Method of modeling dynamic characteristics of a flight vehicle

• US 20100318336A1
• Filed: 12/01/2009
• Published: 12/16/2010
• Est. Priority Date: 06/13/2009
• Status: Active Grant

• Current Assignee: Eric T. Falangas
• Original Assignee: Eric T. Falangas
• Inventors: Falangas, Eric T.
• Granted Patent: US 8,380,473 B2
• Time in Patent Office: Days
• US Class Current: 703/8
• CPC Class Codes: G05B 17/02 electric
• CPC Class Codes: G06F 30/15 Vehicle, aircraft or watercraft design

Abstract

The present invention models dynamic behavior of flight vehicles for simulation, analysis, and design. The present invention allows a user to define the complexity of a flight vehicle model, and such models may be simple rigid body models, models of medium complexity, or very complex models including high order dynamics comprising hundreds of structural flexibility modes and variables related to aero-elasticity, fuel sloshing, various types of effectors, tail-wags-dog dynamics, complex actuator models, load-torque feedback, wind gusts, and other parameters impacting flight vehicles. The present invention accommodates and analyzes multiple vehicle and actuator concepts and configurations as defined in flight vehicle input data, which specifies flight vehicle parameters at a steady-state condition for modeling flight vehicle response to dynamic forces and flight control commands with respect to steady state operation.

Claims

1. A method of modeling dynamic characteristics of a flight vehicle, comprising:

collecting input data specifying flight vehicle parameters at a steady-state condition for modeling variables of flight vehicle response to dynamic forces during steady-state operation of the flight vehicle;

converting the input data into state-space systems data for use by at least one utility program module to create a state-space system modeling one or more components of flight vehicle activity, the at least one utility program module generating a systems data output file comprising at least one matrix mapping the input data to the state-space systems data; and

generating an output file for simulating flight vehicle design and performance based on at least one matrix mapping the input data to the state-space systems data.

2. The method of claim 1, wherein the input data corresponds to the at least one utility program module, the at least one utility program module configured to analyze flight vehicle response to a particular dynamic force.

3. The method of claim 2, wherein the at least one utility program module generates a systems data file for populating the at least one matrix.

4. The method of claim 1, further comprising collecting modal input data including data specifying one or more structural flexibility modes.

5. The method of claim 4, wherein the one or more structural flexibility modes includes a set of bending modes, each bending mode defined by parameters specifying bending displacement of the flight vehicle at key nodes in the flight vehicle.

6. The method of claim 5, wherein the parameters defining each bending mode include at least one of a mode frequency, a damping coefficient, a generalized mass, and a generalized mode shape at the keys in the flight vehicle, the key nodes including force application points and sensors.

7. The method of claim 1, wherein the collecting input data specifying flight vehicle parameters at a steady-state condition further comprises collecting data specifying at least one of mass properties, trajectory, sensors, aerodynamic derivates, engine data, control surface data, slosh parameters, and wind gust.

8. The method of claim 7, wherein the sensors including at least one of a gyro sensor, an accelorometer, and a vane sensor.

9. The method of claim 1, further comprising modifying the system data output file to decouple state-space systems in the system data output file to separate a flight vehicle model into separate systems.

10. The method of claim 3, wherein the at least one utility program module includes a module for modifying the systems data output file.

11. The method of claim 1, wherein collecting input data further comprises collecting actuator data defining variables acting on surfaces controlling movement of the flight vehicle.

12. The method of claim 11, wherein the actuator data includes data specifying engine thrust vector control conditions and control surface slewing conditions.

13. The method of claim 12, further comprising combining the actuator data with the input data defining flight vehicle parameters to model engine thrust vector control conditions and control surface slewing conditions in the at least one matrix.

14. The method of claim 1, wherein collecting input data further comprises collecting effector data defining engine parameters and control surface aero coefficients.

15. The method of claim 14, further comprising combining the effector data with the input data to create an effector mixing logic matrix within the at least one matrix modeling the engine parameters and control surface aero coefficients acting on the flight vehicle.

16. The method of claim 15, wherein the effector data decouples rigid body dynamics acting on the flight vehicle by reducing interaction in at least one direction.

17. The method of claim 16, wherein the reducing interaction in at least one direction includes roll, pitch, and yaw directions.

18. The method of claim 11, wherein collecting input data further comprises collecting tail-wags-dog data.

19. The method of claim 18, further comprising combining the tail-wags-dog data with the input data defining flight vehicle parameters to model reaction forces and moments on the flight vehicle at engine gimbals and control surface hinges in the at least one matrix.

20. The method of claim 1, wherein collecting input data further comprises collecting fuel sloshing data.

21. The method of claim 20, further comprising combining the fuel sloshing data with the input data defining flight vehicle parameters to model dynamic behavior of fuel motion inside a flight vehicle in the at least one matrix.

22. The method of claim 1, further comprising collecting aero-elastic data defining effects of aerodynamic forces on structural flexibility of a flight vehicle.

23. The method of claim 22, wherein the aero-elastic data includes a first set of coefficients describing an effect of modal displacements and modal rates on flight vehicle aerodynamic forces and moments, a second set of coefficients describing excitement of modal displacement caused by effects of vehicle motion, and a third set of coefficients describing the effect of changes in vehicle motion on moments at hinges of control surfaces.

24. The method of claim 23, further comprising combining the aero-elastic data with the input data and modeling aero-elastic effects on a flight vehicle to generate aero-elastic in the at least one program module.

25. The method of claim 1, further comprising compiling the input data into an input data file and managing the input data file with a utility program module.

26. The method of claim 1, wherein the flight vehicle is an aircraft.

27. The method of claim 1, wherein the flight vehicle is a launch vehicle.

28. The method of claim 1, wherein the flight vehicle is a flexible structure capable of interfacing with a flight vehicle.

29. The method of claim 1, wherein the flexible structure is a space station.

30. A method of modeling dynamic characteristics of a flight vehicle, comprising:

compiling an input data file from input data defining a flight vehicle;

executing the input data file to convert the input data defining a flight vehicle into a state-space system file comprising data defining at least one system;

extracting the data defining at least one system from the state-space system file; and

exporting the data defining the at least one system to a file format for simulating performance of the flight vehicle.

31. The method of claim 30, further comprising collecting the input data defining a flight vehicle, the input data including steady-state vehicle parameters at a fixed flight condition.

32. The method of claim 31, wherein the input data defining a flight vehicle is collected via a plurality of pull-down menus in a graphical user interface.

33. The method of claim 31, wherein the collecting the input data defining a flight vehicle further comprises collecting model input data defining one or more structural flexibility modes.

34. The method of claim 33, wherein the collecting the input data defining a flight vehicle further comprises collecting aero-elastic input data defining effects of aerodynamic forces on structural flexibility of a flight vehicle.

35. The method of claim 34, further comprising combining the input data including steady state vehicle parameters at a fixed flight condition with modal input data defining one or more structural flexibility modes and input data specifying aero-elastic input data defining effects of aerodynamic forces on structural flexibility of a flight vehicle.

36. The method of claim 31, wherein the collecting input data including steady-state vehicle parameters at a fixed flight condition further comprises collecting data specifying at least one of mass properties, trajectory, sensors, aerodynamic derivates, engine data, control surface data, slosh parameters, and wind gust.

37. The method of claim 36, wherein the sensors including at least one of a gyro sensor, an accelorometer, and a vane sensor.

38. The method of claim 31, wherein the collecting input data further comprises collecting actuator input data specifying variables acting on surfaces controlling movement of the flight vehicle.

39. The method of claim 31, wherein the collecting input data further comprises collecting vibration data specifying variables for reactionary forces and resonance during operation of the flight vehicle.

40. The method of claim 31, wherein collecting input data further comprises collecting effector data defining engine parameters and control surface aero coefficients.

41. The method of claim 40, further comprising combining the effector data with the input data to create an effector mixing logic matrix within the at least one matrix modeling the engine parameters and control surface aero coefficients acting on the flight vehicle.

42. The method of claim 41, wherein the effector data decouples rigid body dynamics acting on the flight vehicle by reducing interaction in at least one direction.

43. The method of claim 42, wherein the reducing interaction in at least one direction includes roll, pitch, and yaw directions.

44. The method of claim 31, wherein collecting input data further comprises collecting tailwags-dog data.

45. The method of claim 44, further comprising combining the tail-wags-dog data with the input data defining a flight vehicle to model reaction forces and moments on the flight vehicle at engine gimbals and control surface hinges in the at least one matrix.

46. The method of claim 45, wherein collecting input data further comprises collecting fuel sloshing data.

47. The method of claim 46, further comprising combining the fuel sloshing data with the input data defining a flight vehicle to model dynamic behavior of fuel motion inside a flight vehicle in the at least one matrix.

48. The method of claim 31, wherein the input data file includes multiple sets of vehicle data.

49. The method of claim 41, wherein the state-space systems file includes state-space systems data generated by at least one utility program module modeling one or more components of flight vehicle activity, the state-space systems file comprising at least one matrix mapping the input data to the state-space systems data.

50. A method of batch modeling dynamic characteristics of a flight vehicle, comprising:

compiling an batch input data file from multiple sets of batch input data defining flight vehicle parameters at a steady-state condition and defining a set of commands for modeling flight vehicle characteristics;

calling a specific utility program module defined in the batch input data file within a title of the set of commands for the specific utility program module included within input data appropriate for the specific utility program module to convert the input data defining flight vehicle parameters at a steady-state condition into a state-space system file comprising data defining at least one system;

extracting the data defining at least one system from the state-space system file; and

exporting the data defining the at least one system to a file format for simulating performance of the flight vehicle.

51. The method of claim 50, wherein the multiple sets of batch input data are created and processed via a batch utility program module.

52. The method of claim 51, wherein the multiple sets of batch input data include modal input data defining one or more structural flexibility modes.

53. The method of claim 51, wherein the multiple sets of batch input data include aero-elastic input data defining effects of aerodynamic forces on structural flexibility of a flight vehicle.

54. The method of claim 51, wherein the multiple sets of batch input data include actuator input data specifying variables acting on surfaces controlling movement of the flight vehicle.

55. The method of claim 51, wherein the multiple sets of batch input data include vibration data specifying variables for reactionary forces and resonance during operation of the flight vehicle.

56. The method of claim 51, wherein the multiple sets of batch input data include effector data defining engine parameters and control surface aero coefficients.

57. The method of claim 51, wherein the multiple sets of batch input data include tail-wags-dog data for modeling reaction forces and moments on the flight vehicle at engine gimbals and control surface hinges.

58. The method of claim 51, wherein the multiple sets of batch input data include fuel sloshing data for modeling dynamic behavior of fuel motion inside a flight vehicle.