초록 ▼

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 includin

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.

대표청구항 ▼

1. A method of modeling dynamic characteristics of a flight vehicle, comprising: collecting input data including a plurality of flight vehicle parameters at a fixed flight condition and effector data including a plurality of engine parameters and control surface aero coefficients;collecting actuator

1. A method of modeling dynamic characteristics of a flight vehicle, comprising: collecting input data including a plurality of flight vehicle parameters at a fixed flight condition and effector data including a plurality of engine parameters and control surface aero coefficients;collecting actuator parameters defining dynamic models of flight vehicle effectors generating effector motion, as a function of an input command, translated into forces and moments acting on a flight vehicle in motion;computing a mixing-logic gain matrix, based on vehicle geometry and the effector data, configured to decouple vehicle angular and linear acceleration motion in at least roll, pitch, and yaw directions generating control forces acting upon flight vehicle engines and control surfaces;generating a deterministic flight vehicle state-space model from the input data and the effector data that predicts behavior of the flight vehicle in response to at least one of external disturbance inputs and flight control inputs;generating a deterministic actuator model from the actuator parameters defining dynamic models of flight vehicle effectors generating effector motion, the deterministic actuator model defining motion of a flight vehicle engine or a control surface in response to actuator input commands from a flight control system output;generating a flight control state-space model from an output of the mixing logic gain matrix, the flight control state-space model including control loops at a basis of one control loop per axis of angular and linear acceleration;combining the flight vehicle state-space model, the actuator model, and the flight control state-space models together to generate one or more combination dynamic models for a flight vehicle configuration and at a specified degree of complexity, the combining the flight vehicle state-space model, the actuator model, and the flight control system state-space models further includingcreating a combined state-space representation of the flight vehicle state-space model, the actuator model, and the flight control state-space models at a fixed flight condition defined by one or more actuator parameters acting on a vehicle engine or control surface, the combined state-space representation defined by a linear system comprised of a set of four matrices derived from the input data, the effector data, the actuator data, and the output of the mixing-logic gain matrix, andnumerically solving the set of four matrices to determine a dynamic behavior of the combined -space representation in response to the at least one of external disturbance inputs and flight control inputs; andperforming one or more simulations to evaluate flight vehicle performance and control design within the specified degree of complexity. 2. The method of claim 1, wherein the performing one or more simulations includes a frequency response analysis to evaluate flight vehicle performance and control design within the specified degree of complexity that is at least in response to accelerometer and gyro measurements. 3. The method of claim 1, further comprising converting the input data and the effector data at the fixed flight condition, and the output of the mixing-logic gain matrix, into state-space systems data for use in modeling the behavior of the flight vehicle in combination with the engine or control surface actuators, in response to the at least one of external disturbance inputs and flight control inputs. 4. The method of claim 1, further comprising generating the combined state-space systems data in an output systems file prior to performing the one or more simulations. 5. The method of claim 1, wherein the mixing logic matrix further decouples vehicle angular and linear acceleration motion in translational accelerations along at least one of an x-direction, y-direction and a z-direction. 6. The method of claim 1, wherein the effector data includes parameters that define gimbaling engines, throttling engines, and control surfaces. 7. The method of claim 1, wherein actuator data includes parameters that define inertia, stiffness, friction, hydraulic servo, and gains. 8. 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. 9. The method of claim 1, wherein the control forces acting upon flight vehicle engines defined by plurality of actuator parameters further include motion of nozzles and thrust variations, independent of the flight vehicle input data, that propel and steer the flight vehicle. 10. The method of claim 1, further comprising collecting aero-elastic coefficients among the effector data, the aero-elastic coefficients defining effects of aerodynamic forces on structural flexibility of a flight vehicle and including 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. 11. The method of claim 1, wherein the mixing logic gain matrix is generated as a function of flight vehicle geometry, thrust, angle of attack, and mass properties at a specific flight condition, so that the mixing logic gain matrix varies at different flight conditions. 12. The method of claim 1, wherein the flight vehicle configuration is a rigid body representative of an aircraft. 13. The method of claim 1, wherein the flight vehicle configuration is a rigid body representative of a launch vehicle. 14. The method of claim 1, wherein the flight vehicle configuration is a rigid body representative of a spacecraft. 15. The method of claim 1, wherein the flight vehicle configuration is a flexible structure capable of operating in conjunction with a rigid body. 16. The method of claim 1, wherein the flexible structure is a large spacecraft comprising a flexible structure with rigid body dynamics. 17. A system for modeling dynamic characteristics of a flight vehicle, comprising: a computer hardware environment, in which one or more modules are configured to collect input data including a plurality of flight vehicle parameters and effector data at least including engine parameters and control surface aero coefficients at a fixed flight condition, and to collect actuator parameters defining dynamic models of flight vehicle effectors generating effector motion, wherein data collected among the plurality of flight vehicle parameters and engine parameters and control surface aero coefficients varies depending on a type of flight vehicle configuration to be modeled and a specified degree of complexity, and a time chosen along a flight trajectory;a mixing logic process configured to compute a gain matrix to decouple vehicle angular and linear acceleration at least indicative of roll, pitch, and yaw motion based on vehicle geometry and engine parameters and control surface aero coefficients of the effector data;a plurality of modeling modules configured to:model input data and effector data to generate a deterministic flight vehicle state-space model that simulates and predicts the behavior of a flight vehicle in response to at least one of external disturbance inputs and flight control inputs and to perform a frequency response analysis determine a closed-loop vehicle stability and to design a flight control system;model actuator data to generate a deterministic actuator dynamic model to control motion of a flight vehicle engine or a control surface in response to actuator input commands from the flight control system outputs,model a flight control state-space model from an output of the mixing logic process and the gain matrix, the flight control state-space model including control loops at a basis of one control loop per axis of angular and linear acceleration,combine the flight vehicle state-space model, the flight control state-space model which also includes the mixing logic gain, and the actuator model at a fixed flight condition to generate one or more dynamic models for the type of flight vehicle configurations and specified degree of complexity, the combined state-space representation defined by a linear system comprised of a set of four matrices derived from the input data, the effector data, the actuator data, and the decoupling mixing-logic matrix, andnumerically solve the set of four matrices to determine a dynamic behavior of the combined system in response to external disturbances or flight control commands; anda simulation module configured to generate output data representative of design and performance of the flight vehicle configuration with the specified degree of complexity based on the set of four matrices mapping the flight vehicle parameters and the decoupled vehicle motion and angular acceleration data to the state-space systems data,wherein numerically solving the set of four matrices determines the dynamic response of the combined state space system to various types of disturbance or flight control inputs for evaluation of system performance, and performs frequency response analysis for stability margin and robustness evaluation within the computer hardware environment. 18. The system of claim 17, wherein the one or more modules configured to collect input data including a plurality of flight vehicle parameters at a steady-state condition, and to collect effector data including a plurality of engine parameters and control surface aero coefficients that create forces and moments acting on a flight vehicle, the mixing logic process, the plurality of modeling modules, and the simulation module are embodied in at least one data file accessible by a computer program configured to analyze flight vehicle design and performance based on the state-space representation of linear systems embodied in the set of four matrices. 19. The system of claim 17, further comprising a graphical user interface module configured to generate visualizations of output data and modeling options from the analysis module in one or more user-selected menus in a graphical user interface, the graphical user interface module further configured to be responsive to a plurality of user selections from the one or more user-selectable menus and to manipulate the output data from the plurality of user selections, the plurality of user selections at least representative of flight vehicle parameters and effector and sensor parameters that adjust the specified degree of complexity. 20. The system of claim 17, wherein the type of flight vehicle configuration is a rigid body. 21. The system of claim 17, wherein the type of flight vehicle configuration is a flexible structure operating in conjunction with a rigid flight vehicle. 22. The system of claim 17, where the mixing logic process further decouples vehicle angular and linear acceleration motion in translational accelerations along at least one of an x-direction, a y-direction, and a z-direction.