Advanced Rotorcraft Technology, Inc. (ART) has used FLIGHTLAB to develop flight dynamics models with high fidelity dynamics that can support real-time applications. The models are produced and tested in the FLIGHTLAB Development System and code-generated with custom interfaces to expedite system integration with user applications. Fielded trainers may be upgraded with FLIGHTLAB real-time models by substituting the existing flight dynamics model with software that obtains the required interface data from a network interface to PilotStation, the remote host where the FLIGHTLAB flight dynamics model is being run in real-time. This allows state-of-the-art FLIGHTLAB rotorcraft models, running on modern low-cost, high-speed computers, to be readily integrated with both new simulators and existing simulation facilities for a cost effective upgrade.
Real-time FLIGHTLAB flight dynamics models are physically based, have proven fidelity, and are capable of real-time operation on current generation PCs. FLIGHTLAB flight dynamics models are available in two levels of fidelity. The Baseline model has been tested to a reasonability criteria based on performance data in the pilot manual and is suitable for applications requiring certification up to an FAA Level 5 Flight Training Device. The Advanced model has increased modeling detail and sophistication that allows it to be validated to the highest FAA certification standards. ART has provided real time models for use in such programs as the Aviation Combined Arms Tactical Training (AVCATT) simulators and for the Army’s Flight School XXI program based on the FAA’s Level D simulator certification requirements.
Rotor Blade Element Models FLIGHTLAB models the aerodynamic response of each rotor blade as it would actually perform under the conditions of the training scenario being modeled. Variable aerodynamic and structural grid sizes for each blade allow the modeling detail to be customized to the application. This insures a realistic representation of the dynamic response of the rotor system to changes in control and flight conditions while maintaining computational efficiency.
Fuselage Aerodynamics The fuselage aerodynamics are modeled using three dimensional aerodynamic lookup tables for the aerodynamic force and moment coefficients at the reference point as a function of angle of attack and sideslip. The airfoils on the fuselage, such as the horizontal and vertical stabilizers, are modeled as two-dimensional aerodynamic surfaces and the lift, drag and pitching moment coefficients are obtained from table lookups as a function of Mach number and angle of attack.
Turboshaft Engine & Drive Train Models The FLIGHTLAB flight dynamics model includes a detailed, dynamically accurate representation of the aircraft’s engines and drive train components and their effect on operational characteristics.
Flight Control System FLIGHTLAB real-time models include modeling of the primary control system, the stability augmentation system and the flight path stabilization system.
Aerodynamic Interference Helicopters are subject to extensive aerodynamic interference that is the result of changes in air flow between and from the rotor system, fuselage, and external objects such as the ground, buildings and ship superstructures. FLIGHTLAB includes sophisticated modeling of all rotorcraft interference phenomena to properly capture these effects.
Landing Gear A physically based model of the landing gear is provided in the FLIGHTLAB flight dynamics model. A sophisticated ground contact model captures the effects of landing on a sloped surface as well as accounting for terrain conditions ranging from firm and dry to wet and slippery.
Mass Properties The vehicle mass properties are continually updated as a function of configuration and fuel loading. As stores are jettisoned and fuel is burned the location of the center of gravity, the vehicle mass, and the moments of inertia are updated. These properties may also be initialized to any desired state from the Instructor/Operator Station.
Environment FLIGHTLAB supports wide variations of density and pressure altitudes and atmospheric conditions. FLIGHTLAB also allows wind speeds, direction, and turbulence levels to be specified by the console operator. An optional ship air-wake model can reproduce the effects of turbulence from a ship’s superstructure through a wide range of relative wind conditions.
Sling loads Optional single and multiple attach-point sling load models are available in FLIGHTLAB. Two way interactions between the load and the helicopter through the cable are included in all modeling options.
Solution Method FLIGHTLAB models are produced by interconnecting generic modeling components and assigning aircraft specific data values to the parameters of the components. Each component is a self-contained dynamic entity and the methodology used to solve a diverse dynamic architecture created from the arbitrary interconnection of these standardized building blocks is referred to as multi-body dynamics.
