Between-simulator comparison of motion-filter order and break frequency effects on manual control

This paper investigates the interaction effects of motion filter order and break frequency on pilots’ manual control behavior and control performance using two simulators. Eighteen pilots performed the experiment in the Vertical Motion Simulator (VMS) at NASA Ames Research Center and 20 pilots in the SIMONA Research Simulator at Delft University of Technology. The experiment used a full-factorial design with three motion filter orders (first-, second-, and third-order) and two filter break frequencies (0.5 and 2.0  rad/s), in addition to reference no-motion and full-motion conditions. Key task variables, such as the quality of the motion and visual cues and the characteristics of the sidestick, were matched across both simulators. Overall, the expected effects of filter order and break frequency variations were found, with both increasing order and increasing break frequency causing pilots to use less motion feedback in their control strategy, resulting in lower tracking performance. Furthermore, across the wide range of filter orders tested in the experiment, the existing Sinacori–Schroeder motion fidelity criterion was found to be a good predictor of the interaction effects of both filter settings on pilot control behavior. For the same motion condition, there was a consistent offset in the results between simulators, due to the more high-gain control strategy adopted by a number of the VMS pilots. Still, the observed relative trends in pilot control behavior and performance between motion conditions were equivalent in both simulators and thus accurately replicated.