Tuning of the Lateral Specific Force Gain Based on Human Motion Perception in the Desdemona Simulator

Abstract

Generally, motion simulators present motion and visual cues different from each other due to the physical limitations of the motion platform. Nonetheless, high fidelity motion platforms are capable of simulating some maneuvers one-to-one, i.e., motion cues equal to visual cues. However, one-to-one simulation is normally not preferred by subjects and the simulator motion is reported as too strong. In this study we investigated whether this overestimation depends on the frequency and amplitude of inertial motion. The stimuli in this study consisted of translations in the lateral direction. The Desdemona research simulator was used to generate the motion profiles. Six sinusoidal profiles with different combinations of amplitude and frequency were used as reference stimuli. For every experimental condition, the visual and inertial information had equal frequency but different amplitude. Subjects had to change the inertial motion amplitude until they obtained the best relation between the two sources of motion information. Our results showed that stimuli with high amplitude were associated with smaller motion gains than stimuli with lower amplitude. The same occurred for stimuli with higher frequency when compared to stimuli with lower frequency. The findings in this study suggest that a dynamic scaling algorithm for inertial motion could improve the perceived realism of motion simulation.

Relationship Between Optimal Gain and Coherence Zone in Flight Simulation

“…the ratio between the inertial and visual motion, should generally be smaller than one, especially for the highest amplitude. This supports the findings of other studies [6][7][8][9][10] where a motion gain of one was judged as too strong. A reason for one-to-one motion to be judged too strong in a simulation environment may be the quality of the visual display.…”

“…These trends have been found before for optimal gain measurements in sway 10 and coherence zone measurements in yaw. 11,12 The effect of stimulus frequency on the coherence zone was tentatively explained with the influence of the semi-circular canals dynamics, 11,12 which have a higher gain in velocity at higher frequencies.…”

“…As stated before, a previous study 10 showed that the inertial amplitudes measured when subjects are given the optimal gain instructions led to an optimal gain zone. This zone is defined by the upper and lower optimal gain measurements.…”

“…inertial motion equal to visual motion, as too strong in a simulation environment. A previous study, 10 where subjects could select the inertial motion amplitude that best matched their visual stimulus, has shown that in a simulator environment, the inertial amplitude selected by subjects as optimal was not equal to the visual amplitude. It was found that the optimal inertial amplitude, hereby defined as optimal gain, depended on the amplitude and frequency of the visual stimulus presented to the participants.…”

“…4,5 However, a situation where the inertial information is equal to the visual information seems also not optimal. Researchers found [6][7][8][9][10] that subjects judged one-to-one motion, i.e. inertial motion equal to visual motion, as too strong in a simulation environment.…”