Automatic and adaptive calibration of 3D field sensors

Embedded sensors are an emerging trend in mobile consumer devices. Calibration of the sensors in this environment can be prohibitively difficult for the user. We propose an automatic calibration algorithm that can be used for any three-dimensional sensor sensing some external field. In particular, it is suitable for calibrating a three-axis magnetometer. The algorithm is based on recursive fitting of an ellipsoid to collected samples from the sensor. It can adaptively update the calibration parameters and is completely invisible to the user.