Angular Velocity Estimation Using a Magnetometer and Accelerometer
AssigneeKionix, Inc.
InventorErik ANDERSON
Life of this patent
Estimating the term…
Abstract
A system and method for estimating angular velocity are provided. The system and method use an accelerometer and magnetometer to estimate an angular velocity in place of a gyroscope in 9-axis sensor fusion to estimate angular orientation. The final angular velocity estimate is constructed from two partially independent angular velocity estimates, one using only magnetometer measurements and the other using only accelerometer measurements. The unobservable portion of each partial angular velocity estimate is provided by a projection from a third complete estimate that uses both accelerometer and magnetometer data.
Claims23
A system comprising:
- an angular velocity processor stored in memory and executing on a processor and causes the processor to:
- determine a first angular velocity component from field measurements provided by a magnetometer;
- determine a second angular velocity component from field measurements provided by an accelerometer;
- determine a third angular velocity component from the field measurements provided by the magnetometer and accelerometer, wherein the third angular velocity component is not included in the first angular velocity component and the second angular velocity component;
- compensate the first angular velocity component with a projection of the third angular velocity component around a first axis;
- compensate the second angular velocity component with a projection of the third angular velocity component around second axis;
- and
- generate an angular velocity estimate using the compensated first angular velocity component and the compensated second angular velocity component.
A system comprising:
- a first filter stored in memory and executing on a processor and causes the processor to filter first field measurements associated with an accelerometer;
- a second filter stored in memory and executing on a processor and causes the processor to filter first field measurements associated with a magnetometer;
- an angular velocity processor stored in memory and executing on a processor and causes the processor to:
- receive first filtered field measurements provided by the accelerometer;
- receive second filtered field measurements provided by the magnetometer;
- and
- generate, using a rotation matrix, an angular velocity estimate using the first and second field measurements.
Dependencies are inferred from the claim text.