Bidirectional Resonant Propulsion and Localization for AUVs

Abstract

Battery life, reliability, and localization are prominent challenges in the design of autonomous underwater vehicles (AUVs). This work aims to address facets of these challenges using a single system. We describe the design of a bidirectional resonant pump that uses a single electromagnetic voice coil motor (VCM) capable of rotation around a central two degree-of-freedom flexure stage axis. This actuator design produces highly efficient resonant motion that drives two orthogonally oriented diaphragms simultaneously. The operation of this diaphragm pump mechanism produces both adjustable thrust vectors at the aft surface of the AUV and a monotonic relationship between thrust vectors and operating frequency. We propose using the unique frequency to thrust relationship to enhance AUV localization capabilities. We construct a prototype and use it to experimentally demonstrate the feasibility of the directionally-tunable resonance concept.