JP2019219964A - RFID tag filtering device - Google Patents

Abstract

To provide an RFID tag filtering device that can be applied to existing readers and processing devices for a plurality of RFID tags to reduce costs and that can reliably recognize tag information of RFID tags attached to a plurality of types of objects.SOLUTION: A single RFID tag filtering device 11 is connected between an RFID tag reader 12 and a host system 13. RFID tags 22A and 23A having tag information including identification information for each type of multiple types of moving objects are used, and a moving object detection filter for each type is provided. Tag information read by the RFID tag reader 12 is separated for each piece of identification information by ID separation means. The moving object detection filter corresponding to the identification information is configured to include at least a received signal intensity variation filter that extracts moving tag information based on a variation in the intensity of a received signal when read.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an RFID tag filtering apparatus that extracts moving tag information from tag information of a plurality of RFID tags read by a reader.

  In recent years, with the performance improvement of RFID tag chips using UHF band RFID (Radio Frequency Identification) technology, it has become possible to collectively read a large number of RFID tags located at a long distance instantaneously. As a result, applications have been expanded, and for example, they have been used for product management and the like.

  For example, when an RFID tag is attached to each product in product management and used, the reader and the RFID tag are communicated over a long distance (for example, within a range of 10 m). In addition, if all the moving products (RFID tags) are communicated in time series, it is necessary to process about 2,000 pieces of tag information in one second, for example.

  In order to reduce the processing load, it is possible to program it not to respond the second time after the tag information is received by the reader in the communication state once, but to make the communication state only once is stationary. The tag information of the RFID tag and the tag information of the moving RFID tag cannot be distinguished, and the tag information of the moving RFID tag cannot be grasped.

  2. Description of the Related Art Conventionally, a technique for distinguishing tag information of a stationary RFID tag from tag information of a moving RFID tag is known from Japanese Patent Application Laid-Open No. H11-163873. Patent Document 1 discloses that a RFID reader obtains time-series read data of a plurality of RFID tags including a moving RFID tag and a stationary RFID tag, and reads information of the plurality of read RFID tags, and reads a flicker reading filter, an RSSI absolute value filter, A stationary RFID tag and a moving RFID tag are identified by using at least one or more individual stationary RFID tag filters among an RSSI discontinuous rising filter, an RSSI valley type filter, an overread filter, a small phase fluctuation filter, and a vertical movement filter. A technique is described in which a mobile RFID tag is recognized by a computer device or an RFID reader in which the individual stationary RFID tag filter is used.

Japanese Patent No. 5665695

  However, in the technology described in Patent Document 1, providing the individual stationary RFID tag filter in the RFID reader has a small memory capacity, so that when the RFID tag reading process and the filtering process are performed in parallel, the processing capability is reduced. Providing the computer device with the individual static RFID tag filter requires a large amount of CPU resources for the filtering process. Therefore, when the number of moving RFID tags exceeds 20, the processing capability is reduced, and once. However, there is a problem that the number of RFID tags that can be read is reduced.

  In such a case, the processing performance of the RFID tag reader or the computer device may be improved. However, in that case, the existing RFID tag reader or the computer device cannot be used, resulting in an increase in the cost of the entire system.

  In addition, the articles to which the RFID tags are attached are accumulated in a container or the like by a predetermined number, for example, and the RFID tags attached to the objects different from the articles to which the RFID tags are attached are also used for the containers and the like. In the case of reading by the reader, the RFID tag attached to the article and the RFID tag attached to the container or the like cannot be identified by the reading by the RFID reader. There is a problem that a stationary RFID tag and a mobile RFID tag are mixed.

  Accordingly, the present invention has been made in view of the above problems, and is intended to be applicable to existing readers and processing devices for a plurality of RFID tags to reduce cost and to provide tag information of RFID tags attached to a plurality of types of objects. An object of the present invention is to provide an RFID tag filtering device that can be reliably recognized.

  In order to solve the above problem, according to the invention of claim 1, when tag information moving from tag information of a plurality of RFID tags read by a reader is collectively recorded by an upper system, the reader and the upper system are used. A RFID tag filtering device connected between the RFID tag and a mobile object detection filter for extracting tag information moving by a mobile object detection filter from tag information of a plurality of RFID tags read by the reader. And a moving body detecting means having

In the invention according to claims 2 and 3, the “moving object detection filter is configured to perform a process based on a change amount of a received signal strength when read by the reader among tag information of a plurality of RFID tags read by the reader. At least a received signal strength change amount filter for extracting the moving tag information '' is configured.
A configuration is provided in which “a bridge function unit that matches a connection mode from the higher system to the reader” is provided.

  According to the first aspect of the present invention, there is provided an RFID tag filtering device connected between a reader and a host system, wherein an RFID tag provided with tag information including identification information for each type of a plurality of types of moving objects is used. Provided with a moving object detection filter for each type, the tag information read by the reader is separated for each identification information by the ID separation means, and the moving tag information is extracted by the moving object detection filter according to the identification information. The filtering processing capability as a single device that obtains the tag information of a plurality of RFID tags from the reader and provides only the tag information of the moving RFID tags to the host system. It can be applied to existing readers and higher-level systems, and the overall system cost can be reduced. It is possible to achieve, is to reliably recognizable tag information of the RFID tag attached to a plurality of types of target.

  According to the second aspect of the present invention, the change of the received signal strength when the mobile object detection filter provided in the mobile object detection means is read by the reader among the tag information of the plurality of RFID tags read by the reader. By providing at least a received signal strength change amount filter that extracts tag information that moves based on the amount, it is possible to extract the tag information of the moving RFID tag without performing complicated filtering processing. You can do it.

  According to the third aspect of the present invention, by providing the bridge function means for matching the connection state of the reader from the upper system, it is possible to easily connect even if the communication format protocol between the existing reader and the existing upper system is different. It is something that can be made possible.

BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is an explanatory diagram of an entire system to which an RFID tag filtering device according to the present invention is applied. FIG. 2 is a block diagram of the RFID tag filtering device of FIG. 1. FIG. 4 is an explanatory diagram of tag information from an RFID tag reader / writer. It is explanatory drawing of tag information classification by ID classification means. FIG. 6 is an explanatory diagram (1) of a filtering process on the first tag information in FIG. 4A by the moving object detection filter. FIG. 5B is an explanatory diagram (2) of the filtering process on the first tag information in FIG. 4A by the moving object detection filter. FIG. 5 is an explanatory diagram of a part of a filtering process on the second tag information in FIG. 4B by a moving object detection filter.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is an explanatory diagram of an entire system to which an RFID tag filtering device according to the present invention is applied. In FIG. 1A, an RFID tag filtering device (hereinafter, simply referred to as a filtering device) 11 is connected as a single device between an RFID tag reader / writer 12 and a host system (here, a computer) 13. You. The connection form may be wired or wireless, but is preferably wired for transferring a large amount of data.

  Details of the filtering device 11 will be described with reference to FIG. The RFID tag reader / writer 12 and the host system 13 do not have to be of an existing type and have a particularly high processing capability. That is, the RFID tag reader / writer 12 only needs to include a communication antenna and have at least a function as a reader for communicating with the RFID tag and receiving the tag information and transmitting the tag information to the outside. It is sufficient to have software and hardware capable of collecting and recording tag information input as a server or a server and capable of processing the same.

  An external device 14 is connected to the filtering device 11. In this case, the external device 14 is an existing DIO unit 15 having an input / output contact and an indicator 16, and a sensor 17 is connected to the DIO unit 15.

  As an example in which the system as described above is applied to product management of product unloading, in FIG. 1 (B), a first RFID tag 22A for each of a predetermined number of products, which are moving bodies stored in a transport storage body 22, is provided. A case is shown where a second RFID tag 23 </ b> A is attached to a transport container 23, which is another moving body, and a predetermined number of the transport containers 22 are stacked on the transport container 23. In this case, the first RFID tag 22A and the second RFID tag 23A include identification information (ID) in their respective tag information. In the present embodiment, a case is described in which moving tag information for two types of moving objects is read, but the same applies to three or more types of moving objects.

  As shown in FIG. 1 (C), a transport container 23 on which a predetermined number of transport containers 22 are stacked is moved on the transport path 21, and an RFID tag reader is located above a predetermined position of the transport path 21. A writer 12 is arranged, and a sensor 17 is arranged on the upstream side of the transport path of the RFID tag reader / writer 12.

  For example, on both sides of the transport path 21, a plurality of transport containers 23 each having a predetermined number of transport containers 22 as shown in FIG. 1B are on standby, and one transport container 23 is sequentially placed on the transport path 21. To move. Then, the second RFID tag 23A attached to the transport container 23 and the first RFIDs attached to the products stored in the predetermined number of transport containers 22 for the transport container 23 that is moved on the transport path 21. When the tag 22A is detected by the sensor 17, the RFID tag reader / writer 12 communicates with the individual first RFID tag 22A attached to the product in the transport container 22 and the second RFID tag 23A attached to the transport container 23. , And sequentially transmits the read tag information to the filtering device 11.

  Here, FIG. 2 shows a block diagram of the filtering device for RFID tags of FIG. 2A, the filtering device 11 includes a CPU 31, a ROM 32, a RAM 33, a bridge function unit 34, a moving object detection unit 35, and an interface 36.

  The CPU 31 is a physical central processing unit that performs overall processing control of the entire apparatus, and performs an algorithm process based on a program stored in the ROM 32. The RAM 33 serves as a work area for developing and executing a program for performing a filtering process by each filter, and is made of, for example, a semiconductor memory.

  The bridge function means 34 has a function as a protocol converter that matches a protocol according to the connection form from the host system 13 to the RFID tag reader / writer 12, and connects the RFID tag reader / writer 12 to the host system 13. The control command is transmitted in accordance with the protocol of the RFID tag reader / writer 12. Note that if the protocol matches from the beginning, the state is set to the through state.

  As shown in FIG. 2B, the moving object detecting means 35 includes ID separating means 44, moving object detecting filters 40A, 40B,... Corresponding to the RFID tags of each type identified by the identification information (ID). And output means 45. Here, a case is shown in which the moving object detection filter 40A is associated with the first RFID tag 22A, and the moving object detection filter 40B is associated with the second RFID tag 23A.

  The ID discriminating means 44 inputs all tag information of the first RFID tag 22A and the second RFID tag 23A read by the RFID tag reader / writer 12, identifies the IDs of these tag information, and assigns the mobile object assigned to each ID. It is an electronic circuit or a program output to the detection filters 40A and 40B. The output unit 45 is an electronic circuit or a program that outputs the tag information of each moving body obtained from each of the moving body detection filters 40A and 40B to the host system 13 for each identification information (ID).

  Each of the moving object detection filters 40A and 40B includes an RSSI (received signal strength indicator) 41, an appearance frequency filter 42, and an RSSI change amount filter 43. As a whole, all tag information of a plurality of RFID tags of the same ID read by the RFID tag reader / writer 12 is input in a data format unique to the RFID tag reader / writer, and the moving tag information among the tag information The extracted tag information is transmitted in a data format specified by the host system 13 or in a data format unique to the RFID tag reader / writer.

  The RSSI value filter 41 constituting a part of the moving object detection filter is for extracting tag information whose RSSI value read within a specified period is equal to or greater than a threshold, and which is located far from the antenna of the RFID tag reader / writer 12. Exclude tag information for tags. For example, the RSSI value filter 41 of the moving object detection filter 40A extracts tag information whose RSSI value is equal to or more than a first threshold, and the RSSI value filter 41 of the moving object detection filter 40B extracts tag information whose RSSI value is equal to or more than a second threshold value. I do. That is, a corresponding threshold value is set for each of the RSSI value filters 41 of the mobile object detection filters provided for each ID of the tag information, whereby information of RFID tags attached to different mobile objects is mixed. It is possible to reliably extract the tag information of the RFID tag that is moving without being moved.

  The appearance frequency filter 42 constituting a part of the moving body detection filters 40A and 40B extracts tag information in which the number of times of reading of the RFID tag within the designated period is equal to or greater than a third threshold value, and the RFID tag reader / writer 12 uses a metallic body to extract the tag information. The tag information of the RFID tag read by reflection is excluded.

  The RSSI change amount filter 43 constituting a part of the moving object detection filters 40A and 40B is used when the RFID tag reader / writer 12 reads the tag information of the plurality of RFID tags read by the RFID tag reader / writer 12. Tag information that is moving based on the amount of change in received signal strength is extracted. Specifically, data in which the total RSSI change amount of tag information read within a specified period is equal to or greater than a fourth threshold is extracted. , And excludes the tag information of the stationary RFID tag.

  When the tag information of the moving RFID tag is extracted by the moving object detection filters 40A and 40B, the tag information of the moving RFID tag can be extracted only by the RSSI change amount filter 43. By using the RSSI value filter 41 and the appearance frequency filter 42, the processing load of the RSSI change amount filter 43 can be reduced. Further, an on / off function that does not perform the processing by the RSSI value filter 41 and the appearance number filter 42 may be provided.

  The interface 36 is connected to an output terminal of the DIO unit 15 of the external device 14 and to a general-purpose input / output port (GPIO) of the RFID tag reader / writer 12. That is, when the sensor 17 detects the first RFID tag 22A and the second RFID tag 23A to be read, a detection signal is transmitted to the RFID tag reader / writer 12 via the DIO unit 15 as a trigger, and the RFID tag reader / writer 12 The reading of the tag information for the tag is started, and the reading is performed in a time series within a designated period preset in the RFID tag reader / writer 12. The indicator lamp 16 is turned on in response to a detection signal from the sensor 17 via the DIO unit 15 to start reading.

  The external device 14 (DIO unit 15 and indicator 16) and the sensor 17 may be connected to the RFID tag reader / writer 12, and in this case, the interface 36 becomes unnecessary.

  Here, FIG. 3 shows an explanatory diagram of the tag information from the RFID tag reader / writer, and FIG. 4 shows an explanatory diagram of the tag information classification by the ID classification means. The ID sorting means 44 includes a first RFID tag read by the RFID reader / writer 12 with the sensor 17 for the transport container 23 moving on the transport path 21 and the loaded transport container 22 shown in FIG. All tag information (first moving tag, first stationary tag, first reflection, second reflection tag, second stationary tag, second reflection) for the 22A and the second RFID tag 23A is acquired. That is, as shown in FIG. 3, the tag information of the RSSI value with respect to the elapsed time, including the ID, is input from the RFID tag reader / writer 12 to the ID classification means 44.

  The ID discriminating means 44 recognizes and identifies the input ID, and outputs the first tag information shown in FIG. 4A for the first RFID tag 22A and the second tag shown in FIG. 4B for the second RFID tag 23A. The first tag information is output to the mobile object detection filter 40A, and the second tag information is output to the mobile object detection filter 40B.

  FIGS. 5 and 6 are explanatory diagrams of the filtering processing on the first tag information of FIG. 4A by the moving object detection filter. For all the first tag information shown in FIG. 4 (A), in the moving object detection filter 40A, the RSSI value filter 41, as shown in FIG. The first tag information having a value equal to or greater than a first threshold is extracted, and the tag information of the RFID tag located far from the antenna of the RFID tag reader / writer 12 is excluded.

  Further, as shown in FIG. 5B, among the tag information whose RSSI value is equal to or greater than the first threshold, the number-of-appearances filter 42 determines that the number of times of reading the RFID tag within the specified period is equal to or greater than the third threshold. Is extracted, and the first tag information of the first RFID tag 22A read by the reflection by the metal body in the RFID tag reader / writer 12 is excluded. The order of the processes of the RSSI value filter 41 and the appearance frequency filter 42 does not matter.

  Subsequently, as shown in FIG. 5B, the RSSI change amount filter 43 uses the RSSI value filter 41 to perform RFID processing based on all the first tag information of the plurality of first RFID tags 22A read by the RFID tag reader / writer 12. The first tag information of the first RFID tag 22A located far from the antenna of the tag reader / writer 12 is excluded, and the first tag information of the first RFID tag 22A that is read by the appearance frequency filter 42 by reflection from the metal body is excluded. Among the 1 tag information, data in which the total RSSI change amount of the first tag information read within the designated period is equal to or greater than the fourth threshold is extracted, and the first tag information of the stationary first RFID tag 22A is excluded. .

  That is, the total amount of the RSSI change amount a (x) of the predetermined first tag information and the total amount of the RSSI change amount b (x) of the other first tag information in the first RFID tag 22A shown in FIG. It is determined whether or not the value is equal to or more than the fourth threshold value, and the first tag information of the RSSI change amount b (x) equal to or less than the fourth threshold value is excluded, and the RSSI change amount a (x) equal to or more than the fourth threshold value illustrated in FIG. The corresponding first tag information is extracted as that of the moving first RFID tag 22A.

  Next, FIG. 7 is an explanatory diagram of a part of the filtering processing on the second tag information of FIG. 4B by the moving object detection filter. FIG. 7 is a diagram corresponding to FIG. That is, as shown in FIG. 7, in the moving object detection filter 40B, the RSSI value filter 41 performs the operation for all the second tag information of the second RFID tag 23A shown in FIG. The second tag information of the second RFID tag 23A that is equal to or greater than the second threshold value is extracted from the RSSI value read in the second tag, and the second tag information of the second RFID tag 23A located far from the antenna of the RFID tag reader / writer 12 is excluded. .

  That is, the second RFID tag 23A attached to the transport container 23 is closer to the sensor 17 than the first RFID tag 22A in the transport container 22 and has a different received signal strength. , 40B, when filtering is performed with the same threshold value, the tag information that is moving and the tag that is stationary are mixed. Therefore, by individually setting a threshold value according to the received signal strength, it is possible to prevent mixing.

  Note that the filtering processing for extracting the second tag information of the moving second RFID tag 23A is the same processing as in FIGS. 5B and 6 and will not be described.

  As described above, it is possible to improve the filtering processing capability as a single device that obtains tag information of a plurality of RFID tags from the RFID tag reader / writer 12 and provides only the tag information of the moving RFID tag to the host system 13. The present invention can be applied to existing RFID tag readers and reader / writers and the host system 13, which can reduce the cost of the entire system, and can apply RFID tags (first RFID tags 22 </ b> A , The second RFID tag 23A) (the first tag information and the second tag information) can be reliably recognized.

  Also, tag information (first tag information, first tag information, second tag ID) of RFID tags (first RFID tag 22A, second RFID tag 23A) moving without performing complicated filtering processing by a moving object detection filter (particularly, RSSI change amount filter 43). 2 tag information) can be extracted. Furthermore, the bridge function means 34 can easily connect even if the communication format protocol with the existing RFID tag reader or reader / writer and the host system 13 is different.

  INDUSTRIAL APPLICABILITY The filtering device for an RFID tag of the present invention can be used in industrial fields such as manufacture, sale, and use of a system for collecting and recording RFID tag information.

Reference Signs List 11 RFID tag filtering device 12 RFID tag reader / writer 13 Host system 14 External device 15 DIO unit 16 Indicator 17 Sensor 21 Transport path 22 Transport container 22A First RFID tag 23 Transport container 23A Second RFID tag 34 Bridge function means 35 Moving object detection Means 36 Interface 40A, 40B Moving object detection filter 41 RSSI value filter 42 Number of appearances filter 43 RSSI change amount filter 44 ID classification means 45 Output means

Claims (3)

An RFID tag having tag information including identification information for each type of a plurality of types of moving objects is used, and tag information moving from tag information of the RFID tag read by a reader is collected and recorded by a host system. A filtering device for an RFID tag connected between the reader and the host system,
Tag information classification means for classifying tag information of the RFID tag read by the reader for each of the identification information;
A moving body detecting unit that includes a moving body detecting filter for each type of the moving body, and extracts tag information moving by a moving body detecting filter according to the identification information separated by the tag information separating unit;
A filtering device for an RFID tag, comprising:   2. The RFID tag filtering device according to claim 1, wherein the moving object detection filter changes a received signal strength when the reader reads the tag information of the plurality of RFID tags read by the reader. 3. A filtering device for an RFID tag, comprising at least a received signal strength change amount filter for extracting tag information moving based on the amount.   3. The filtering device for an RFID tag according to claim 1, further comprising a bridge function unit for matching a connection mode of the reader from the upper system.

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