Calibration Model
The STorM32 controller implements a relatively simple calibration model for the accelerometers and gyros.
Importantly, the calibration constants are with respect to the IMU frame, i.e., applied before the rotation into the gimbal frame as specified by the IMU orientation settings. The offset value is however applied after this rotation, i.e., is with respect to the gimbal frame.
Accelerometer
Each axis is converted as follows:
- a = (a_meas - a_zero) * a_scale - a_offset
a_meas: value obtained form the IMU
a_zero: 'Acc Zero' calibration constant determined by calibration procedure
a_scale: 'Acc Scale' calibration constant determined by calibration procedure
a_offset: offset entered in the GUI ("Pitch Offset" or "Roll Offset" or "Yaw Offset")
Gyro
Each axis is converted as follows:
- g = g_meas - g_zero
g_meas: value obtained form the IMU
g_zero: bias determined during gyro calibration at startup, or 'Gyro Zero' calibration constant determined by calibration procedure