Torque Analysis of a Flat Reconfigurable Magnetic Coupling Thruster for Marine Renewable Energy Systems Maintenance AUVs

Abstract

The concept of reconfigurable magnetic coupling thrusters (RMCT) applied to the vectorial thrust of autonomous underwater vehicles (AUV) has been recently developed and presented. This technology ensures greater robot watertightness with enhanced maneuvering capabilities, which are desired features in agile AUVs for marine renewable energy (MRE) system maintenance. It is possible since in RMCTs the driving torque is magnetically transmitted to the propeller, which has its orientation changed. This work is focused on the coupling and control torque calculation and further analysis of the latest prototype version (Flat-RMCT), in the static condition for the full thrust vector range. For this purpose, a numerical model is implemented and validated with experimental results. The numerical model is based on the finite volume integral method. The results indicate that the minimum magnetic reluctance propensity creates not only the expected magnetic spring effect but also an auto-driving torque due to the non-axial symmetry of coupling rotors, which exists only for reconfigurable couplings. Mathematical functions are proposed to model these effects and they are used to extend the understanding of the coupling. These models can be used to compose a full and accurate dynamic model for a better RMCT simulation, identification, and control.

Tidal Stream Turbine Biofouling Detection and Estimation: A Review-Based Roadmap

“…A recent development in this field involves the implementation of reconfigurable magnetic coupling thrusters in the vectorial thrust of autonomous underwater vehicles. This technology offers improved water-tightness and enhanced maneuvering capabilities, which are highly desirable features in agile underwater vehicles used for visual inspection and maintenance of TSTs [43,44]. While the concept shows great promise, it is important to develop viable submersible prototypes that feature full waterproof mechanisms in order to effectively implement the technology.…”

Advances in Reconfigurable Vectorial Thrusters for Adaptive Underwater Robots

“…To create a torque between rotors, it is necessary to create a misalignment between them, with θ l = θ m . This behaviour makes the magnetic coupling working as a non-linear torsional spring, which allows naming the difference between θ l and θ m as the magnetic spring angle θ [101]. Sometimes, θ is defined as the relative mechanical displacement angle [102].…”

“…A further torque analysis of this F-RMC is addressed in [101]. It states that, when α = 0°we have classical magnetic couplings (parallel rotors axes).…”

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“…As far as most available AUVs, propulsion systems can be classified into three kinds: Propeller propulsion, biomimetic propulsion and vectorial propulsion [8,9]. In this paper, our team focuses on vectorial propulsion system because it outperforms the others in excellent steering ability.…”