System and method for occupancy detection

• US 8,654,197 B2
• Filed: 03/04/2009
• Issued: 02/18/2014
• Est. Priority Date: 03/04/2009
• Status: Active Grant

• Current Assignee: Raytheon Company (Rtx Corporation)
• Original Assignee: Raytheon Company (Rtx Corporation)
• Inventors: Nizko, Henry J., Woodington, W. Gordon, Manoogian, David V., Russell, Mark E., Toolin, Maurice J., Walzer, Jonathan H.
• Primary Examiner(s): Etienne, Ario
• Assistant Examiner(s): RUBIN, BLAKE J
• Application Number:
  US12/397,691
• Publication Number:
  US 20100225764A1
• Time in Patent Office: 1,812 Days
• Field of Search: 348/152
• US Class Current: 348/152
• CPC Class Codes: G01S 13/04 Systems determining presence of a target based on relative movement of target G01S13/56
• CPC Class Codes: G01S 13/87 Combinations of radar systems, e.g. primary radar and secondary radar
• CPC Class Codes: G01S 7/4004 of parts of a radar system
• CPC Class Codes: G01S 7/415 Identification of targets based on measurements of movement associated with the target
• CPC Class Codes: H01Q 17/001 for modifying the directional characteristic of an aerial

Abstract

A detection system includes a plurality of sensors including an entry sensor having a field of view oriented to detect object entry with respect to an entry portion of an occupancy volume, and an exit sensor having a field of view oriented to detect object exit with respect to an exit portion of the occupancy volume, the exit portion different than the entry portion. The detection system further includes at least one approach sensor having a field of view oriented to detect object approach relative to the entry portion of the occupancy volume, and at least one retreat sensor having a field of view oriented to detect object retreat relative to the exit portion of the occupancy volume.

Claims

1. A detection system, comprising:

a plurality of sensors, comprising;

an entry sensor having a field of view oriented to detect object entry into an occupancy volume via an entry portion of the occupancy volume, object entry corresponding to a first state of the occupancy volume in which an object is present within the occupancy volume and at least a portion of a security scan of the object is performed to detect unwanted materials, wherein the entry sensor includes an absorber box to block unwanted break-beam responses and to fan sensor break-beams across different detection areas; and

an exit sensor having a field of view oriented to detect object exit from the occupancy volume via an exit portion of the occupancy volume, object exit corresponding to a second state of the occupancy volume in which the object is absent from the occupancy volume;

at least one approach sensor having a field of view oriented to detect object approach relative to the entry portion of the occupancy volume; and

at least one retreat sensor having a field of view oriented to detect object retreat relative to the exit portion of the occupancy volume, wherein an occurrence of the first state of the occupancy volume followed by the second state of the occupancy volume corresponds to an occupancy volume crossed state in which the object is determined to have crossed the occupancy volume.

2. The system of claim 1, wherein the at least one approach sensor comprises:

a first approach sensor having a first approach field of view oriented with respect to an approach volume adjacent to the entry portion and outside of the occupancy volume; and

a second approach sensor having a second approach field of view oriented with respect the approach volume, wherein the second approach field of view is at least partially different than the first approach field of view.

3. The system of claim 2, wherein the first approach field of view is opposed to the second approach field of view to maximize object detection within the approach volume.

4. The system of claim 2, wherein the at least one retreat sensor comprises:

a first retreat sensor having a first retreat field of view oriented with respect to a retreat volume adjacent to the exit portion and outside of the occupancy volume; and

a second retreat sensor having a second retreat field of view oriented with respect the retreat volume, wherein the second retreat field of view is at least partially different than the first retreat field of view.

5. The system of claim 4, wherein the first retreat field of view is opposed to the second retreat field of view to maximize object detection within the retreat volume.

6. The system of claim 1, wherein at least one of the entry and exit sensors is a frequency-modulation continuous-wave microwave multi-beam radar sensor mounted within an absorber box including an inner microwave-absorbent surface to narrow beam spread of the radar sensor.

19. The detection system of claim 1, wherein the occupancy volume has a predetermined width, a predetermined height, and a predetermined depth defining a crossing zone between a first area and a second area.

20. The detection system of claim 19, wherein the first area corresponds to a first country, the second area corresponds to a second country, and the crossing zone corresponds to a border between the first country and the second country.

21. The detection system of claim 19, wherein crossing zone corresponds to a security zone about a building or a facility and one of the first or second areas corresponds to a secured area.

22. The detection system of claim 1, wherein the field of view of the entry sensor and the field of view of the exit sensor combine to form a gap-less sensor area that fills the occupancy volume.

23. The detection system of claim 1, wherein the occupancy volume is a box shaped volume defining a crossing area, the entry portion is defined along an entry side of the crossing area and the exit portion is defined along an exit side of the crossing area opposing the entry side of the crossing area.

24. The detection system of claim 1, wherein object approach relative to the entry portion of the occupancy volume corresponds to a third state of the occupancy volume to alert of an approach of the object relative to the occupancy volume and object retreat relative to the exit portion of the occupancy volume corresponds to a fourth state of the occupancy volume in which preparations for a scan of another object are performed.

25. The detection system of claim 1, wherein the occupancy volume corresponds to a security checkpoint and the security scan of the first state of the occupancy volume enables a determination as to whether the object may cross the security checkpoint and the occurrence of the occupancy volume crossed state enables a determination that the object is allowed to cross the security checkpoint based on the results of the security scan.

7. A detection system, comprising:

a first sensor having a first field of view oriented to detect object entry into an occupancy volume via an entry portion of the occupancy volume, object entry corresponding to a first state of the occupancy volume in which an object is present within the occupancy volume and at least a portion of a security scan of the object is performed to detect unwanted materials, wherein the first sensor includes an absorber box to block unwanted break-beam responses and to fan sensor break-beams across different detection areas;

a second sensor having a second field of view oriented to detect object exit from the occupancy volume via an exit portion of the occupancy volume, object exit corresponding to a second state of the occupancy volume in which the object is absent from the occupancy volume;

a third sensor having a third field of view oriented to detect object approach relative to the occupancy volume;

a fourth sensor having a fourth field of view oriented to detect object retreat relative to the occupancy volume,

wherein an occurrence of the first state of the occupancy volume followed by the second state of the occupancy volume corresponds to an occupancy volume crossed state in which the object is determined to have crossed the occupancy volume.

8. The system of claim 7, further comprising:

a fifth sensor having a fifth field of view opposed to the third field of view of the third sensor to further detect object approach relative to the occupancy volume; and

a sixth sensor having a sixth field of view opposed to the fourth field of view of the fourth sensor to further detect object retreat relative to the occupancy volume.

9. The system of claim 8, wherein the entry portion and the exit portion of the occupancy volume are generally opposed to each other and the first sensor is positioned along the entry portion, the second sensor is positioned along the exit portion, the third and fifth sensors are positioned along the entry portion, and the fourth and sixth sensors are positioned along the exit portion.

10. The system of claim 9, wherein

the third field of view of the third sensor is oriented to detect object approach within an approach volume adjacent to the entry portion and outside of the occupancy volume, and the fifth field of view of the fifth sensor is oriented to detect object approach within the approach volume, the fifth field of view is at least partially different than the third field of view, and

the forth field of view of the fourth sensor is oriented to detect object retreat within a retreat volume adjacent to the exit portion and outside of the occupancy volume, and the sixth field of view of the sixth sensor is oriented to detect object retreat within the retreat volume, the sixth field of view is at least partially different than the forth field of view.

11. The system of claim 7, wherein the first sensor produces a first break-beam significantly reduced in longitudinal width by a first absorber box to provide object detection coverage across the entry portion of the occupancy volume, and the second sensor produces a second break-beam significantly reduced in width by a second absorber box to provide object detection coverage across the exit portion of the occupancy volume.

12. The system of claim 7, wherein the first sensor is a multi-beam radar sensor mounted within a first absorber box, and the second sensor is a multi-beam radar sensor mounted within a second absorber box, at least one of the first absorber box or second absorber box including an inner microwave-absorbent surface to narrow sensor beam spread.

13. The system of claim 7, wherein the third sensor is a multi-beam radar sensor providing a first elevation of object approach coverage relative to the ground plane of the occupancy volume coincident with ground level and the fourth sensor is a multi-beam radar sensor providing a second elevation of object retreat coverage relative to the ground plane of the occupancy volume.

14. A detection system, comprising:

a first sensor having a first field of view oriented to detect object entry into a portal zone from a lane entry zone adjacent to the portal zone at an entry portion of the portal zone, object entry corresponding to a first state of the portal zone in which an object is present within the portal zone and at least a portion of a security scan of the object is performed to detect unwanted materials, wherein the first sensor includes an absorber box to block unwanted break-beam responses and to fan sensor break-beams across different detection areas;

a second sensor having a second field of view oriented to detect object exit from the portal zone into a lane exit zone adjacent to the portal zone at an exit portion of the portal zone opposing the entry portion of the portal zone, object exit corresponding to a second state of the portal zone in which the object is absent from the portal zone;

a third sensor having a third field of view oriented to detect object approach toward the portal zone within the lane entry zone; and

a forth sensor having a forth field of view oriented to detect object retreat from the portal zone within the lane exit zone,

wherein an occurrence of the first state of the portal zone followed by the second state of the portal zone corresponds to a portal zone crossed state in which the object is determined to have crossed the portal zone.

15. The system of claim 14, wherein the portal zone is defined by a first side and a second side laterally opposing the first side, the first and second sides substantially parallel to a direction of object travel, further comprising:

a fifth sensor having a fifth field of view oriented to detect object approach toward the portal zone within the lane entry zone and laterally opposing the third field of view; and

a sixth sensor having a sixth field of view oriented to detect object retreat from the portal zone within the lane exit zone and laterally opposing the forth field of view,

wherein the first, third, and fourth sensors are substantially aligned with the first side and the second, fifth, and sixth sensors are substantially aligned with the second side.

16. The system of claim 15, further comprising:

a first vertical body positioned along the first side of the portal zone at the entry portion of the portal zone adjacent to the lane entry zone; and

a second vertical body positioned along the second side of the portal zone at the exit portion of the portal zone adjacent to the lane exit zone,

wherein the first, third, and forth sensors are mounted to the first vertical body and the second, fifth, and sixth sensors are mounted to the second vertical body.

17. The system of claim 16, wherein the first sensor is mounted within a first absorber box to reduce the longitudinal width of the first field of view, the second sensor is mounted within a second absorber box to reduce the longitudinal width of the second field of view, the third sensor is mounted within a third absorber box to further reduce the third field of view and the fourth sensor is mounted within a fourth absorber box to further reduce the fourth field of view and the fifth sensor is mounted within a fifth absorber box to further reduce the fifth field of view and the sixth sensor is mounted within a sixth absorber box to further reduce the fifth field of view.

18. The system of claim 17, wherein the third field of view is further oriented toward ground level at one side of the late entry zone and the fifth field of view is further oriented toward ground level at another side of the late entry zone opposing the one side of the late entry zone, and the forth field of view is further oriented toward ground level at one side of the late exit zone and the sixth field of view is further oriented toward ground level at another side of the late exit zone opposing the one side of the lane exit zone.