I'm trying to compensate a 3-axis MEMS accelerometer for temperature. I can access a climate chamber where the device can be rotated in ONE axis. There is another place where I can rotate two axis, but only at room temperature.
My goal is to measure the euler angles in the space. There are NO other accelerations disturbing the earth gravity field.
I wonder what the correct order is.
First temperature compensation, then calibration (I use a nonlinear optimization to estimate the cross axis sensitivity, scale factors and bias terms) or the other way round?
My attempt to compensate the temperature is to find a function that maps the raw values at given temperature to the raw values at a reference temperature.
The sensor cannot be turned in 2 axis in the climate chamber. To compensate all three axis in one attempt (the heating takes a lot of time...) I've got to tilt the sensor first about 45°, then rotate them with a motor, otherwise one axis would not deliver information (the axis I turn around). Due to misaligment errors etc it does matter, if I turn the device left or right round for sure. But that makes it impossible to find a bijective function.
So should I calibrate the sensor first at room temperature and then apply a temperature compensation? How?
Thank you very much for your ideas!