Development of Low Volume Shape Memory Alloy Variable Ballast System for AUV Use
Abstract
The long term goal is to develop a near silent, air free, electrically operated ballast system for use in underwater vehicles. Objectives are to arrive at a workable design for a ballast system that decreases and increases buoyancy at a range of depths, in increments small enough for precise control. It would operate on command, silently, electrically, controllably, and without release of any material or air. Examine how the fabrication and shape memory training methods effect each other for the different actuator designs. Operate and test actuators for system performance: buoyancy to volume ratio, life cycle performance, fatigue, response speed, power consumption, robustness, reliability, depth, etc. The basic concept is that a shape memory alloy (SMA) will enclose a small volume of air or vacuum. The transformation of the shape memory alloy between crystalline phases effects a transformation between two shapes. If these shapes are selected so as to enclose different volumes, then the volume enclosed by the shape memory alloy--and thus its wet displacement--will change when they do. (see figure 1) By splitting the enclosed volume among many identical elements, we achieve robustness to imprecise design/manufacturing or material failures. Also any number of the individually sealed elements can be used to fill whatever volume is required providing great design flexibility.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 30, 1998
- Accession Number
- ADA544785
Entities
People
- Graeme J. Rae
Organizations
- Florida Institute of Technology