The Effect of Apparent Latency on Simulator Sickness While Using a See-Through Helmet-Mounted Display

Abstract

Objective: The aim of this study was to determine the effect of head movement frequency and predictive compensation on (a) latency produced in a monocular see-through helmet-mounted display (HMD) test bed and (b) simulator sickness experienced by users wearing the HMD. Background: There is conflicting research regarding latency as a significant factor in the onset of simulator sickness. Predictive compensation has been shown to mitigate the magnitude of latency, but little is known about the extent of its effect on simulator sickness. Method: A video camera recorded HMD and simulator imagery to accurately measure apparent latency produced at three head movement frequencies. Predictive compensation strategies were manipulated to measure the difference in apparent latency produced by the test bed in various conditions. Similar methodology was employed with human participants to measure simulator sickness experienced by users of this test bed. Results: In Experiment 1, apparent latency increased significantly as head movement frequency increased. Predictive compensation strategies significantly reduced apparent latency present in the test bed. In Experiment 2, predictive compensation significantly reduced the magnitude of simulator sickness. Conclusion: Predictive compensation can be effectively implemented to reduce apparent latency, resulting in a lower magnitude of simulator sickness. Application: Potential applications include HMD use in which head position is tracked and visual imagery is linked to head or body movement, such as in virtual and augmented reality systems, and is thus critical to functionality and performance.