JP2019029880A - Filtering device for RFID tag - Google Patents

Abstract

To provide a filtering device for an RFID tag which extracts tag information that is moving from tag information of a plurality of RFID tags read by a reader and in which the plurality of RFID tags can be applied to existing readers and processing apparatuses and that reduce the cost by extracting a large number of moving tag information from the tag information of the plurality of RFID tags.SOLUTION: A single filtering device 11 for an RFID tag connected between an RFID tag reader 12 and a host system 13 includes moving object detection means that transmits, to the host system 13, tag information of a moving RFID tag by a moving object detection filter including at least a received signal intensity change amount filter that extracts the information of the tag moving based on the change amount of the received signal intensity at the time of reading from among the tag information of the plurality of RFID tags read by the RFID tag reader 12.SELECTED DRAWING: Figure 1

Description

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

  In recent years, along with the improvement in the performance of RFID tag chips using RFID (Radio Frequency Identification) technology in the UHF band, it has become possible to instantaneously read a large number of RFID tags located at long distances at once. Therefore, the application has been expanded and used for product management, for example.

  For example, when an RFID tag is attached to each product for use in product management, the reader and the RFID tag communicate with each other over a long distance (for example, a range of 10 m). In addition, if all the products (RFID tags) that are moving are in a time-series communication state, it is necessary to process, for example, about 2,000 tag information per second.

  Therefore, in order to reduce the processing load, it is possible to programmatically not respond the second time after the tag information is received by the reader in a one-time communication state, but the one-time communication state 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.

  Conventionally, Patent Document 1 discloses a technique for distinguishing tag information of a stationary RFID tag and tag information of a moving RFID tag. In Patent Document 1, time series read data of a plurality of RFID tags including a moving RFID tag and a stationary RFID tag is acquired by an RFID reader, and a flicker reading filter, an RSSI absolute value filter, Identifying stationary RFID tag and moving RFID tag using at least one individual stationary RFID tag filter among RSSI non-continuous rising filter, RSSI valley filter, overread filter, low phase fluctuation filter, vertical movement filter, A technique for identifying a moving RFID tag, in which the individual stationary RFID tag filter is provided in a computer device or an RFID reader is described.

Japanese Patent No. 5656695

  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 stationary RFID tag filter requires a large amount of CPU resources for the filtering process, so that the processing capability is reduced when there are more than 20 RFID tags being moved. There is a problem that the number of RFID tags that can be read easily decreases.

  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 computer device cannot be used, resulting in an increase in the cost of the entire system.

  Therefore, the present invention has been made in view of the above problems, and can be applied to existing readers and processing devices for a plurality of RFID tags, and a large number of moving tag information can be extracted from tag information of a plurality of RFID tags. It is an object of the present invention to provide an RFID tag filtering device that achieves cost reduction.

  In order to solve the above problem, in the invention of claim 1, when tag information moving from tag information of a plurality of RFID tags read by a reader is collected and recorded by the host system, the reader and the host system are recorded. RFID tag filtering apparatus connected between and a mobile body detection filter for extracting tag information moving by a mobile body detection filter from tag information of a plurality of RFID tags read by the reader It is set as the structure which has a mobile body detection means provided with.

In the second and third aspects of the invention, “the mobile object detection filter is based on a change amount of a received signal intensity 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 that extracts moving tag information ”
The configuration is “equipped with a bridge function means for matching the connection form from the host system to the reader”.

  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, and the tag information of a plurality of RFID tags read by the reader is moved by a moving body detection filter. By providing a moving body detection means for extracting the tag information that is being obtained, the tag information of the plurality of RFID tags is obtained from the reader, and only the tag information of the moving RFID tags is provided to the host system. As a device, it is possible to improve the filtering processing capability, and it can be applied to an existing reader and a host system, and the cost of the entire system can be reduced.

  According to the second aspect of the present invention, the mobile body detection filter provided in the mobile body detection means changes the received signal intensity when read by the reader among the tag information of the plurality of RFID tags read by the reader. By adopting a configuration including at least a received signal intensity change amount filter that extracts tag information that is moving based on the amount, it is possible to extract tag information of the RFID tag that is moving without performing complicated filtering processing It can be done.

  According to the invention of claim 3, by providing the bridge function means for matching the connection state from the host system to the reader, it is easy to connect even if the protocol of the communication form between the existing reader and the existing host system is different. It can be made possible.

It is explanatory drawing of the whole system with which the filtering apparatus for RFID tags which concerns on this invention is applied. It is a block block diagram of the RFID tag filtering apparatus of FIG. It is explanatory drawing (1) of the filtering process by the filtering apparatus for RFID tags of FIG. It is explanatory drawing (2) of the filtering process by the filtering apparatus for RFID tags of FIG.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is an explanatory diagram of the entire system to which the 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 an independent device between an RFID tag reader / writer 12 and a host system (herein referred to as a computer) 13. The The connection form may be either 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 are existing and need not have a high processing capability. That is, the RFID tag reader / writer 12 includes a communication antenna, and may have at least a function as a reader that communicates with the RFID tag, receives tag information, and transmits the tag information to the outside. It is sufficient to have the ability to process and process software and hardware that collect and record tag information input as a server.

  An external device 14 is connected to the filtering device 11. Here, the external device 14 is an existing DIO unit 15 and an indicator lamp 16 having input / output contacts, and a sensor 17 is connected to the DIO unit 15.

  When the system as described above is applied to product management for product carry-out, as shown in FIG. 1B, for example, the RFID tag reader / writer 12 is disposed above a predetermined position of the transport means 21 such as a transport conveyor. A sensor 17 is disposed on the upstream side of the RFID tag reader / writer 12.

  For example, a transport storage body 22 in which a predetermined number of products attached with individual RFID tags to be transported is placed on both sides of the transport means 21 is put on standby, and one transport storage body 22 is sequentially placed on the transport means 21. To be transported. Then, when the transport storage body 22 transported on the transport means 21 is detected by the sensor 17, the RFID tag reader / writer 12 communicates with each individual RFID tag attached to the product in the transport storage body 22, The read tag information is sequentially transmitted to the filtering device 11.

  Here, FIG. 2 shows a block diagram of the RFID tag filtering device of FIG. 2, the filtering device 11 includes a CPU 31, a ROM 32, a RAM 33, a bridge function unit 34, a moving body detection unit 35, and an interface 36. The moving body detection unit 35 serves as an RSSI (Received Signal Strength) as a moving body detection filter. Indicator) 41, appearance frequency filter 42, and RSSI change amount filter 43.

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

  The bridge function means 34 has a function as a protocol converter for matching the protocol according to the connection form from the host system 13 to the RFID tag reader / writer 12, and puts the RFID tag reader / writer 12 into the host system 13. The control command for this is transmitted in accordance with the protocol of the RFID tag reader / writer 12. If the protocol matches from the beginning, the through state is assumed.

  The moving body detection means 35 generally inputs all tag information of a plurality of RFID tags read by the RFID tag reader / writer 12 in a data format unique to the RFID tag reader / writer, and moves among the tag information. Tag information that is moving by the body detection filter is extracted, and the extracted tag information is transmitted in a data format designated by the host system 13 or a data format unique to the RFID tag reader / writer.

  The RSSI value filter 41 constituting a part of the moving object detection filter extracts tag information whose RSSI value read within a specified period is equal to or greater than a threshold value, and is located at a position far from the antenna of the RFID tag reader / writer 12. Exclude tag information for tags.

  The appearance frequency filter 42 constituting a part of the moving object detection filter extracts tag information whose RFID tag reading count within a specified period is equal to or greater than a threshold value, and is read by the RFID tag reader / writer 12 by reflection by a metal body. The tag information of the RFID tag is excluded.

  The RSSI change amount filter 43 that constitutes a part of the moving object detection filter is the received signal intensity when read by the RFID tag reader / writer 12 among the tag information of a plurality of RFID tags read by the RFID tag reader / writer 12. The tag information that is moving based on the amount of change in the tag information is extracted, specifically, the data whose RSSI change total amount of the tag information read within the specified period is equal to or greater than the threshold is extracted and is stationary. The tag information of the RFID tag is excluded.

  In addition, when extracting the tag information of the RFID tag that is moving by the moving body detection filter, it is possible to extract the tag information of the RFID tag that is moving only by the RSSI change amount filter 43, but the RSSI By using the value filter 41 and the appearance frequency filter 42, the processing load of the RSSI change amount filter 43 can be reduced. Moreover, you may provide the on / off function which does not perform the process by the RSSI value filter 41 and the appearance frequency filter 42.

  The interface 36 is connected to the output terminal of the DIO unit 15 of the external device 14 and to the general-purpose input / output port (GPIO) of the RFID tag reader / writer 12. In other words, when the sensor 17 detects the RFID tag to be read (the above-mentioned RFID tag-attached product carrying container 22), the detection signal is transmitted to the RFID tag reader / writer 12 through the DIO unit 15 as a trigger, and the RFID tag The tag reader / writer 12 starts reading tag information for the RFID tag, and the reading is performed in time series within a specified period preset in the RFID tag reader / writer 12. The indicator lamp 16 is turned on as a reading start via the DIO unit 15 in response to a detection signal from the sensor 17.

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

  FIG. 3 and FIG. 4 are explanatory diagrams of filtering processing by the RFID tag filtering device of FIG. FIG. 3A is a graph in which tag information of all RFID tags read in time series from the RFID tag reader / writer 12 in a specified period is input to the moving body detection unit 35 of the filtering device 11. The tag information includes tag information of a moving RFID tag, tag information of a stationary RFID tag, and tag information read by reflection with a metal body.

  For all the tag information shown in FIG. 3A, the RSSI value filter 41 extracts tag information whose RSSI value read within a specified period is equal to or greater than a threshold value, as shown in FIG. 3B. Then, the tag information of the RFID tag located far from the antenna of the RFID tag reader / writer 12 is excluded.

  Subsequently, as shown in FIG. 4A, the appearance frequency filter 42 extracts tag information having the RSSI reading frequency within the specified period from the tag information having the RSSI value equal to or higher than the threshold, The RFID tag reader / writer 12 excludes tag information of the RFID tag read by reflection by a metal body. In addition, the process of the said RSSI value filter 41 and the appearance frequency filter 42 does not ask | require the order.

  Then, as shown in FIG. 4B, the RSSI variation filter 43 uses the RSSI value filter 41 to detect the antenna of the RFID tag reader / writer 12 from all the tag information of the plurality of RFID tags read by the RFID tag reader / writer 12. The tag information read out during the designated period out of the tag information in which the tag information of the RFID tag read by the reflection by the metal body is excluded by the appearance frequency filter 42 is excluded. Data whose RSSI change total amount of information is equal to or greater than a threshold value is extracted, and tag information of a stationary RFID tag is excluded.

  That is, whether or not the total amount of RSSI change amount a (x) of predetermined tag information and the total amount of RSSI change amount b (x) of other tag information in the RFID tag shown in FIG. An RFID tag that has moved and moved tag information corresponding to the RSSI change amount a (x) greater than or equal to the threshold shown in FIG. 4B, excluding tag information of the RSSI change amount b (x) that is less than or equal to the threshold value It is extracted as a thing.

  In this way, 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 tags to the host system 13. Thus, the present invention can be applied to the existing RFID tag reader / reader / writer and the host system 13, and the entire system can be reduced in cost.

  Further, the tag information of the RFID tag that is moving can be extracted without performing complicated filtering processing by the moving body detection filter (particularly the RSSI variation filter 43). Further, the bridge function means 34 can be easily connected even if the protocol of the communication form with the reader / reader / writer for the existing RFID tag and the host system 13 is different.

  The RFID tag filtering device of the present invention can be used in industrial fields such as manufacture, sales, and use of a system that collects and records tag information of RFID tags.

DESCRIPTION OF SYMBOLS 11 RFID tag filtering apparatus 12 RFID tag reader / writer 13 Host system 14 External device 15 DIO unit 16 Indicator light 17 Sensor 21 Transport means 22 Transport storage body 34 Bridge function means 35 Moving body detection means 36 Interface 41 RSSI value filter 42 Appearance frequency filter 43 RSSI variation filter

Claims (3)

An RFID tag filtering device connected between a reader and the host system when tag information moved from tag information of a plurality of RFID tags read by the reader is collected and recorded by the host system. ,
An RFID tag filtering apparatus comprising: a moving body detection unit that extracts tag information that is moving by a moving body detection filter among tag information of a plurality of RFID tags read by the reader.   The RFID tag filtering device according to claim 1, wherein the moving body detection filter includes a change in received signal intensity when read by the reader among tag information of a plurality of RFID tags read by the reader. An RFID tag filtering device comprising at least a received signal intensity change amount filter for extracting tag information moving based on a quantity.   3. The RFID tag filtering apparatus according to claim 1, further comprising a bridge function unit that matches a connection form from the host system to the reader.

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