RecNet: An Invertible Point Cloud Encoding through Range Image Embeddings for Multi-Robot Map Sharing and Reconstruction

In the field of resource-constrained robots and the need for effective place recognition in multi-robotic systems, this article introduces RecNet, a novel approach that concurrently addresses both challenges. The core of RecNet's methodology involves a transformative process: it projects 3D point clouds into depth images, compresses them using an encoder-decoder framework, and subsequently reconstructs the range image, seamlessly restoring the original point cloud. Additionally, RecNet utilizes the latent vector extracted from this process for efficient place recognition tasks. This unique approach not only achieves comparable place recognition results but also maintains a compact representation, suitable for seamless sharing among robots to reconstruct their collective maps. The evaluation of RecNet encompasses an array of metrics, including place recognition performance, structural similarity of the reconstructed point clouds, and the bandwidth transmission advantages, derived from sharing only the latent vectors. This reconstructed map paves a groundbreaking way for exploring its usability in navigation, localization, map-merging, and other relevant missions. Our proposed approach is rigorously assessed using both a publicly available dataset and field experiments, confirming its efficacy and potential for real-world applications.