SYSTEM AND METHOD FOR TRACKING

• US 20140125459A1
• Filed: 10/31/2013
• Published: 05/08/2014
• Est. Priority Date: 11/02/2012
• Status: Active Grant

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Ng, Wei Beng, Masuda, Hisashi, Sabahialshoara, Meysam
• Granted Patent: US 9,735,464 B2
• Time in Patent Office: Days
• US Class Current: 340/10.1
• 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 centre 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 an RF beam across a detection range,

a passive RFID tag configured to be enabled when the tag and/or an RF antenna is located substantially in the RF beam, and

an RFID reader configured to detect the tag once enabled.

2. The system of claim 1, wherein the tag is configured to connect to the RF antenna and to toggle a switch to enable the tag when the RF antenna is located substantially in the RF beam.

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

4. The system in any preceding claims wherein the RF beam is at a first frequency in an ISM band substantially located about 2.45 GHz or 5.80 GHz.

5. The system of claim 1, wherein the RFID reader is configured to detect the tag using a second frequency in an RFID band substantially located about 866-869 MHz, 928-950 MHz or 2.4-2.5 GHz.

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

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

8. The system of claim 1, wherein the RF beam is sequentially steered at a series of spaced discrete angles, and if the RFID tag is detected, a tag location is determined as one of the discrete angles.

9. The system of claim 1, wherein the RF beam is continuously steered across the detection range, and if the RFID tag is detected, a tag location is determined as the centre of the range of RF beam steering angles where the RFID tag was detected, or as the angle at which a RSSI is the highest.

10. A method comprising:

scanning a beam of RF radiation over a plurality of sectors;

switching a modified RFID tag from invisible to visible when the tag receives the RF beam is in the currently scanned sector;

detecting visible RFID tags, and

determining the location of the tag of locating a tag relative to the RF beam origin based on the current sector in which an RFID tag can be detected.

11. The method of claim 10 further comprising focusing power RF radiation at the determined location.

12. The method of claim 11 further comprising tracking any change in the determined location.