Methods and apparatus for ceiling-mounted RFID-enabled tracking

• US 9,418,260 B2
• Filed: 02/25/2014
• Issued: 08/16/2016
• Est. Priority Date: 07/30/2004
• Status: Active Grant

• Current Assignee: Quake Global, Inc.
• Original Assignee: Quake Global, Inc.
• Inventors: Karani, Chetan Shantilal, Waidmann, Luke Christopher, Bolger-Kumm, Walker Edward, Wisdom, Ronan
• Primary Examiner(s): Alam, Mirza
• Application Number:
  US14/189,883
• Publication Number:
  US 20140240097A1
• Time in Patent Office: 903 Days
• Field of Search: 340/10.1, 340/572.7, 340/539.13, 340/10.3, 340/539.22, 235/385, 235/451, 455/562.1, 455/272
• US Class Current: 1/1
• CPC Class Codes: G01S 13/66 Radar-tracking systems; Analogous systems
• CPC Class Codes: G01S 13/74 Systems using reradiation of radio waves, e.g. secondary radar systems; Analogous systems
• CPC Class Codes: G01S 7/03 Details of HF subsystems specially adapted therefor, e.g. common to transmitter and receiver
• 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: G06Q 10/00 Administration; Management
• CPC Class Codes: G06Q 10/06 Resources, workflows, human or project management; Enterprise or organisation planning; Enterprise or organisation modelling

Abstract

Systems and methods for tracking a subject using radio-frequency identification (RFID). In an embodiment, an antenna array comprising a plurality of articulating brackets and a plurality of antennas is provided. Each of the articulating brackets is configured to move one of the plurality of antennas into a plurality of positions, and each of the antennas is configured to receive a RFID signal. In addition, a processor receives RFID data based on RFID signals received by the antennas of the antenna array, and determines a trajectory of a subject based on the RFID data. Based on the determined trajectory of the subject, the processor controls one or more of the articulating brackets to move one or more of the antennas into a position to track the subject.

Claims

1. An apparatus for tracking a subject using radio-frequency identification (RFID), the apparatus comprising:

an antenna array comprising a plurality of articulating brackets, mounted to a surface, and a plurality of antennas each mounted on a corresponding one of the plurality of articulating brackets, wherein each of the plurality of articulating brackets is configured to move a corresponding one of the plurality of antennas into a plurality of positions within a range of angles with respect to an axis that is orthogonal to the surface and within a range of angles with respect to an axis that is parallel to the surface, and wherein each of the plurality of antennas is configured to receive a RFID signal;

one or more sensors configured to detect one or more environmental conditions, wherein the one or more environmental conditions comprise a presence of a subject; and

at least one processor that

when the presence of the subject is not detected by the one or more sensors, switches the antenna array into a low power mode, and when the presence of the subject is detected, switches the antenna array into an active power mode,

determines a distance between the subject and the antenna array based on a strength of the one or more signals received by the antenna array;

determines a trajectory of the subject based on the determined distance; and

based on the determined trajectory of the subject, controls a first one of the plurality of articulating brackets of the antenna array to move a first one of the plurality of antennas into a different position relative to a second one of the plurality of antennas to track the subject.

2. The apparatus of claim 1, wherein moving the first one of the plurality of antennas into a position to track the subject comprises changing an orientation of the first one of the plurality of antennas.

3. The apparatus of claim 2, wherein changing the orientation of the first one of the plurality of antennas comprises changing a directionality of the first one of the plurality of antennas to be directed towards the determined trajectory of the subject.

4. The apparatus of claim 1, wherein determining the trajectory of the subject based on a strength of each of the one or more signals received by the one or more antennas comprises determining a location of the subject based on the strength of each of the one or more signals received by the one or more antennas.

5. The apparatus of claim 1, wherein the one or more signals received by the one or more antennas comprises a plurality of signals, and wherein determining the trajectory of the subject based on the determined distance further comprises determining a direction of the subject based on the plurality of signals.

6. The apparatus of claim 1, wherein the one or more signals received by the one or more antennas comprises a plurality of signals, and wherein determining the trajectory of the subject based on the determined distance further comprises determining a speed of the subject based on the plurality of signals.

7. The apparatus of claim 1, wherein determining the trajectory of the subject based on the determined distance further comprises determining the trajectory of the subject based on one or more of a strength, sampling rate, direction, phase, and time span of the one or more signals received by the one or more antennas.

8. The apparatus of claim 1, wherein the at least one processor is configured to control the plurality of articulating brackets such that directionalities of the plurality of antennas form a plurality of zones.

9. The apparatus of claim 8, wherein two or more of the plurality of zones overlap one another.

10. The apparatus of claim 1, further comprising:

a mounting plate comprising a first side and a second side, wherein the antenna array and the at least one processor are attached to the mounting plate on the first side; and

a base plate attached to the second side of the mounting plate.

11. The apparatus of claim 10, further comprising one or more mounting brackets, wherein each of the one or more mounting brackets comprise a track and a slider mechanism that slides along the track and is fixed to the base plate.

12. The apparatus of claim 11, wherein the slider mechanism comprises a push-to-release spring-loaded locking pin, and wherein the track comprises a plurality of holes for receiving the locking pin.

13. The apparatus of claim 11, further comprising, for each of the one or more mounting brackets, a clamping mechanism configured to clamp the slider mechanism against the track to releasably fix a position of the base plate with respect to the mounting bracket.

14. The apparatus of claim 13, wherein the slider mechanism comprises a screw, and wherein the clamping mechanism comprises a wing nut.

15. The apparatus of claim 11, wherein each of the one or more mounting brackets further comprises a clip that is configured to attach to a segment of a ceiling tile grid.

16. The apparatus of claim 11, wherein each of the one or more mounting brackets further comprises a clip that is configured to attach to a segment of a raised floor grid.

17. The apparatus of claim 1, further comprising a communication device configured to communicate with an external control device.

18. The apparatus of claim 17, wherein the communication between the communication device and the external control device comprises wireless communication.

19. A method for tracking a subject using an antenna array comprising a plurality of articulating brackets, mounted to a surface, and a plurality of antennas each mounted on a corresponding one of the plurality of articulating brackets, wherein each of the plurality of articulating brackets is configured to move a corresponding one of the plurality of antennas into a plurality of positions, wherein each of the plurality of antennas is configured to receive a radio-frequency identification (RFID) signal, and wherein the method comprises using at least one hardware processor to:

determine a presence of a subject based on information received from one or more sensors, and

when the subject is determined to not be present, switch the antenna array into a low power mode, and

when the subject is determined to be present, switch the antenna array into an active power mode,

determine a distance between the subject and the antenna array based on a strength of one or more signals received by the antenna array;

determine a trajectory of the subject based on the determined distance; and

based on the determined trajectory of the subject, control a first one of the plurality of articulating brackets of the antenna array to move a first one of the plurality of antennas, within a range of angles with respect to an axis that is orthogonal to the surface and a range of angles with respect to an axis that is parallel to the surface, into a different position relative to a second one of the plurality of antennas to track the subject.

20. The method of claim 19, wherein determining the trajectory of the subject based on the determined distance further comprises determining the trajectory of the subject based on one or more of a strength, sampling rate, direction, phase, and time span of the one or more signals received by the one or more antennas.

21. The method of claim 19, further comprising using the at least one hardware processor to control the plurality of articulating brackets such that directionalities of the plurality of antennas form a plurality of zones.

22. An apparatus for tracking a subject using radio-frequency identification (RFID), the apparatus comprising:

an antenna array comprising a plurality of articulating brackets and a plurality of antennas, wherein each of the plurality of articulating brackets is configured to move a corresponding one of the plurality of antennas into a plurality of positions and directionalities of the plurality of antennas form a plurality of zones that define a combined zone, and wherein each of the plurality of antennas is configured to receive an RFID signal from at least one of the plurality of zones;

one or more sensors configured to detect one or more environmental conditions, wherein the one or more environmental conditions comprise a presence of a subject; and

at least one processor that

when the presence of the subject is not detected by the one or more sensors, switches the antenna array into a low power mode, and when the presence of the subject is detected, switches the antenna array into an active power mode,

receives RFID data based on one or more RFID signals received by one or more of the plurality of antennas of the antenna array,

determines a location of the subject based on a strength of each of the one or more RFID signals received by the one or more antennas,

determines a distance between the subject and the one or more antennas based on the strength of each of the one or more RFID signals received by the one or more antennas,

determines a speed of the subject based on the strength of each of the one or more RFID signals received by the one or more antennas,

determines a trajectory of the subject based on the location and distance and speed, and

based on the determined trajectory of the subject, controls a first articulating bracket of the antenna array to move a first antenna of the antenna array into a different position relative to a second antenna of the antenna array to alter at least one of the plurality of zones and alter the combined zone.