  We present a single neural network architecture composed of task-agnostic
components (ViTs, convolutions, and LSTMs) that achieves state-of-art results
on both the ImageNav ("go to location in <this picture>") and ObjectNav ("find
a chair") tasks without any task-specific modules like object detection,
segmentation, mapping, or planning modules. Such general-purpose methods offer
advantages of simplicity in design, positive scaling with available compute,
and versatile applicability to multiple tasks. Our work builds upon the recent
success of self-supervised learning (SSL) for pre-training vision transformers
(ViT). However, while the training recipes for convolutional networks are
mature and robust, the recipes for ViTs are contingent and brittle, and in the
case of ViTs for visual navigation, yet to be fully discovered. Specifically,
we find that vanilla ViTs do not outperform ResNets on visual navigation. We
propose the use of a compression layer operating over ViT patch representations
to preserve spatial information along with policy training improvements. These
improvements allow us to demonstrate positive scaling laws for the first time
in visual navigation tasks. Consequently, our model advances state-of-the-art
performance on ImageNav from 54.2% to 82.0% success and performs competitively
against concurrent state-of-art on ObjectNav with success rate of 64.0% vs.
65.0%. Overall, this work does not present a fundamentally new approach, but
rather recommendations for training a general-purpose architecture that
achieves state-of-art performance today and could serve as a strong baseline
for future methods.
