METHOD AND SYSTEM FOR AUTOMATICALLY MONITORING THE READ QUALITY OF AN RFID SYSTEM

• US 20070213951A1
• Filed: 03/09/2007
• Published: 09/13/2007
• Est. Priority Date: 03/13/2006
• Status: Abandoned Application

• Current Assignee: iPico Innovation Inc.
• Original Assignee: iPico Innovation Inc.
• Inventors: Van Eeden, Hendrick L.
• Application Number:
  US11/684,445
• Publication Number:
  US 20070213951A1
• Time in Patent Office: Days
• US Class Current: 702/116
• CPC Class Codes: G06K 7/0008 General problems related to the reading of electronic memory record carriers, independent of its reading method, e.g. power transfer
• CPC Class Codes: G06K 7/10435 the interrogation device being positioned close to a conveyor belt or the like on which moving record carriers are passing conveying in accordance with bodily destination marks, see B65G47/46, sorting of objects carrying identity markings, see B07C5/34

Abstract

A radio frequency identification system comprises a reader associated, in use, with a transmitted beam of radio frequency energy and a plurality of transponders to be energized by the energy and each of which intermittently retransmits a response signal to be read by the reader. A method of monitoring the read quality of the reader comprises the steps of causing the transponders and beam to move relative to one another and defining a sequence of groups of transponders in the beam. For each transponder in a group, receiving the response signals transmitted and recording (68) a read count which is equal to the number of times the response signals was received and read by the reader while the transponder is in the beam. Thereafter computing (70) a statistical distribution of number of transponders against read count in the group. Data associated with the distribution is processed and compared (72) to stored historical data relating to a previously computed distribution for a previous group in the sequence. If in the comparison a predetermined deviation is established, a first indication is provided (74).

Claims

1. A method of monitoring the reading quality of a radio frequency identification system comprising a reader associated, in use, with a transmitted beam of radio frequency energy and a plurality of transponders to be energized by the energy and each of which intermittently retransmits a response signal to be read by the reader, the method comprising the steps of:

causing the transponders and beam to move relative to one another;

defining a sequence of groups of transponders in the beam;

for each transponder in a group, receiving the response signals transmitted and recording a read count which is equal to the number of times the response signals was received and read by the reader while the transponder is in the beam;

computing a statistical distribution of number of transponders against read count for the group of transponders;

processing data associated with the distribution and comparing the data to stored historical data relating to a previously computed distribution for a previous group in the sequence; and

if in the comparison, a predetermined deviation is established, causing a first indication to be provided.

2. A method as claimed in claim 1 wherein the groups are defined by a sliding window based on time, alternatively total number of transponders in the group.

3. A method as claimed in claim 1 wherein the data associated with the distribution comprises data relating to at least one key value of the distribution selected from the group comprising average value and standard deviation.

4. A method as claimed in claim 1 comprising the step of, for each transponder in the group, comparing the read count to a first threshold value and if the read count is less than the first threshold value, to cause a second indication to be provided.

5. A method as claimed in claim 4 wherein the first threshold value is a user selectable value and represents a lower acceptable limit value for the read count of any transponder.

6. A system for monitoring the read quality of a radio frequency identification system comprising a reader associated in use with a transmitted beam of radio frequency energy and a plurality of transponders to be energized by the energy and each of which transponders intermittently retransmits a response signal to be read by the reader, the system comprising:

a controller connected to the reader and for receiving from the reader, read data relating to each transponder in the beam;

a computing device connected to the controller for determining and recording from the read data and for each transponder, a read count which is equal to the number of times that a response signal from the transponder was received and read by the reader while the transponder is in the beam;

the computing device being configured to compute a statistical distribution of number of transponders against read count;

the computing device further being configured to process data associated with the distribution;

a comparator for comparing the data associated with the distribution to historical data stored in a memory arrangement and associated with a previously computed distribution; and

an indicator operable by the controller to provide a first indication if in the comparison, a predetermined deviation is established.

7. A method of reading a predetermined proportion of a clump of an unknown number of transponders of a radio frequency identification system, the method comprising the steps of:

maintaining the clump and an energizing signal beam of a reader of the system substantially stationary relative to one another;

during each of a plurality of time periods, taking sample data relating to a total number of transponders in the clump read for a first time;

utilizing the sample data to compute an expected total time to read the predetermined proportion; and

causing the reader to read for the expected total time.

8. A reading system for automatically reading a predetermined proportion of a clump of an unknown number of transponders of a radio frequency identification system, the reading system comprising:

a reader which in use is held stationary relative to the clump;

a controller connected to the reader and configured to determine during a plurality of time periods, respective sample data relating to a total number of transponders in the clump read for a first time;

a computing device for computing from the sample data a total time period to read the predetermined proportion of the transponders; and

the controller being configured to cause the reader to read transponders for the total time period.