A vibrotactile display for aiding extravehicular activity (EVA) navigation in space

A tactile display to increase an astronaut's situational awareness during an extravehicular activity (EVA) has been developed and ground tested. The Tactor Locator System (TLS) is a non-intrusive, intuitive display that can be configured to convey position information via a vibrotactile stimulus applied to the subject's torso region. In the Earth's 1-G environment, perception of position and velocity is determined by the body's individual sensory systems: the visual, vestibular and somatosensory systems (skin, muscle and joint sensors). Under normal sensory conditions, redundant information from these sensory systems provide humans with an accurate sense of their position and motion. However, altered environments, including exposure to weightlessness, can lead to conflicting visual and vestibular cues, resulting in decreased situational awareness. The TLS was designed to provide somatosensory cues to complement the visual system during EVA operations. An EVA task was simulated on a computer graphics workstation with a display of the International Space Station (ISS) and a target astronaut at an unknown location. Subject's were required to move about the ISS and acquire the target astronaut using either an auditory cue at the outset, or the TLS. Subject's used a 6 degree-of-freedom input device for translation and rotation. The TLS in this experiment was configured to act as a position aid, providing target direction information to the subject through a localized stimulus. Results show that the TLS decreases reaction time (p = 0.001) and movement time (p = 0.001) for subject (astronaut) movement about the ISS. The TLS is a useful aid in increasing an astronaut's situational awareness, and warrants further testing to explore other uses, tasks and configurations. Thesis Supervisor: Dr. Dava J. Newman Tile: Associate Professor of Aeronautics and Astronautics