Ensuring accuracy of angle estimation in eCompass

Here's a discussion on the relationship between errors in the outputs from accelerometer and magnetometer sensors and the resulting errors in the roll, pitch and yaw angles computed by a tilt-compensated electronic compass (eCompass) or 3-D Pointer application.

The error analysis starts by determining the relationship between accelerometer errors and errors in the estimated roll and pitch angles. The consequent error in compass angle is then derived from the roll and pitch angle errors. Expressions are then derived for the errors in the compass heading angle resulting from errors in the magnetometer sensor and the hard and soft iron calibration. The final section extends the discussion to the statistics of time varying sensor outputs.

View the PDF document for more information.

Originally published by Freescale Semiconductor Inc. at www.freescale.com as "Accuracy of Angle Estimation in eCompass and 3-D Pointer Applications".