Design and Simulation of a Novel High-Speed Omnidirectional Fully-Actuated Underwater Propulsion Mechanism

Abstract

This paper details the design and simulation of a novel position control mechanism for marine operations or inspection in extreme, hostile, or high-speed turbulent environments where unprecedented speed and agility are necessary. The omnidirectional mechanism consists of a set of counter-rotating blades operating at frequencies high enough to dampen vibrational effects on onboard sensors. Each rotor is individually powered to allow for roll control via relative motor effort and attached to a servo-swashplate mechanism, enabling quick and powerful manipulation of fluid flow direction in a hull’s coordinate frame without the need to track rotor position. The mechanism inherently severs blade loads from servo torques, putting all load on the main motors and minimizing servo response time, while exploiting consistent blade momentum to minimize the corresponding force response time. The mechanical design and kinematic analysis of each subsystem is presented, followed by kinematic and hydrodynamic analysis of the hull and surrounding fluid forces during various blade maneuvers. Special maneuvers are verified using Computational Fluid Dynamic (CFD) software. Finally, a controller is constructed with decoupled parameters for each degree of freedom.