Perception and Sensing Technologies for Underwater Robots: A Review

Environmental perception, a cornerstone technology for underwater robotics in marine exploration, confronts significant challenges due to the complexity of underwater environments. This paper systematically reviews recent advancements and trends in underwater environmental perception technologies. Focusing on the two dominant sensing modalities: acoustics and optics, we present key techniques including target detection, positioning, and communication based on acoustic sensing, as well as image enhancement, target recognition and classification, and 3D reconstruction based on optical sensing. The application of multimodal sensor fusion is also explored. Furthermore, an extended discussion evaluates other modalities such as magnetic and electric field sensing, highlighting their potential and constraints in underwater scenarios. Finally, the study synthesizes existing technological bottlenecks and outlines future research directions, serving as a reference for environmental perception in underwater robots.