Date of Award

3-21-2013

Document Type

Thesis

Degree Name

Master of Science in Systems Engineering

Department

Department of Systems Engineering and Management

First Advisor

Michael E. Miller, PhD.

Abstract

Forty years of innovations have greatly improved Helmet-Mounted Displays (HMDs) and their integration into military systems. However, a significant issue with HMDs is the effect of vibration and the associated Vestibulo-Ocular Reflex (VOR). When a human’s head is subject to low-frequency vibration, the VOR stabilizes the eye with respect to objects in the external environment. However, this response is inappropriate in HMDs as the display moves with the user’s head and the VOR blurs the image as it is projected on the human retina. Current compensation techniques suggest increasing the size of displayed graphics or text to compensate for the loss of perceived resolution, which reduces the benefit of advanced high-definition HMDs. While limited research has been done on the VOR in real world settings, this research sought to understand and describe the VOR in the presence of head slued imagery as a function of whole body low-frequency vibration. An experimental HMD was designed and developed to allow a user to perform visual tasks, while also recording and tracking eye movements via video recording and EOG. A human subject experiment was executed to collect initial data on the effect of vibration on eye movements while performing simple tasks chosen to isolate specific eye motions. The results indicate that when fixating on a stationary target, the magnitude of eye movement was greatest at 4-6 Hz of, before steadily decreasing beyond this range. The addition of motion to this target increased the magnitude at 4-6 Hz. The findings are consistent with previous research, which has found a decline in visual performance in this frequency range.

AFIT Designator

AFIT-ENV-13-M-32

DTIC Accession Number

ADA582197

Download

Share

COinS