Orient-2: a realtime wireless posture tracking system using local orientation estimation

A realtime posture tracking system has been developed using a network of compact wireless sensor devices worn by the user. Each device is a complete inertial/magnetic tracking unit which performs in situ orientation estimation based on its own sensor readings, using a complementary quaternion-based filter. Compared to existing systems which transmit raw sensor data to a PC for processing, it is shown that this technique reduces bandwidth requirements by 79% for typical usage. In combination with a time division multiple access scheme, this reduction allows for full-body tracking using 15 devices at a 64Hz update rate through a single 250kbps receiver. The data is applied to a rigid body model of the subject to provide a realtime display, and can be exported for use in major animation packages.