A Cybernetic Analysis of Biodynamic Effects in Touchscreen Operation in Turbulence

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.