Simulation System Fidelity Assessment at the Vertical Motion Simulator

Quantifying simulation fidelity – the ability of a flight simulator to accurately recreate a flight environment – is a challenge that is incomplete. Assessing the cueing fidelity of a ground-based flight simulator requires a comparison with actual flight data. Two experiments conducted at the Vertical Motion Simulator (VMS) compared the handling qualities measured for a UH-60A Black Hawk simulation with those obtained from flight for the same tasks. Prior to the experiment, the simulator's motion and visual system frequency responses were measured and the aircraft math model was adjusted to incorporate the simulator motion system delays, ensuring that the overall helicopter response to control inputs closely matched those of the actual aircraft. The motion system gains and washouts were also adjusted to provide the most realistic motion cues for each evaluation task. The optimized motion system fidelity was then evaluated against the modified Sinacori simulation fidelity assessment criteria. In the first experiment, the handling qualities ratings (HQRs) in the VMS simulation for the Sidestep and Bob-up maneuvers were within one HQR of those given in the flight tests. The second experiment HQRs for the ADS-33 Slalom maneuver were nearly identical between flight and the simulation. The ADS-33 Vertical maneuver HQRs results were mixed, with one pilot rating the simulation equivalent, and the second pilot rating the simulation worse than flight. In addition to recording HQRs in the second experiment, a new Simulation Fidelity Rating (SFR) scale developed by the University of Liverpool and the National Research Council, Ottawa was evaluated for use on a research and development simulator. It is recommended that, when using SFR ratings for assessment of simulator fidelity, the pilot be given time to become acquainted to the simulator layout. Furthermore, the selected maneuvers should give the pilots the opportunity to adapt their techniques in order to obtain appropriate performance on their first simulation run.