Accelerometers compensation

[youngguekim]

I am writing to ask some advice.

I am Using sensor fusion development kit (FRDM-FXS-MULT2-B and FRDM-K64F) and Toolbox for window with USB cable

before i use sensor, other Accelerometers need a offset compensation to find a correct 0g and i can get a compensation value without second compensation

for example, slow, fast, inline calibration

Accelerometer in sensor fusion development already did a calibration??  How it progress a compensation?

Thank you.

[michaelestanley · Accepted solution]

For most applications to date, we've generally found it unnecessary to do additional calibration of our accelerometers used for sensor fusion.  The factory calibration is pretty good, and any post-layout offsets get gobbled up by the acceleration noise terms.  The exception to this would be where we want the best possible inertial navigation.  I don't generally believe in pure inertial navigation, but when combined with various wireless technologies, it can help lower battery use while maintaining precision.  For those cases, we have some additional (proprietary) routines in our back pocket.  But so far, we haven't needed them.

Regards,

Mike

[josol]

if raw accelerometer value is ( 0, 0, 1.03) in stationary state

To correct accelerometer offset, just should i write -30mg to OFF_Z register(0x31) ??

[markpedley]

In general no, that is not a good approach.

The error you see if caused by three sources:

- the largest is the offset error

- the second largest is the gain error

- the smallest is the cross axis error where a stimulus in one axis affects another.

Your 30mg error is the result of all three errors so a simple offset subtraction will, in general, not be suitable.

[youngguekim]

Thank you so much