System and method for detecting an intruder using impulse radio technology

• US 20020130807A1
• Filed: 09/14/2001
• Published: 09/19/2002
• Est. Priority Date: 09/14/2000
• Status: Active Grant

• Current Assignee: Humatics Corporation
• Original Assignee: Time Domain Corporation (Humatics Corporation)
• Inventors: Hall, David J., Yano, Scott M., Schantz, Hans G.
• Granted Patent: US 6,614,384 B2
• Time in Patent Office: Days
• US Class Current: 342/28
• CPC Class Codes: G01S 13/003 Bistatic radar systems; Multistatic radar systems
• CPC Class Codes: G01S 13/0209 Systems with very large relative bandwidth, i.e. larger than 10 %, e.g. baseband, pulse, carrier-free, ultrawideband
• CPC Class Codes: G01S 13/04 Systems determining presence of a target based on relative movement of target G01S13/56
• CPC Class Codes: G01S 13/42 Simultaneous measurement of distance and other co-ordinates indirect measurement G01S13/46
• CPC Class Codes: G01S 13/878 Combination of several spaced transmitters or receivers of known location for determining the position of a transponder or a reflector G01S13/874 takes precedence
• CPC Class Codes: G01S 7/282 Transmitters
• CPC Class Codes: G01S 7/285 Receivers
• CPC Class Codes: G01S 7/292 Extracting wanted echo-signals
• CPC Class Codes: G08B 13/187 by interference of a radiation field
• CPC Class Codes: H04B 2001/6908 using time hopping

Abstract

An intrusion detection system and method are provided that can utilize impulse radio technology to detect when an intruder has entered a protection zone. In addition, the intrusion detection system and method can utilize impulse radio technology to determine a location of the intruder within the protection zone and also track the movement of the intruder within the protection zone. Moreover, the intrusion detection system and method can utilize impulse radio technology to create a specially shaped protection zone before trying to detect when and where the intruder has penetrated and moved within the protection zone.

Claims

1. A security system comprising:

a transmitting impulse radio unit capable of transmitting an impulse radio signal including a series of impulses;

a receiving impulse radio unit capable of receiving the impulse radio signal and generating a first waveform corresponding to the received impulse shape of the impulse radio signal;

said receiving impulse radio unit further capable of receiving the impulse radio signal at a subsequent time and generating a second waveform corresponding to the received impulse shape of the impulse radio signal after the subsequent time; and

a processor for comparing the first waveform to the second waveform to determine whether there is a change between the first waveform and the second waveform caused by an intruder entering a protection zone.

2. The security system of claim 1, wherein said change between the first waveform and the second waveform is a multipath reflection part caused by the intruder that was absent in the first waveform but present in the second waveform.

3. The security system of claim 1, further comprising at least two more receiving impulse radio units that operate in a similar manner as the receiving impulse radio unit thus enabling a current position of the intruder to be determined within the protection zone.

4. The security system of claim 3, wherein said transmitting impulse radio unit is capable of interacting with each of the receiving impulse radio units to track the movement of a test subject so as to create a shape of the protection zone.

5. The security system of claim 1, wherein said receiving impulse radio unit further includes an ultra-wideband scanning receiver.

6. The security system of claim 1, wherein the transmitted impulse radio signal is a transmitted Gaussian waveform having a known pseudorandom sequence of pulses.

7. The security system of claim 1, wherein said first waveform is a time domain representation of the actual distortion between the transmitted impulse radio signal and the received impulse radio signal.

8. The security system of claim 1, wherein said second waveform is a time domain representation of the actual distortion between the impulse radio signal transmitted at a subsequent time and the impulse radio signal received after the subsequent time.

9. A method for detecting an intruder, said method comprising the steps of:

transmitting, from a transmitting impulse radio unit, an impulse radio signal including a series of impulses;

receiving, at a receiving impulse radio unit, the impulse radio signal;

generating, at the receiving impulse radio unit, a first waveform corresponding to the impulse shape of the received impulse radio signal;

receiving, at the receiving impulse radio unit and at a subsequent time, the impulse radio signal;

generating, at the receiving impulse radio unit, a second waveform corresponding to the impulse shape of the impulse radio signal received after the subsequent time; and

comparing the first waveform to the second waveform to determine whether there is a change between the first waveform and the second waveform caused by the intruder entering a protection zone.

10. The method of claim 9, further comprising the step of determining a distance between the intruder and the receiving impulse radio unit by calculating an elapsed time between an initial wavefront of the second waveform and a multipath reflection part of the second waveform caused by the intruder that was absent in the first waveform but present in the second waveform.

11. The method of claim 9, further comprising the step of enabling a current position of the intruder to be determined within the protection zone by utilizing at least one more receiving impulse radio unit that operates in a similar manner as the receiving impulse radio unit.

12. The method of claim 10, further comprising the steps of:

receiving, at a second receiving impulse radio unit, the impulse radio signal;

generating, at the second receiving impulse radio unit, a first waveform corresponding to the impulse shape of the impulse radio signal;

receiving, at the second receiving impulse radio unit at a subsequent time, the transmitted second impulse radio signal;

generating, at the second receiving impulse radio unit, a second waveform corresponding to the impulse shape of the impulse radio signal received after the subsequent time;

comparing the first waveform to the second waveform to determine whether there is a change between the first waveform and the second waveform caused by the intruder entering the protection zone;

determining a distance between the intruder and the second receiving impulse radio unit by calculating an elapsed time between an initial wavefront of the second waveform and a multipath reflection part of the second waveform caused by the intruder that was absent in the first waveform but present in the second waveform generated by the second receiving impulse radio unit;

receiving, at a third receiving impulse radio unit, the impulse radio signal;

generating, at the third receiving impulse radio unit, a first waveform corresponding to the impulse shape of the impulse radio signal;

receiving, at the third receiving impulse radio unit and at a subsequent time, the impulse radio signal;

generating, at the third receiving impulse radio unit, a second waveform corresponding to the impulse shape of the impulse radio signal received after the subsequent time;

comparing the first waveform to the second waveform to determine whether there is a change between the first waveform and the second waveform caused by the intruder entering the protection zone;

is determining a distance between the intruder and the third receiving impulse radio unit by calculating an elapsed time between an initial wavefront of the second waveform and a multipath reflection part of the second waveform caused by the intruder that was absent in the first waveform but present in the second waveform generated by the third receiving impulse radio unit; and

determining a current position of the intruder in the protection zone using the determined distances between the intruder and the first, second and third receiving impulse radio units.

13. The method of claim 9, further comprising the step of creating a shape of the protection zone.

14. The method of claim 13, wherein said step of creating a shape of the protection zone further includes the steps of:

determining a current position of a test subject by utilizing at least two more receiving impulse radio units that operate in a similar manner as the first receiving impulse radio unit; and

tracking the movement of the test subject to outline the shape of the protection zone.

15. The method of claim 9, further comprising the step of alerting security personnel when the intruder has entered the protection zone.

17. The security system of claim 16, wherein said transmitting impulse radio unit is capable of interacting with each of the receiving impulse radio units to track the movement of a test subject to create a shape of the protection zone.

18. The security system of claim 16, wherein each of said plurality of receiving impulse radio units further includes an ultra-wideband scanning receiver.

19. The security system of claim 16, wherein the transmitted first impulse radio signal and the transmitted second impulse radio signal are each a transmitted Gaussian waveform having a known pseudorandom sequence of pulses.

20. The security system of claim 16, wherein said first waveform is a time domain representation of the actual distortion between the transmitted impulse radio signal and the received impulse radio signal.

21. The security system of claim 16, wherein said second waveform is a time domain representation of the actual distortion between the impulse radio signal transmitted at a subsequent time and the impulse radio signal received after the subsequent time.

16. A security system comprising:

a transmitting impulse radio unit capable of transmitting an impulse radio signal;

a plurality of receiving impulse radio units each of which is capable of receiving the impulse radio signal and generating a first waveform corresponding to the received impulse shape of the impulse radio signal;

each of said plurality of receiving impulse radio units are further capable of receiving the impulse radio signal at a subsequent time and generating after the subsequent time a second waveform corresponding to the received impulse shape of the impulse radio signal, each receiving impulse radio unit further includes;

a processor for comparing the first waveform to the second waveform to determine a distance between the intruder and the respective receiving impulse radio unit by calculating an elapsed time between an initial wavefront of the second waveform and a multipath reflection part of the second waveform caused by the intruder that was absent in the first waveform but present in the second waveform;

each of said plurality of receiving impulse radio units are further capable of transmitting the determined distance between the intruder and the respective receiving impulse radio unit to said transmitting impulse radio unit; and

said transmitting impulse radio unit is further capable of calculating a current position of the intruder using the determined distances.

22. An intrusion detection system comprising:

a transmitting impulse radio unit capable of transmitting an impulse radio signal including a series of impulses; and

a receiving impulse radio unit capable of comparing at least two scanned waveforms corresponding to at least two impulse shapes of the impulse radio signal that were generated at different times to determine whether a protection zone has been breached by an intruder.

23. The intrusion detection system of claim 22, further comprising at least one more receiving impulse radio units that operate in a similar manner as the receiving impulse radio unit thus enabling the transmitting impulse radio unit to determine a current position of the intruder within the protection zone.

24. The intrusion detection system of claim 23, wherein said transmitting impulse radio unit is capable of interacting with each of the receiving impulse radio units to track the movement of a test subject so as to create a shape of the protection zone.

25. The intrusion detection system of claim 23, wherein said transmitting impulse radio unit further includes at least one directive antenna.

26. The intrusion detection system of claim 25, wherein said at least one directive antenna enables the transmitting impulse radio unit to transmit the impulse radio signal in a predetermined direction.