Vertical Accelerator for Visual-Vestibular Acuity Testing and Training

Military personnel are often subjected to significant vertical acceleration while carrying out their duties. Such acceleration can interfere with the individual’s ability to view platform-fixed displays by inducing spatial disorientation and/or motion sickness. The resulting decrease in personnel performance arises from head movements and posture-maintaining muscle coordination that are the body’s response to vestibular-ocular reflexes. Suppression of these reflexes can lead to improved functional performance; repeated exposure to vertical linear motions can desensitize a person from these natural reflexes. The development of a vertical linear accelerator (VLA) system will enable researchers to accurately test for, evaluate, and even provide rehabilitation for the effects of vertical acceleration on the vestibular-ocular reflexes. In the Phase I effort, Dynamic Structures and Materials (DSM) produced a 1/3rd scale VLA prototype using linear motors and air bearing technologies that tracked commanded position within +/-100 microns at speeds up to 7 ft/s. Operational frequencies of up to 4 Hz were demonstrated. Velocity tracking was within 0.9% of the commanded velocity. Sound measurements were within ambient noise levels. DSM proposes this Phase II effort to develop and install a full-scale VLA that will provide an important training and testing tool for both screening and desensitization applications.