FAST GNSS RECEIVER CONVERGENCE BY RELATIVE POSITIONING

• US 20160231430A1
• Filed: 02/11/2015
• Published: 08/11/2016
• Est. Priority Date: 02/11/2015
• Status: Active Grant

• Current Assignee: Trimble Inc.
• Original Assignee: Trimble Navigation Limited (Trimble Inc.)
• Inventors: Wilson, Eric, Seeger, Stephan
• Granted Patent: US 10,234,566 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G01S 19/44 Carrier phase ambiguity resolution; Floating ambiguity; LAMBDA [Least-squares AMBiguity Decorrelation Adjustment] method
• CPC Class Codes: G01S 19/51 Relative positioning

Abstract

A method of implementing fast GNSS convergence by relative positioning is disclosed. A GNSS receiver which is coupled with a mobile machine is shut down. The GNSS receiver is in a converged state at shut down. A movement sensor is monitored to determine if net movement of a GNSS antenna coupled with the mobile machine exceeds a threshold net movement parameter while the GNSS receiver is shut down. Upon power up of the GNSS receiver, a shorter convergence algorithm is initiated in response to determining that the threshold net movement parameter has not been exceeded. The shorter convergence algorithm is also initiated upon power up of the GNSS receiver in response to determining that the threshold net movement parameter has been exceeded but information from the movement sensor has been used to update the location of the GNSS receiver since said shut down.

Claims

1. A method of implementing fast GNSS convergence by relative positioning, said method comprising:

shutting down a GNSS receiver which is coupled with a mobile machine, wherein said GNSS receiver is in a converged state at shut down;

monitoring a movement sensor to determine if net movement of a GNSS antenna coupled with said mobile machine exceeds a threshold net movement parameter while said GNSS receiver is shut down; and

upon power up of said GNSS receiver,

initiating a shorter convergence algorithm in response to determining that said threshold net movement parameter has not been exceeded; and

initiating said shorter convergence algorithm in response to determining that said threshold net movement parameter has been exceeded but information from said movement sensor has been used to update the location of said GNSS receiver since said shut down.

2. The method of claim 1, further comprising:

initiating a longer convergence algorithm in response to determining that said threshold net movement parameter has been exceeded and an estimated new location of said GNSS antenna is not known.

3. The method of claim 1 wherein said mobile machine is equipped with a telematics box and said method further comprises:

monitoring said movement sensor which is disposed outside of said telematics box.

4. The method of claim 1 wherein said mobile machine is equipped with a telematics box and said method further comprises:

monitoring said movement sensor which comprises a component of said telematics box.

5. The method of claim 1 further comprising:

using an image capture device, capturing a first image of an identifiable feature prior to shutting down said GNSS receiver;

using said image capture device, capturing a second image of said identifiable feature upon power up of said GNSS receiver; and

determining a change in the location of said GNSS antenna based upon a photogrammetric analysis of said first image and said second image.

6. The method of claim 5 further comprising:

receiving an indication from said movement sensor that movement of said GNSS antenna has exceeded said threshold net movement parameter; and

initiating said capturing of said second image and said determining said change in the location of said GNSS antenna based upon receiving said indication.

7. The method of claim 5 further comprising:

initiating a longer convergence algorithm in response to determining that said threshold net movement parameter has been exceeded and that said identifiable feature captured in said first image cannot be detected in said second image.

8. A non-transitory computer readable storage medium having computer readable instructions stored thereon for causing a computer system to perform a method of implementing fast GNSS convergence by relative positioning, said method comprising:

shutting down a GNSS receiver which is coupled with a mobile machine, wherein said GNSS receiver is in a converged state at shut down;

monitoring a movement sensor to determine if net movement of a GNSS antenna coupled with said mobile machine exceeds a threshold net movement parameter while said GNSS receiver is shut down; and

upon power up of said GNSS receiver,

initiating a shorter convergence algorithm in response to determining that said threshold net movement parameter has not been exceeded; and

initiating said shorter convergence algorithm in response to determining that said threshold net movement parameter has been exceeded but information from said movement sensor has been used to update the location of said GNSS receiver since said shut down.

9. The non-transitory computer readable storage medium of claim 8, further comprising:

initiating a longer convergence algorithm in response to determining that said threshold net movement parameter has been exceeded and an estimated new location of said GNSS antenna is not known.

10. The non-transitory computer readable storage medium of claim 8 wherein said mobile machine is equipped with a telematics box and said method further comprises:

monitoring said movement sensor which is disposed outside of said telematics box.

11. The non-transitory computer readable storage medium of claim 8 wherein said mobile machine is equipped with a telematics box and said further comprises:

monitoring said movement sensor which comprises a component of said telematics box.

12. The non-transitory computer readable storage medium of claim 8 further comprising:

using an image capture device, capturing a first image of an identifiable feature prior to shutting down said GNSS receiver;

using said image capture device, capturing a second image of said identifiable feature upon power up of said GNSS receiver; and

determining a change in the location of said GNSS antenna based upon a photogrammetric analysis of said first image and said second image.

13. The non-transitory computer readable storage medium of claim 12 further comprising:

receiving an indication from said movement sensor that movement of said GNSS antenna has exceeded said threshold net movement parameter; and

initiating said capturing of said second image and said determining said change in the location of said GNSS antenna based upon receiving said indication.

14. The non-transitory computer readable storage medium of claim 12 further comprising:

initiating a longer convergence algorithm in response to determining that said threshold net movement parameter has been exceeded and that said identifiable feature captured in said first image cannot be detected in said second image.

15. A navigation system comprising:

a Global Navigation Satellite System (GNSS) receiver coupled with a mobile machine;

a movement sensor configured to monitor movement of a GNSS antenna coupled with said mobile machine while said GNSS receiver is shut down; and

a processor configured to cause said GNSS receiver to transition into a shut down state from a converged state and, upon subsequent power up of said GNSS receiver, to monitor said movement sensor to determine if net movement of a GNSS antenna coupled with said mobile machine exceeds a threshold net movement parameter while said GNSS receiver is shut down, to initiate a shorter convergence algorithm upon power up of said GNSS receiver in response to determining that said threshold net movement parameter has not been exceeded, and to initiate said shorter convergence algorithm upon power up of said GNSS receiver in response to determining that said threshold net movement parameter has been exceeded but information from said movement sensor has been used to update the location of said GNSS receiver since said shut down.

16. The navigation system of claim 15, wherein said processor is further configured to:

initiate a longer convergence algorithm in response to determining that said threshold net movement parameter has been exceeded and an estimated new location of said GNSS antenna is not known.

17. The navigation system of claim 15 further comprising:

a telematics box, wherein said movement sensor is disposed outside of said telematics box.

18. The navigation system of claim 15 further comprising:

an image capture device configured to capture a first image of an identifiable feature prior to shutting down said GNSS receiver using said image capture device, to capture a second image of said identifiable feature upon power up of said GNSS receiver, and

wherein said processor is configured to determine a change in the location of said GNSS antenna based upon a photogrammetric analysis of said first image and said second image.

19. The navigation system of claim 18 wherein said processor is further configured to:

receive an indication from said movement sensor that movement of said GNSS antenna has exceeded said threshold net movement parameter; and

to initiate said capturing of said second image and said determining a change in the location of said GNSS antenna based upon receiving said indication.

20. The navigation system of claim 18 wherein said processor is further configured to:

initiate a longer convergence algorithm in response to determining that said threshold net movement parameter has been exceeded and that said identifiable feature captured in said first image cannot be detected in said second image.