Underwater Vehicle Bouyancy System

Abstract

A multiple stage buoyancy changing system, or variable buoyancy device, for an underwater vehicle. The multiple stage buoyancy changing system comprises: a pressure hull containing a flexibly-sized internal fluid reservoir; a flexibly-sized external fluid reservoir attached to the pressure hull and connected to the internal reservoir; a system of devices and channels configured to move fluid between the internal fluid reservoir and the external fluid reservoir to change a displaced volume of the vehicle. Each stage of the variable buoyancy device can be optimized for maximum energy efficiency while changing the vehicle's displaced volume within an ambient pressure range. A control system for the variable buoyancy device engages different stages depending on ambient external pressure such that maximum energy efficiency is achieved over a large range of pressures / depths.

Description

INTRODUCTION [0001]This application claims priority to U.S. Provisional Patent Application Ser. No. 61 / 309,420, filed Mar. 1, 2010, titled Underwater Glider, and is a continuation of U.S. patent application Ser. No. 12 / 890,584, filed Sep. 24, 2010, titled Autonomous Underwater Vehicle, the disclosures of which are incorporated herein by reference in their entireties.[0002]The present teachings relate to a multiple stage buoyancy changing system for underwater vehicles.BACKGROUND[0003]Underwater vehicles that are propelled by changes in buoyancy have become commercial in recent years and have demonstrated the ability to operate at sea for long periods. Such vehicles, including underwater gliders, are in use, and continue to be developed, for oceanic research, coastline monitoring, and other applications. Existing designs for a buoyancy changing system, or “buoyancy engine,” are typically specialized to perform energy efficiently in limited ranges of depths, or pressures, such as, for...

AI Technical Summary

Benefits of technology

[0010]The present teachings further provide a multiple stage variable buoyancy device for an autonomous underwater vehicle that includes a pump and motor combination with a continuous variable transmission that can electronically adapt to a torque-speed curve to rapidly obtain an optimal pumping rate for changing buoyancy.

Problems solved by technology

The energy-efficient operation of existing underwater vehicles is therefore limited to a particular band of underwater depths.

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