Full Flight-Envelope Simulation and Piloted Fidelity Assessment of a Business Jet Using a Model Stitching Architecture

Abstract

This paper presents the development and piloted assessment of a full flight-envelope simulation model of a light business jet using a model stitching architecture. Individual state-space models and trim data for discrete flight conditions were combined to produce a continuous simulation model, which was integrated into a fixed-base simulation facility. Back-to-back flight/simulation piloted evaluations of a similar light business jet in flight and the stitched model in simulation were performed to assess the fidelity of the stitched model. Overall pilot impressions were that the stitched simulation model was representative of the actual aircraft. Simulation Fidelity Ratings were given to quantify simulation fidelity for each of the evaluated qualitative tasks, in which mostly Fidelity Level 1 ratings were assigned, suggesting full transfer of training for those tasks. Guidance on flight testing for the development of fixed-wing aircraft stitched models is provided.

Piloted Simulation Handling Qualities Assessment of a Business Jet Fly-By-Wire Flight Control System

“…A more complete description of the bare-airframe stitched model used in this study is provided by Tobias et al 11 Tobias also presents the results of a simulation fidelity test using back-to-back flight and simulator testing, which show excellent agreement in pilot control strategy and workload between the stitched model and actual aircraft. …”

“…10 For the piloted simulation evaluation, a continuous, full-envelope model is needed, in lieu of the individual point models. This was accomplished using the model stitching technique, 8,11 which refers to the process of combining a collection of linear state-space models at various fight conditions with trim data into a full-envelope simulation model. As shown in Figure 3, model stitching is accomplished by implementing lookup tables of the aircraft state trim values, control input trim values, and stability and control derivatives with respect to total instantaneous x-body axis relative velocity, U , based on the point models and trim data extracted from the AAA nonlinear simulation model.…”

A Model Stitching Architecture for Continuous Full Flight-Envelope Simulation of Fixed-Wing Aircraft and Rotorcraft from Discrete Point Linear Models

“…Trim data were included for flap settings of 15 and 35 deg, while the stability and control derivatives remain at the nominal (flaps-up) configuration (see Section 3.8). This approach ensures that flaps-down trim is correct, which is important for piloted simulation [17], and allows for efficient flight testing. Cost permitting, it may be advantageous, however, to directly identify the dynamics of a single flaps-down approach configuration using system identification flight testing.…”

“…This technique provided continuous look-up of trim and derivatives with deflection of flaps and changes in airspeed for a high-fidelity simulated approach to landing. Pilot reaction indicated that trim behavior, and the corresponding migration of the controls, however, were the most important effects upon deployment of flaps [17].…”

“…[17]. For the piloted simulation, the effects of flaps on both trim and derivatives, as determined from AAA, were applied to the baseline point models as a function of flap deflection and airspeed, and stored as an additional interpolation dimension in the lookup tables.…”