Method and system for proximity tracking-based adaptive power control of radio frequency identification (RFID) interrogators

• US 20060197652A1
• Filed: 03/04/2005
• Published: 09/07/2006
• Est. Priority Date: 03/04/2005
• Status: Abandoned Application

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Reason, Johnathan M., Hild, Stefan G., Moskowitz, Paul A.
• Application Number:
  US11/071,174
• Publication Number:
  US 20060197652A1
• Time in Patent Office: Days
• US Class Current: 340/10.2
• CPC Class Codes: G06K 19/0701 at least one of the integrated circuit chips comprising an arrangement for power management
• 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 7/10128 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 7/10356 using a plurality of antennas, e.g. configurations including means to resolve interference between the plurality of antennas

Abstract

A radio frequency identification (RFID) system (and method), includes at least one RFID reader to read at least one RFID tag, a sensor for determining a proximity parameter for the at least one tag with respect to the at least one reader, and a controller that controls the RF power of the at least one reader.

Claims

1. A radio frequency identification (RFID) system, comprising:

at least one RFID reader to read at least one RFID tag;

a sensor for determining a proximity parameter for said at least one tag with respect to said at least one reader; and

a controller that controls the RF power of said at least one reader.

2. The system of claim 1, wherein said proximity parameter comprises one of distance, speed, and direction of motion.

3. The system of claim 1, wherein said sensor comprises one of a sonar system, a radar system, a laser device, an infrared device, and an imaging system.

4. The system of claim 1, wherein said at least one reader comprises a plurality of readers.

5. The system of claim 4, further comprising:

at least one computing system for controlling said plurality of readers to vary the RF power levels of said readers over a range of values.

6. The system of claim 5, wherein said at least one computing system comprises a plurality of computing systems communicating with one another over a network.

7. The system of claim 1, wherein said controller controls the power of said at least one reader by employing a value of said proximity parameter.

8. The system of claim 1, wherein said controller controls the power of said at least one reader by employing a schedule of updates.

9. The system of claim 7, wherein said controller controls the power of said at least one reader by further employing a quality metric.

10. The system of claim 9, wherein said quality metric comprises one of a strength of a signal received by said at least one reader from said at least one tag and a count of the number of tags read by said reader.

11. The system of claim 9, wherein said controller receives information regarding the quality metric to control the power.

12. The system of claim 1, wherein said RFID system is employed in one of a supply chain distribution center, retail store point-of-sale check-out system, electronic toll collection system, and a customer service counter.

13. The system of claim 1, wherein said controller further comprises means for varying the power level over a range of values.

14. The system of claim 1, further comprising a logging unit that provides information to track the progress of RFID tags.

15. A method of using a radio frequency identification (RFID) system, comprising:

reading at least one RFID tag by an RFID reader;

determining a proximity parameter for said at least one RFID tag with respect to said at least one reader using a sensor; and

controlling the RF power of said at least one reader.

16. The method of claim 15, wherein said proximity parameter comprises one of distance, speed, and direction of motion.

17. The method of claim 15, wherein said at least one reader comprises a plurality of readers, said method further comprising:

controlling said plurality of readers to vary the RF power levels of said readers over a range of values.

18. The method of claim 15, wherein said controlling comprises controlling the power of said at least one reader by employing a value of said proximity parameter.

19. The method of claim 15, wherein said controlling controls the power of said at least one reader by employing a schedule of updates.

20. A signal-bearing medium tangibly embodying a program of machine-readable instructions executable by a digital processing apparatus to perform a method of using a radio frequency identification (RFID) system, comprising:

reading at least one RFID tag by an RFID reader;

determining a proximity parameter for said at least one RFID tag with respect to said at least one reader using a sensor; and

controlling the RF power of said at least one reader.