Mechanical Engineering Commons^™

Computational Investigation Of The Biomechanics Of Babywearing In Regards To Developmental Dysplasia Of The Hip, Gaurav Girish

Doctoral Dissertations and Master's Theses

Developmental Dysplasia of the Hip (DDH) is a congenital condition where an infant’s hip socket is either loose or otherwise unstable. DDH causes a joint instability where the femoral head is not properly situated inside the acetabulum. Etiology of the condition is in part congenital and developmental, with a difference of DDH prevalence between ethnicities. Incidence of DDH is also in some part dependent on cultural practices and activities of the mother and child. The exact nature of this cultural incidence is not clearly understood. A computational approach is hypothesized to identify the impact of babywearing position on the healthy …

Maritime Object Detection, Tracking, And Classification Using Lidar And Vision-Based Sensor Fusion, David John Thompson

Doctoral Dissertations and Master's Theses

Autonomous Surface Vehicles have the capability of replacing dull, dirty, and dangerous jobs in the maritime field. However, few successful ASV systems exist today, as there is a need for greater sensing capabilities. Furthermore, a successful ASV system requires object detection and recognition capabilities to enable autonomous navigation and situational awareness. This thesis demonstrates an application of LiDAR sensors in maritime environments for object detection, classification, and camera sensor fusion. This is accomplished through the integration of a high-fidelity GPS/INS system, 3D LiDAR sensors, and a pair of cameras. After rotating LiDAR returns into a global reference frame, they are …

Mission Tasking, Path Planning, And System Integration For An Autonomous Surface Vessel, Timothy Zuercher

Doctoral Dissertations and Master's Theses

This thesis presents the design and development of a fully autonomous surface vessel for use as a research platform for the Office of Naval Research and as a competition entry to the International Maritime RobotX Challenge in 2014 and 2016. The author’s contributions to this include the development of safety systems, power distribution systems, communications software, tasking software, and planning algorithms. The results of these developments include a hardware based safety system, a modular power and health monitoring system, an easy to use autoconfiguring inter-process communications stack, a dynamic tasking engine, and a comparison of two solutions to planning with …

Supervisory Controls Strategy To Reduce Utility Factor Weighted Criteria Emissions For A Plug-In Hybrid Electric Vehicle, Thomas Francis Gorgia Iii

Doctoral Dissertations and Master's Theses

Criteria emission reduction techniques are being more sought out in the automotive industry due to current government regulation for light duty vehicles. Parallel-series plug in hybrid electric vehicles can have multiple strategies to balance emissions and fuel consumption. Common controls strategies in industry target fuel economy by using a large electric vehicle range, known as charge depletion, followed by maintaining a state of charge after a specific vehicle threshold, or charge sustaining. A charge preserve strategy works by running an engine at an optimal loading condition, the engine will burn the fuel more complete reducing criteria emissions. Charge preserve will …

Development Of An Emulated Free-Floating Environment For On-Earth Testing Of Space Robots, Narendran Muraleedharan

Doctoral Dissertations and Master's Theses

The ability to perform experiments on space robotic systems within a laboratory setting is crucial to development and testing of satellites and space robots prior to launch. One of the most widely used techniques which recreate the on-orbit motion of space robots and targets is hardware-in-the-loop simulation. This method requires extensive knowledge of the space robot model dynamic parameters. This research proposes a method which uses force feedback to control a robotic platform on which the space robot is mounted. The robotic platform is driven in such a way that the gravity-compensated forces and torques at the mounting interface are …

Ab Initio Computation Of Radiative Properties Of Monatomic Hydrogen, Fanny Thomas

Doctoral Dissertations and Master's Theses

With renewed interest in planetary atmospheric entry, descent, and landing, NASA has noted a need for improved physics modeling in computational fluid dynamics. Uncertainty in experimental data used in radiation heat transfer computations leads to “over-engineering” of entry body heat shields, at large weight and cost penalties. There is interest in developing hypersonic thermophysics models from the known “first principles” of physics.

A method for computing high temperature gas emissivity and absorptivity from quantum mechanics principles is developed. The Schroedinger wave equation is cast as a discretized matrix eigenvalue problem which is solved using the ERAU parallel supercomputer. The numerical …

Numerical Investigation Of A Phase-Change Material Based Photovoltaic Panel Temperature Regulation System, Rohit Gulati

Doctoral Dissertations and Master's Theses

As the production of clean electricity has gained importance, photovoltaic (PV) panels have become a widely used technology. But, during operation, PV panels heat up due to the solar insolation and suffer a drop in electrical output. The goal of this investigation is to use phase-change materials (PCM) to passively cool PV panels. The PCM is inside an aluminum container attached to the back surface of the PV panel. Four configurations of the container are investigated. The first configuration is a container with bulk PCM occupying its entire interior volume. The depth of this container is varied. The second configuration …

Dynamic Understeer Control Using Active Rear Toe, Mark Oliver Dixon Kaufman

Doctoral Dissertations and Master's Theses

This thesis was conducted to show the ability of Active Rear Toe to control the understeer characteristics of a vehicle. Active rear toe is the ability to control the angle of the rear wheels around the vertical axis, allowing the car’s turning radius to change. By changing this radius, the lateral acceleration can be controlled, therefore the understeer of the vehicle can be controlled. The controls scheme is a sliding mode control, specifically a hyperbolic tangent boundary layer and a type 1 zeno controller. The system shows effectiveness to control the understeer of the vehicle up until limit grip on …

Multi-Agent Path Planning For Locating A Radiating Source In An Unknown Environment, Stephanie M. Schwartz

Doctoral Dissertations and Master's Theses

A situation is addressed in which multiple autonomous agents are used to search an unknown environment for a target, the position and orientation of which is known with respect to each agent. A controlling framework is proposed to inform and coordinate the agents’ movements in order to reduce the time required to locate the target. Four primary variables are considered: the cost function used to select the agents’ paths, the number of agents in a given scenario, the distance over which the agents are assumed to communicate, and the size of the environment in which the agents are operating. It …

Computational Modeling Of Thoracic Injury Response Due To Impact Of A Small Unmanned Aerial System (Suas), Alexander Fumiyoshi Dori

Doctoral Dissertations and Master's Theses

This study aims to establish a computational model that will predict the injury response after a sUAS impacts the thorax. A rotary and fixed winged sUAS were chosen for analysis. A vast number of numerical simulations were carried out with varying masses, impact velocities, and impact angles. From the simulation results, the maximum viscous criterion was then calculated. A nonlinear surrogate model was established by setting the impact parameters as independent variables and the viscous criterion as the dependent variable. A correlation analysis showed the impact velocity and angle to significantly influence the results more, when compared to the mass. …