Magneto-mechanical systems for ultra-low frequency data transmission: Dynamics, losses, and driving mechanisms

Effective communication in underwater and underground environments is crucial for applications such as environmental monitoring, search and rescue operations, and navigation. Traditional radio frequency (RF) communication systems are ineffective in these settings due to significant signal attenuation in conductive media like seawater and soil. Alternative methods, such as acoustic and optical communications, have limitations, including limited range, data rate, and susceptibility to environmental factors. Ultra-low frequency (ULF) communication offers a promising solution due to its lower signal attenuation in conductive media. However, conventional ULF transmission methods require impractically large antennas and immense power, constrained by fundamental physical limits like Chu's limit. These challenges underscore the need for innovative approaches to achieve efficient ULF communication in RF-denied environments. This thesis introduces resonance-based oscillatory magneto-mechanical transmitters (MMTs) as an efficient and compact solution for ULF communication in conductive media. The working principles of MMTs are explored, detailing both single-rotor and multi-rotor designs and demonstrating how data can be encoded using amplitude modulation. A comprehensive dynamical model is developed to account for both linear and nonlinear behaviors, including near-field magnetic interactions, enhancing frequency prediction, and system performance. To address intrinsic loss mechanisms, particularly eddy current losses, a simplified analytical model is proposed for estimating these losses without relying on complex simulations, and it is validated through experimental comparisons. Two novel driving mechanisms are introduced to optimize efficiency across different oscillation amplitudes, including an efficiency optimization method for low amplitudes and an adaptive driving circuit for high amplitudes that maintains the desired motion at resonance. Additionally, two innovative suspension systems, wire bearings, and levitated wire bearings, are designed specifically for resonance-based oscillatory MMTs to minimize energy loss while providing the necessary mechanical support and oscillation amplitude. Finally, a zero-loss suspension system, which aims to entirely eliminate power loss in the suspension system, is proposed as a future development direction. Collectively, these contributions advance the practical implementation of MMTs, offering a promising solution for reliable ULF communication in challenging underwater and underground environments.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Mechanical Engineering

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2024

Author dc:creator

• Jing, Jiheng

Contributors dc:contributor

• Bahl, Gaurav
• Tawfick, Sameh H.
• Bernhard, Jennifer
• King, William P.

• Mode Shapes
• Model Analysis
• Moment Of Inertia
• Mutual Interaction
• Near-field Effects
• Net Dipole
• Nonlinear Regime
• Optimization Method
• Oscillation Amplitude
• Operating Frequency
• Magnetic Field
• Magnetic Moment
• Coil Current
• Eddy Current Loss
• Electrical Domain
• Magnetic Signal
• Power Consumption
• Resonance Frequency
• Time-varying Magnetic Field
• Ultra-low Frequency
• Ac Magnetic Field
• Amplitude Modulation
• Angular Displacement
• Average Power Consumption
• Axial Length
• Coil Resistance
• Compensation Capacitor
• Dc Magnetic Field
• Dc Field
• Dipole Antenna
• Dipole Approximation
• Dipole Model
• Eddy Current
• Efficient Optimization Method
• Equations Of Motion
• Experimental Prototype
• Frequency Range
• Induction Coil
• Inertial Frame
• Linear Dynamics
• Linear Stiffness
• Local Stiffness
• Magnetic Dipole
• Magnetic Field Generation
• Magnetic Flux
• Magnetic Interactions
• Magnetic Rotor
• Magnetic Strength
• Mechanical Damping
• Mechanical Resonance

Statement dc:rights

• This work is under a 2-year embargo until December 6, 2026.

Language dc:language

en, eng

Handle dc:identifier

https://hdl.handle.net/2142/127508

OAI record oai:identifier

https://www.ideals.illinois.edu/oai-pmh?verb=GetRecord&metadataPrefix=etdms&identifier=oai%3Awww.ideals.illinois.edu%3A2142%2F127508