The study described in this paper investigated the effects of two different hexapod motion configurations on the training and transfer of training of a simultaneous roll and pitch control task. Pilots were divided between two groups which trained either under a baseline hexapod motion condition, with motion typically provided by current training simulators, or an optimized hexapod motion condition, with increased fidelity of the motion cues most relevant for the task. All pilots transferred to the same full-motion condition, representing motion experienced in flight. A cybernetic approach was used that gave insights into the development of pilots' use of visual and motion cues over the course of training and after transfer. Based on the current results, neither of the hexapod motion conditions can unambiguously be chosen as providing the best motion for training and transfer of training of the used multi-axis control task. However, the optimized hexapod motion condition did allow pilots to generate less visual lead, control with higher gains, and have better disturbance-rejection performance at the end of the training session compared to the baseline hexapod motion condition. Significant adaptations in control behavior still occurred in the transfer phase under the full-motion condition for both groups. Pilots behaved less linearly compared to previous single-axis control-task experiments; however, this did not result in smaller motion or learning effects. Motion and learning effects were more pronounced in pitch compared to roll. Finally, valuable lessons were learned that allow us to improve the adopted approach for future transfer-of-training studies.

This paper describes a human-in-the-loop experiment performed in TU Delft's SIMONA Research Simulator to explicitly investigate the effects of biodynamic feedthrough (BDFT) on the execution of a two-dimensional touchscreen waypoint dragging task in turbulence. In the experiment, 16 participants performed the same task in a stationary simulator and whilst being perturbed in either surge, sway, or heave directions by the same motion disturbance signal. In addition, the effect of screen location on biodynamic effects was tested by considering two touchscreen display positions, i.e., representative for the Primary Flight Display (PFD) and the Control Display Unit (CDU), respectively. The collected results show significantly more issues with loss of screen contact for the PFD display, due to the extended arm position when operating this display. Despite the fact that small biodynamic effects are also found for off-axis disturbances, the results clearly show that issues with BDFT predominantly occur when motion disturbances are aligned with the touchscreen control input direction. Due to the use of a multisine motion disturbance signal in the experiment, explicit BDFT detection and identification was possible with spectral methods. For the conditions where sufficient BDFT was detected to allow for modeling the BDFT dynamics, a second-order BDFT model was proposed and found to explain at least 70% of the BDFT input components. With consistent BDFT model parameter estimates between conditions, this approach shows clear merit for quantitative analysis of biodynamic effects on touchscreen operation and potentially even for BDFT mitigation through model-based input cancellation. Nomenclature