Surveillance systems and methods
View Patent ↗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.
1. 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;
a first attenuator driving said first loop antenna;
a second attenuator driving said second loop antenna;
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;
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;
a splitter coupled to said signal processing component,
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 configured to estimate said orientation.
2. The system according to claim 1 , further comprising: a third loop antenna substantially orthogonal to both said first and second loop antennas.
3. The system according to claim 2 , further comprising:
a third attenuator driving said third loop antenna.
4. The system according to claim 3 , further comprising:
an x ramp generator to provide a x control signal to said third attenuator.
5. The system according to claim 1 , wherein said signal processing component is capable of estimating a position of said tag.
6. The system according to claim 1 , further comprising: a video-processing component in communication with said signal-processing component to receive said orientation.
7. The system according to claim 6 , wherein said video-processing component is capable of initiating surveillance when said tag is in an interrogation zone.
8. The system according to claim 6 , wherein said video-processing component is capable of initiating surveillance when a person touches said tag.
9. The system according to claim 6 , wherein said video processing component comprises:
a tracking mechanism;
an object verification mechanism; and
a recognition mechanism.
10. 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;
a first attenuator driving said first loop antenna;
a second attenuator driving said second loop antenna;
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;
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;
a splitter coupled to said signal processing component; and
a video-processing component in communication with said signal-processing component to receive said orientation,
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;
an angle calculator coupled to said modulation minimum detector, said angle calculator configured to estimate said orientation.
11. The system according to claim 10 , wherein said video-processing component is capable of initiating surveillance when said tag is in an interrogation zone.
12. The system according to claim 10 , wherein said video-processing component is capable of initiating surveillance when a person touches said tag.
13. The system according to claim 10 , wherein said video processing component comprises:
a tracking mechanism;
an object verification mechanism; and
a recognition mechanism.
14. 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;
a third loop antenna substantially orthogonal to both said first and second loop antennas;
a first attenuator driving said first loop antenna;
a second attenuator driving said second loop antenna;
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;
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;
a splitter coupled to said signal processing component; and
a video-processing component in communication with said signal-processing component to receive said orientation,
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 configured to estimate said orientation.
15. The system according to claim 14 , further comprising: a third attenuator driving said third loop antenna.
16. The system according to claim 15 , further comprising: an x ramp generator to provide a x control signal to said third attenuator.