KR100954317B1 - A book searching system and method using RFID - Google Patents

Abstract

The present invention relates to a book search system and method using RFID.

The present invention is proposed to shorten the time required to find the position of a specific book in library materials, and can find the position of a specific book using an RFID tag, and predict the relative distance to the book according to the number of times of RFID tag recognition. It is to provide a book search method through a book search algorithm.

In the book search method according to the present invention, the book search method using RF ID uses a bit counter method to measure a distance from a tag recognition time to a relative tag, and the RFID reader recognizes a tag at regular time intervals. Transmitting a frequency for; Shifting the corresponding bit counter to the right at regular time intervals; Shifting the bit counter to the right and inserting a bit (1 = recognition, 0 = unrecognition) about the current reading on the left side; And determining a relative distance to the tag from the current number of bit counters (size).

Book Search, RFID Tag, RFID Reader, PDA, Position Estimation, Aging Counter, Bit Counter, Positioning LED, Infrared Communication Module, Positioning Module

Description

A book searching system and method using RFID

The present invention relates to a book search system and method using an RFID ID, the book search using the RFID tag to search the location of the book and the number of RFID tags can be predicted relative distance to the RFID reader through the book search using RFID ID System and method.

Most libraries today use barcodes to manage their materials. Barcodes have many benefits, including the ability to automate loans and returns through scanning. However, in order to recognize barcodes, there is a problem that a person needs to scan a label by hand, which makes it difficult to achieve true library automation.

Recently, the application of RFID technology to an automated system of a library has been studied as a way to overcome such a conventional problem.

RFID technology, a wireless information recognition technology, uses wireless RF communication to recognize ID data in microchips embedded in tags, labels, or cards. The basic function of an RFID system is similar to that of a bar code system, except that RFID tags can wirelessly recognize ID information stored in a tag within a certain range without a human having to aim and scan the tag.

RF signals can pass through most non-metallic objects, and multiple tags can be read simultaneously. Microchips used in RFID tags can be small enough to be inserted into paper, and the price of tags continues to be cheaper, The technology is getting more mature. Therefore, various RFID applications are expected to be introduced in a wide range in the future, and the library is one of the initial introduction areas of RFID technology.

A typical RFID system consists of a tag, an RFID reader, and an antenna, which is divided into passive and active by storing data in a microchip.

The passive tag operates by receiving energy from a radio wave signal of an RFID reader without an internal power source. Specifically, the passive tag operates by using corresponding magnetic field by converting the magnetic field into a current using a magnetic field formed in the reader. However, the passive tag has an advantage that the internal power is not necessary, and in order to identify the unique information of the object, the recognition distance may be applied only at a short distance of several meters, so that the application range is limited.

In this case, the active tag does not need to rely on the magnetic field forming distance of the reader because the small chip has a built-in battery to operate on its own. That is, there is an advantage that radio transmission can be performed over a long distance of several tens of meters or more, but such an active tag has a disadvantage in that a system construction cost is expensive as compared to a passive tag.

RFID technology is being actively researched around the world and efforts are being made to standardize the various components of the system, in particular ID definitions and air interfaces.

In addition, since RFID systems have different characteristics depending on the frequency band, the application must be made in consideration of this. RFID systems in the 13.56 MHz frequency band vary in voltage, but typically have a distance of several tens of centimeters and pass through non-metallic objects, including the human body.

The RFID library system consists of components such as loan / return machine, self-loan machine, book feeder, anti-lost machine, and book checker, all of which work around RFID tags attached to library items such as books and CDs. do. The tag information can be integrated by the software of the library management system, and the use of such a system can make the management of book materials more convenient. But some chronic problems still exist.

One of the most serious problems in libraries today is the inability to know the actual location of books. Therefore, there is a need for a method for providing the location information of a book and this function is called localization.

In the case of a traditional library, the user could not easily find the location of the desired book. If the book is misplaced, you have to search many other places to find it, and if the library is large, this process can take hours or even days.

If a barcode or RFID system is applied to the library, the book can be returned to indicate whether the book exists inside the library. However, it is impossible by prior art to indicate where the book is located. If users don't know the location of the material they want, the fundamental meaning of the library will fade, and if the books are placed in the correct place, they must search through multiple shelves to find the book. It may happen.

Accordingly, an object of the present invention is to provide a book retrieval system and method capable of retrieving a book's position using an RFID tag.

In addition, another object of the present invention is to propose a book search algorithm that can relatively predict the position of a book according to the number of times RFID tags are recognized.

In order to achieve the above object, the present invention provides a plurality of book tags that are separately attached to each book; A plurality of shelf tags attached to each shelf to separate the regions; A positioning LED that is installed in pairs with the shelf tag 20 and emits light, and emits light at a location of a book to be searched; An RFID reader that recognizes the book tag and shelf tag information and transmits and receives the recognized tag information to the library server side; A library server for managing a plurality of book information in association with a database, including a positioning module for estimating a relative distance according to the number of recognition of a tag and deriving a relationship between the tags to determine a book position; A book information database for storing the position information of the book tag or shelf tag; A PDA for requesting location information of the book or receiving location information of the book by wireless data transmission and reception with the library server; An infrared communication module mounted on a bookshelf to receive an infrared control signal transmitted from the PDA to analyze a unique ID value of the PDA and transmit the corresponding signal to the LED controller; An LED controller which determines an ID value of the PDA through a control signal transmitted from the infrared communication module and transmits a light emission control signal to a positioning LED; And a wireless communication network providing a wireless data communication environment between the RFID reader and the PDA and the library server.

Preferably, the positioning LED is characterized in that the light emitting in the form of outputting the ID value of the PDA requested to search.

In the book retrieval method using RFID, it is characterized in that a plurality of signal values transmitted from a tag are received, and the distance to the relative tag is measured from the number of recognition of the tag accumulated on the RFID reader side.

Preferably, the book retrieval method using RF ID uses a bit counter method to measure the distance to the relative tag from the number of times of tag recognition, and the RFID reader transmits a frequency for tag recognition at regular time intervals. Process; Shifting the corresponding bit counter to the right at regular time intervals; Shifting the bit counter to the right and inserting a bit (1 = recognition, 0 = unrecognition) about the current reading on the left side; And determining a relative distance to the tag from the current number of bit counters (size).

Preferably, the positioning module built in the library server, tag recognition module for classifying the recognized tag into a shelf tag and a book tag and delivers to the shelf positioning module and the book positioning module, respectively; A shelf positioning module for determining shelf tags received from the tag recognition module by using an aging counter algorithm and returning a value of the currently closest shelf tag; A book positioning module for separating book tags received from the tag recognition module into book tags close to the current RFID reader using an aging counter algorithm and setting the positions of the tags to the tags determined by the shelf positioning module; And an inventory class module for generating a list of pairs of tags determined from the shelf positioning module and the book positioning module and delivering the list to the book information database to update the location information. .

According to the book search system and method using the RF ID according to the present invention, by measuring the relative distance between the tag attached to the book and the tag attached to the shelf to derive an association relationship to determine the location of the book, The LED lights up so that you can find books more conveniently.

In addition, even if the book is placed incorrectly, it is possible to solve the problem that can not contact the book due to the uncertain position because it is possible to determine the location through the scan.

In addition, the book retrieval system using the aging counter based on the Aging Counter proposed in the present invention is possible to build the system by adding only the software using the existing RFID library system infrastructure, more realistic and cheaper book position estimation solution There is also an effect that can be built.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

1 is a block diagram schematically showing a book search system using an RF ID according to the present invention, Figure 2 is an exemplary view of a book search system using an RF ID.

As shown in FIG. 1 or FIG. 2, the present invention provides a book tag 10, a shelf tag 20, a positioning LED 30, an RFID reader 50, a library server 60, And a book information database 70, a PDA 80, an infrared communication module 90, an LED controller 100, and a wireless communication network 110.

The book tag 10 is attached to each book to be distinguished, and the shelf tag 20 is attached to each shelf to be distinguished.

The positioning LED 30 is installed in pairs with the shelf tag 20 to emit light. The positioning LED 30 is installed separately on each shelf, and the positioning LED 30 of the area where the book is located when the user searches for the book is It will emit light. In addition, when there are a plurality of PDA 80 requesting a book search to provide a distinguishing power for the received signal, the positioning LED 30 outputs a unique ID value of the PDA 80 used in the book search request To emit light. Preferably, the positioning LED 30 is characterized in that the 7-segment LED device is applied to output a unique ID value for each PDA 80 in the form of a number.

The RFID reader 50 is used to receive the information of the book tag 10 and the shelf tag 20 and includes a function of wirelessly transmitting and receiving the tag information and the location information of the book with the library server 60.

The library server 60 manages a plurality of book information in association with a database, and includes a function of wirelessly transmitting and receiving data related to the book information with the RFID reader 50 and the PDA 80. In addition, the library server 60 includes a positioning module 120 in which a location estimation program is constructed, and after estimating a relative distance according to the number of recognition of the tags 10 and 20, deriving a correlation between the tags. Provides the ability to determine the location of the book.

The book information database 70 stores book information together with the position information of the book tag 10 or the shelf tag 20, and is configured to be linked to the library server 60.

The PDA 80 may request location information of the book or receive location information of the book by wireless data transmission and reception with the library server 60, and transmit a control signal to the infrared communication module 90 of the bookshelf side. It is a terminal device that includes a function.

The infrared communication module 90 is mounted on the bookshelf side to receive the infrared control signal transmitted from the PDA 80 to analyze the unique ID value of the PDA 80 and transmit the corresponding signal to the LED controller 100. .

The LED controller 100 determines the ID value of the PDA 80 through the control signal transmitted from the infrared communication module 90 and transmits a light emission control signal to the positioning LED 30. Is to transmit the light emission control signal so that the positioning LED 30 in the area where the search target book is located. In addition, the light emission control signal includes the ID value of the PDA 80.

The wireless communication network 110 is a communication means for providing a wireless data communication environment between the RFID reader 50 and the PDA 80 and the library server 60.

According to the embodiment of the present invention according to the above configuration, each shelf divided into a plurality of areas is equipped with a positioning LED 30 using a 7-segment LED and the shelf tag 20 formed in a group . The shelf tag 20 serves as a reference position for informing its position to the RFID reader 50 side.

The RFID reader 50 is used to recognize unique information of the book tag 10 and the shelf tag 20 and transmits a frequency at regular time intervals for tag recognition. That is, the distance to a specific tag can be predicted according to the number of times the tag is recognized at a predetermined time interval. When the user moves in one direction, the tags 10 and 20 are transmitted from the RFID reader 50. The number of books and shelves can be determined based on the number of times of recognition and reference location information.

In addition, the PDA 80 is used to search the location of the book. When the library 80 requests the library server 60 for the location of the specific book using the PDA 80, the server locates the book information stored in the book information database 70. Call to wirelessly transmit to the PDA 80 side.

When the user requests the display of the book position by the manipulation of the PDA 80 on the bookshelf side, the infrared control signal transmitted from the PDA 80 is transmitted to the infrared communication module 90 on the bookshelf side, and the LED controller 100 receives the control. The signal is analyzed to emit the positioning LED 30 on the shelf side where the book is located. In this case, the infrared communication module 90 receives the unique ID value of the PDA 80 and the positioning LED 30 outputs the ID value of the corresponding PDA 80 in the process of transmitting and receiving the infrared control signal. This is to distinguish it from other PDA 80 users who use it together.

Hereinafter, the book search method using the RF ID according to the present invention will be described in detail.

In general, a location estimation method using an RFID system in a library is to locate a book by reading a tag of a book by installing a plurality of antennas on each shelf and setting it as a fixed position. However, such a method requires an expensive RFID antenna, resulting in an increase in system construction cost.

The present invention applies RFID technology to a library system, and proposes a book retrieval method capable of estimating a book position by implementing a location estimation program that predicts the position of an RFID tag and a tag without expensive antenna configuration.

Defining the symbols used in the following description,ID _book = Book tag (10) ","ID _shelf = Shelf tag 20 ".

The key to the location estimation of a book according to the invention is the generation of information about which shelf tag is placed around the shelf tag. Theoretically, f ( ID _book ) returns the closest ID _shelf (shelf tag ID) on which ID _book (BookTag ID) is placed, thus constructing a function f that maps the ID _book to the ID _shelf . The concept of associating ID _books in multiple ID _shelves is similar to the cellular system of mobile telephony communication, but there is a technical difference in applying the cellular system to the RFID system to measure the signal strength between the base station and the terminal.

That is, the cellular system does not provide a method of selecting a base station that has received the strongest signal from the terminal side, or a reader of the RFID system to measure the size of the signal. However, even if the signal strength cannot be measured, the relative signal strength between the reader and the tag can be inferred from the fact that tags close to the reader are read more often.

The present invention describes a method of determining shelf tag cells using the number of tag recognitions in a reader. Further, the book tag ID, and a cell (shelf tag ID) to establish an algorithm on how associating, ID (for location estimation function of f for determining the ID _book placed near ID _shelf using the algorithm _book, ID _shelf ) To define a pair.

1. Distance measurement using RFID system

In the RFID system, a tag near the antenna has a high number of recognition and a tag far away has a low number of recognition. By accumulating the number of recognition times of the tag using this feature, the relative distance between the reader and the tag can be measured.

Based on this idea, an example of determining the current cell using the accumulated number of recognition when the leader is moving to the right is shown in FIG. 3. However, in this method, when the reader passes Tag B, Tag A, which has the highest recognition frequency, is determined as the current cell (shelf tag) even though the closest tag is Tag B. This is because the number of recognition of all tags is accumulated to distinguish between the past recognition and the recent recognition. The same problem occurs when the reader passes before tag C. In fact, since the librarian moves all the shelves of the shelves with one library checker (scanner) and scans the books (tags), the librarian cannot measure the distance in this way. Do.

2. Tag Positioning Using Aging Counter Algorithm

Hereinafter, the present invention describes an algorithm based on aging as a method that can reflect mobility in a method of measuring a relative distance through the number of recognition of a tag (Aging Counter).

4 is a flowchart illustrating a process of measuring a relative distance of a tag using an aging counter according to an embodiment of the present invention.

This algorithm uses a bit counter to store the number of recognitions.

First, the RFID reader 50 transmits a frequency for recognition of a tag at regular time intervals (S110). Preferably, said time interval is made once every few milliseconds.

Next, before the bit is inserted according to whether the tag is recognized, the bit counter is shifted to the right (S120). This is done at regular time intervals to distinguish the past from the present.

Next, a bit counter is inserted according to whether the tag is recognized (S130). That is, if the tag is recognized at every frequency transmission, '1' is inserted into the bit counter. If the tag is not recognized, '0' is inserted into the bit counter. = Recognition, 0 = unrecognized).

If the above process (S110 ~ S130) is repeated, only the total number of counters will remain and the information on whether the previous recognition will continue to disappear. Accordingly, only the recent record as many as the number of bit counters (size) is left, and the relative distance between the RFID reader 50 and the tags 10 and 20 can be measured according to the number of times the tags 10 and 20 are recognized ( S140).

If there is no recognition bit value in the bit counter, since it is not a recently read tag, a recently recognized tag can be distinguished from a tag recognized in the past. In addition, according to the number of '1' bits in the counter, it is possible to know that a tag having a large counter value is much closer to the reader than a few tags, so that a relative distance measurement is possible. In addition, if the recognition bit of the counter is filled and then the recognition bit is reduced again after filling up, it can be seen that the tag is closer to the reader and away from the reader. Therefore, this can reflect that the leader is moving.

Table 1 is an example of the meaning according to the bit distribution of the aging counter using 12 bits. In the bit distribution, '110100100000' is located farther than the tag in the case where the bit distribution is 5 or more, and additionally, since the recognition bit value is concentrated on the left side, it can be seen that the tag has been recognized. In addition, it can be seen that '000000010010' is a tag that was recognized sparsely but is not recognized at present, so that 0 is inserted, that is, a tag that is gradually moving away from the reader's recognition range.

<Meaning according to bit distribution>  Bit distribution  value  meaning  111111111111  12  Very close  101011101011  8  Close distance  101010101010  6  Middle distance  100100100100  4  distance  110100100000  4  Long distance, closer to the leader  000000010010  2  Very long distance away from leader  000000000000  0  Past or unrecognized tags

5 is an exemplary diagram for determining a current position using an 8-bit aging counter. As shown in FIG. 5, tags are distinguished as the reader moves from left to right.

3. Determine cell (shelf tag) of book tag

Since the RFID reader 50 scans in front of the shelf, the shelf tag 20 and the book tag 10 will be recognized together. At this time, the shelf tag 20 and the book tag 10 is separated and processed at the same time.

First, the shelf tag 20 is recognized as an aging counter to determine the shelf currently recognized, and the book tag 10 is recognized as an aging counter, and the tags recognized are associated with the determined shelf tag 20. Will determine the position of.

It will be described in detail as follows.

Because book tags can be read from multiple shelf tag cells, we need a way to determine the ID _shelf closest to ID _book to define the function f ( ID _book ). ID _book of Figure 6 to the reader and the cell ID of the _shelf B books 1, 2, 3, 4 are read in this range. It is difficult to associate all of these with ID _shelf B because some book tags may have been recognized within cells of ID _shelf A and ID _shelf C. Therefore, when establishing the relationship, the one with the highest number of book tag recognition values is used. That is, once the relationship between ID _book and ID _shelf is established, the aging counter value of ID _book used to define the relationship is recorded. In subsequent scans, if a larger ID _book counter appears, modify the relationship using the ID _shelf of the current cell. For example, if the counter value of ID _book 2 is 1 in the cell of ID _shelf A, f (2) = A. The scan continues and if the value of ID _book 2 reaches 3 in ID _shelf B, the function f is updated to f (2) = B. When in the range of ID _shelf C, if the value of ID _book 2 is 1, the function f remains unchanged. This is because the counter value does not exceed the determined current value of f (2). Therefore, Book No. 2 is recognized in each of A, B, and C shelves, but can be determined to be in the position of B shelf tag because it has the largest aging counter value in relation to B shelf.

Note that in this way the book is relocated elsewhere. The process needs attention. Although the new scan process finds a new relationship, if the new ID _book counter value is smaller than the one used in the current relationship definition, the new relocation is not reflected. Therefore, to overcome this problem, the algorithm maintains a set of ID _shelves from which ID _books are read. If the ID _book is read around another set of ID _shelves , the algorithm discards the current ( ID _book , ID _shelf ) relationship and begins establishing a new one.

4. Book positioning module

A positioning module 120, ie an aging counter, for determining the position of the book is configured as shown in FIG.

In the tag recognition module 121, the recognized tags are classified into shelf tags and book tags and transmitted to the shelf positioning module 122 and the book positioning module 123, respectively. The shelf positioning module 122 evaluates the received shelf tags using an aging counter algorithm and returns the value of the currently closest shelf tag. The book positioning module 123 separates only the book tags close to the current RFID reader by using the aging counter algorithm and sets the positions of the tags to the tags determined by the shelf positioning module 122.
In addition, the inventory class module 124 generates a list of pairs of the tags 10 and 20 determined from the shelf positioning module 122 and the book positioning module 123 described above. 70) to update the location information, the inventory class (Inventory Class) module 124 through the above process determined from the shelf positioning module 122 and the book positioning module ( ID _book , ID) _shelf ) A list of pairs is created, and this relationship is periodically sent to the database to update the location information.

1 is a block diagram schematically showing the configuration of a book search system using RFID according to the present invention.

Figure 2 is an illustration of a book search system using the RF ID,

3 is an exemplary view of measuring a relative distance of a tag using a simple cumulative number according to an embodiment of the present invention.

4 is a flowchart illustrating a process of measuring a relative distance of a tag using an aging counter according to an embodiment of the present invention.

5 is an exemplary diagram of measuring a relative distance of a tag using an 8-bit aging counter according to an embodiment of the present invention.

6 is a conceptual diagram for establishing a relationship between a book tag and a shelf tag.

7 is a block diagram schematically illustrating a positioning module of a book.

<Explanation of symbols for the main parts of the drawings>

10: book tag 20: shelf tag

30: Positioning LED

50: RFID reader 60: library server

70: Book Information Database 80: PDA

90: infrared communication module 100: LED control unit

110: wireless communication network 120: positioning module

Claims (5)

delete delete delete RF ID which receives a plurality of signal values transmitted from the tags 10 and 20 and measures the distance to the relative tags 10 and 20 from the number of recognition of the tags 10 and 20 accumulated on the RFID reader 50 side. In the book search method using, By using the bit counter method to measure the distance to the relative tag (10, 20) relative to the number of recognition of the tag (10, 20), The RFID reader 50 transmits a frequency for recognizing a tag at regular time intervals (S110); Shifting the corresponding bit counter to the right at regular time intervals (S120); Shifting the bit counter to the right and inserting a bit (1 = recognition, 0 = unrecognition) about the current reading on the left (S130); And determining a relative distance from the corresponding number of bit counters (sizes) with the tags (10, 20) (S140). A plurality of book tags 10 separately attached to each book; A plurality of shelf tags 20 which are separately attached to each shelf; A positioning LED 30 which is installed in pairs with the shelf tag 20 and emits light, and emits light at a location of a book to be searched; An RFID reader 50 that recognizes the information of the book tag 10 and the shelf tag 20 and transmits and receives the recognized tag information to and from the library library server 60; Positioning module 120 that manages a plurality of book information in connection with the database, to estimate the relative distance according to the number of recognition of the tag (10, 20), and then to derive the relationship between the tags to determine the position of the book Library server including a 60; A book information database 70 for storing position information of the book tag 10 or the shelf tag 20; A PDA (80) for requesting location information of the book or receiving location information of the book by wireless data transmission and reception with the library server (60); An infrared communication module 90 mounted on a bookshelf to receive an infrared control signal transmitted from the PDA 80 to analyze a unique ID value of the PDA 80 and to transmit the corresponding signal to the LED controller 100; An LED controller 100 which determines an ID value of the PDA 80 through a control signal transmitted from the infrared communication module 90 and transmits a light emission control signal to the positioning LED 30; And a wireless communication network 110 that provides a wireless data communication environment between the RFID reader 50 and the PDA 80 and the library library server 60. The positioning module 120 built in the library server 60 classifies the recognized tags 10 and 20 into shelf tags and book tags, respectively, to determine the shelf positioning module 122 and the book positioning module 123. Tag recognition module 121 for transmitting to; A shelf positioning module 122 for determining shelf tags received from the tag recognition module 121 by using an aging counter algorithm and returning a value of a shelf tag closest to the present; The book position received from the tag recognition module 121 is separated into book tags close to the current RFID reader using the aging counter algorithm, and the book positions are set to the tags determined by the shelf positioning module 122. A determination module 123; Inventory class for generating a list of pairs of tags 10 and 20 determined from the shelf positioning module 122 and the book positioning module 123 and transferring the information to the book information database 70 to update the position information. (Inventory Class) module 124; Book Search system using an RFID, characterized in that comprises a.

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