Dynamic motion control

• US 20090292495A1
• Filed: 05/20/2008
• Published: 11/26/2009
• Est. Priority Date: 05/20/2008
• Status: Active Grant

• Current Assignee: Airmar Technology Corporation (Amphenol Corporation)
• Original Assignee: Airmar Technology Corporation (Amphenol Corporation)
• Inventors: Navarro, Alfonso R. JR., Boericke, Frederic S. II, Boucher, Stephen G., Rolt, Kenneth D., Tancrell, Roger H.
• Granted Patent: US 8,326,561 B2
• Time in Patent Office: Days
• US Class Current: 702/92
• CPC Class Codes: G01C 19/42 for indicating rate of turn; for integrating rate of turn
• CPC Class Codes: G01C 21/1654 with electromagnetic compass
• CPC Class Codes: G01C 21/203 Specially adapted for sailing ships

Abstract

In one embodiment a method and corresponding apparatus are arranged to determine an accurate device heading by continuously combining an average magnetic heading with the compensated inertial heading. The example embodiment obtains the compensated inertial heading by compensating for a time delay of an inertial heading.

Claims

1. A method comprising:

compensating a time delay of an inertial heading;

determining an accurate device heading as a function of continuously combining an average magnetic heading with the compensated inertial heading.

2. The method of claim 1 including determining the average magnetic heading as a function of translating a magnetic heading from a device frame of reference to earth'"'"'s frame of reference.

3. The method of claim 2 wherein determining the average magnetic heading includes correcting the magnetic heading to remove artifacts.

4. The method of claim 3 wherein correcting the magnetic heading includes applying at least one low-pass filter to the magnetic heading to remove the artifacts.

5. The method of claim 2 wherein determining the average magnetic heading includes correcting orientation measurements of the device frame of reference to remove short term dynamic accelerations.

6. The method of claim 5 wherein correcting orientation measurements includes applying at least one low-pass filter to the orientation measurements of the device frame of reference to remove the short term dynamic accelerations.

7. The method of claim 1 wherein compensating the time delay of the inertial heading includes correcting orientation corruptions in the inertial heading.

8. The method of claim 7 wherein correcting orientation corruptions in the inertial heading includes applying at least one low-pass filter to the orientation corruptions in the inertial heading.

9. The method of claim 8 including adjusting the at least one low-pass filter by long term measurements from the inertial heading.

10. The method of claim 1 wherein compensating the time delay of the inertial heading includes filtering long term drift from measurements of the inertial heading.

11. A method comprising continuously combining an inertial heading and an average magnetic heading to provide accurate device heading.

12. The method of claim 11 including correcting orientation corruptions in the inertial heading.

13. The method of claim 12 wherein correcting the orientation corruptions in the inertial heading includes applying at least one low-pass filter to the orientation corruptions.

14. The method of claim 13 including adjusting the at least one low-pass filter by long term measurements from the inertial heading.

15. The method of claim 13 including adjusting the at least one low-pass filter by long term measurements from the magnetic heading.

16. The method of claim 11 including determining the average magnetic heading as a function of translating a magnetic heading from a device frame of reference to earth'"'"'s frame of reference.

17. The method of claim 16 wherein determining the average magnetic heading includes correcting the magnetic heading to remove artifacts.

18. The method of claim 17 wherein correcting the magnetic heading includes applying at least one low-pass filter to the magnetic heading to remove artifacts.

19. The method of claim 16 wherein determining the average magnetic heading includes correcting orientation measurements of the device frame of reference to remove short term dynamic accelerations.

20. The method of claim 19 wherein correcting orientation measurements includes applying at least one low-pass filter to the orientation measurements of the device frame of reference to remove the short term dynamic accelerations.

21. An apparatus comprising:

a compensation module to compensate a time delay of an inertial heading;

a determination module to determine an accurate device heading as a function of continuously combining an average magnetic heading with the compensated inertial heading.

22. The apparatus of claim 21 including a second determination module arranged to translate a magnetic heading from a device frame of reference to earth'"'"'s frame of reference to determine the average magnetic heading.

23. The apparatus of claim 22 wherein the second determination module is arranged to determine the average magnetic heading as a function of correcting the magnetic heading to remove artifacts.

24. The apparatus of claim 23 wherein the second determination module is arranged to correct the magnetic heading as a function of applying at least one low-pass filter to the magnetic heading to remove artifacts.

25. The apparatus of claim 22 wherein the second determination module is arranged to determine the average magnetic heading as a function of correcting orientation measurements of the device frame of reference to remove short term dynamic accelerations.

26. The apparatus of claim 25 wherein the second determination module is arranged to correct orientation measurements as a function of applying at least one low-pass filter to the orientation measurements of the device frame of reference to remove the short term dynamic accelerations.

27. The apparatus of claim 21 wherein the compensation module is arranged to compensate the time delay of the inertial heading as a function of correcting orientation corruptions in the inertial heading.

28. The apparatus of claim 27 wherein the compensation module is arranged to correct orientation corruptions in the inertial heading as a function of applying at least one low-pass filter to the orientation corruptions in the inertial heading.

29. The apparatus of claim 28 wherein the compensation module is arranged to adjust the at least one low-pass filter by long term measurements from the inertial heading.

30. The apparatus of claim 21 wherein the compensation module is arranged to compensate the time delay of the inertial heading as a function of filtering long term drift from measurements of the inertial heading.

31. An apparatus comprising:

a combination module to continuously combine inertial heading and average magnetic heading to provide accurate device heading;

a reporting module to report the provided accurate device heading.

32. The apparatus of claim 31 including a correction module to correct orientation corruptions in the inertial heading.

33. The apparatus of claim 32 wherein the correction module is arranged to correct the orientation corruptions in the inertial heading as a function of applying at least one low-pass filter to the orientation corruptions.

34. The apparatus of claim 33 including an adjustment module arranged to adjusting the at least one low-pass filter by long term measurements from the inertial heading.

35. The apparatus of claim 33 including an adjustment module arranged to adjusting the at least one low-pass filter by long term measurements from the magnetic heading.

36. The apparatus of claim 31 including a determination module arranged to translate a magnetic heading from a device frame of reference to earth'"'"'s frame of reference to determine the average magnetic heading.

37. The apparatus of claim 36 wherein the determination module is arranged to determine the average magnetic heading as a function of correcting the magnetic heading to remove artifacts.

38. The apparatus of claim 37 wherein the determination module is arranged to correct the magnetic heading as a function of applying at least one low-pass filter to the magnetic heading to remove artifacts.

39. The apparatus of claim 36 wherein the determination module is arranged to determine the average magnetic heading as a function of correcting orientation measurements of the device frame of reference to remove short term dynamic accelerations.

40. The apparatus of claim 39 wherein the determination module is arranged to correct orientation measurements as a function of applying at least one low-pass filter to the orientation measurements of the device frame of reference to remove the short term dynamic accelerations.

41. A computer program product comprising a computer readable medium having computer readable code stored thereon, which, when executed by a processor, causes the processor to:

compensate a time delay of an inertial heading;

determine an accurate device heading as a function of continuously combining an average magnetic heading with the compensated inertial heading.