In many sports, the orientation of an athlete or a sports device plays a major role for the outcome on an event. The orientation can be determined using magnetometers and inertial measurement units (IMU) attached to the moving person or object. Applications of an orientation determination might be simple style evaluations or advanced pattern recognition based performance analyses and feedback systems. An example of the latter one is given by ski jumping. The length of a jump is highly influenced by the take-of angle and the orientation of the skis and the athlete during the jump. A pattern recognition based feedback system could analyze the jump phases and suggest the best possible orientation for each phase.

Our current research is focused on the orientation determination using angular rate measurements of gyroscopes and magnetometer data supported by the readings of an accelerometer. Quaternion based integration methods allow an accurate calculation of the orientation of a gyroscope (and thereby the sports device) at all times. Magnetometers can provide additional information about the orientation but are highly influenced by soft-iron and hard-iron effects. In combination with an accelerometer, gyroscope and magnetometer data can be fused to an accurate and robust orientation determination.

Further investigations in the area of IMU-based orientation determination are currently conducted in the fields of rowing (boat orientation) and scuba diving (diver's body pose and fin kick motion).