SYSTEM FOR DETECTING INTRUDERS IN A POPULATED SPACE

• US 20070001835A1
• Filed: 07/25/2005
• Published: 01/04/2007
• Est. Priority Date: 01/25/2003
• Status: Active Grant

• Current Assignee: Ubisense Incorporated (IQGeo Group Plc)
• Original Assignee: Ubisense Incorporated (IQGeo Group Plc)
• Inventors: Webster, Paul, Ward, Andrew, Curwen, Rupert, Steggles, Peter
• Granted Patent: US 7,466,224 B2
• Time in Patent Office: Days
• US Class Current: 340/522
• CPC Class Codes: G07C 9/28 the pass enabling tracking or indicating presence
• CPC Class Codes: G08B 13/2448 Tag with at least dual detection means, e.g. combined inductive and ferromagnetic tags, dual frequencies within a single technology, tampering detection or signalling means on the tag
• CPC Class Codes: G08B 13/2454 Checking of authorisation of a person accessing tagged items in an EAS system
• CPC Class Codes: G08B 13/248 EAS system combined with another detection technology, e.g. dual EAS and video or other presence detection system
• CPC Class Codes: G08B 13/2491 Intrusion detection systems, i.e. where the body of an intruder causes the interference with the electromagnetic field

Abstract

A system for monitoring the presence of persons within a zone, the system comprising: one or more remotely detectable markers, each capable of being carried by a person; a first sensor arrangement capable of identifying the presence of the body of at least one person within the zone; a second sensor arrangement capable of identifying the presence of at least one marker within the zone; and a processing arrangement responsive to the first sensor arrangement and the second sensor arrangement to generate an alarm signal if the first sensor arrangement identifies the presence of a body without the second sensor arrangement identifying a marker corresponding in a first predetermined manner to that body.

Claims

1. A system for monitoring the presence of persons within a zone, the system comprising:

one or more remotely detectable markers, each capable of being carried by a person;

a first sensor arrangement capable of identifying the presence of the body of at least one person within the zone;

a second sensor arrangement capable of identifying the presence of at least one marker within the zone; and

a processing arrangement responsive to the first sensor arrangement and the second sensor arrangement to generate an alarm signal if the first sensor arrangement identifies the presence of a body without the second sensor arrangement identifying a marker corresponding in a first predetermined manner to that body.

2. A system as claimed in claim 1, wherein:

each marker has a unique identity;

the second sensor arrangement is capable of sensing the identity of a marker that is located within the zone.

3. A system as claimed in claim 2, wherein the processing arrangement has access to a data store storing the identities of markers permitted in the zone and is arranged to generate an alarm signal if the identity of a marker sensed in the zone by the second sensor arrangement is not that of a marker that is permitted in the zone.

4. A system as claimed in claim 2, wherein:

the system comprises a third sensor arrangement for sensing an attribute of the or each person within the zone; and

the processing arrangement has access to a data store storing for each marker one or more characteristics associated with that marker and is arranged to generate an alarm signal if the sensed attribute(s) do not correspond in a second predetermined manner to the characteristic(s) stored for the marker(s) sensed in the zone.

5. A system as claimed in claim 4, wherein the attribute is weight.

6. A system as claimed in claim 5, wherein the characteristic is an indication of the weight of a person associated with the respective marker.

7. A system as claimed in claim 5, wherein the characteristic is an indication of the type of a person associated with the respective marker, and the processing arrangement is arranged to estimate the weight of the person based on that indication.

8. A system as claimed in claim 5, wherein the second predetermined manner is such that if the weight sensed by the third sensing means differs by more than a predetermined threshold from the weight of the person as derived from the characteristic associated with the or each marker sensed in the zone then the sensed attribute does not correspond to the characteristic.

9. A system as claimed in claim 1, wherein the first predetermined manner is such that a marker does not correspond in the first predetermined manner to a body if the number of marker(s) identified in the zone at a time exceeds the number of markers sensed in the zone at the time.

10. A system as claimed in claim 9, wherein the zone is such that only one person can be present in the zone at a time.

11. A system as claimed in claim 9, wherein the first sensor arrangement is capable of determining the number of bodies of people within the zone.

12. A system as claimed in claim 1, wherein the first sensor arrangement is capable of characterising the location of the body of at least one person within the zone, the second sensor arrangement is capable of characterising the location of at least one marker within the zone;

and the first predetermined manner is such that a marker does not correspond in the first predetermined manner to a body if no marker is identified having the characterised location at which the body is identified.

13. A system as claimed in claim 12, wherein a location is characterised as a bearing from a respective sensor arrangement.

14. A system as claimed in claim 12, wherein a location is characterised as a distance from a respective sensor arrangement.

15. A system as claimed in claim 1, wherein the zone is located at the periphery of a space, the first sensor arrangement is capable of identifying whether a body is moving towards or away from the space, and the first predetermined manner is such that an alarm is generated if the body to which a marker does not correspond is moving towards the space.

16. A system as claimed in claim 1, wherein each marker has an active state and a low power state in which it uses less power than in the active state, and the system comprises means for causing a marker to enter the active state on entry into the zone.

17. A system as claimed in claim 1, wherein each marker is remotely detectable by means of radio frequency communication.

18. A system as claimed in claim 17, wherein each marker is a radio frequency transponder.

19. A method for monitoring the presence of persons within a zone by means of one or more remotely detectable markers, the method comprising:

identifying the presence of the body of at least one person within the zone;

identifying the presence of at least one marker within the zone; and

generating an alarm signal if the first sensor arrangement identifies the presence of a body without the second sensor arrangement identifying a marker corresponding in a first predetermined manner to that body.

20. (canceled)