TARGET MANEUVER DETECTION

• US 20070295855A1
• Filed: 06/23/2006
• Published: 12/27/2007
• Est. Priority Date: 06/23/2006
• Status: Active Grant

• Current Assignee: Lockheed Martin Corporation (Martin Marietta Corporation)
• Original Assignee: Lockheed Martin Corporation (Martin Marietta Corporation)
• Inventors: Lam, Vincent C., Quam, David L.
• Granted Patent: US 7,755,011 B2
• Time in Patent Office: Days
• US Class Current: 244/3.1
• CPC Class Codes: F41G 7/2253 Passive homing systems, i.e. comprising a receiver and do not requiring an active illumination of the target
• CPC Class Codes: F41G 7/2286 using radio waves
• CPC Class Codes: G01S 13/723 by using numerical data

Abstract

The present invention includes, in its various aspects and embodiments, a method and apparatus for determining whether a moving target is maneuvering. The method comprises determining an expected motion for the target assuming the target is not maneuvering; determining an upper bound and a lower bound for the expected motion; and determining whether the actual motion exceeds at least one of the upper and lower bounds of the expected motion. In one aspect, the apparatus is a program storage medium encoded with instructions that, when executed by a computing apparatus, perform such a method. In another aspect, the apparatus is a computing apparatus programmed to perform such a method.

Claims

1. A method for determining whether a moving target is maneuvering, comprising:

determining an expected motion for the target assuming the target is not maneuvering;

determining an upper bound and a lower bound for the expected motion; and

determining whether the actual motion exceeds at least one of the upper and lower bounds of the expected motion.

2. The method of claim 1, wherein determining the target'"'"'s expected motion includes:

resolving the target'"'"'s acceleration along the velocity frame of the target; and

determining the expected acceleration of the target from aerodynamic drag and gravity.

3. The method of claim 1, wherein determining the upper and lower bounds includes determining the upper and lower bounds for the expected acceleration of the target from aerodynamic drag and gravity.

4. The method of claim 3, wherein determining the upper and lower bounds includes determining the upper and lower bounds from filter measurement uncertainties.

5. The method of claim 3, wherein determining whether the actual motion exceeds at least one of the upper and lower bounds includes determining whether the target'"'"'s actual acceleration exceeds the expected acceleration due to aerodynamic drag and gravity.

6. The method of claim 2, wherein determining whether the actual motion exceeds at least one of the upper and lower bounds includes determining whether the target'"'"'s actual acceleration exceeds the expected acceleration due to aerodynamic drag and gravity.

7. The method of claim 1, wherein determining the target'"'"'s expected motion includes determining the expected flight path angular rates due to gravity.

8. The method of claim 7, wherein determining the upper and lower bounds includes adding and subtracting the filter measurement uncertainties to and from, respectively, the expected flight path angular rates due to gravity.

9. The method of claim 8, wherein determining whether the actual motion exceeds at least one of the upper and lower bounds includes determining whether the actual flight path angular rates exceed the expected flight path angular rates.

10. The method of claim 7, wherein determining whether the actual motion exceeds at least one of the upper and lower bounds includes determining whether the actual flight path angular rates exceed the expected flight path angular rates.

11. The method of claim 1, wherein determining the upper and lower bounds includes combining a plurality of errors.

12. The method of claim 1, wherein determining the upper and lower bounds includes examining the gradient of the expected motion in a North-East-Down frame.

13. The method of claim 12, wherein examining the gradient of the expected motion includes examining the gradient of the target'"'"'s acceleration in the velocity frame.

14. The method of claim 12, wherein examining the gradient of the expected motion includes examining the gradient of the flight path angular rates.

15. The method of claim 1, wherein determining whether the actual motion exceeds at least one of the upper and lower bounds of the expected motion includes a direct numerical comparison.

16. The method of claim 1, further comprising sensing the actual motion of the target over time.

17. The method of claim 1, wherein the target is a ballistic target.

18. A program storage medium encoded with instructions that, when executed by a computing apparatus, perform a method for determining whether a moving target is maneuvering, the method comprising:

determining an expected motion for the target assuming the target is not maneuvering;

determining an upper bound and a lower bound for the expected motion; and

determining whether the actual motion exceeds at least one of the upper and lower bounds of the expected motion.

19. The program storage medium of claim 18, wherein determining the target'"'"'s expected motion in the method includes:

resolving the target'"'"'s acceleration along the velocity frame of the target; and

determining the expected acceleration of the target from aerodynamic drag and gravity.

20. The program storage medium of claim 19, wherein determining the upper and lower bounds in the method includes determining the upper and lower bounds for the expected acceleration of the target from aerodynamic drag and gravity.

21. The program storage medium of claim 18, wherein determining the target'"'"'s expected motion in the method includes determining the expected flight path angular rates due to gravity.

22. The program storage medium of claim 21, wherein determining the upper and lower bounds in the method includes adding and subtracting the filter measurement uncertainties to and from, respectively, the expected flight path angular rates due to gravity.

23. The program storage medium of claim 18, wherein determining the upper and lower bounds in the method includes combining a plurality of errors.

24. The program storage medium of claim 18, wherein determining the upper and lower bounds in the method includes examining the gradient of the expected motion in a North-East-Down frame.

25. A method for determining whether a moving target is maneuvering, comprising:

resolving the target'"'"'s acceleration along the velocity frame of the target assuming the target is not maneuvering;

determining the expected acceleration of the target from aerodynamic drag and gravity;

determining an upper bound and a lower bound for the expected acceleration of the target from aerodynamic drag and gravity of the expected motion; and

determining whether the actual motion exceeds at least one of the upper and lower bounds of the expected motion.

26. The method of claim 25, wherein determining the upper and lower bounds includes determining the upper and lower bounds from filter measurement uncertainties.

27. The method of claim 25, wherein determining the upper and lower bounds includes combining a plurality of errors.

28. The method of claim 25, wherein determining the upper and lower bounds includes examining the gradient of the expected motion in a North-East-Down frame.

29. A method for determining whether a moving target is maneuvering, comprising:

determining the expected flight path angular rates due to gravity assuming the target is not maneuvering;

adding and subtracting the filter measurement uncertainties to and from, respectively, the expected flight path angular rates due to gravity to determine an upper bound and a lower bound for the expected motion; and

determining whether the actual motion exceeds at least one of the upper and lower bounds of the expected motion.

30. The method of claim 29, wherein determining whether the actual motion exceeds at least one of the upper and lower bounds includes determining whether the actual flight path angular rates exceed the expected flight path angular rates.

31. The method of claim 29, wherein determining the upper and lower bounds includes combining a plurality of errors.

32. The method of claim 29, wherein determining the upper and lower bounds includes examining the gradient of the expected motion in a North-East-Down frame.

33. An apparatus, comprising:

a processor;

a bus system;

a storage communicating with the processor over the bus system;

a software application residing on the storage that, when invoked by the processor, performs a method for determining whether a moving target is maneuvering, the method comprising;

determining an expected motion for the target assuming the target is not maneuvering;

determining an upper bound and a lower bound for the expected motion; and

determining whether the actual motion exceeds at least one of the upper and lower bounds of the expected motion.

34. The apparatus of claim 33, wherein determining the target'"'"'s expected motion in the method includes:

resolving the target'"'"'s acceleration along the velocity frame of the target; and

determining the expected acceleration of the target from aerodynamic drag and gravity.

35. The apparatus of claim 34, wherein determining the upper and lower bounds in the method includes determining the upper and lower bounds for the expected acceleration of the target from aerodynamic drag and gravity.

36. The apparatus of claim 33, wherein determining the target'"'"'s expected motion in the method includes determining the expected flight path angular rates due to gravity.

37. The apparatus of claim 36, wherein determining the upper and lower bounds in the method includes adding and subtracting the filter measurement uncertainties to and from, respectively, the expected flight path angular rates due to gravity.

38. The apparatus of claim 33, wherein determining the upper and lower bounds in the method includes combining a plurality of errors.

39. The apparatus of claim 33, wherein determining the upper and lower bounds in the method includes examining the gradient of the expected motion in a North-East-Down frame.

40. The apparatus of claim 33, further comprising a software component residing on the storage that receives command responsive to the determination.

41. The apparatus of claim 40, wherein the software component comprises either a guidance navigation control component or a targeting algorithm.

42. The apparatus of claim 33, further comprising a sensor for generating data on which the software application operates.

43. The apparatus of claim 33, further comprising a flight control mechanism controlled responsive to the determination by the software application.

44. The apparatus of claim 33, further comprising a weapon.

45. The apparatus of claim 44, wherein the weapon comprises a directed energy weapon.