ZodiAq: An Isotropic Flagella-Inspired Soft Underwater Drone for Safe Marine Exploration.

2025-01-23

Soft Robotics

AI Summary

To address challenges in complex underwater environments—including strong fluid disturbances, severe dynamic coupling, and the need for safe interaction with marine life—this paper proposes ZodiAq, a dodecapod soft underwater unmanned vehicle inspired by prokaryotic bacterial flagella. It features a regular dodecahedral topology and isotropic soft actuation arms, introducing the first flagellum-inspired soft architecture for underwater robotics. A high-fidelity digital twin is established using Cosserat rod strain modeling, and an adaptive hydrodynamic controller is designed based on model reduction. The system integrates a Raspberry Pi embedded platform for multimodal sensing (IMU, depth, vision) and acoustic communication. Experiments demonstrate stable crawling gaits, robust obstacle traversal over complex terrain, and non-invasive inspection capabilities in ecologically sensitive areas such as coral reefs and shipwrecks. ZodiAq significantly enhances underwater operational safety, environmental adaptability, and ecological compatibility.

Technology Category

• Intelligent Robots: Other Foundations and Applications
• Humans and AI: Human-Aware Planning and Behavior Prediction
• Multiagent Systems: Multiagent Systems under Uncertainty

Application Category

• Systems and Infrastructure for Web, Mobile and WoT: Energy management for devices in mobile Web and WoT environments
• Responsible Web: Data and user privacy-enhancing technologies for the Web
• Search and Retrieval-Augmented AI: Vertical and domain-specific search

Abstract

The inherent challenges of robotic underwater exploration, such as hydrodynamic effects, the complexity of dynamic coupling, and the necessity for sensitive interaction with marine life, call for the adoption of soft robotic approaches in marine exploration. To address this, we present a novel prototype, ZodiAq, a soft underwater drone inspired by prokaryotic bacterial flagella. ZodiAq's unique dodecahedral structure, equipped with 12 flagella-like arms, ensures design redundancy and compliance, ideal for navigating complex underwater terrains. The prototype features a central unit based on a Raspberry Pi, connected to a sensory system for inertial, depth, and vision detection, and an acoustic modem for communication. Combined with the implemented control law, it renders ZodiAq an intelligent system. This article details the design and fabrication process of ZodiAq, highlighting design choices and prototype capabilities. Based on the strain-based modeling of Cosserat rods, we have developed a digital twin of the prototype within a simulation toolbox to simplify analysis and control. To optimize its operation in dynamic aquatic conditions, a simplified model-based controller has been developed and implemented, facilitating intelligent and adaptive movement in the hydrodynamic environment. Extensive experimental demonstrations highlight the drone's potential, showcasing its design redundancy, embodied intelligence, crawling gait, and practical applications in diverse underwater settings. This research contributes significantly to the field of underwater soft robotics, offering a promising new avenue for safe, efficient, and environmentally conscious underwater exploration.

Problem

• Addressing hydrodynamic challenges in underwater robotic exploration
• Developing a soft drone for sensitive marine life interaction
• Optimizing adaptive movement in complex aquatic environments

Innovation

• Soft drone with 12 flagella-like arms
• Digital twin using Cosserat rod modeling
• Model-based controller for adaptive movement