This paper presents AquaMILR+, an untethered limbless robot designed for agile navigation in complex aquatic environments. The robot features a bilateral actuation mechanism that models musculoskeletal actuation in many anguilliform swimming organisms which propagates a moving wave from head to tail allowing open fluid undulatory swimming. This actuation mechanism employs mechanical intelligence, enhancing the robot's maneuverability when interacting with obstacles. AquaMILR+ also includes a compact depth control system inspired by the swim bladder and lung structures of eels and sea snakes. The mechanism, driven by a syringe and telescoping leadscrew, enables depth and pitch control-capabilities that are difficult for most anguilliform swimming robots to achieve. Additional structures, such as fins and a tail, further improve stability and propulsion efficiency. Our tests in both open water and indoor 2D and 3D heterogeneous aquatic environments highlight AquaMILR+'s capabilities and suggest a promising system for complex underwater tasks such as search and rescue and deep-sea exploration.
@article{arxiv.2409.18383,
title = {AquaMILR+: Design of an untethered limbless robot for complex aquatic terrain navigation},
author = {Matthew Fernandez and Tianyu Wang and Galen Tunnicliffe and Donoven Dortilus and Peter Gunnarson and John O. Dabiri and Daniel I. Goldman},
journal= {arXiv preprint arXiv:2409.18383},
year = {2024}
}