Method for the operation of an RFID tag with precise localization

• US 20080278289A1
• Filed: 04/30/2008
• Published: 11/13/2008
• Est. Priority Date: 05/11/2007
• Status: Abandoned Application

• Current Assignee: Identec Solutions AG
• Original Assignee: Identec Solutions AG
• Inventors: Gantner, Reinhold
• Application Number:
  US12/112,064
• Publication Number:
  US 20080278289A1
• Time in Patent Office: Days
• US Class Current: 340/10.1
• 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 7/10079 the collision being resolved in the spatial domain, e.g. temporary shields for blindfolding the interrogator in specific directions

Abstract

The invention relates to a method for the operation of an RFID transponder (1, 2), wherein with the help of a marker (5-8) an inductive/magnetic near field (9-12) is generated whose field intensity is measured by the RFID transponder (1, 2) which transmits data to a reader, characterized in that at least two markers (5-8) are provided whose field intensities of the inductive/magnetic near fields (9-12) are measured by the RFID transponder (1, 2). As a result of this a good and precise localization of the transponder in the space in the case of the presence of different markers is achieved (FIG. 1).

Claims

1. A method for the operation of an RFID transponder wherein with the help of a marker an inductive/magnetic near field is generated whose field intensity is measured by the RFID transponder which transmits data to a reader, characterized in that at least two markers are provided whose field intensities of the inductive/magnetic near fields are measured by the RFID transponder.

2. The method according to claim 1, characterized in that the inductive near fields possess an attenuation of circa 60 dB/decade of the distance.

3. The method according to claim 1, characterized in that the near fields of at least two markers are measured by the RFID transponder.

4. The method according to claim 1, characterized in that the near fields of at least two markers overlap.

5. The method according to claim 1, characterized in that in the course of a mathematical trilation the different field intensities of the inductive near fields are calculated with each other and the distance of the marker from the RFID transporter is calculated.

6. The method according to claim 1, characterized in that a frequency range for the inductive near fields of the individual markers is selected in the range of less than 20 MHz.

7. The method according to claim 1, characterized in that at a certain time the near fields act on receiving antenna of a decoder of the transponder and in the decoder a telegram from the marker of the near field is decoded and the field intensity of the near fields is determined in a field intensity module.

8. The method according to claim 7, characterized in that at the exit of the decoder (22) an evaluation of the corresponding data diagram takes place in an evaluation circuit (24) and with the help of a CPU (25) the decision making is carried out which near field (9-12) is allocated to which marker (5-8) and that the result of the near field consideration is given to a transmitter (27) which for example gives as a frequency modulated or phase modulated signal or an amplitude modulated signal in a specified transmitting range to a transmitting antenna (28), which is in communication with the reader in the reader now the local information is finally received, at which place in the space the transponder 1 is precisely located in reference to the generated near fields 9-12 at which place in the space the transponder (1, 2) is precisely located in reference to the generated near fields (9-12).

9. The method according to claim 7, characterized in that the local field (localization)-determination is taking place in a higher-level arithmetic-logic unit, which for example is arranged in the reader.

10. The method according to claim 2, characterized in that the near fields of at least two markers are measured by the RFID transponder.

11. The method according to claim 2, characterized in that the near fields of at least two markers overlap.

12. The method according to claim 3, characterized in that the near fields of at least two markers overlap.

13. The method according to claim 2, characterized in that in the course of a mathematical trilation the different field intensities of the inductive near fields are calculated with each other and the distance of the marker from the RFID transporter is calculated.

14. The method according to claim 3, characterized in that in the course of a mathematical trilation the different field intensities of the inductive near fields are calculated with each other and the distance of the marker from the RFID transporter is calculated.

15. The method according to claim 4, characterized in that in the course of a mathematical trilation the different field intensities of the inductive near fields are calculated with each other and the distance of the marker from the RFID transporter is calculated.

16. The method according to claim 2, characterized in that a frequency range for the inductive near fields of the individual markers is selected in the range of less than 20 MHz.

17. The method according to claim 3, characterized in that a frequency range for the inductive near fields of the individual markers is selected in the range of less than 20 MHz.

18. The method according to claim 4, characterized in that a frequency range for the inductive near fields of the individual markers is selected in the range of less than 20 MHz.

19. The method according to claim 5, characterized in that a frequency range for the inductive near fields of the individual markers is selected in the range of less than 20 MHz.

20. The method according to claim 2, characterized in that at a certain time the near fields act on receiving antenna of a decoder of the transponder and in the decoder a telegram from the marker of the near field is decoded and the field intensity of the near fields is determined in a field intensity module.