Commercial motion-capture systems produce excellent in-studio
reconstructions, but offer no comparable solution for acquisition
in everyday environments. We present a system for acquiring motions
almost anywhere. This wearable system gathers ultrasonic
time-of-flight and inertial measurements with a set of inexpensive
miniature sensors worn on the garment. After recording, the information
is combined using an Extended Kalman Filter to reconstruct
joint configurations of a body. Experimental results show that even
motions that are traditionally difficult to acquire are recorded with
ease within their natural settings. Although our prototype does not
reliably recover the global transformation, we show that the resulting
motions are visually similar to the original ones, and that the
combined acoustic and inertial system reduces the drift commonly
observed in purely inertial systems. Our final results suggest that
this system could become a versatile input device for a variety of
augmented-reality applications.
