Idhl Holdings, Inc.

Hillcrest Laboratories, Inc.

Yun Li

Bryan Austin Cook

Mark A Turner

Matthew G Liberty

Methods, apparatus, and systems for calibrating the Zero Rate Offset (ZRO) of a gyroscope are disclosed.

Methods and apparatus for determining the zero rate output of a sensor using a learning algorithm

Methods, apparatus, and systems for estimating and calibrating a gyroscope's scale using a magnetometer mounted on the same device by rotating the device about an axis multiple times; and, during the first rotation, storing the magnetometer magnetic field reading and a heading (from integration of the gyroscope readings) at each of a plurality of angular reference points; then, during each subsequent rotation, determining magnetometer/gyroscope-heading output pairs for which the magnetometer output matches the magnetometer reading corresponding to one of the reference points, thereby indicating that the device has reached the same heading as the matching reference point; then, for each matching output sample pair, using that magnetometer/gyroscope-heading output sample pair to update the gyroscope scale factor for the corresponding angular reference point; and averaging those scale estimates to generate a final gyroscope scale factor estimate.

Methods, apparatus and systems for gyroscope scale calibration

A variable mapped on an orientation of a device is smoothed to have a gradual evolution by adjusting the estimated orientation of the device obtained via sensor fusion or other sensor processing to take into consideration a current measured angular velocity.

Mapped variable smoothing evolution method and device

The present inventions generally relate to methods and dedicated apparatuses outputting a variable mapped on a device orientation in a non-inertial reference system, with the device orientation being estimated using measurements of motion sensors (such as 3D accelerometers and gyroscopes) and a magnetometer or other similar sensors including cameras. A variable mapped on an orientation of a device is smoothed to have a gradual evolution by adjusting the estimated orientation of the device obtained via sensor fusion or other sensor processing to take into consideration a current measured angular velocity.

A method, a filtering module, and a computer-readable medium are configured to filter measurements acquired in a sensor reference system. Filtered measurements of motion sensors and a magnetometer attached to the device may then be used to determine orientation of a device in a non-inertial reference system. The measurements are filtered in a reference system, whose position relative to the sensor system can be calculated, and in which gravity and Earth's magnetic field have substantially constant direction and magnitude during the filtering window.

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Clarksburg, MD, United States of America

Yun Li