Hello,
I am trying to use the output of the LSM6DSL (accelerometer + gyroscope) to feed an orientation filter. While the accelerometer part is easy to interpret, I am having some trouble with the gyroscope. Apologies if my question is trivial, I have not found any clear answer on the subject so I must have missed something very obvious.
The LSM6DSL returns the angular velocity of the device as a vector of 3 Euler angles, one per axis. With this sort of representation this usually means that the underlying rotation R is a composition of 3 axial rotations, either intrinsic or extrinsic, such as R = R_x * R_y * R_z or any of the permutations. The actual order of the permutation being crucial. The documentation is not 100% clear to me in what order I should apply the axial rotations to describe R.
There is no textual mention of this in the Application Note but on page 2 there is a diagram showing:
- The axis of the accelerometer
- The rotation Omega_Y, Omega_P, Omega_R
Where I guess that Omega_Y, _P and _R respectively stand for Yaw, Pitch, Roll. From my understanding when using this sort of notations, this implies that:
- The rotation is intrinsic
- The rotation around the Yaw axis should be applied first, then the pitch, finally the Roll, as in R = R_roll * R_pitch * R_yaw.
When matching this information with the axis of the accelerometer, this would mean that R = Ry * Rx * Rz.
Is this correct ? Or should this still be R = Rx * Ry * Rz which is the most widespread (and natural) rotation order ? Or any other thing really ?
Thank you for your time,
AdB
