LOTUSim: Multi-Domain Simulator for Marine Robotics

2026-07-03

AI Summary

This work addresses the limitations of existing marine robotics simulation platforms, which struggle to support large-scale, heterogeneous maritime unmanned systems in real-time collaborative missions due to low-fidelity environmental modeling and insufficient multi-user human–robot interaction capabilities. To overcome these challenges, the authors propose an open-source, real-time, multi-domain simulation platform that integrates aerial, surface, and underwater systems and enables collaborative multi-operator control. Key innovations include an efficient layered ocean current model grounded in Ekman theory, a distributed real-time simulation architecture, and a validation methodology incorporating ocean reanalysis data. Experimental results demonstrate that the platform maintains high visual fidelity and strict real-time performance while scaling to large unmanned swarms, with the proposed current model significantly outperforming conventional Gauss-Markov approaches in accuracy when validated against real-world oceanographic data.

Abstract

Simulation is essential for maritime robotics, supporting operator training, mission rehearsal, and human-vehicle interaction in environments where real-world testing is costly or hazardous. Existing simulators focus primarily on autonomy systems and often lack human-in-the-loop interaction and realistic environmental physics. This paper introduces LOTUSim, an open-source, real-time maritime simulator supporting multi-user interaction across aerial, surface, and underwater robotic systems for coordinated naval-style operations. The first contribution of this work is enabling real-time interactive performance for users while ensuring scalability to large fleets operating within a shared interactive simulation environment. Validation demonstrates robust human-in-the-loop performance, maintaining strict real-time execution and high visual fidelity while scaling to large heterogeneous maritime drone swarms. The second contribution is a computationally efficient, Ekman-inspired layered, underwater current model that captures wind-driven, depth-dependent flow dynamics with sufficient physical fidelity for large-scale simulations. Validation against ocean reanalysis data demonstrates substantially improved accuracy compared to commonly used stochastic Gauss-Markov current models. These results confirm LOTUSim's suitability as a simulation platform for operatorin-the-loop maritime robotics research.

Problem

• marine robotics
• human-in-the-loop
• real-time simulation
• multi-domain simulation
• underwater current modeling

Innovation

• multi-domain simulation
• human-in-the-loop
• real-time interaction
• layered underwater current model
• heterogeneous drone swarms