raw_linear_acceleration

Eigen::Vector3d raw_linear_acceleration = Eigen::Vector3d::Zero()

Proper linear acceleration read by the IMU, in m/s².

The acceleration read by an accelerometer is:

\[ {}_I a_{WI} - {}_I g \]

with \({}_I a_{WI}\) the proper linear acceleration of the IMU frame \(I\), and \({}_I g\) the standard acceleration of gravity in the IMU frame.

Pay attention to the fact that proper acceleration is different from coordinate acceleration, which would be the acceleration of the IMU with respect to the mobile IMU frame in this case. (There is a gyroscopic term in the latter but not in the former.) See for instance the Wikipedia Accelerometer article.