JP5122245B2 - Wireless communication apparatus and wireless communication system - Google Patents

Description

  The present invention relates to a wireless communication apparatus and a wireless communication system for reading unique information from an article and a wireless tag attached to a storage location thereof and grasping the storage position of the article.

  In recent years, a wireless tag (also referred to as an IC tag, an RFID tag, an electronic tag, a transponder, or the like) including an IC chip and a wireless communication device, both of which communicate data via an antenna, RFID (Radio Frequency Identification) systems that can read information on a wireless tag in a wireless communication apparatus in a non-contact manner have become widespread.

  This RFID system has been devised for application to, for example, equipment and asset management (see, for example, Patent Document 1).

  In the asset management system described in Patent Document 1, a wireless tag is attached to an asset to be managed, a management area is divided, a wireless tag reader is installed for each section, an identifier of the wireless tag reader and an identifier of the read wireless tag The movement and installation location of assets are managed by the identifier.

RFID systems are also used for inventory in warehouses and stores in the manufacturing, distribution, and retail industries. The RFID system for inventory is equipped with a wireless tag reader with a RFID tag having an IC storing unique identification information attached to a product to be managed, a package containing the product, a cardboard containing the product, a pallet, a container, etc. There is a method of detecting the presence / absence of each article and the storage position by reading the identification information from a handy terminal or an automatic inventory device in a non-contact manner. At that time, No. for identifying each storage shelf. In addition, the reading operation is performed after registering the area information in advance, and the identification information of the read RFID tag and the area information are combined into inventory data.
JP-A-2005-202502

  However, no. It is cumbersome and time consuming to register area information in advance. Furthermore, depending on the output of the wireless tag reader and frequency characteristics, there is a possibility that even the identification information of the wireless tag outside the area assumed to be read is read, which is not accurate, and it is repeated to move to the next shelf and take inventory. If there is more than one data for the same product at the same time, or if duplicate check processing is performed, it will be overwritten with the data read later, and it seems that there are only a lot of products on the last shelf or table There were problems such as becoming data.

  The present invention has been made in view of the above circumstances, and the purpose thereof is to grasp accurate position information of a product without requiring position information to be input every time a reading range is changed in an inventory operation using a wireless tag. It is to provide a wireless communication device and a wireless communication system that can be used.

The wireless communication device according to the present invention radiates radio waves for reading to a wireless tag storing unique article data related to an article to be managed, and a wireless tag storing unique position data related to a storage position of the article, In a wireless communication apparatus comprising an antenna that receives a response radio wave and converts it into a high-frequency signal, and a receiver that demodulates the high-frequency signal converted by the antenna into article data or position data, the radio wave intensity of the response radio wave is Radio wave intensity measuring means for measuring, reading data table for storing article data and position data together with the radio wave intensity measured by the radio wave intensity measuring means, and from all the position data stored in the read data table , select one condition that the field intensity is highest as measured by the radio wave strength measuring means, the reading de Storage position specifying means for specifying the storage position of the article indicated by the article data stored in the data table, and adding the storage position specified by the storage position specifying means to the article data and the radio wave intensity stored in the read data table. When the inventory data table for storing the read data and the article data stored in the read data table are not registered in the inventory data table, the reading data relating to the article data is registered in the inventory data table. The data registration means and the article data stored in the reading data table are already registered in the inventory data table and the radio wave intensity stored together with the article data in the reading data table is the article data stored in the inventory data table. If the radio field intensity stored with the And reading the data updating means for updating by the reading data stored in the data table, by comprising a are characterized.

  According to the present invention in which such measures are taken, wireless communication that can grasp accurate position information of a product without requiring input of position information every time the reading range is changed in an inventory work using a wireless tag. An apparatus and a wireless communication system can be provided.

The best mode for carrying out the present invention will be described below with reference to the drawings.
The present embodiment is a case where the inventory work is performed using a handy terminal that is a wireless communication device according to the present invention for a plurality of products that are articles to be managed that are stored in a shelf that is a storage facility. .

[1] The first embodiment will be described.
FIG. 1 shows a configuration of a wireless communication system according to the present embodiment. The wireless communication system includes position information tags 4-1, 4-2, 4-3 and product tags 6-1 to 6 -n (n), which are wireless tags each storing unique information in a built-in IC. An integer), and is composed of a handy terminal 10 used for reading information stored in each wireless tag.

  The position information tag 4-1 has unique identification information (position data P1) of the shelf 1 and is attached to a predetermined position of the shelf 1. The position information tag 4-2 has unique identification information (position data P2) of the shelf 2, and is attached to a predetermined position of the shelf 2. The position information tag 4-3 has unique identification information (position data P 3) of the shelf 3 and is attached to a predetermined position of the shelf 3.

  The product tag 6-1 to the product tag 6-n have unique identification information (product data C1 to product data Cn) of the products 5-1 to 5-n, and the product 5-1 to the product 5-n. Affixed. These products 5-1 to 5-n are stored in one of the shelves 1, 2, and 3.

  FIG. 2 shows a main configuration of the control circuit of the handy terminal 10. The handy terminal 10 includes a control unit 11 mainly composed of a CPU (Central Processing Unit), a storage unit 12 composed of a ROM (Read Only Memory) and a RAM (Random Access Memory), a communication cable, or by wireless communication. A communication unit 13 that performs data communication with a host device, a display unit 14 that displays various statuses, and various input keys such as a numeric key, a clear key, and a determination key are detected to generate an input signal. An input unit 15 for transmitting a radio wave for reading a radio tag and receiving a response radio wave, a mechanical switch (SW) 17, and a radio unit 20 for transmitting and receiving data by radio.

  While being pressed, the switch 17 continuously inputs a control signal for instructing a reading process of the wireless tag to the control unit 11. Then, the control unit 11 sends digital data for reading the wireless tag to the wireless unit 20 while the control signal is input.

  The radio unit 20 includes a PLL (Phase Locked Loop) circuit 21, a transmission unit 22, a circulator 23, a reception unit 24, and an RSSI circuit (Receive Signal Strength Indicator) 25. The PLL circuit 21 generates a high-frequency sine wave signal. The transmission unit 22 modulates the digital data sent from the control unit 11, amplifies a signal obtained by adding the modulation signal and the high-frequency signal generated by the PLL circuit 21, and outputs the amplified signal to the circulator 23. When a signal is input from the transmission unit 22 side, the circulator 23 outputs the signal to the antenna 16, and at this time, the antenna 16 transmits a radio wave according to this signal. When this radio wave is received by the wireless tag, backscatter modulation is performed to change the amount of reflection of the high-frequency signal with information stored in the IC chip. Thereby, the backscatter modulated radio wave is received by the antenna 16 as a response radio wave. The high-frequency signal of the backscatter modulated wave received by the antenna 16 is input to the circulator 23 and output to the receiving unit 24. The receiving unit 24 amplifies the input high-frequency signal, then combines the amplified high-frequency signal and the high-frequency signal of the PLL circuit 21 to convert it to a baseband signal, and demodulates the baseband signal into digital data. The data is converted and output to the control unit 11.

  The receiving unit 24 outputs the demodulated signal to the RSSI circuit 25 which is a radio wave intensity measuring unit of the response radio wave, and the RSSI circuit 25 generates an analog signal indicating the level of this signal. From this analog signal, the radio wave intensity of the response radio wave received by the antenna 16 can be measured.

  The storage unit 12 stores a radio wave intensity table for determining the radio wave intensity L (integer, L ≧ 0) of the response radio wave received by the antenna 16 based on the analog signal generated by the RSSI circuit 25. Yes.

  The storage unit 12 stores the product data specified by the response radio wave received during the reading process of the wireless tag, the read data table t1 for storing the position data, and the product data stored in the read data table t1. It has an inventory data table t2 for storing.

  FIG. 3 shows an example of the data structure of the read data table t1. “No.” is a number assigned to each data in order. “Tag data” stores product data and position data read by the handy terminal 10, and “Radio wave intensity” contains product data, position. The radio field intensity L obtained by referring to the radio field intensity table based on the analog signal generated by the RSSI circuit 25 when data is received is stored.

  FIG. 4 shows an example of the data structure of the inventory data table t2. “No.” is a number sequentially assigned to each data, and “tag data” and “radio wave intensity” store the product data stored in the read data table t1 and the radio wave intensity L thereof. In “Information”, the types of the shelves 1, 2, and 3 determined based on the position data stored in the read data table t1 are stored.

  FIG. 5 is a flow of processing executed by the control unit 11 when performing inventory work using the handy terminal 10. When a control signal instructing reading processing of the wireless tag is input by pressing the switch 17, the control unit 11 creates a counter i (integer) in the working memory area of the storage unit 12 as ST (step) 101. Initialize this.

  Thereafter, the control unit 11 sends the digital data to the transmission unit 22 as ST102. The transmitter 22 modulates the digital data, amplifies a signal obtained by adding the modulated signal and the high frequency signal generated by the PLL circuit 21, and outputs the amplified signal to the circulator 23. This signal is output to the antenna 16 via the circulator 23, and a reading radio wave is transmitted from the antenna 16.

  In response to the read radio wave transmitted at this time, the response radio wave received by the antenna 16 from the radio tag is converted into digital data by the receiving unit 24 and output to the control unit 11. In addition, an analog signal indicating the level of the high-frequency signal received from the RSSI circuit 25 is generated, and the radio wave intensity L corresponding to the analog signal is specified with reference to the radio wave intensity table.

  Here, the control unit 11 stores the product data, the position data, and the radio wave intensity L specified by the digital data in ST103 in the read data table t1.

  6 and 7 are examples of the read data table t1 in which product data and radio wave intensity are stored. Product data C1 to product data C11 and position data P1 and P2 are stored in the read data table t1-1 shown in FIG. 6, and product data C7 to product data are stored in the read data table t1-2 shown in FIG. Data C20 and position data P1, P2, and P3 are stored, and for each product data, the radio wave intensity L when the response radio wave is received is stored.

  Next, the control unit 11 acquires the number k (integer) of product data stored in the read data table t1 as ST104. That is, the number k is 11 in the read data table t1-1 shown in FIG. 6, and the number k is 13 in the read data table t1-2 shown in FIG.

  Next, the control unit 11 determines one position data to be adopted from the data stored in the read data table t1 as ST105. FIG. 8 is a flow of processing executed by the control unit 11 in this position data adoption processing. First, the control unit 11 scans the read data table t1 and extracts all position data as ST201. That is, the position data P1, P2 are extracted from the read data table t1-1 shown in FIG. 6, and the position data P1, P2, P3 are extracted from the read data table t1-2 shown in FIG.

  At this time, when no position data is extracted (No in ST202), the control unit 11 displays a reading error message on the display unit 14 as ST203 and notifies the user. When even one piece of position data is extracted (Yes in ST202), the control unit 11 specifies position data having the maximum radio wave intensity from ST204, and shelf 1 is specified from the corresponding position data as ST205. , 2 and 3 are set in the shelf information of the reading process (storage position specifying means). That is, in the read data table t1-1 shown in FIG. 6, the position data P1 having the maximum radio wave intensity L is applicable, and the shelf 1 specified from the position data P1 is adopted as the shelf information, as shown in FIG. In the read data table t1-2, the position data P2 having the maximum radio wave intensity L is applicable, and the shelf 2 specified from the position data P2 is adopted as the shelf information.

  After such position data adoption processing, the control unit 11 acquires the product data of number (No.) i from the read data table t1 as ST106, and the competitive data (same product data) in the inventory data table t2 as ST107. Is stored.

  When the competitive data is not stored (No in ST107), the control unit 11 registers the product data of No. i, the radio wave intensity L, and the shelf information adopted in the above-described position data adoption processing in ST108 in the inventory data table t2. (Reading data registration means). When the competitive data is stored (Yes in ST107), the control unit 11 compares the radio wave intensity L of the product data of number i with the radio wave intensity L ′ of the competitive data in ST108 (ST109).

  When the radio wave intensity L <the radio wave intensity L ′ (No in ST109), the control unit 11 discards the product data of the number i and the radio wave intensity L as ST110, and when the radio wave intensity L ≧ the radio wave intensity L ′ (ST109). In step ST111, the radio wave intensity L ′ of the competitive data and the shelf information are updated with the radio wave intensity L of the number i and the shelf information adopted in the position data adoption process (read data update unit).

  Thereafter, the control unit 11 compares the counter i with the number k of the product data stored in the read data table t1 as ST112 (ST112). When the counter i = the number k (Yes in ST112), the inventory is performed as ST113. The product data in the data table t2 is arranged in ascending order and the next wireless tag reading process is awaited. When the number of product data k ≠ i (No in ST112), the control unit 11 increments the counter i in ST114 and repeats the process from ST106 again.

  Here, the data structure of the inventory data table t2-1 when the read data table t1-1 shown in FIG. 6 is created in the first wireless tag reading process after the inventory work is started is illustrated. 9 shows. In the first reading process, since there is no competing product data (No in ST107), all product data is registered as it is (ST108). At this time, since the position data P1 is adopted as the shelf information as described above, “shelf 1” is stored in the shelf information of each product.

  Further, FIG. 10 shows a data structure of the inventory data table t2 when the read data table t1-2 shown in FIG. 7 is created in the second wireless tag reading process. First, the product data C9 is extracted from the read data table t1-2 (ST106), but since the competitive data exists in the inventory data table t2-1 (Yes in ST107), the radio field intensities of the two are compared. (ST109). Here, the radio wave intensity is “5” in the first reading process, whereas the radio wave intensity is “2” in the second reading process, so the second read data is discarded (ST110). ). Similarly, the second read data is discarded in the product data C7 and C8.

  Next, there is competitive data in the product data C10 (ST107), but the radio wave intensity is “2” in the first reading, whereas the radio wave intensity is “5” in the second reading. Therefore, the inventory data table t2-1 is updated (ST111). That is, the radio wave intensity is updated to “5”, and the position data P2 is adopted as the shelf information as described above, so the shelf information is updated to “shelf 2”. Similarly, the inventory data table t2-1 is updated in the product data C11.

  Next, since there is no competing data in the product data C12 to product data C20 (No in ST107), new data registration of product data, radio wave intensity, and shelf information is performed.

  As described above, the reading process of the wireless tag is repeated a plurality of times, so that the product data and the position data are stored in the inventory data table without the need to input the position information every time the reading range of the wireless tag is changed. Since it is stored at t2, the accurate storage position of the product can be grasped.

[2] A second embodiment will be described.

  In the second embodiment, a threshold value of the radio wave intensity L that can be set by a user input is provided in the position data adoption process, and whether or not the position data can be adopted is determined based on this threshold value. The main configuration and operation of the handy terminal 10 in this embodiment are the same as those in the first embodiment.

  If the user operates the input unit 15 before starting the reading process to instruct the start of the radio field intensity threshold setting process, the handy terminal 10 shifts to a threshold value acceptance state. The control unit 11 detects pressing of the numeric key of the input unit 15 in this receiving state, displays the input numerical value on the display unit 14, and waits for pressing of the enter key. When the enter key is pressed, the numerical value displayed on the display unit 14 is stored in the RAM of the storage unit 12 as the radio field intensity threshold value Lmin. That is, the above processing of the control unit 11, the input unit 15, the display unit 14, and the storage unit 12 constitutes a threshold value input unit.

  After such a radio field intensity threshold setting process, the handy terminal 10 shifts to a standby state of a wireless tag reading process. FIG. 11 is a flow of processing executed by the control unit 11 in the position data adoption processing using a threshold value. First, the control unit 11 scans the read data table t1 and extracts all position data in ST301.

  At this time, if there is no position data (No in ST302), the control unit 11 displays a reading error message on the display unit 14 as ST303 to notify the user. When even one piece of position data is extracted (Yes in ST302), the control unit 11 specifies position data having the maximum radio wave intensity from among them as ST304.

  Here, the control unit 11 compares the radio wave intensity L of the position data adopted as ST305 with the threshold value Lmin set in the radio wave intensity threshold value setting process. When the radio wave intensity L ≧ Lmin (Yes in ST305), the control unit 11 sets the types of the shelves 1, 2, and 3 specified from the position data adopted in the process of ST304 as ST306 as shelf information of this reading process. The position data adoption process is terminated. When the radio wave intensity of the selected position data is less than the threshold value (No in ST305), a reading error message is displayed on the display unit 14 to notify the user (ST303).

  In this way, since the reading range of the wireless tag is narrowed by adopting it as shelf information only when the reception intensity of the response radio wave from the position information tag is equal to or higher than the set threshold value, a more accurate storage position of the product can be set. I can grasp it. Furthermore, since the user can change the threshold value of the radio field intensity, the reading range of the wireless tag can be adjusted according to the usage situation.

[3] Modification In the second embodiment, the threshold value of the radio wave intensity is set by the input from the input unit 15. However, the communication with the host computer is performed via the communication unit 13, and the input from the host computer is received. You may make it accept and set a threshold value.

  In addition, if an antenna whose response signal strength is weaker than the response strength of the product tag response signal is used for the location information tag, the response range of the location information tag is narrowed and more accurate location information It becomes possible to grasp. The same effect can be expected by providing directivity to the position information tag and limiting the reading range by the handy terminal 10.

In addition, various inventions can be formed by appropriately combining a plurality of constituent elements disclosed in the above embodiments. For example, some components may be deleted from the overall components shown in each embodiment. Furthermore, the constituent elements over different embodiments may be combined.
The invention described in the scope of claims at the beginning of the filing of the present application is appended below.
[1] A radio wave storing unique article data related to an article to be managed and a radio tag storing unique position data relating to the storage position of the article are radiated for reading and receiving a response radio wave. In a wireless communication apparatus comprising an antenna for converting to a high-frequency signal and a receiving unit for demodulating the high-frequency signal converted by the antenna into article data or position data, radio wave intensity measuring means for measuring the radio wave intensity of the response radio wave A read data table for storing the article data and the position data together with the radio wave intensity measured by the radio wave intensity measuring means, and one satisfying a predetermined condition among all the position data stored in the read data table Storage position specification for specifying the storage position of the article indicated by the article data stored in the read data table. And an inventory data table for storing read data obtained by adding the storage position specified by the storage position specifying means to the article data and radio wave intensity stored in the read data table, and the read data table. When the article data is not registered in the inventory data table, read data registration means for registering the read data related to the article data in the inventory data table; and the article data stored in the read data table is the inventory data. When the radio wave intensity already registered in the table and stored in the read data table together with the article data is equal to or higher than the radio wave intensity stored in the inventory data table together with the article data, the registered read data is stored in the read data table. Reading data updating means for updating with the reading data stored in Wireless communication device, characterized in that the.
[2] The storage position specifying unit selects one of all the position data stored in the read data table on the condition that the radio field intensity measured by the radio field intensity measuring unit is the highest, The wireless communication apparatus according to [1], wherein the storage position of the article indicated by the article data stored in the read data table is specified.
[3] The storage position specifying means is provided on the condition that the radio field intensity measured by the radio field intensity measuring unit is the highest among all the position data stored in the read data table and is not less than a predetermined threshold value. The wireless communication apparatus according to [1], wherein one is selected as the storage position of the article indicated by the article data stored in the read data table.
[4] The wireless communication apparatus according to [3], further comprising threshold input means for receiving an input of the predetermined threshold by a user.
[5] An article detection wireless tag in which unique article data relating to an article to be managed is stored, a position detection wireless tag in which unique position data relating to the storage position of the article is stored, and the article detection A radio communication device that radiates a radio wave for reading to the radio tag and the position detection radio tag, receives a response radio wave, and demodulates the product data and the position data, and the radio communication device A radio wave intensity measuring means for measuring the radio wave intensity of the response radio wave, a read data table for storing article data and position data together with the radio wave intensity measured by the radio wave intensity measuring means, and the read data table stored therein From all the position data, the one having the highest radio field intensity measured by the radio field intensity measuring means is selected and stored in the read data table. Storage position specifying means for specifying the storage position of the article indicated by the article data, and reading data obtained by adding the storage position specified by the storage position specifying means to the article data and radio wave intensity stored in the reading data table are stored. Inventory data table for reading, and when the article data stored in the read data table is unregistered in the inventory data table, read data registration means for registering read data related to the article data in the inventory data table; The item data stored in the reading data table is already registered in the inventory data table, and the radio field intensity stored together with the item data in the reading data table is the radio field intensity stored together with the item data in the inventory data table. At this time, the registered read data is stored in the read data table. Wireless communication system, characterized by comprising: a reading data updating means for updating the data read was a.
[6] The radio according to [5], wherein the position detection radio tag returns a response radio wave having a lower radio field intensity than the article detection radio tag to the radio communication device. Communications system.

The figure which shows the structure of the radio | wireless communications system in each embodiment of this invention. The block diagram which shows the principal part structure of the control circuit of the handy terminal in 1st Embodiment. FIG. 3 is a diagram illustrating an example of a data structure of a read data table according to the first embodiment. The figure which shows an example of the data structure of the inventory data table in 1st Embodiment. The flowchart of the process which a control part performs when performing an inventory work in 1st Embodiment. The figure which shows an example of the data stored in the reading data table in 1st Embodiment. The figure which shows an example of the data stored in the reading data table in 1st Embodiment. The flowchart for demonstrating the procedure of the position data adoption process in 1st Embodiment. The figure which shows an example of the data stored in an inventory data table in 1st Embodiment. The figure which shows an example of the data stored in an inventory data table in 1st Embodiment. The flowchart for demonstrating the procedure of the employment | adoption processing of the position data in 2nd Embodiment.

Explanation of symbols

1-3 ... Shelf, 4 ... Location information tag, 5 ... Product, 6 ... Product tag, 10 ... Handy terminal, 11 ... Control unit, 12 ... Storage unit, 13 ... Communication unit, 14 ... Display unit, 15 ... Input unit , 16 ... Antenna, 17 ... Switch, 20 ... Radio unit, 21 ... PLL circuit, 22 ... Transmitter, 23 ... Circulator, 24 ... Receiver, 25 ... RSSI circuit

Claims (5)

The radio tag storing unique article data related to the article to be managed and the radio tag storing unique position data relating to the storage position of the article radiate reading radio waves and receive response radio waves to generate high frequency signals. In a wireless communication apparatus comprising an antenna for conversion and a receiving unit that demodulates a high-frequency signal converted by the antenna into article data or position data,
Radio wave intensity measuring means for measuring the radio wave intensity of the response radio wave;
A read data table for storing article data and position data together with the radio wave intensity measured by the radio wave intensity measuring means;
From all the position data stored in the read data table, one is selected on condition that the radio field intensity measured by the radio field intensity measuring means is the highest, and the article data stored in the read data table is Storage position specifying means for specifying the storage position of the article to be shown;
An inventory data table for storing read data obtained by adding the storage position specified by the storage position specifying means to the article data and radio wave intensity stored in the read data table;
Reading data registration means for registering reading data related to the article data in the inventory data table when the article data stored in the reading data table is not registered in the inventory data table;
The article data stored in the read data table is already registered in the inventory data table, and the radio wave intensity stored together with the article data in the read data table is the radio wave stored together with the article data in the inventory data table. A read data update means for updating the registered read data with the read data stored in the read data table when the intensity is equal to or higher than the strength;
A wireless communication apparatus comprising: The radio tag storing unique article data related to the article to be managed and the radio tag storing unique position data relating to the storage position of the article radiate reading radio waves and receive response radio waves to generate high frequency signals. In a wireless communication apparatus comprising an antenna for conversion and a receiving unit that demodulates a high-frequency signal converted by the antenna into article data or position data,
Radio wave intensity measuring means for measuring the radio wave intensity of the response radio wave;
A read data table for storing article data and position data together with the radio wave intensity measured by the radio wave intensity measuring means;
From all the position data stored in the read data table, one is selected on condition that the radio wave intensity measured by the radio wave intensity measuring means is the highest and is equal to or greater than a predetermined threshold value, and the read data Storage position specifying means for specifying the storage position of the article indicated by the article data stored in the table;
An inventory data table for storing read data obtained by adding the storage position specified by the storage position specifying means to the article data and radio wave intensity stored in the read data table;
Reading data registration means for registering reading data related to the article data in the inventory data table when the article data stored in the reading data table is not registered in the inventory data table;
The article data stored in the read data table is already registered in the inventory data table, and the radio wave intensity stored together with the article data in the read data table is the radio wave stored together with the article data in the inventory data table. A read data update means for updating the registered read data with the read data stored in the read data table when the intensity is equal to or higher than the strength;
A wireless communication apparatus comprising: Threshold input means for accepting input of the predetermined threshold by a user;
The wireless communication apparatus according to claim 2 , further comprising: A wireless tag for article detection in which unique article data related to the article to be managed is stored;
A wireless tag for position detection in which unique position data relating to the storage position of the article is stored;
A radio communication device that radiates a radio wave for reading to the radio tag for detecting the article and the radio tag for position detection, receives a response radio wave, and demodulates the article data and the position data;
Have
The wireless communication device
Radio wave intensity measuring means for measuring the radio wave intensity of the response radio wave;
A read data table for storing article data and position data together with the radio wave intensity measured by the radio wave intensity measuring means;
The storage position of the article indicated by the article data stored in the read data table is selected from all the position data stored in the read data table. Storage position specifying means for specifying,
An inventory data table for storing read data obtained by adding the storage position specified by the storage position specifying means to the article data and radio wave intensity stored in the read data table;
Reading data registration means for registering reading data related to the article data in the inventory data table when the article data stored in the reading data table is not registered in the inventory data table;
The article data stored in the read data table is already registered in the inventory data table, and the radio wave intensity stored together with the article data in the read data table is the radio wave stored together with the article data in the inventory data table. A read data update means for updating the registered read data with the read data stored in the read data table when the intensity is equal to or higher than the strength;
A wireless communication system comprising: 5. The wireless communication system according to claim 4 , wherein the position detection wireless tag returns a response radio wave having a lower radio field intensity to the wireless communication device than the article detection wireless tag.

Images