SYSTEM AND METHOD FOR DIVERT AND ATTITUDE CONTROL IN FLIGHT VEHICLES

• US 20110082604A1
• Filed: 10/01/2009
• Published: 04/07/2011
• Est. Priority Date: 10/01/2009
• Status: Active Grant

• Current Assignee: Raytheon Company (Rtx Corporation)
• Original Assignee: Raytheon Company (Rtx Corporation)
• Inventors: Lam, Frank C.
• Granted Patent: US 8,306,674 B2
• Time in Patent Office: Days
• US Class Current: 701/4
• CPC Class Codes: B64G 1/26 using jets
• CPC Class Codes: F42B 10/66 Steering by varying intensity or direction of thrust thrust vector control of rocket engine plants F02K9/80 ; guiding or controlling apparatus using jets adapted for cosmonautic vehicles B64G1/26
• CPC Class Codes: F42B 15/01 Arrangements thereon for guidance or control steering arrangements F42B10/60; aircraft flight control B64C; guidance systems other than those installed aboard F41G7/00, F41G9/00; locating by use of radio or other waves G01S; flight control in general G05D1/00; computer aspects G06]

Abstract

A system and method is provided for thruster control in a flight vehicle. The system and method uses a proportional derivative matrix control technique to determine thrust commands in a Divert and Attitude control (DAC) system. The proportional derivative matrix control system is configured to receive pitch, roll and yaw commands as inputs, and generate thrust commands as outputs. The performance of the proportional derivative matrix controller is such that the thrust commands can achieve the desired attitude angles quickly and with reduced fuel consumption. The matrix control system can efficiently control a variety of thrusters, including asymmetric thrusters having different moment arms. The matrix control system is particularly suitable to the control of DAC systems with asymmetric thrusters that are configured for attitude control.

Claims

1. A thruster control system for a flight vehicle comprising a plurality of thrusters, the thrust control system comprising:

a processor configured to receive pitch, yaw and roll commands, and responsive to the pitch, yaw and roll commands generate a plurality of thruster commands for the plurality of thrusters using a matrix control technique.

2. The thruster control system of claim 1 wherein the processor is further configured to receive data indicating center-of-gravity shift moments in the flight vehicle, and wherein the processor is further configured to compensate for the center-of-gravity shift moments with the plurality of thruster commands using the matrix control technique.

3. The thruster control system of claim 1 wherein the processor is further configured to receive line-of-sight rate commands for the flight vehicle, and wherein the processor is further configured to generate the plurality of thruster commands responsive to the line-of-sight rate commands using the matrix control technique.

4. The thruster control system of claim 1 wherein the plurality of thrusters comprise at least one asymmetric thruster.

5. The thruster control system of claim 1 wherein the plurality of thrusters are part of a liquid divert and attitude control system on the flight vehicle.

6. The thruster control system of claim 1 wherein the processor is configured to generate the plurality of thruster commands for the plurality of thrusters by generating an array of thruster values and shifting the array of thruster values such that all of the thruster values are positive values.

7. The thruster control system of claim 1 wherein the processor is configured to generate the plurality of thruster commands for the plurality of thrusters by generating an array of thruster values and shifting the array of thruster values such that at least one thruster value is shifted to zero.

8. The thruster control system of claim 7 wherein the processor is configured to generate the plurality of thruster commands for the plurality of thrusters by further normalizing the array of thruster values by a largest thruster value in the array of thruster values if the largest thruster value exceeds a maximum value.

9. The thruster control system of claim 8 wherein the processor is configured to generate the plurality of thruster commands for the plurality of thrusters by further normalizing the array of thruster values by the maximum value if the largest thruster value does not exceed the maximum value.

10. A thruster controller system for a flight vehicle comprising a plurality of thrusters, wherein at least one of the plurality of thrusters is asymmetric to another thruster in the plurality of thrusters, the thruster controller system comprising:

a processor configured to receive;

pitch, yaw and roll commands for the flight vehicle;

data indicating center-of-gravity shift moments in the flight vehicle; and

line-of-sight rate commands for the flight vehicle;

wherein the processor is further configured to generate a plurality of thruster rate commands responsive to the pitch, yaw and roll commands and the line-of-sight commands, and configured to compensate for the center-of-gravity shift moments, using a proportional derivative matrix technique, and wherein the processor is configured to generate the plurality of thruster commands for the plurality of thrusters by generating an array of thruster values and shifting the array of thruster values such that all the thruster values are positive and at least one thruster value in the array of thruster values is shifted to zero, normalizing the array of thruster values by a largest thruster value in the array of thruster values if the largest thruster value exceeds a maximum value, and normalizing the array of thruster values by the maximum value if the largest thruster value does not exceed the maximum value.

11. A method for thruster control in a flight vehicle that includes a plurality of thrusters, the method comprising the steps of:

receiving pitch, yaw and roll commands;

generating a plurality of thruster commands for the plurality of thrusters in response to the pitch, yaw and roll commands and using a matrix control technique.

12. The method of claim 11 further comprising the steps of

receiving data indicating center-of-gravity shift moments in the flight vehicle;

and

wherein the step of generating the plurality of thruster commands comprises compensating for the center-of-gravity shift moments with the plurality of thruster commands using the proportional derivative matrix technique.

13. The method of claim 11 further comprising the steps of

receiving line-of-sight rate commands for the flight vehicle;

and

wherein the step of generating the plurality of thruster commands comprises generating the plurality of thruster commands responsive to the line-of-sight rate commands using the proportional derivative matrix technique.

14. The method of claim 11 wherein the plurality of thruster comprise at least one asymmetric thruster.

15. The method of claim 11 wherein the plurality of thruster are part of a liquid divert and attitude control system on the flight vehicle.

16. The method of claim 11 wherein the step of generating a plurality of thruster commands for the plurality of thrusters comprises:

generating an array of thruster values; and

shifting the array of thruster values such that all the thruster values are positive values.

17. The method of claim 11 wherein the step of generating a plurality of thruster commands for the plurality of thrusters comprises:

generating an array of thruster values; and

shifting the array of thruster values such that at least one thruster value in the array of thruster values is shifted to zero.

18. The method of claim 17 wherein the step of generating a plurality of thruster commands for the plurality of thrusters further comprises:

normalizing the thruster values by a largest thruster value in the array of thruster values if the largest thruster value exceeds a maximum value.

19. The method of claim 17 wherein the step of generating a plurality of thruster commands for the plurality of thrusters further comprises:

normalizing the array of thruster values by the maximum value if the largest thruster value does not exceed the maximum value.