Moving object command link system and method

• US 9,739,571 B2
• Filed: 01/06/2015
• Issued: 08/22/2017
• Est. Priority Date: 01/06/2015
• Status: Active Grant

• Current Assignee: Teledyne Scientific & Imaging, LLC (Teledyne Technologies Incorporated)
• Original Assignee: Teledyne Scientific & Imaging, LLC (Teledyne Technologies Incorporated)
• Inventors: Winker, Bruce, Mahajan, Milind, Taber, Don, Gregory, Brian, Mansell, John
• Primary Examiner(s): GREGORY, BERNARR E
• Application Number:
  US14/590,627
• Publication Number:
  US 20160195365A1
• Time in Patent Office: 959 Days
• Field of Search: 342 62
• CPC Class Codes: F41G 7/001 Devices or systems for testing or checking
• CPC Class Codes: F41G 7/306 for transmitting guidance signals; F41G7/308 takes precedence
• CPC Class Codes: F41G 7/308 for guiding a plurality of missiles

Abstract

A moving object command link system includes a transmitter which outputs a EM beam and a steering mechanism which directs the beam toward one or more objects, at least one of which is moving. The system may include a variable attenuator which modulates the average output power of the beam, and/or a divergence controller to maintain a desired beam size. The beam may be polarized, and the system may include a polarization modulator which changes the beam'"'"'s polarization in accordance with a predetermined sequence and schedule. The system may include a 1×2 switch to selectively provide the beam to one of first and second outputs. A tiltable dichroic beam splitter may be used to couple beams received from first and second objects to track cameras having respective boresights that are offset with respect to each other.

Claims

1. A system for creating a command link between a transmitter and one or more objects, at least one of which is moving, comprising:

at least one moving object which is capable of receiving commands via a free space link;

a source which outputs a beam of electromagnetic radiation;

a steering mechanism arranged to direct said electromagnetic beam toward one or more of said objects;

a variable attenuator arranged to modulate the average output power of said beam to control the amplitude of the beam at said one or more objects; and

a divergence controller arranged to maintain a desired beam size at said at least one moving object when said beam is directed on said object.

2. The system of claim 1, wherein said beam of electromagnetic radiation is a pulsed laser beam.

3. The system of claim 2, wherein said pulsed laser beam is generated by a source arranged to encode guidance commands into said beam, said at least one moving object arranged to detect and decode said pulses and thereby detect said guidance commands.

4. The system of claim 1, wherein said beam is coupled to said variable attenuator via free space or optical fiber.

5. The system of claim 1, wherein said divergence controller is arranged to maintain a beam of approximately fixed size at said at least one moving object.

6. The system of claim 1, wherein said divergence controller is arranged to provide a beam at said at least one moving object which has a size that varies with distance.

7. The system of claim 1, wherein said divergence controller comprises first and second lenses, at least one of said lenses capable of being translated linearly with respect to the other.

8. The system of claim 1, further comprising a receiver on said at least one moving object, said receiver arranged to detect said beam when said beam is directed toward said receiver.

9. The system of claim 1, wherein said beam is linearly polarized, said polarization being a base polarization.

10. The system of claim 1, further comprising at least one steering mirror arranged to direct said beam of electromagnetic radiation toward one or more of said objects as desired.

11. The system of claim 1, wherein at least one of said moving objects is put into motion at a time t=0 with a launching device, further comprising a means of detecting time t=0.

12. The system of claim 11, wherein said means of detecting time t=0 comprises an accelerometer mounted on said launching device.

13. The system of claim 11, wherein said means of detecting time t=0 comprises a microphone.

14. The system of claim 11, wherein said launching device is a firearm, and said means of detecting time t=0 comprises an optical muzzle flash detector.

15. A system for creating a command link between a transmitter and one or more objects, at least one of which is moving, comprising:

at least one moving object which is capable of receiving commands via a free space link;

a source which outputs a beam of electromagnetic radiation;

a steering mechanism arranged to direct said electromagnetic beam toward one or more of said objects; and

a divergence controller arranged to maintain a desired beam size at said at least one moving object when said beam is directed on said object;

wherein said divergence controller is arranged to provide a beam at said at least one moving object which has a size that varies with time.

16. The system of claim 15, wherein said divergence controller includes a storage means into which a divergence profile is loaded which represents a desired beam size over time, said divergence controller operated in response to said divergence profile to control the divergence of said pulsed laser beam over time.

17. A system for creating a command link between a transmitter and one or more objects, at least one of which is moving, comprising:

at least one moving object which is capable of receiving commands via a free space link;

a source which outputs a beam of electromagnetic radiation;

a steering mechanism arranged to direct said electromagnetic beam toward one or more of said objects; and

a receiver on said at least one moving object, said receiver arranged to detect said beam when said beam is directed toward said receiver; and

a variable attenuator arranged to modulate the average output power of said beam, wherein said receiver has an associated noise floor and saturation level, said variable attenuator arranged to modulate the output power of said beam such that the signal received by said receiver is above said receiver'"'"'s noise floor and below said receiver'"'"'s saturation level.

18. The system of claim 17,

wherein said beam of electromagnetic radiation is a pulsed laser beam and said variable attenuator is a variable optical attenuator (VOA), further comprising:

a detector, an array of detectors, and/or a camera arranged to receive light reflected from said at least one moving object;

said VOA arranged to modulate the average output power of said pulsed laser beam based on the brightness of said reflected light.

19. A system for creating a command link between a transmitter and one or more objects, at least one of which is moving, comprising:

at least one moving object which is capable of receiving commands via a free space link;

a source which outputs a beam of electromagnetic radiation, wherein said beam is linearly polarized, said polarization being a base polarization;

a steering mechanism arranged to direct said electromagnetic beam toward one or more of said objects; and

a polarization modulator which operates to change the polarization of said beam directed toward said at least one moving object in accordance with a predetermined sequence and schedule.

20. The system of claim 19, further comprising a receiver on said at least one moving object, said receiver arranged to detect said beam when said beam is directed toward said receiver, said receiver arranged to process said detected beam in accordance with said predetermined sequence and schedule and to thereby detect said base polarization.

21. The system of claim 19, wherein said source is arranged to encode the polarization state of said beam in said beam.

22. A system for creating a command link between a transmitter and one or more objects, at least one of which is moving, comprising:

at least one moving object which is capable of receiving commands via a free space link;

a source which outputs a beam of electromagnetic radiation;

a steering mechanism arranged to direct said electromagnetic beam toward one or more of said objects; and

at least one steering mirror arranged to direct said beam of electromagnetic radiation toward one or more of said objects as desired;

wherein said at least one steering mirror is directed by means of a voice coil which is actuated in response to a control voltage.

23. The system of claim 22, wherein said one or more objects comprise a first object and a second object, said system arranged to provide control voltages to said voice coil as needed to direct said beam of electromagnetic radiation toward said first and second objects as desired.

24. A system for creating a command link between a transmitter and one or more objects, at least one of which is moving, comprising:

at least one moving object which is capable of receiving commands via a free space link;

a source which outputs a beam of electromagnetic radiation, wherein said beam of electromagnetic radiation is a pulsed laser beam;

a steering mechanism arranged to direct said pulsed laser beam toward one or more of said objects; and

a variable optical attenuator (VOA) arranged to modulate the average output power of said pulsed laser beam;

wherein said one or more objects comprise a first object and a second object, at least one of which is a moving object, further comprising;

a collimator coupled to the output of said VOA;

a 1×

2 switch coupled to the output of said collimator at an input and which selectively provides said collimator output to one of first and second outputs;

a first object tracking mirror coupled to receive said first output of said 1×

2 switch and to direct said output toward said first object;

a second object tracking mirror coupled to receive said second output of said 1×

2 switch and to direct said output toward said second object.

25. The system of claim 24, wherein both of said first and second objects are moving, said first object being a guided object.

26. The system of claim 24, wherein the locations of said first and second objects are monitored, said system including first and second closed loops arranged to control said first and second object tracking mirrors such that the directing of said 1×

2 switch outputs toward said first and second objects is maintained over time.

27. The system of claim 24, further comprising a divergence controller coupled to the output of said first object tracking mirror, said divergence controller arranged to maintain a beam of approximately fixed size at one of said at least one moving objects.

28. The system of claim 27, wherein said pulsed laser beam is linearly polarized, said polarization being a base polarization, further comprising a polarization modulator coupled to the output of said divergence controller and which operates to change the polarization of said divergence controller output in accordance with a predetermined sequence and schedule.

29. The system of claim 27, wherein said pulsed laser beam is linearly polarized, said polarization being a base polarization, further comprising a polarization modulator interposed between the output of said first object tracking mirror and said divergence controller and which operates to change the polarization of said divergence controller output in accordance with a predetermined sequence and schedule.

30. A system for creating a command link between a transmitter and one or more objects, at least one of which is moving, comprising:

at least one moving object which is capable of receiving commands via a free space link;

a source which outputs a beam of electromagnetic radiation, wherein said beam of electromagnetic radiation is a pulsed laser beam; and

a steering mechanism arranged to direct said pulsed laser beam toward one or more of said objects;

wherein said at least one moving object comprises a retroreflector arranged to reflect said pulsed laser beam, said system further comprising a detector, an array of detectors, and/or a camera arranged to receive said reflected beam.

31. A system for creating a command link between a transmitter and one or more objects, at least one of which is moving, comprising:

at least one moving object which is capable of receiving commands via a free space link;

a source which outputs a beam of electromagnetic radiation, wherein said beam of electromagnetic radiation is a pulsed laser beam; and

a steering mechanism arranged to direct said pulsed laser beam toward one or more of said objects;

wherein said one or more objects comprise a first object and a second object, said first object being a guided object, further comprising;

a first object track camera for tracking said first object;

a second object track camera for tracking said second object, said track cameras having respective boresights that are offset with respect to each other; and

a dichroic beam splitter, said system arranged such that respective beams sent or reflected from said first object and said second object are directed to said dichroic beam splitter, said dichroic beam splitter arranged to couple said first object beam and said second object beam to said first object track camera and said second object track camera, respectively.

32. The system of claim 31, further comprising a first steerable mirror arranged to reflect said first and second object beams to said dichroic beam splitter.

33. The system of claim 32, further comprising a wide field-of-view (FOV) camera arranged to image said first and second objects, said system arranged such that the position of said steerable mirror is at least in part controlled by said wide FOV camera.

34. The system of claim 32, wherein said wide FOV camera has a FOV that is greater than 6 degrees and said first and second object track cameras have FOVs that are less than 6 degrees.

35. The system of claim 31, wherein said dichroic beam splitter is tiltable, said system arranged to adjust said tilt as needed to accommodate an angular offset between said first object beam and said second object beam.

36. The system of claim 35, said dichroic beam splitter arranged to transmit incoming light that is within a first spectral band to said first object track camera and to reflect incoming light that is within a second spectral band to said second object track camera.

37. The system of claim 36, wherein said source is arranged to output a laser beam having first and second wavelengths that are within said first and second spectral bands, respectively.

38. The system of claim 37, further comprising a steerable mirror arranged to reflect the output of said source.

39. The system of claim 38, wherein said second steerable mirror is steered via control voltages Vx and Vy;

wherein said first object track camera is arranged to report the x,y pixel location of said received beam having said first wavelength (Px1, Py1), and said second object track camera is arranged to report the x,y pixel location of said received beam having said second wavelength (Px2, Py2);

said system arranged to provide multiple values of Vx, Vy so as to obtain multiple Px1, Py1 and Px2, Py2 values;

further comprising a means of generating two sets of functional fits that correlate Vx and Vy to said multiple Px1, Py1 values and to said multiple Px2, Py2 values.

40. The system of claim 38, wherein said transmitter, said steerable mirrors, said dichroic beam splitter and said first and second object track cameras are mounted to a platform, further comprising an angular motion sensor mounted on said platform which provides an output that varies with the angular tip and tilt of said platform, said system arranged to provide compensating control signals to said first and second steerable mirrors based on said angular motion sensor output to compensate for said angular tip and tilt.

41. The system of claim 31, further comprising:

a range finding detector; and

a beam splitter interposed between said dichroic beam splitter and said second object track camera and arranged to couple said first object beam received from said dichroic beam splitter to said first object track camera and to said range finding detector.

42. The system of claim 31, wherein said first and second object track cameras are narrow field-of-view (FOV) cameras.

43. A method of calibrating a system, said system arranged to create a command link between a transmitter and one or more objects, at least one of said one or more objects is moving, and which includes a source that outputs a beam of electromagnetic (EM) radiation, a steering mechanism which directs said EM beam toward one or more of said objects in response to one or more control signals, a track camera having an associated field of view (FOV), and a spot tracker capable of providing the location of a beam within said FOV, said method comprising:

providing control signals to said steering mechanism such that said EM beam is directed at a first discrete location within said track camera'"'"'s FOV;

using said spot tracker to provide the location of said beam;

providing control signals to said steering mechanism such that said EM beam is directed at one or more additional discrete locations within said track camera'"'"'s FOV;

using said spot tracker to provide the locations of said beam after each set of control signals is provided to said steering mechanism; and

using a functional fit over said FOV to derive a function which relates the control signals provided to said steering mechanism with the beam locations provided by said spot tracker.

44. The method of claim 43, further comprising correcting said derived function for parallax errors.