System and method for tracking

• US 9,735,464 B2
• Filed: 10/31/2013
• Issued: 08/15/2017
• Est. Priority Date: 11/02/2012
• Status: Active Grant

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Sabahialshoara, Meysam, Ng, Wei Beng, Masuda, Hisashi
• Primary Examiner(s): Alizada, Omeed
• Application Number:
  US14/068,434
• Publication Number:
  US 20140125459A1
• Time in Patent Office: 1,384 Days
• Field of Search: 340 101
• CPC Class Codes: G01S 13/751 wherein the responder or reflector radiates a coded signal
• CPC Class Codes: G01S 13/758 using a signal generator powered by the interrogation signal
• CPC Class Codes: G01S 13/765 with exchange of information between interrogator and responder
• CPC Class Codes: G01S 2013/0245 Radar with phased array antenna
• CPC Class Codes: G06K 7/10099 the directional field being used for pinpointing the location of the record carrier, e.g. for finding or locating an RFID tag amongst a plurality of RFID tags, each RFID tag being associated with an object, e.g. for physically locating the RFID tagged object in a warehouse
• CPC Class Codes: H01Q 1/2216 used in interrogator/reader equipment
• CPC Class Codes: H01Q 1/2225 used in active tags, i.e. provided with its own power source or in passive tags, i.e. deriving power from RF signal
• CPC Class Codes: H01Q 1/248 provided with an AC/DC converting device, e.g. rectennas
• CPC Class Codes: H01Q 23/00 Antennas with active circuits or circuit elements integrated within them or attached to them
• CPC Class Codes: H01Q 3/26 varying the relative phase or relative amplitude of energisation between two or more active radiating elements; varying the distribution of energy across a radiating aperture H01Q3/12, H01Q3/22, H01Q3/24 take precedence
• CPC Class Codes: H01Q 5/40 Imbricated or interleaved structures; Combined or electromagnetically coupled arrangements, e.g. comprising two or more non-connected fed radiating elements
• CPC Class Codes: H01Q 9/24 Shunt feed arrangements to single active elements, e.g. for delta matching
• CPC Class Codes: H01Q 9/285 Planar dipole H01Q9/065 takes precedence; patch antenna H01Q9/0407

Abstract

A tracking system comprising: a transmitter configured to steer an RF beam across a detection range, a passive RFID tag configured to be enabled for locating substantially when located in the center of the RF beam of the transmitter, and an RFID reader configured to detect the tag 104 once enable.

Claims

1. A tracking system, comprising:

a transmitter configured to steer a radio frequency (RF) beam at a first frequency across a detection range;

a radio frequency identification (RFID) tag configured to be switched from a non-readable state into a readable state based on the RFID tag that is located in the RF beam,

wherein the RFID tag comprises a switch that selectively connects an RFID chip, that has a unique identifier, to an inductive loop; and

an RFID reader configured to transmit a power signal at a second frequency to detect a location of the RFID tag based on the RFID tag that is switched into the readable state,

wherein the RF beam is configured to sequentially steer at a series of spaced discrete angles.

2. The tracking system of claim 1, wherein the RFID tag is further configured to:

connect to an RF antenna, and

toggle the switch such that the RFID tag is switched from the non-readable state into the readable state based on the location of the RF antenna in the RF beam.

3. The tracking system of claim 2, wherein the RF antenna is a rectenna.

4. The tracking system of claim 1, wherein the RF beam is at the first frequency in an ISM band of about 2.45 GHz or 5.80 GHz.

5. The tracking system of claim 1, wherein the RFID reader is further configured to detect the location of the RFID tag based on the second frequency in an RFID band of about 866-869 MHz, 928-950 MHz, or 2.4-2.5 GHz.

6. The tracking system of claim 1, wherein the transmitter comprises a steerable phased array antenna for the RF beam or for the RFID reader to detect the location of the RFID tag.

7. The tracking system of claim 3, wherein the rectenna is one of omni-directional or directive.

8. The tracking system of claim 1, wherein based on the detection of the location of the RFID tag, the RFID tag location is determined as one of the spaced discrete angles.

9. A tracking method, comprising:

scanning a radio frequency (RF) beam at a first frequency over a plurality of sectors;

switching a radio frequency identification (RFID) tag from a non-readable state into a readable state by use of a switch in the RFID tag based on a location of the RFID tag in the RF beam, the switch selectively connecting an RFID chip, having a unique identifier, to an inductive loop; and

transmitting a power signal at a second frequency by an RFID reader to detect the location of the RFID tag that is in the readable state,

wherein the location of the RFID tag that is switched from the non-readable state into the readable state is detected relative to an origin of the RF beam based on a sector, of the plurality of sectors, in which the RFID tag is detected, and

wherein the RF beam is configured to sequentially steer at a series of spaced discrete angles.

10. The tracking method of claim 9, further comprising focusing power of RF beam at the detected location.

11. The tracking method of claim 10, further comprising tracking a change in the detected location.