  Motion estimation approaches typically employ sensor fusion techniques, such
as the Kalman Filter, to handle individual sensor failures. More recently, deep
learning-based fusion approaches have been proposed, increasing the performance
and requiring less model-specific implementations. However, current deep fusion
approaches often assume that sensors are synchronised, which is not always
practical, especially for low-cost hardware. To address this limitation, in
this work, we propose AFT-VO, a novel transformer-based sensor fusion
architecture to estimate VO from multiple sensors. Our framework combines
predictions from asynchronous multi-view cameras and accounts for the time
discrepancies of measurements coming from different sources.
  Our approach first employs a Mixture Density Network (MDN) to estimate the
probability distributions of the 6-DoF poses for every camera in the system.
Then a novel transformer-based fusion module, AFT-VO, is introduced, which
combines these asynchronous pose estimations, along with their confidences.
More specifically, we introduce Discretiser and Source Encoding techniques
which enable the fusion of multi-source asynchronous signals.
  We evaluate our approach on the popular nuScenes and KITTI datasets. Our
experiments demonstrate that multi-view fusion for VO estimation provides
robust and accurate trajectories, outperforming the state of the art in both
challenging weather and lighting conditions.
