How to remove Gravity factor from Accelerometer readings in Android 3-axis accelerometer

Question

Can anyone help on removing the g factor from accelerometer readings?

I am using SensorEventListener with onSensorChanged() method for getting Sensor.TY

Answer 1

Just subtract out g (~9.8m/s^2) times the z direction of the rotation matrix. Or to be more explicit about it, let

a = your accelerometer reading,
R = your rotation matrix (as a 9-long vector).

Then what you want is

(a[0]-g*R[6], a[1]-g*R[7], a[2]-g*R[8]).