Mechanical Engineering Commons^™

Fuzzy Attitude Control Of Solar Sail, Joshua Baculi

Mechanical Engineering Master's Theses

This study presents various fuzzy type controllers for a solar sail. First, a Twin Parallel Distributed Compensator (TPDC) is built for a Takagi-Sugeno fuzzy model of the solarsail. The T-S fuzzy model is constructed by linearizing the existing nonlinear equations fo motion of the solar sail. The T-S fuzzy model is used to solve a set of linear matrix inequalities to derive state feedback controller gains. The TPDC controls the solar sail using a combination of reaction wheels and roll stabilizer bars for attitude control and trim masses for disturbance rejection. The TPDC tracks and stabilizes the solar sail to …

An Algorithm For Calculating The Inverse Jacobian Of Multirobot Systems In A Cluster Space Formulation, Christopher Jude Waight

Mechanical Engineering Master's Theses

Multirobot systems have characteristics such as high formation re-configurability that allow them to perform dynamic tasks that require real time formation control. These tasks include gradient sensing, object manipulation, and advanced field exploration. In such instances, the Cluster Space Control approach is attractive as it is both intuitive and allows for full degree of freedom control. Cluster Space Control achieves this by redefining a collection of robots as a single geometric entity called a cluster. To implement, it requires knowing the inverse Jacobian of the robotic system for use in the main control loop. Historically, the inverse Jacobian has been …

Passive Unitized Regenerative Fuel Cell (Purefc) For Energy Storage Applications, Sandeep Lele

Mechanical Engineering Master's Theses

Passive Unitized Regenerative Fuel Cell (PUReFC) prototypes were designed, fabricated, and tested as new energy storage devices capable of meeting demands in offgrid applications. Although flooded lead-acid batteries are typically used to provide low cost energy storage, improper disposal infrastructure and lack of education on battery maintenance can lead to serious health concerns. A Passive Unitized Regenerative Fuel Cell can generate energy in a sustainable manner and possesses the ability to run in reverse, providing energy storage capability.

As Proton Exchange Membrane (PEM) fuel cells rely on effective internal water transport to provide stable operation, an energy efficient flood mitigation …

Effects Of The Fiber Distribution And Number Of Nearby Fibers On The Thermal Conductivity For Aligned Cnt-Silicon Oil Composites, Diana Grandio

Mechanical Engineering Master's Theses

Carbon Nanotubes (CNT) are seen as promising materials for thermal transport applications. The high thermal conductivity and structural flexibility of the CNT present them as very attractive components to be used as particle fillers in thermal interface materials. It is important to understand the effective thermal conductivity for CNT-matrix composites at high CNT volume fraction.

In prior work, an effective medium approach (EMA) has been developed to evaluate composite physical properties such as thermal conductivity, dielectric function or elastic modulus (C-W Nan, Prog. Mat. Sci. V 37, 1993). This model combined with the Kapitza interface resistance can predict the effective …

Molecular Dynamics Study On The Grain Growth In Nanocrystalline Aluminum, Jielong Yin

Mechanical Engineering Master's Theses

In recent years, nano-materials have been a popular direction of research in the field of materials science. Nanocrystalline aluminum has been of particular intrest among the nano-materials. This thesis describes the results of three-dimensional molecular dynamics simulations that have been performed to study grain growth in nanocrystalline FCC aluminum. This project built the models by using the Voronoi geometry method to study the grain growth mechanism, grain boundary structure and the effects of temperature and grain size on the crystal structure and grain growth by Energy Analysis, Radial Distribution Function (RDF) analysis, and investigating changes in Centro symmetric parameters.

The …