Method and apparatus for data filtering in a tracking system

• US 20050162309A1
• Filed: 02/25/2005
• Published: 07/28/2005
• Est. Priority Date: 01/16/2004
• Status: Abandoned Application

• Current Assignee: SkyGuard LLC (Wireless Matrix Corporation)
• Original Assignee: MCI Incorporated (Verizon Communications Inc.)
• Inventors: Wadsworth, Jay B., Summers, Bracey C., Dement, James F., Humphries, Laymon Scott
• Application Number:
  US11/065,913
• Publication Number:
  US 20050162309A1
• Time in Patent Office: Days
• US Class Current: 342/357.310
• CPC Class Codes: G01S 19/05 providing aiding data
• CPC Class Codes: G01S 19/20 Integrity monitoring, fault detection or fault isolation of space segment
• CPC Class Codes: G01S 19/396 Determining accuracy or reliability of position or pseudorange measurements
• CPC Class Codes: G01S 5/0027 of actual mobile position, i.e. position determined on mobile

Abstract

An approach is provided for tracking a telemetry device over a wireless network. Data, e.g., Global Positioning System (GPS) information, corresponding to the tracking of the device is received. The data is filtered for errant information according to one or more filter parameters.

Claims

1. A method for tracking a device, the method comprising the steps of:

receiving data corresponding to tracking of the device; and

filtering the data for errant information according to one or more filter parameters.

2. A method according to claim 1, wherein the filter parameters are selected based on status of a trigger.

3. A method according to claim 1, wherein the data includes position information and speed information, and the filter parameter includes a distance threshold, the method further comprising the step of:

determining whether a new position of the device is within the distance threshold of a prior unfiltered position of the device based on the position information; and

if the new position is within the distance threshold, declaring the new position to be identical to the prior unfiltered position and setting the speed information to zero.

4. A method according to claim 3, wherein the device is coupled to a vehicle, and the filter parameter includes a second distance threshold, the method further comprising:

determining whether the vehicle is on or off,

wherein if the vehicle is off, the data is filtered according to the second distance threshold.

5. A method according to claim 1, wherein the device is tracked using Global Positioning System (GPS) satellites, the device selectively operating in an assisted GPS mode or an autonomous GPS mode.

6. A method according to claim 5, wherein the data includes speed information and position information, and the filter parameters include a maximum speed threshold and a satellite count threshold, the method further comprising the step of:

determining whether the maximum speed threshold is exceeded based on the speed information;

determining whether the number of available GPS satellites is below the satellite count threshold; and

declaring the speed information and the position information to be invalid if the maximum speed threshold is exceeded and the number of available GPS satellites is below the satellite count threshold.

7. A method according to claim 5, wherein the data includes position information, and the filter parameter includes a maximum movement threshold and a satellite count threshold, the method further comprising the step of:

determining distance traveled from a prior valid position based on the position information;

determining whether the number of available GPS satellites is below the satellite count threshold; and

declaring the position information to be invalid if the distance traveled exceeds the maximum movement threshold and the number of available GPS satellites is below the satellite count threshold.

8. A method according to claim 7, wherein the filter parameter further includes a maximum invalid count, the method further comprising the steps of:

tracking the number of consecutive invalid position information;

determining whether the number of consecutive invalid position information exceeds the maximum invalid count; and

if the maximum invalid count is exceeded, declaring a prior invalid position information to not be invalid.

9. A method according to claim 1, further comprising the step of:

receiving a configuration request message from a host over a data network, wherein the configuration request message specifies the filter parameter.

28. A method according to claim 1, wherein the filter parameters are selected based on status of a trigger.

10. An apparatus for supporting tracking of a device, the apparatus comprising:

a communication interface configured to receive data corresponding to tracking of the device; and

a processor configured to filter the data for errant information according to one or more filter parameters.

11. An apparatus according to claim 10, wherein the filter parameters are selected based on status of a trigger.

12. An apparatus according to claim 10, wherein the data includes position information and speed information, and the filter parameter includes a distance threshold, the processor being further configured to determine whether a new position of the device is within the distance threshold of a prior unfiltered position of the device based on the position information, wherein if the new position is within the distance threshold, the processor declares the new position to be identical to the prior unfiltered position and sets the speed information to zero.

13. An apparatus according to claim 12, wherein the device is coupled to a vehicle, and the filter parameter includes a second distance threshold, the processor being further configured to determine whether the vehicle is on or off, wherein if the vehicle is off, the data is filtered according to the second distance threshold.

14. An apparatus according to claim 10, wherein the device is tracked using Global Positioning System (GPS) satellites, the device selectively operating in an assisted GPS mode or an autonomous GPS mode.

15. An apparatus according to claim 14, wherein the data includes speed information and position information, and the filter parameters include a maximum speed threshold and a satellite count threshold, the processor being further configured to determine whether the maximum speed threshold is exceeded based on the speed information, and to determine whether the number of available GPS satellites is below the satellite count threshold, the processor declaring the speed information and the position information to be invalid if the maximum speed threshold is exceeded and the number of available GPS satellites is below the satellite count threshold.

16. An apparatus according to claim 14, wherein the data includes position information, and the filter parameter includes a maximum movement threshold and a satellite count threshold, the processor being further configured to determine distance traveled from a prior valid position based on the position information, and to determine whether the number of available GPS satellites is below the satellite count threshold, the processor declaring the position information to be invalid if the distance traveled exceeds the maximum movement threshold and the number of available GPS satellites is below the satellite count threshold.

17. An apparatus according to claim 16, wherein the filter parameter further includes a maximum invalid count, the processor being further configured to track the number of consecutive invalid position information and to determine whether the number of consecutive invalid position information exceeds the maximum invalid count, wherein if the maximum invalid count is exceeded, the processor declares a prior invalid position information to not be invalid.

18. An apparatus according to claim 10, wherein the communication interface is further configured to receive a configuration request message from a host over a data network, and the configuration request message specifies the filter parameter.

19. A method for tracking a device, the method comprising the steps of:

generating a request message specifying one or more filter parameters; and

transmitting the request to a computing system configured to receive data corresponding to tracking of the device,

wherein the computing system is further configured to filter the data for errant information according to the one or more filter parameters.

20. A method according to claim 19, wherein the filter parameters are selected based on status of a trigger.

21. A method according to claim 19, wherein the data includes position information and speed information, and the filter parameter includes a distance threshold, the computing system being further configured to determine whether a new position of the device is within the distance threshold of a prior unfiltered position of the device based on the position information, wherein if the new position is within the distance threshold, the computing system declares the new position to be identical to the prior unfiltered position and sets the speed information to zero.

22. A method according to claim 21, wherein the device is coupled to a vehicle, and the filter parameter includes a second distance threshold, the computing system being further configured to determine whether the vehicle is on or off, wherein if the vehicle is off, the data is filtered according to the second distance threshold.

23. A method according to claim 19, wherein the device is tracked using Global Positioning System (GPS) satellites, the device selectively operating in an assisted GPS mode or an autonomous GPS mode.

24. A method according to claim 23, wherein the data includes speed information and position information, and the filter parameters include a maximum speed threshold and a satellite count threshold, the computing system being further configured to determine whether the maximum speed threshold is exceeded based on the speed information, and to determine whether the number of available GPS satellites is below the satellite count threshold, the computing system declaring the speed information and the position information to be invalid if the maximum speed threshold is exceeded and the number of available GPS satellites is below the satellite count threshold.

25. A method according to claim 23, wherein the data includes position information, and the filter parameter includes a maximum movement threshold and a satellite count threshold, the computing system being further configured to determine distance traveled from a prior valid position based on the position information, and to determine whether the number of available GPS satellites is below the satellite count threshold, the computing system declaring the position information to be invalid if the distance traveled exceeds the maximum movement threshold and the number of available GPS satellites is below the satellite count threshold.

26. A method according to claim 25, wherein the filter parameter further includes a maximum invalid count, the computing system being further configured to track the number of consecutive invalid position information and to determine whether the number of consecutive invalid position information exceeds the maximum invalid count, wherein if the maximum invalid count is exceeded, the computing system declares a prior invalid position information to not be invalid.

27. A method for tracking a device, the method comprising the steps of:

receiving data including Global Positioning System (GPS) information corresponding to tracking of the device coupled to a vehicle; and

filtering the data to account for GPS signal errors according to one of a minimum movement filter, an excessive speed filter or an erroneous position filter,

wherein the minimum movement filter yields non-movement of the vehicle based on a predetermined radial distance threshold,

wherein the excessive speed filter invalidates speed of the vehicle based on the number of GPS satellites used to determine the speed,

wherein the erroneous position filter invalidates position of the vehicle based on a determined distance traveled over time interval or the number of GPS satellites.