Virtual fence system and method

• US 6,342,847 B1
• Filed: 09/28/2000
• Issued: 01/29/2002
• Est. Priority Date: 09/28/2000
• Status: Expired due to Fees

• Current Assignee: GPS Technology Solutions, LLC
• Original Assignee: National Systems & Research Co. (CMTSU Liquidation, Inc.)
• Inventors: Archuleta, Anthony Thomas, McDermott, Paul Joseph, Langdon, Kim Donald
• Primary Examiner(s): TRIEU, VAN THANH
• Application Number:
  US09/675,444
• Time in Patent Office: 488 Days
• Field of Search: 340/568.1, 340/568.5, 340/571, 340/572.4, 340/573.1, 340/573.3, 340/573.4, 340/541, 340/686.1, 340/988, 340/989, 340/992, 340/995, 340/996, 342/357.06, 342/357.07, 342/456, 348/155, 348/170
• US Class Current: 340/988
• CPC Class Codes: G08G 1/207 with respect to certain areas, e.g. forbidden or allowed areas with possible alerting when inside or outside boundaries

Abstract

A remote tracking and sensing device (20) includes a global positioning system receiver (22). A processor (24) receives a position signal from the global positioning system receiver (22). A communication interface (30) connects the processor (24) to at least two wireless communication systems (26, 28). A power management system (32) provides power to the processor (24) based on an output (38) from a motion sensor (40).

Claims

1. A method of operating a moving fence system, comprising the steps of:

(a) recording a reported position of a device;

(b) determining if a time is within an operation period or a nonoperation period;

(c) when the time is within an operation period, determining if the device has crossed a predetermined number of moving fences;

(d) determining if the device has been within a moving fence for a predetermined amount of time;

(e) when the device has moved the predetermined number of moving fences and has been within the moving fence for the predetermined amount of time, the device transmitting a position message.

2. The method of claim 1, further including the steps of:

(f) determining if the device has crossed predetermined number of moving fences;

(g) determining if the device has been within the moving fence for a predetermined amount of time;

(h) when the device has crossed the predetermined number of moving fences and has been within the moving fence for the predetermined amount of time, transmitting the position message.

3. The method of claim 2, further including the steps of:

(i) retaining the reported position in a memory until the position message is transmitted.

4. The method of claim 2, further including the steps of:

(h) cataloging a plurality of devices within the defined area.

5. The method of claim 1, wherein step (a) includes the steps of:

(a1) establishing the operation period and a nonoperation period;

(a2) establishing the predetermined number of moving fences and the predetermined amount of time for the operation period;

(a3) establishing a nonoperation predetermined number of moving fences and a nonoperation predetermined amount of time;

(a4) when the time is within the operation period, using the operation predetermined number of moving fences and the operation amount of time;

(a5) when the time is within the nonoperation period, using the nonoperation predetermined number of moving fences and the nonoperation predetermined amount of time.

6. The method of claim 1, wherein step (c) includes the steps of:

(c1) when the device crosses a previous moving fence, creating the moving fence;

(c2) when the device crosses the new moving fence, creating a subsequent moving fence;

(c3) determining a new position;

(c4) establishing the new moving fence boundary.

7. The method of claim 1, wherein step (e) includes the step of:

(e1) when the device has moved the predetermined number of moving fences and has not been within the moving fence for the predetermined amount of time, the position message is not transmitted.

8. The method of claim 1, further including the steps of:

(e1) when a predetermined amount of time has elapsed, transmitting the position message.

9. The method of claim 1, further including the steps of:

(e1) when the device has moved a predetermined number of moving fences, transmitting the position message.

10. The method of claim 1, wherein step (e) includes the step of:

(e1) when the device has not moved the predetermined number of moving fences and has been within the moving fence for the predetermined amount of time, the position message is not transmitted.

11. The method of claim 1, wherein step (b) includes the step of:

(b1) crossing a previous moving fence.

12. The method of claim 1, further including the steps of:

(f) receiving the position message at a monitoring site;

(g) determining if the device is within a defined area.

13. The method of claim 1, wherein the position message further comprises a time, a location, and an equipment identification information.

14. A method of operating a site fence system, comprising the steps of:

(a) defining a monitoring area;

(b) determining when a device enters and departs the monitoring area;

(c) determining if the device is within the monitoring area; and

(d) when the device is within the monitoring area, adding the device to a catalog list.

15. The method of claim 14, further including the step of:

(e) receiving a position message, including a device'"'"'s engine hours.

16. The method of claim 15, further including the steps of:

(f) comparing the device'"'"'s engine hours to a predetermined maintenance interval; and

(g) when the device'"'"'s engine hours meets or exceeds the predetermined maintenance interval, alerting the monitoring site.

17. The method of claim 14, further including the step of:

(e) when a device crosses a site fence, transmitting a position message.

18. The method of claim 14, wherein step (a) includes the step of:

(a1) when a base station establishes the monitoring area, cataloguing and transmitting the description of the monitoring area to the device.

19. The method of claim 14, wherein step (b) includes the step of:

(b1) when the device crosses into the monitoring area, transmitting an entry message.

20. The method of claim 14, wherein step (b) includes the step of:

(b1) when the device crosses the monitoring area, transmitting a date and time.

21. The method of claim 14, wherein step (b) includes the step of:

(b1) when the device crosses out of the monitoring area, transmitting a departure message.

22. A method of operating a moving fence system, comprising the steps of:

(a) recording a reported position of a device;

(b) when the device has satisfied a reporting criteria, transmitting a position message;

(c) storing the position message at the device;

(d) discarding the reported position.

23. The method of claim 22, wherein the reporting criteria comprises the device crossing a moving fence and traveling a predetermined distance.

24. The method of claim 22, wherein the reporting criteria includes the device crossing a predetermined number of moving fences.

25. The method of claim 24 wherein the predetermined number of moving fences is a single moving fence.

26. The method of claim 22, wherein the reporting criteria comprises the device crossing a predetermined number of moving fences and being within a moving fence for a predetermined amount of time.

27. The method of claim 22, wherein the reporting criteria comprises a predetermined period of time.

28. The method of claim 22, wherein step (b) further includes the steps of:

(b1) determining a received signal strength for a wireless communication system;

(b2) when the received signal strength is less than a predetermined signal strength, switching to a second wireless communication system and sending the position message.