System and method for triggering an explosive device

• US 20060087472A1
• Filed: 10/22/2004
• Published: 04/27/2006
• Est. Priority Date: 10/22/2004
• Status: Active Grant

• Current Assignee: Cedar Ridge Research LLC
• Original Assignee: Time Domain Corporation (Humatics Corporation)
• Inventors: Richards, James L., Fullerton, Larry W., Fluhler, Herbert U., Fitzpatrick, Douglas D., Troutman, Dennis L.
• Granted Patent: US 7,417,582 B2
• Time in Patent Office: Days
• US Class Current: 342/68
• CPC Class Codes: F42C 11/008 Power generation in electric fuzes F42C11/02, F42C11/04 and F42C15/295 take precedence
• CPC Class Codes: F42C 13/042 based on distance determination by coded radar techniques
• CPC Class Codes: G01S 13/0209 Systems with very large relative bandwidth, i.e. larger than 10 %, e.g. baseband, pulse, carrier-free, ultrawideband

Abstract

A proximity fuze (proximity fuse) comprising an ultra wideband (UWB) radar transmitter, a UWB radar receiver, an antenna, a timing system, and a signal processor. One embodiment includes an antenna with an annular conical radiation pattern. In another embodiment, a trigger delay is produced that is related to target detection range. In a further embodiment, multiple range shells are utilized to further discriminate target characteristics including velocity. A method is disclosed that utilizes target range, velocity, signal amplitude, and radar signal phase to identify the target and trigger the detonation. A proximity fuze system having a long storage life is disclosed comprising a proximity fuze element powered by a turbine generator and internal gas source.

Claims

1. A proximity fuze for triggering a warhead comprising:

a UWB radar transmitter for transmitting a UWB radar signal;

a UWB radar receiver for receiving a return signal;

an antenna coupled to said UWB radar transmitter and said UWB radar receiver;

a timing system coupled to said UWB radar transmitter and said UWB radar receiver, wherein said timing system provides timing signals to said transmitter and said receiver;

a signal processor coupled to said UWB radar receiver;

a logic unit coupled to said signal processor for generating a trigger signal to trigger said warhead.

2. The proximity fuze of claim 1 wherein said timing system includes a sampling delay between said transmitter timing signals and said receiver timing signals, said sampling delay for receiving reflected signals in accordance with a predetermined range shell.

3. The proximity fuze of claim 2 wherein said trigger signal is generated upon detecting a return at a predetermined distance.

4. The proximity fuze of claim 2 wherein said range shell is at a distance between 1 and 30 meters.

5. The proximity fuze of claim 2 wherein said range shell is at a distance less than 1 meter.

6. The proximity fuze of claim 2 further including additional receivers coupled through additional respective sampling delays;

said additional receivers for receiving said return signal at said additional sampling delays wherein said logic unit is responsive to said additional receivers for generating a trigger signal responsive to additional range shells.

7. The proximity fuze of claim 6 wherein said logic unit provides a processing delay after reaching a threshold associated with at least one range shell before further logic processing.

8. The proximity fuze of claim 1 further including a modulation source for modulating said transmitter signal.

9. The proximity fuze of claim 8 wherein said transmitter signal is time modulated.

10. The proximity fuze of claim 8 wherein said transmitter signal is frequency modulated.

11. The proximity fuze of claim 8 wherein said transmitter signal is polarity modulated.

12. The proximity fuze of claim 8 wherein said modulation is a pseudorandom code.

13. The proximity fuze of claim 8 wherein said modulation is a maximal length PN sequence.

14. The proximity fuze of claim 8 wherein said modulation deviates less than ¼

cycle of the center frequency of said UWB signal during the time interval between said transmitter timing signal and said receiver timing signal.

15. The proximity fuze of claim 1 wherein said signal processor further includes at least one pass band filter for processing the receiver output signal and said trigger signal is responsive to said pass band filter.

16. The proximity fuze of claim 15 wherein said signal processor includes a threshold comparator coupled to the output of said pass band filter and wherein said warhead is triggered when the output of said pass band filter exceeds a predefined threshold.

17. The proximity fuze of claim 1 wherein said signal processor includes Fourier Transform Processing.

18. The proximity fuze of claim 1 wherein said signal processor includes pattern matching.

19. The proximity fuze of claim 18 wherein said pattern matching includes a correlation process.

20. The proximity fuze of claim 19 wherein said signal processor combines amplitude information and correlation information to generate said trigger signal.

21. The proximity fuze of claim 18 wherein said pattern matching process compares said return signal with a plurality of patterns.

22. The proximity fuze of claim 21 wherein said plurality of patterns comprises pattern scaled over a range of time scales related to a range of closing velocities.

23. The proximity fuze of claim 1 wherein said trigger signal is responsive to said target in accordance with aliased range shells.

24. The proximity fuze of claim 1 further including a summing process to sum said receiver output signals, said summing process generating a sum signal.

25. The proximity fuze of claim 24 wherein said code reduces the response of said sum signal to objects in said aliased range shell.

26. The proximity fuze of claim 1 wherein said signal processor comprises at least two channels and wherein said transmitter is polarity modulated by a code and each of said channels is polarity demodulated with a shifted copy of said code in accordance with a respective range response shell.

27. The proximity fuze of claim 26 wherein said code is one of the group consisting of a maximal length PN sequence, a Kassami code, a Barker code, and a Gold code.

28. A proximity fuze for triggering a warhead comprising:

a UWB radar transmitter for transmitting a UWB radar signal;

a first UWB radar receiver for receiving a return signal in accordance with a sampling signal;

a second UWB radar receiver for receiving said return signal in accordance with a delayed sampling signal wherein said delay is substantially ¼

cycle of the center frequency of said UWB signal;

a vector processing unit for determining an angle in accordance with the outputs of said first receiver and said second receiver;

a logic unit coupled to said signal processor for generating a trigger signal to trigger said warhead in response to said angle.

29. The proximity fuze of claim 28 further including an amplitude processor for determining an amplitude of the combination of the outputs of said first receiver and said second receiver, wherein said trigger signal is responsive to both said angle and said amplitude.

30. The proximity fuze of claim 28 further including a filter wherein said filter has a bandwidth wider than that of said return signal, and said sampling signal is unidirectional.

31. The proximity fuze of claim 28 wherein said sampling signal comprises a matched template.

32. The proximity fuze of claim 28 wherein said receiver includes a matched filter.

33. The proximity fuze of claim 28 wherein said antenna is a planar horn.

34. The proximity fuze of claim 28 wherein said planar horn includes one of the group consisting of Vivaldi taper, Heden taper, and exponential taper.

35. The proximity fuze of claim 28 wherein said antenna is circularly polarized.

36. The proximity fuze of claim 35 wherein said antenna comprises a pair of crossed planar horn antennas.

37. The proximity fuze of claim 35 wherein said antenna comprises an antenna array comprising a first antenna element and a second antenna element;

said antenna array fed by a hybrid coupler;

said hybrid coupler having an input port, an isolated port, a zero degree port and a ninety degree port, wherein said transmitter is coupled to said input port, said receiver is coupled to said isolated port and first antenna element is coupled to said zero degree port and said second antenna element is coupled to said ninety degree port.

38. The proximity fuze of claim 28 wherein said antenna has an annular conic coverage pattern.

39. The proximity fuze of claim 28 wherein said antenna is a modified biconnical antenna.

40. The proximity fuze of claim 28 wherein said antenna is a conformal elliptical dipole.

41. The proximity fuze of claim 28 wherein said antenna is an array of conformal elliptical dipoles.

42. A proximity fuze for triggering a warhead comprising:

a UWB radar transmitter for transmitting a UWB radar signal;

a UWB radar receiver for receiving a return signal;

an antenna coupled to said UWB radar transmitter and said UWB radar receiver;

a signal processor coupled to said UWB radar receiver to determine distance;

a logic unit coupled to said signal processor for generating a trigger signal to trigger said warhead.

43. The proximity fuze of claim 42 wherein said trigger signal is generated after a predetermined fuzing delay after detecting a return signal at a predetermined distance.

44. The proximity fuze of claim 42 wherein said trigger signal is generated after a fuzing delay, said fuzing delay generated in accordance with the detection of a return signal within a range of distances.

45. The proximity fuze of claim 44 wherein said fuzing delay is proportional to said distance.

46. Method for supplying electrical power to a projectile comprising:

providing a turbine generator;

providing a high pressure gas source;

providing a valve between said gas source and said turbine generator;

wherein said valve is opened upon firing of said projectile.

47. The method of claim 46 wherein said gas source includes a continuous hermetic seal and opening said valve includes breaking said hermetic seal.

48. The method of claim 46 wherein said high pressure gas source comprises tubing warmed by a projectile component.

49. The method of claim 48 wherein said projectile includes a nose, wherein said projectile component is said nose of said projectile.

50. A method for supplying electrical power to a projectile comprising:

providing a turbine generator;

providing a pyrotechnic high pressure warm gas generator for supplying high pressure gas to said turbine generator;

wherein said pyrotechnic warm gas generator is fired upon launch of said projectile to initiate flow of high pressure gas.

51. (canceled)

52. (canceled)

53. (canceled)