BEAM STEERING ELEMENT FEED FORWARD COMMAND AIDING ARCHITECTURE

• US 20130242123A1
• Filed: 02/26/2013
• Published: 09/19/2013
• Est. Priority Date: 03/14/2012
• Status: Active Grant

• Current Assignee: Raytheon Company (Rtx Corporation)
• Original Assignee: Raytheon Company (Rtx Corporation)
• Inventors: NORMAN, Walter W., NORMAN, David E., Kluver, David A. Sr.
• Granted Patent: US 8,994,836 B2
• Time in Patent Office: Days
• US Class Current: 348/208.14
• CPC Class Codes: G02B 27/644 compensating for large deviations, e.g. maintaining a fixed line of sight while a vehicle on which the system is mounted changes course
• CPC Class Codes: H04N 23/68 for stable pick-up of the scene, e.g. compensating for camera body vibrations
• CPC Class Codes: H04N 23/6812 based on additional sensors, e.g. acceleration sensors
• CPC Class Codes: H04N 23/684 performed by controlling the image sensor readout, e.g. by controlling the integration time
• CPC Class Codes: H04N 23/685 performed by mechanical compensation

Abstract

A feed forward command aiding architecture with corresponding method, system, and computer product are provided. The feed forward command aiding architecture includes generating angle and rate commands from a received inertial data input. The angle command is feed into a proper order position loop producing an intermediate result. An angle feedback is differentiated producing a rate loop feedback. The intermediate result, rate command, and rate loop feedback are then feed into a proper order rate loop producing a torque command. The proper order rate loop is nested inside of the proper order position loop. The torque command being generated moves a beam steering element of an electro-optic sensor to deflect a line of sight of the electro-optic sensor by an angle approximating the received inertial angular input.

Claims

1. A feed forward command aiding architecture method, the method comprising:

generating angle and rate commands from a received inertial data input;

feeding the angle command into a proper order position loop producing an intermediate result;

differentiating an angle feedback producing a rate loop feedback; and

feeding the intermediate result, rate command, and rate loop feedback into a proper order rate loop producing a torque command, the proper order rate loop nested inside of the proper order position loop, the torque command being generated moves a beam steering element of an electro-optic sensor to deflect a line of sight of the electro-optic sensor by an angle approximating the received inertial angular input.

2. The method of claim 1 wherein the received inertial data input is inertial angular input, and generating the angle and rate commands includes differentiating the inertial angular input producing a rate, the rate command being generated based on the produced rate.

3. The method of claim 1 wherein the received inertial data input is inertial rate input, and generating the angle and rate commands includes integrating the inertial rate input producing an angle, the angle command being generated based on the produced angle.

4. The method of claim 1 wherein feeding the angle command includes differencing the angle command with the angle feedback producing an error signal;

and processing the error signal thru the proper order position loop controller to produce the intermediate result.

5. The method of claim 1 wherein feeding the intermediate result, rate command, and rate loop feedback into the proper order rate loop includes combining rate command and rate loop feedback producing a rate error signal, the torque command being produced based on the produced rate error signal, and processing the rate error signal thru the proper order rate loop controller to produce the torque command.

6. The method of claim 1 wherein the proper order position loop and proper order rate loop are proportional plus integral control loops, proportional plus derivative, proportional integral and derivative control loops or combinations thereof.

7. The method of claim 1 wherein the beam steering element is any one of reflective design or refractive design.

8. The system of claim 7 wherein the beam steering element of reflective design includes a two-axis fast steering mirror.

9. The system of claim 7 wherein the beam steering element of refractive design includes a Risley prism.

10. The method of claim 1 further comprising generating an angle feedback based on an angle measured directly using an eddy current sensor, linear variable differential transformer or optical encoder;

and

differentiating the measured angle producing a rate feedback.

11. The method of claim 1 further comprising moving the beam steering element based on the torque command.

12. A feed forward command aiding architecture system, the system comprising:

a generation module configured to generate angle and rate commands from a received inertial data input;

a position loop module communicatively coupled to the generation module configured to feed the angle command into a proper order position loop producing an intermediate result;

a differentiation module configured to differentiate an angle feedback producing a rate loop feedback; and

a rate loop module communicatively coupled to the position loop module and differentiation module configured to feed the intermediate result, rate command, and rate loop feedback into a proper order rate loop producing a torque command, the proper order rate loop nested inside of the proper order position loop, the torque command being generated moves a beam steering element of an electro-optic sensor to deflect a line of sight of the electro-optic sensor by an angle approximating the received inertial angular input.

13. The system of claim 12 wherein the received inertial data input is inertial angular input, and the generation module configured to differentiate the inertial angular input producing a rate, the rate command being generated based on the produced rate.

14. The system of claim 12 wherein the received inertial data input is inertial rate input, and the generation module configured to integrate the inertial rate input producing an angle, the angle command being generated based on the produced angle.

15. The system of claim 12 wherein the position loop module is further configured to difference the angle command with the angle feedback producing an error signal.

16. The system of claim 12 wherein the rate loop module is further configured to combine rate commands and rate loop feedback producing a rate error signal, the torque command being produced based on the produced rate error signal.

17. The system of claim 12 wherein the proper order position loop and proper order rate loop are proportional plus integral control loops, proportional plus derivative, proportional integral and derivative control loops or combinations thereof.

18. The system of claim 12 wherein the beam steering element is any one of reflective design or refractive design.

19. The system of claim 18 wherein the beam steering element of reflective design includes a two-axis fast steering mirror.

20. The system of claim 18 wherein the beam steering element of refractive design includes a Risley prism.

21. The system of claim 12 further comprising an eddy current sensor, linear variable differential transformer or optical encoder measuring an angle, directly;

and the differentiation module further configured to differentiate the measured angle producing a rate feedback.

22. The system of claim 12 further comprising an actuator moving the beam steering element based on the torque command.

23. A computer program product, tangibly embodied in an information carrier, the computer program product including instructions being operable to cause a data processing apparatus to:

generate angle and rate commands from a received inertial data input;

feed the angle command into a proper order position loop producing an intermediate result;

differentiate an angle feedback producing a rate loop feedback;

feed the intermediate result, rate command, and rate loop feedback into a proper order rate loop producing a torque command, the proper order rate loop nested inside of the proper order position loop, the torque command being generated moves a beam steering element of an electro-optic sensor to deflect a line of sight of the electro-optic sensor by an angle approximating the received inertial angular input.