Boundary crossing object detection system

• US 20070222663A1
• Filed: 03/24/2006
• Published: 09/27/2007
• Est. Priority Date: 03/24/2006
• Status: Active Grant

• Current Assignee: TDK Corporation
• Original Assignee: TDK Corporation
• Inventors: Humphrey, Denver, Clarke, Bryan
• Granted Patent: US 7,492,306 B2
• Time in Patent Office: Days
• US Class Current: 342/28
• 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: G08B 13/1609 using active vibration detection systems

Abstract

An boundary monitoring apparatus comprising an object detection device arranged to transmit a signal into a detection region and to detect an object in said detection region upon receipt of a reflected signal from said object; means for defining a boundary in said detection region; means for determining a path of said object in the detection region; means for performing an evaluation of the determined path of the object with respect to the boundary; and means for causing an alarm event depending on the evaluation.

Claims

1. A boundary monitoring apparatus comprising:

an object detection device arranged to transmit a signal into a detection region and to detect an object in said detection region upon receipt of a reflected signal from said object;

means for defining a boundary in said detection region;

means for determining a path of said object in the detection region;

means for performing an evaluation of the determined path of the object with respect to the boundary; and

means for causing an alarm event depending on the evaluation.

2. An apparatus as claimed in claim 1, wherein said reflected signal is received during use by said object detection device at an incident angle, the apparatus including means for determining said incident angle.

3. An apparatus as claimed in claim 2, wherein said apparatus includes means for determining a distance of said object from said object detection device, and wherein determination of said path by said path determining means is based on respective incident angles and corresponding distances determined for said object over time.

4. An apparatus as claimed in claim 1, wherein said object detection device comprises a radar device.

5. An apparatus as claimed in claim 4, wherein said radar device comprises first and second receiving antennas each receiving, in use, a respective reflected signal from a detected object;

and a summation and subtraction unit for summing and subtracting the respective reflected signals to produce, respectively, a sun reflected signal and a difference reflected signal.

6. An apparatus as claimed in claim 5, wherein an incident angle for the detected object is determined from a ratio of said sum reflected signal and said difference reflected signal.

7. An apparatus as claimed in claim 1, wherein said path determining means is arranged to determine a linear path for said detected object.

8. An apparatus as claimed in claim 1, wherein said evaluation performing means is arranged to determine if the determined path of said object intersects with said boundary.

9. An apparatus as claimed in claim 8, wherein said evaluation performing means is arranged to determine a distance of the determined path of said object from said object detection device or other reference location, and wherein said alarm event causing means causes an alarm event if the path of the object is determined to intersect said boundary and if said determined distance of the path is less than a threshold value.

10. An apparatus as claimed in claim 8, wherein said evaluation performing means is arranged to determine an angle of inclination of the determined path of said object from a reference axis, and wherein said alarm event causing means causes an alarm event if the path of the object is determined to intersect said boundary and depending on said determined angle of inclination.

11. An apparatus as claimed in claim 1, further including means for defining a post-boundary region beyond said boundary with respect to said object detection device, the apparatus being arranged to monitor the movement of objects detected in the post-boundary region.

12. An apparatus as claimed in claim 1, further including means for defining a pre-boundary region between said boundary and said object detection device, the apparatus being arranged to monitor the movement of objects detected in the pre-boundary region.

13. An apparatus as claimed in claim 1, wherein, in respect of an object first detected outside of said boundary, said evaluation performing means is arranged to determine if said determined path indicates that said object is travelling towards the apparatus.

14. An apparatus as claimed in claim 1, wherein, in respect of an object first detected inside of said boundary, said evaluation performing means is arranged to determine if said determined path indicates that said object is travelling away from the apparatus.

15. An apparatus as claimed in claim 1, further including means for adjusting a size threshold for detectable objects.

16. A method of monitoring a boundary in an apparatus comprising an object detection device arranged to transmit a signal into a detection region and to detect an object in said detection region upon receipt of a reflected signal from said object, the method comprising defining a boundary in said detection region;

determining a path of said object in the detection region;

performing an evaluation of the determined path of the object with respect to the boundary; and

causing an alarm event depending on the evaluation.