Available at: https://digitalcommons.calpoly.edu/theses/2929
Date of Award
6-2024
Degree Name
MS in Mechanical Engineering
Department/Program
Mechanical Engineering
College
College of Engineering
Advisor
Eric Espinoza-Wade
Advisor Department
Mechanical Engineering
Advisor College
College of Engineering
Abstract
Autonomous underwater vehicles (AUVs) play a vital role in the surveillance and mapping of our oceans, often requiring extensive travel in extreme environments. These data-gathering missions benefit from extended durations, making the minimization of power consumption a key consideration in AUV design. One effective strategy to reduce energy use in AUVs is to implement a variable buoyancy system (VBS) for depth control. The purpose of this work is to design, develop, test, and model a variable buoyancy system to enhance the efficiency and capabilities of a high-speed, long-range AUV.
After evaluating various VBS designs, a piston-cylinder buoyancy system was selected and developed. A prototype was produced, featuring two manually controlled piston-cylinder units housed within a cylindrical acrylic shell. This setup was tested at shallow depths, successfully demonstrating the VBS’s ability to achieve depth control and its potential for additional functionalities such as orientation control. A Simulink model of the system was also created to simulate its performance. The results from these simulations were compared to both theoretical calculations and experimental data. This model is then used to establish a framework for the design of a depth controller for the VBS once integrated onto an AUV.