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RFID TAG MOVEMENT DISTINGUISHING METHOD AND RFID TAG MOVEMENT DISTINGUISHING PROGRAM

  • US 20140167920A1
  • Filed: 07/12/2012
  • Published: 06/19/2014
  • Est. Priority Date: 07/12/2011
  • Status: Active Grant
First Claim
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1. An RFID tag movement distinguishing method of identifying a moving RFID tag among a plurality of RFID tags using the plurality of RFID tags and an RFID reader that receives radio waves from the plurality of RFID tags,wherein the RFID reader is configured to acquire chronological read data of the plurality of RFID tags including a moving RFID tag and a static RFID tag, and a static RFID tag filter is configured based on a certain parameter to specify the static RFID tag based on information of the plurality of read RFID tags, and the moving RFID tag among the plurality of RFID tags is distinguished,the static RFID tag filter includes an individual static RFID tag filter including any one of the following steps (1) to (6), andthe static RFID tag filter identifies the moving RFID tag by identifying the static RFID tag and the moving RFID tag using at least one or more of a plurality of individual static RFID tag filters,the RFID tag movement distinguishing method, comprising:

  • (1) calculating the number of possible readings per second using a function having the number of tags being read as a variable, and performing identification based on a comparison with the number of readings per second read by the RFID reader;

    (2) identifying the static RFID tag and the moving RFID tag by chronological analysis of received radio wave strength;

    (3) tracing up to a predetermined chronological data and determining whether there is another point having high received radio wave strength when chronological data of received radio wave strength of an RFID tag read by the RFID reader has a valley shape, that is, when a point having high received radio wave strength occurs, and identifying an RFID tag to be the static RFID tag when there is a point having high received radio wave strength;

    (4) identifying the static RFID tag and the moving RFID tag using at least one of a degree in which an overall mountain shape represented by the chronological data of the received radio wave strength of the RFID tag or a rising portion of the mountain shape is fit into as a linear or non-linear curve, a difference between each maximum strength value and a minimum strength value of the mountain shape, and a rate of a point increased from a previous point in chronological order in the mountain shape;

    (5) identifying the static RFID tag and the moving RFID tag by chronological analysis of a phase of a transmission carrier wave of the RFID reader and a carrier wave reflected and returned from an RFID tag; and

    (6) identifying a moving direction by comparing either of a phase inflection point of an RFID tag response and a point at which a frequency is zero (0) with at point at which a received radio wave strength peak occurs.

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