Method for implementing and operating, and a read/write unit, for a system including multiple wirelessly readable transponders

• US 9,147,093 B2
• Filed: 08/24/2012
• Issued: 09/29/2015
• Est. Priority Date: 08/25/2011
• Status: Active Grant

• Current Assignee: Siemens AG
• Original Assignee: Siemens AG
• Inventors: Horst, Dieter, Weinlnder, Markus, Neidig, Jrg
• Primary Examiner(s): Bee, Andrew
• Application Number:
  US13/594,545
• Publication Number:
  US 20130049937A1
• Time in Patent Office: 1,131 Days
• Field of Search: 340/10.1, 340/10.4, 340/10.5, 235/375, 235/376
• US Class Current: 1/1
• 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 7/10118 the sensing being preceded by at least one preliminary step
• CPC Class Codes: G06K 7/10128 the step consisting of detection of the presence of one or more record carriers in the vicinity of the interrogation device
• CPC Class Codes: G06K 7/10366 the interrogation device being adapted for miscellaneous applications

Abstract

A method for configuring and operating a read/write unit connected to an industrial control device in a system including multiple transponders having unique identification numbers, the read/write unit. During a recognition phase, a plurality of the transponders are detected, at least two of the transponders are repeatedly detected, and during each detection, the unique identification number of each detected transponder and a number of features relating to each detection of that transponder are registered. During an evaluation phase, the registered features are evaluated statistically for each detected transponder, statistical variables are determined for each detected transponder, and the statistical variables are respectively filtered using filter criteria. The unique identification number of one of the detected transponders that meets the filter criteria is reported to the industrial control device as a detected transponder to provide unambiguous identification of the closest transponder to the read/write unit, even in densely packed surroundings.

Claims

1. A method for configuring and operating a read/write unit in a system that includes a plurality of wirelessly readable transponders each having a unique identification number, the read/write unit being connected to a control device, the method comprising the steps of:

detecting, by the read/write unit, the plurality of the wirelessly readable transponders in a recognition phase;

detecting repeatedly at least two transponders of the plurality of transponders during the recognition phase;

registering, during each detection of each transponder of the plurality of transponders, the unique identification number of the detected transponder and a number of features relating to the detected transponder;

evaluating statistically, during an evaluation phase, the number of features for each respective detected transponder of the plurality of transponders;

determining statistical variables for each detected transponder of the plurality of transponders, said statistical variables comprising at least one of (i) a variance of a received signal strength indication (RSSI) value, (ii) a root mean square error, and (iii) an average ratio between the RSSI value and transmitted power;

filtering the determined statistical variables for each detected transponder of the plurality of transponders using filter criteria; and

reporting to the control device the unique identification number of at least one detected transponder of the plurality of transponders which meets the filter criteria as the at least one detected transponder;

wherein if the statistical variables determined from more than one detected transponder of the plurality of transponders satisfy the filter criteria, then the statistical variables determined from the more than one detected transponder are compared and related to each other; and

wherein if the statistical variables determined for one detected transponder of the plurality of detected transponders surpass the statistical variables of other detected transponders of the plurality of detected transponders, at least with respect to one of the filter criteria, then the one detected transponder of the plurality of detected transponders is reported to the control device.

2. The method as claimed in claim 1, wherein exactly one transponder of the plurality of detected transponders is reported to the control device as detected.

3. The method as claimed in claim 1, further comprising the steps of:

performing a check before the report of the detected transponder of the plurality of detected transponders to determine whether a minimum distance between the statistical variables determined from the one detected transponder of the plurality of detected transponders and the other detected transponders of the plurality of detected transponders, at least with regard to at least one of the filter criteria, is satisfied; and

suppressing the report of the detected transponder of the plurality of detected transponders if the at least one of the filter criteria is unsatisfied.

4. A read/write unit for use in a system that includes a plurality of wirelessly readable transponders, wherein the read/write unit is configured to:

detect the plurality of wirelessly readable transponders in a recognition phase;

detect repeatedly at least two transponders of the plurality of transponders during the recognition phase;

register, during each detection of each transponder of the plurality of transponders, the unique identification number of the detected transponder and a number of features relating to the detected transponder;

evaluate statistically, during an evaluation phase, the number of features for each respective detected transponder of the plurality of transponders;

determine statistical variables for each detected transponder of the plurality of transponders, said statistical variables comprising at least one of (i) a variance of a received signal strength indication (RSSI) value, (ii) a root mean square error, and (iii) an average ratio between the RSSI value and transmitted power;

filter the determined statistical variables for each detected transponder of the plurality of transponders using filter criteria;

report to a control device the unique identification number of at least one detected transponder of the plurality of transponders which meets the filter criteria as the at least one detected transponder;

comparing and relating the statistical variables determined from more than one detected transponder to each other if the statistical variables determined from more than one detected transponder of the plurality of transponders satisfy the filter criteria; and

reporting the one detected transponder of the plurality of detected transponders to the control device if the statistical variables determined for the one detected transponder of the plurality of detected transponders surpass the statistical variables of other detected transponders of the plurality of detected transponders, at least with respect to one of the filter criteria.