SAFT: Real-Time Tracking and Mapping With Self-Supervised Robust Stereo Matching for Underwater Vehicles

Robust and efficient tracking and mapping are critical for underwater vehicles, but remain challenging due to degraded visual quality, ambiguous features, and limited computational resources. Although recent deep learning-based stereo matching methods have significantly improved geometric perception for robots, most existing approaches struggle to simultaneously achieve high speed and strong generalization. To address these challenges, we propose SAFT, a tracking and mapping framework based on self-supervised, robust, and real-time stereo matching. SAFT introduces three key innovations: 1) SAFT-Stereo, a novel stereo matching network that integrates cost aggregation with iterative optimization to enable efficient disparity estimation in feature-sparse regions; 2) a spatiotemporal self-supervised loss that leverages both spatial and temporal constraints to provide stable training signals in textureless regions; and 3) SAFT-DSOL, a real-time tracking and mapping algorithm that integrates the self-supervised models to achieve robust localization and dense reconstruction. Extensive experiments on both public and custom underwater datasets demonstrate that SAFT-Stereo achieves the best generalization performance among all real-time methods, while requiring only 1/6 of the inference time of RT-IGEV++. Moreover, the proposed SAFT-DSOL enables stable and efficient tracking and achieves real-time dense reconstruction in indoor shipwreck scenarios. The code is available at github.com/c237814486/SAFT-Stereo.