  Multiple rigidly attached Inertial Measurement Unit (IMU) sensors provide a
richer flow of data compared to a single IMU. State-of-the-art methods follow a
probabilistic model of IMU measurements based on the random nature of errors
combined under a Bayesian framework. However, affordable low-grade IMUs, in
addition, suffer from systematic errors due to their imperfections not covered
by their corresponding probabilistic model. In this paper, we propose a method,
the Best Axes Composition (BAC) of combining Multiple IMU (MIMU) sensors data
for accurate 3D-pose estimation that takes into account both random and
systematic errors by dynamically choosing the best IMU axes from the set of all
available axes. We evaluate our approach on our MIMU visual-inertial sensor and
compare the performance of the method with a purely probabilistic
state-of-the-art approach of MIMU data fusion. We show that BAC outperforms the
latter and achieves up to 20% accuracy improvement for both orientation and
position estimation in open loop, but needs proper treatment to keep the
obtained gain.
