  For the safe and successful navigation of autonomous vehicles in unstructured
environments, the traversability of terrain should vary based on the driving
capabilities of the vehicles. Actual driving experience can be utilized in a
self-supervised fashion to learn vehicle-specific traversability. However,
existing methods for learning self-supervised traversability are not highly
scalable for learning the traversability of various vehicles. In this work, we
introduce a scalable framework for learning self-supervised traversability,
which can learn the traversability directly from vehicle-terrain interaction
without any human supervision. We train a neural network that predicts the
proprioceptive experience that a vehicle would undergo from 3D point clouds.
Using a novel PU learning method, the network simultaneously identifies
non-traversable regions where estimations can be overconfident. With driving
data of various vehicles gathered from simulation and the real world, we show
that our framework is capable of learning the self-supervised traversability of
various vehicles. By integrating our framework with a model predictive
controller, we demonstrate that estimated traversability results in effective
navigation that enables distinct maneuvers based on the driving characteristics
of the vehicles. In addition, experimental results validate the ability of our
method to identify and avoid non-traversable regions.
