  Accurately perceiving location and scene is crucial for autonomous driving
and mobile robots. Recent advances in deep learning have made it possible to
learn egomotion and depth from monocular images in a self-supervised manner,
without requiring highly precise labels to train the networks. However,
monocular vision methods suffer from a limitation known as scale-ambiguity,
which restricts their application when absolute-scale is necessary. To address
this, we propose SelfOdom, a self-supervised dual-network framework that can
robustly and consistently learn and generate pose and depth estimates in global
scale from monocular images. In particular, we introduce a novel coarse-to-fine
training strategy that enables the metric scale to be recovered in a two-stage
process. Furthermore, SelfOdom is flexible and can incorporate inertial data
with images, which improves its robustness in challenging scenarios, using an
attention-based fusion module. Our model excels in both normal and challenging
lighting conditions, including difficult night scenes. Extensive experiments on
public datasets have demonstrated that SelfOdom outperforms representative
traditional and learning-based VO and VIO models.
