Ground-based performance evaluation of a wearable vision+inertial navigation system for iss net habitable volume estimation

Astronauts living and working onboard the International Space Station (ISS) provide a unique opportunity to capture and quantify the architectural layout and 3-D space utilization in a microgravity environment. As NASA looks to design and build future space exploration vehicles, information gathered from the ISS human-system operational environment will provide critical data on minimum net habitable volume (NHV). Fourteen datasets were collected from walking specified routes and performing representative “tasking” in the ISS mockup facility at Johnson Space Center using a hand-portable custom multi-sensor assembly developed by Draper for the U.S. Army. This totaled a cumulative traverse distance of approximately 1,943 meters (1.2 miles) over more than 60 minutes of recording. The average route was approximately 139 m (455 ft.), and 4.3 minutes in duration. Distance estimation, final position estimation error, and tasking location were estimated using Draper's “Mischief” vision+inertial navigation algorithm. The results demonstrated final position errors of less than 1% of the estimated total route distance. Additionally, initial testing of the position accuracy of the system demonstrated the ability to estimate a position with regard to a specific rack (1.02 m; 40 in. wide) in the ISS Destiny module mockup. Overall, the results are encouraging for further development of a wearable kinematic system for use onboard the ISS to quantify astronaut position and orientation to validate NHV models for the design of future habitats.