SEANav-Sim: Realistic Underwater Simulation for AUVs with Unity

Simulation tools play a crucial role in the development, testing, and validation of Autonomous Underwater Vehicles (AUVs), significantly reducing the costs, risks, and time associated with traditional sea trials. This paper introduces an advanced simulation environment, SEANav-Sim, specifically developed to support the detection and tracking of pipelines and cables using AUVs. As AUVs are increasingly deployed across diverse underwater missions, reliable and realistic simulation tools have become essential for optimizing their design and operational effectiveness. SEANav-Sim leverages the Unity 3D engine to generate realistic underwater environments, accurately simulating the hydrodynamic behavior of AUVs and emulating sensors such as side-scan sonars and cameras. We begin by reviewing existing underwater simulators to justify our selection of Unity combined with ROS2 integration. Subsequently, we detail the development of a side-scan sonar emulator using ray-tracing techniques. Preliminary results obtained through Hardware-in-the-Loop (HIL) testing demonstrate the simulator's effectiveness in supporting algorithm development and validation, highlighting its potential to significantly reduce the development time and deployment costs of AUVs.