Manipulider: A Multi-Engine Buoyancy-Controlled Robot for Thrusterless Underwater Gliding and Manipulation
This work addresses the need for safe, entanglement-free underwater robots for delicate environments, but the results are preliminary and incremental.
The paper presents Manipulider, a buoyancy-actuated underwater robot that achieves thrusterless gliding and manipulation via four syringe-based buoyancy engines, demonstrating a 40 mL displacement range per engine, maximum static tilts of 64.6°, and proof-of-concept payload transport without thrusters.
The Manipulider is a buoyancy-actuated underwater robot that enables thrusterless, glide-like locomotion and attitude-based manipulation, while providing a magnetic modular interface for rapid payload swapping (e.g., a gripper or sensors). Four syringe-based buoyancy engines distributed around the body jointly regulate net buoyancy and the center of buoyancy, allowing the vehicle to maintain large tilt angles through static force balance without continuous thrust and to avoid propeller entanglement risks. We present the mechanical and electrical design, calibration procedure, and control architecture. Experiments with a gripper attached (no external payload) show a controllable buoyancy-displacement range of 40 mL per engine ({\approx}160 g total buoyancy authority), maximum statically stable tilts of 64.6° (single-engine) and 61.8° (dual-engine), and representative vertical and tilt-transition dynamics. We further demonstrate tilt regulation, controlled ascent/descent primitives, and a proof-of-concept gripper-based payload-transport sequence without thrusters.