when the object to be attached 85 is in the prohibited installation state. Note that the polarization direction information may be used by being stored in association with an ID unique to the electronic tag in the storage device 101 or the like of the device 100 instead of being written in the electronic tag 10.

  If a circularly polarized wave is used as the antenna 160 and the electronic tag 10 of the reader / writer 150, the above characteristics can be used by making use of the characteristic that communication between the reader / writer 150 and the electronic tag 10 cannot be communicated. Similarly, it is possible to detect the installation state of the pasting object 85. For example, a circularly polarized electronic tag 10 is attached to a document stored on a shelf or a document set on a fax machine, and an antenna 160 of a circularly polarized reader / writer 150 is installed on the shelf or fax machine. By doing so, the front and back sides of the document can be discriminated with respect to the combination of turning of the communication radio waves. Specifically, since the communication possibility differs depending on whether the communication radio wave is applied from the back side of the document and the communication radio wave is applied from the front side of the document, the reader / writer 150 indicates that the document is set upside down in the fax machine. For example, it is detected based on whether or not communication is possible, and a warning is sent in advance to send a blank sheet. Alternatively, in order to discharge the document that is likely to be transmitted by the sorter mechanism or the like of the fax machine, it is possible to send a discharge instruction or a reverse side instruction of the document set in the sorter mechanism or the like.

--- Processing flow example 4 ---
FIG. 6 is a diagram showing a processing procedure example 4 of the electronic tag management method of the present embodiment. In this example, it is assumed that the reader / writer 150 detects the position of the electronic tag 10 using the two antennas 160a and 160b. The polarization characteristics of the electronic tag 10 are linear polarization, and the polarization characteristics of the antennas 160a and 160b of the reader / writer 150 are circular polarization.

  In this case, first, the reader / writer 150 of the device 100 tries to communicate with the electronic tag from each of the antennas 160a and 160b (s400). If no antenna can be used to communicate with the electronic tag 10 (s401: YES), the process ends. On the other hand, when communication with the electronic tag 10 is possible (s401: NO), the situation acquisition unit 111 detects the direction with the highest received power and sets the antenna in that direction (s402). This direction setting is executed by the reader / writer 150 if the reader / writer 150 of the apparatus 100 is provided with an antenna orientation adjustment mechanism. Alternatively, when there are a large number of antennas 160, the reader / writer 150 may select and use an antenna that has the maximum received power.

  Further, when communication with the electronic tag 10 can be performed using both antennas 160a and 160b (s403: YES), the position of the electronic tag 10 is determined from the distance between the two antennas and the direction (angle) of each antenna. Estimate (s404) and end the communication with the electronic tag.

  On the other hand, when communication with the electronic tag 10 can be performed using only one antenna 160a of the antennas 160a and 160b (s403: NO to s405), the situation acquisition unit 111 determines the communication characteristics of the electronic tag 10 with which communication was possible. Data is read from the electronic tag 10 (s406).

  Then, the estimation unit 112 estimates the existence section of the electronic tag 10. Here, first, from the step s405, it is estimated that the electronic tag 10 exists on the main axis of the antenna 160a with which communication was possible. On the other hand, from the antenna gain, matching loss, reflected power, required received power, half-value angle, FB ratio, transmission / reception power of the reader / writer 150, and transmission / reception sensitivity of the communication characteristic data, the main axis of the antenna 160a and the electronic tag 10 For each angle at which the antenna 160a intersects, the position (region 47) of the electronic tag 10 on the main axis of the antenna 160a can be estimated as shown in FIG. 12 (s407). The directivity gain at each angle other than the half-value angle may be approximated by a second order polynomial from 0 degree, half-value angle, and null angle.

  Next, the estimation unit 112 determines whether or not communication is possible using the antenna 160b that has failed to communicate for each position of the electronic tag 10 and the orientation of each electronic tag 10 estimated in step s407. Judgment is made from data (acquisition by communication by the antenna 160a). As a result of this determination, the position (area 46) obtained by removing the position (area 45) of the electronic tag communicable with the antenna 160b that has failed to communicate from the position of the electronic tag in area 47 is the estimated position of the electronic tag 10. Determination is made (s408).

  With the above method, the position of the electronic tag 10 can be accurately determined even when the electronic tag 10 has directivity or when only a predetermined number of reader / writers 150 can communicate with each other. It can be detected well.

  According to the present embodiment, the communication distance can be estimated easily and accurately even in a situation where there are various types of electronic tags and sticking targets, and the installation status of the electronic tags and sticking targets can be estimated.

  As mentioned above, although embodiment of this invention was described concretely based on the embodiment, it is not limited to this and can be variously changed in the range which does not deviate from the summary.

It is a network block diagram containing the electronic tag management apparatus in this embodiment. It is a figure which shows each data structure example of the communication characteristic table of (a) reader-writer in this embodiment, and the communication characteristic table of (b) electronic tag. It is a figure which shows the process example 1 of the electronic tag management method of this embodiment. It is a figure which shows process sequence example 2 of the electronic tag management method of this embodiment. It is a figure which shows process sequence example 3 of the electronic tag management method of this embodiment. It is a figure which shows the process sequence example 4 of the electronic tag management method of this embodiment. It is a figure which shows the communication distance calculation formula of this embodiment. It is a figure which shows the tag label illustration example of this embodiment. It is a figure which shows the tag label sticking example of this embodiment. It is a figure which shows the antenna illustration example of the reader / writer of this embodiment. It is a figure which shows the example of a communication condition by the polarization direction of this embodiment. It is a figure which shows the electronic tag detection condition by the multiple antenna of this embodiment.

Explanation of symbols

10 ... Electronic tag 11 ... ROM
12… EEPROM
13 ... RAM
14 ... CPU
DESCRIPTION OF SYMBOLS 15 ... Characteristic transmission part 20 ... IC chip 21 ... Mold 22 ... (Electronic tag) antenna 23 ... Wireless communication interface face 100 ... Electronic tag management apparatus 11, 101 ... Storage device 102 ... Program 103 ... Memory 104 ... CPU
105 ... Input interface 106 ... Output interface 107 ... Communication device (reader / writer)
110 ... Characteristic acquisition unit 111 ... Situation acquisition unit 112 ... Estimation unit 113 ... Output unit 114 ... Warning unit 16, 125 ... Communication characteristic table 140 ... Network 150 ... Reader / writer 160 ... (reader / writer) antenna

Claims (5)

It is a device that manages the status of electronic tags,
A reader / writer that performs wireless communication with the electronic tag;
A storage device that stores data of transmission power and antenna gain of the reader / writer of the electronic tag, which is its own communication characteristic data;
When communicating with an electronic tag, a characteristic acquisition process of reading reflected power data of the electronic tag stored in the electronic tag as a communication characteristic data and storing it in a storage device;
The reader / writer communicates with the electronic tag at a predetermined antenna power transmission level, and at the time of the communication, as the actual communication status data , the received power at the reader / writer is detected.
Each data of the reflected power of the electronic tag as communication characteristic data regarding the electronic tag, the transmission power and antenna gain of the reader / writer as its own communication characteristic data, and the received power of the reader / writer as the actual communication status data The received power of the reader / writer is subtracted from the transmission power of the reader / writer, the antenna gain and the reflected power of the electronic tag are added to the subtracted value, and the sum is multiplied by a predetermined value. Taking an exponential function of the obtained value, multiplying the value obtained by dividing the value by a predetermined value by the wavelength of the radio communication radio wave, and calculating a distance between the electronic tag and the reader / writer,
An output process for outputting the calculated distance to an output interface;
An electronic tag management device comprising: The storage device
It stores the polarization characteristics of communication radio waves as its own communication characteristics data.
The arithmetic unit is:
When communicating with the electronic tag in the characteristic acquisition process, the polarization characteristic of the communication radio wave in the electronic tag is read into the storage device as the communication characteristic data related to the electronic tag stored in the electronic tag to be communicated. Store and
In the situation acquisition process, it is detected whether or not the received power of a predetermined level or more has been obtained in actual communication with the electronic tag,
The polarization characteristics of the electronic tag and the own polarization characteristics in the storage device are collated, the polarization characteristics of the two are different, and more than a predetermined level in actual communication with the electronic tag If the received power is obtained, the electronic tag management device according to claim 1, characterized in that to perform a warning process to output a notification to alert the installation condition abnormality in the electronic tag to the output interface. The arithmetic unit is:
In the status acquisition process, the actual communication status data is detected for each antenna angle of the reader / writer of the electronic tag,
In the estimation process, based on the communication status data, communication can be performed at the other antenna angle B, which should not be able to be communicated based on the communication characteristics of the electronic tag and the reader / writer, from the group of electronic tags that can communicate at the antenna angle A The electronic tag is specified except for the electronic tag, and the distance is calculated for the specified electronic tag.
The electronic tag management apparatus according to claim 1 or 2 , wherein A computer comprising a reader / writer that performs wireless communication with an electronic tag, and a storage device that stores data of transmission power and antenna gain of the electronic tag reader / writer, which is its own communication characteristic data ,
When communicating with an electronic tag, a characteristic acquisition process of reading reflected power data of the electronic tag stored in the electronic tag as a communication characteristic data and storing it in a storage device;
The reader / writer communicates with the electronic tag at a predetermined antenna power transmission level, and at the time of the communication, as the actual communication status data , the received power at the reader / writer is detected.
Each data of the reflected power of the electronic tag as communication characteristic data regarding the electronic tag, the transmission power and antenna gain of the reader / writer as its own communication characteristic data, and the received power of the reader / writer as the actual communication status data The received power of the reader / writer is subtracted from the transmission power of the reader / writer, the antenna gain and the reflected power of the electronic tag are added to the subtracted value, and the sum is multiplied by a predetermined value. Taking an exponential function of the obtained value, multiplying the value obtained by dividing the value by a predetermined value by the wavelength of the radio communication radio wave, and calculating a distance between the electronic tag and the reader / writer,
An output process for outputting the calculated distance to an output interface;
The electronic tag management method characterized by performing. In a computer comprising a reader / writer that performs wireless communication with an electronic tag, and a storage device that stores the transmission power and antenna gain data of the reader / writer of the electronic tag, which is its own communication characteristic data ,
When communicating with an electronic tag, a characteristic acquisition process of reading reflected power data of the electronic tag stored in the electronic tag as a communication characteristic data and storing it in a storage device;
The reader / writer communicates with the electronic tag at a predetermined antenna power transmission level, and at the time of the communication, as the actual communication status data , the received power at the reader / writer is detected.
Each data of the reflected power of the electronic tag as communication characteristic data regarding the electronic tag, the transmission power and antenna gain of the reader / writer as its own communication characteristic data, and the received power of the reader / writer as the actual communication status data The received power of the reader / writer is subtracted from the transmission power of the reader / writer, the antenna gain and the reflected power of the electronic tag are added to the subtracted value, and the sum is multiplied by a predetermined value. Taking an exponential function of the obtained value, multiplying the value obtained by dividing the value by a predetermined value by the wavelength of the radio communication radio wave, and calculating a distance between the electronic tag and the reader / writer,
An output process for outputting the calculated distance to an output interface;
An electronic tag management program characterized in that