Surveillance systems and methods

• US 20050073418A1
• Filed: 10/02/2003
• Published: 04/07/2005
• Est. Priority Date: 10/02/2003
• Status: Active Grant

• Current Assignee: UTC Fire & Security Americas Corporation, Inc. (Carrier Global Corporation)
• Original Assignee: General Electric Company
• Inventors: Tu, Peter Henry, Tomlinson, Harold Woodruff, Rittscher, Jens, Kelliher, Timothy Patrick, Chean, Kevin
• Granted Patent: US 7,049,965 B2
• Time in Patent Office: Days
• US Class Current: 340/572.100
• CPC Class Codes: G08B 13/19608 Tracking movement of a target, e.g. by detecting an object predefined as a target, using target direction and or velocity to predict its new position
• CPC Class Codes: G08B 13/19634 Electrical details of the system, e.g. component blocks for carrying out specific functions
• CPC Class Codes: G08B 13/19641 Multiple cameras having overlapping views on a single scene
• CPC Class Codes: G08B 13/19697 Arrangements wherein non-video detectors generate an alarm themselves
• CPC Class Codes: G08B 13/2417 having a radio frequency identification chip
• CPC Class Codes: G08B 13/2462 Asset location systems combined with EAS inventory, tracking, logistic G06Q10/00; entrance control systems G07C9/00
• CPC Class Codes: G08B 13/2471 Antenna signal processing by receiver or emitter
• CPC Class Codes: G08B 13/248 EAS system combined with another detection technology, e.g. dual EAS and video or other presence detection system

Abstract

Surveillance systems and methods having both a radio frequency component and a video image are provided. The radio frequency component can determine the orientation and position of an RFID tag within a surveillance area. The orientation of the RFID tag is can be determined with respect to two or more orthogonal planes using inductance and a predetermined number of mutually orthogonal antenna loops.

Claims

1. A surveillance system comprising:

a video subsystem for detecting a video image of a tagged item;

a radio frequency identification subsystem for detecting a position of said tagged item; and

a processor in electrical communication with said video subsystem and said radio frequency identification subsystem, said processor monitoring a condition of said tagged item based at least in part on said video image and said position.

2. The system according to claim 2, wherein said radio frequency identification subsystem detects an orientation of said tagged item.

3. The system according to claim 2, wherein said processor monitors said condition based at least in part on said video image, said position, and said orientation.

4. A surveillance system comprising:

a first loop antenna;

a second loop antenna substantially orthogonal to said first loop antenna, said first and second loop antennas being inductively couplable with a tag through magnetic fields; and

a signal processing component for estimating an orientation of said tag based on a magnitude of an inductively coupled modulated signal from said tag as an orientation of a coupling field generated from said first and second loop antennas is scanned through a range of angles.

5. The system according to claim 4, further comprising:

a first attenuator driving said first loop antenna; and

a second attenuator driving said second loop antenna.

6. The system according to claim 5, further comprising:

a z ramp generator to provide a z control signal to said first attenuator; and

a y ramp generator to provide a y control signal to said second attenuator.

7. The system according to claim 6, further comprising:

a splitter coupled to said signal processing component.

8. The system according to claim 7, wherein said signal processing component comprises:

a bandpass filter coupled to said splitter;

an envelope detector coupled to said bandpass filter;

a modulation minimum detector coupled to said envelope detector; and

an angle calculator coupled to said modulation minimum detector, said angle calculator to estimate said orientation.

9. The system according to claim 4, further comprising:

a third loop antenna substantially orthogonal to both said first and second loop antennas.

10. The system according to claim 9, further comprising:

a first attenuator driving said first loop antenna;

a second attenuator driving said second loop antenna; and

a third attenuator driving said third loop antenna.

11. The system according to claim 10, further comprising:

a z ramp generator to provide a z control signal to said first attenuator;

a y ramp generator to provide a y control signal to said second attenuator; and

an x ramp generator to provide a x control signal to said third attenuator.

12. The system according to claim 4, wherein said signal processing component is capable of estimating a position of said tag.

13. The system according to claim 4, further comprising:

a video-processing component in communication with said signal-processing component to receive said orientation.

14. The system according to claim 13, wherein said video-processing component is capable of initiating surveillance when said tag is in an interrogation zone.

15. The system according to claim 13, wherein said video-processing component is capable of initiating surveillance when a person touches said tag.

16. The system according to claim 4, wherein said video processing component comprises:

a tracking mechanism;

an object verification mechanism; and

a recognition mechanism.

17. A surveillance method comprising:

determining an orientation of an RFID tag;

determining a position of said RFID tag; and

providing said orientation and said position to a video-processing component.

18. The method according to claim 17, wherein said orientation is related to three substantially orthogonal planes.

19. The method according to claim 17, wherein said orientation and said position are determined within a video frame time.

20. The method according to claim 17, wherein determining said orientation of said RFID tag comprises:

calculating an angle phi in a y-z plane, when an x-antenna signal is zero and a tag modulation minimum occurs;

calculating an angle alpha in an x-z plane, when a y-antenna signal is zero and said tag modulation minimum occurs; and

calculating an angle theta in an x-y plane, when a z-antenna signal is zero and said tag modulation minimum occurs.

21. The method according to claim 17, wherein determining said position of said RFID tag comprises:

calculating an x-amplitude from a first modulation amplitude, when a y-antenna signal is zero and a z-antenna signal is zero;

calculating a y-amplitude from a second modulation amplitude, when an x-antenna signal is zero and said z-antenna signal is zero; and

calculating a z-amplitude from a third modulation amplitude, when said x-antenna signal is zero and said y-antenna signal is zero.