On The Development Of A Human Thumb Tracking Device For Telemanipulation,
2018
University of Texas at Arlington
On The Development Of A Human Thumb Tracking Device For Telemanipulation, Abdul Hafiz Abdul Rahaman
Mechanical and Aerospace Engineering Theses - Archive
The human thumb is the first digit of the hand and influences the grasping capability of the human hand. Based on literature, most sensor gloves available capture the motion of the fingers, however, they lack the ability to capture the motion of the thumb. This research focuses on developing a methodology and associated hardware to capture the complex joint motion of the thumb and map it to an in-house developed multi-degree of freedom robotic thumb. A sensor device was developed to measure four joint angles of the human thumb, namely three flexion/extension (flex/ext) joint angles of carpometacarpal (CMC), metacarpophalangeal (MCP), …
Fea Of Carbon Composite As A Substitute For Steel (A992) In Case Of Square Or Rectangular Hollow Cross-Sections As Beams And Columns,
2018
University of Texas at Arlington
Fea Of Carbon Composite As A Substitute For Steel (A992) In Case Of Square Or Rectangular Hollow Cross-Sections As Beams And Columns, Pradeep Ganesh Pai
Mechanical and Aerospace Engineering Theses - Archive
Improvement to an existing design is an ongoing and never-ending process in every field. The improvement can be in a myriad of areas like an increase in strength, reduction in weight, stiffness to a loading condition and so on. The way it is achieved can range from changing the properties of the material used by incorporating various manufacturing processes or by using an alternative material which can sustain the same loading conditions or for that matter, work better than the existing material. Composite materials like Carbon Fiber, Glass Fiber or Kevlar Fiber reinforced plastics, to name few, are being used …
Research Of A Non-Linearity Control Algorithm For Uav Target Tracking Based On Fuzzy Logic Systems,
2018
Missouri University of Science and Technology
Research Of A Non-Linearity Control Algorithm For Uav Target Tracking Based On Fuzzy Logic Systems, Chaoying Pei, Jingjuan Zhang, Xueyun Wang, Qian Zhang
Mechanical and Aerospace Engineering Faculty Research & Creative Works
Target tracking is one of the most widely used applications of UAVs and visual based tracking is the main method for non-cooperative tracking. In non-cooperative tracking missions, the UAV circles around the target and the gimbal rotates to keep the optic axis of the onboard camera pointing to the target. Compared with the biaxial gimbal, the single-axis gimbal system consists of only one torque motor, forming a great lightweight sensor suite, which also increases the requirement of the control accuracy. In the process of tracking moving target using a UAV with single-axis gimbal, there are still several challenges: (1) The …
Modeling And Control Of A 6-Dof Multi-Rotorcraft: Air-Ball,
2018
Florida Institute of Technology
Modeling And Control Of A 6-Dof Multi-Rotorcraft: Air-Ball, Jerry Ja Wang
Theses and Dissertations
The Air-Ball project seeks to develop an omnidirectional, unmanned aerial vehicle with six degrees of freedom. The Air-Ball vehicle uses six propellers powered by six independent electric motors for propulsion and control. Each motor is attached to a hollow shaft that can rotate ±360° actuated by electric servos. Four of these propulsion shafts are configured in an orientation resembling a quad-copter, where the shafts are 90° apart. The other two propulsion shafts extrude perpendicular from each side of the plane of the quadcopter configuration. Under this unique configuration, Air-Ball is capable of decoupling the motion in the translational and rotational …
Stochastic Finite Element Thermal Analysis Of A Ball Grid Array Package,
2018
University of Texas at Arlington
Stochastic Finite Element Thermal Analysis Of A Ball Grid Array Package, Rahul Upreti
Mechanical and Aerospace Engineering Theses - Archive
This study provides an insight into the factors which have a major impact on the probability of failure of a Ball Grid Array package. A stochastic finite element analysis was done on the package using First-order reliability method (FORM). The effects of uncertainty in material thermal conductivities, heat source, heat transfer coefficient and ambient temperature were studied. The average temperature at the die-junction interface was selected as failure criterion because the excess temperature at the junction is often a cause of failure. The performance of Finite Difference Method(FDM) and Semi-Analytic Complex Variable Method(SACVM) in computing sensitivities are compared. Results show …
Air Flow Pattern And Path Flow Simulation Of Airborne Particulate Contaminants In A Cold-Aisle Containment High-Density Data Center Utilizing Airside Economization,
2018
University of Texas at Arlington
Air Flow Pattern And Path Flow Simulation Of Airborne Particulate Contaminants In A Cold-Aisle Containment High-Density Data Center Utilizing Airside Economization, Gautham Thirunavakkarasu
Mechanical and Aerospace Engineering Theses - Archive
The energy used by Information Technology Equipment (ITE) and the supporting data center equipment keeps rising as data center expansion continues worldwide. To contain the rising operation costs, data center administrators are resorting to cost cutting measures by not adhering to the ambient data center environment standards. In many cases, free cooling techniques are adopted to partially or completely relieve the usage of refrigeration units, which adds to huge cost savings but also allows for the increased risk of particulate and gaseous contaminations. The ASHRAE TC9.9 subcommittee, on Mission Critical Facilities, Data Centers, Technology Spaces, and Electronic Equipment, has provided …
The Performance Of Quadrilateral Element With Rotational Degrees Of Freedom In Statics And Dynamics Analysis And Optimization,
2018
University of Texas at Arlington
The Performance Of Quadrilateral Element With Rotational Degrees Of Freedom In Statics And Dynamics Analysis And Optimization, Xingzhi Wang
Mechanical and Aerospace Engineering Theses - Archive
Finite Element Method (FEM) is widely used in structural analysis, and the standard approach to increase the accuracy of analysis is increasing the total degrees of freedom (DOFs), namely, refine the mesh. By introducing the rotational DOFs, better accuracy can be achieved without change the mesh. The objective of this study was to investigate the performance of elements with rotational DOFs in statics and dynamics analysis and applying these elements to optimization. The implementation of three representative elements with rotational DOFs for statics analysis is reproduced. Also, this work implements these elements to dynamics analysis and optimization. The results show …
Computational Study Of Form Factor Of 3rd Generation Open Compute Servers Using Different Dielectric Fluids For Single-Phase Immersion Cooling,
2018
University of Texas at Arlington
Computational Study Of Form Factor Of 3rd Generation Open Compute Servers Using Different Dielectric Fluids For Single-Phase Immersion Cooling, Pranavi Rachamreddy
Mechanical and Aerospace Engineering Theses - Archive
Computer system dependency has been increased in the modern world and that has encouraged the rapid growth of data centers in leading business units like banking, education, transportation, social media and many more. Data center is a facility that incorporates an organisation’s IT operations and equipment, as well as where it stores, processes, and manages the data. To fulfil the demands of data storage and data processing, corresponding increase in power density of servers are needed. The data center energy efficiency largely depends on the thermal management of servers. Currently, air cooling is the most widely used thermal management technique …
A New Adaptive Multiscale Approach For The Dynamic Modeling And Simulation Of Biomolecular Systems,
2018
University of Texas at Arlington
A New Adaptive Multiscale Approach For The Dynamic Modeling And Simulation Of Biomolecular Systems, Ashley Chase Guy
Mechanical and Aerospace Engineering Dissertations - Archive
This dissertation presents three developments in the simulation of sub-micron dynamical systems. First, a new thermostat formulation is shown to strictly enforce the constant temperature constraint necessary in many thermodynamic ensembles. This formulation also allows the system to quickly evolve to a low-potential state. Next, this new thermostat formulation is leveraged to extend a continuum-regime multiscale formulation to the atomistic regime allowing for equivalent time histories to be generated in significantly less computation time. Finally, an adaptive multiscale formulation allows for potential forces with time varying magnitudes to contribute to the overall dynamics similarly resulting in equivalent time histories in …
Robust Predictive Analytics For Determining Acclimation Parameter Of It Equipment,
2018
University of Texas at Arlington
Robust Predictive Analytics For Determining Acclimation Parameter Of It Equipment, Premsanth Sadasivam
Mechanical and Aerospace Engineering Theses - Archive
Acclimation is the process in which an IT equipment adjusts to a change in its environment such as a change in temperature and humidity, allowing it to maintain performance across a range of environmental conditions. In commissioning of a new cold shipped IT equipment in data centers, environmental acclimation is an important step. Proper acclimation also minimizes the risk of powering on a machine that may still be wet due to moisture condensation. An experimental study is carried out to find how the acclimation occurs and the factors influencing it. These experiments are designed with various temperature ranges and using …
A Novel Magnetorheological Fluid Damper For A Small Spacecraft With Flexible Appendages,
2018
Embry-Riddle Aeronautical University
A Novel Magnetorheological Fluid Damper For A Small Spacecraft With Flexible Appendages, Robert Waelchli
Doctoral Dissertations and Master's Theses
Small satellites have become increasingly popular over the past thirty years, particularly since the adoption of the common CubeSat architecture early this century. Because of their restricted volume and electrical budgets however, there are practical limits to the missions that small satellites may adopt. One potential near-term solution to the problem of limited electrical power may be the adoption of larger, flexible solar arrays. However, spacecraft with flexible appendages have historically presented attitude control challenges relating to platform stability given the dynamic response of the flexible components to applied torques. These challenges may be particularly disruptive to a small spacecraft …
Propulsive Battery Packs Sizing For Aviation Applications,
2018
Embry-Riddle Aeronautical University
Propulsive Battery Packs Sizing For Aviation Applications, Tianyuan Zhao
Doctoral Dissertations and Master's Theses
This thesis derives analytical methods for sizing the propulsive battery packs for designing an electric-driven aircraft. Lithium-Ion (Li-Ion) battery is the primary choice of battery cell chemistry in this thesis research due to its superior specific energy and market availability. The characteristics of Lithium-Ion battery cells are first determined and studied using experimental test results and manufacturers published data. Based on the design requirement to the battery system, the battery sizing will fall into one of the two sizing categories. The first category is power sizing, which requires the battery’s ability to deliver full power demanded by the electric motor. …
Development Of A Small Unmanned Aerial Vehicle Longitudinal Model For Future Flutter Testing,
2018
Embry-Riddle Aeronautical University
Development Of A Small Unmanned Aerial Vehicle Longitudinal Model For Future Flutter Testing, Said S. Hamada
Doctoral Dissertations and Master's Theses
This thesis presents the system identification of the longitudinal motion of a small unmanned aerial vehicle with flexible characteristics. The unmanned aerial vehicle of study is an off-the-shelf aircraft with limited knowledge about the dynamic model. The first task in obtaining a model for flutter testing is determining the rigid body model. Specifically, this thesis will focus in the development of the aircraft and obtaining the longitudinal rigid body model. This involves the assembly and configuration of the avionics and sensors, performing experiments to determine mass and inertia properties and using software tools for aerodynamic analysis to get preliminary values …
Vision-Aided Navigation Using Tracked Landmarks,
2018
Embry-Riddle Aeronautical University
Vision-Aided Navigation Using Tracked Landmarks, Nicodemus Myhre
Doctoral Dissertations and Master's Theses
This thesis presents vision-based state estimation algorithms for autonomous vehicles to navigate within GPS-denied environments. To accomplish this objective, an approach is developed that utilizes a priori information about the environment. In particular, the algorithm leverages recognizable ‘landmarks’ in the environment, the positions of which are known in advance, to stabilize the state estimate. Measurements of the position of one or more landmarks in the image plane of a monocular camera are then filtered using an extended Kalman filter (EKF) with data from a traditional inertial measurement unit (IMU) consisting of accelerometers and rate gyros to produce the state estimate. …
Homography-Based State Estimation For Autonomous Exploration In Unknown Environments,
2018
Embry-Riddle Aeronautical University
Homography-Based State Estimation For Autonomous Exploration In Unknown Environments, Andres S. Chavez Armijos
Doctoral Dissertations and Master's Theses
This thesis presents the development of vision-based state estimation algorithms to enable a quadcopter UAV to navigate and explore a previously unknown GPS denied environment. These state estimation algorithms are based on tracked Speeded-Up Robust Features (SURF) points and the homography relationship that relates the camera motion to the locations of tracked planar feature points in the image plane. An extended Kalman filter implementation is developed to perform sensor fusion using measurements from an onboard inertial measurement unit (accelerometers and rate gyros) with vision-based measurements derived from the homography relationship. Therefore, the measurement update in the filter requires the processing …
Experimental Investigation Of Enhanced Damage Resistant Fiber Metal Laminates,
2018
Embry-Riddle Aeronautical University
Experimental Investigation Of Enhanced Damage Resistant Fiber Metal Laminates, Cannelle Metang Tefoung
Doctoral Dissertations and Master's Theses
Fiber metal laminates (FMLs) are hybrid composite structures made from fiber reinforced polymeric materials sandwiched between layers of thin metal alloy sheets. FMLs combine the advantages of metallic materials and fiber reinforced matrix systems. Some of these advantages include: lighter weight, enhanced impact tolerance, improved corrosion resistance, better fire resistance, longer fatigue life, greater tensile strength, easier repair ability and maintainability, etc. The most well-known commercially available FML is GLARE (Glass Laminate Aluminum Reinforced Epoxy), however there are ongoing issues, which include a very high fabrication cost compared to many competing material systems and substantial delamination upon impact and failure. …
Aerospace Mission Outcome: Predictive Modeling,
2018
Portland State University
Aerospace Mission Outcome: Predictive Modeling, Ephraim Suhir
Mechanical and Materials Engineering Faculty Publications and Presentations
Human-in-the-Loop (HITL)-related models can be applied in various aerospace vehicular problems, when human qualifications and performance are crucial and the ability to quantify them is therefore imperative; since nobody is perfect, these evaluations should preferably be done on a probabilistic basis. The suggested models can also be used in many other areas of applied science and engineering, not even necessarily vehicular engineering, when a human encounters an extraordinary situation and should possess a sufficiently high human capacity factor (HCF) to successfully cope with an elevated mental workload (MWL). The incentive for probabilistic predictive modeling and the rationale for such modeling …
The Measurement Of The Adhesion Of Glaze Ice.,
2018
University of Louisville
The Measurement Of The Adhesion Of Glaze Ice., Andrew Hardesty Work Jr.
Electronic Theses and Dissertations
Icing is a lethal and costly aviation hazard affecting aircraft of all sizes ranging from small UAVs to large commercial craft such as the Boeing 787, resulting in hundreds of deaths over the last century and resulting in billions of dollars of economic impact. Three predominant types of icing, namely, airframe icing, engine icing, and rotorcraft icing, dominate aircraft icing research. Each type poses unique challenges. In the case of rotor icing, attention needs to give to the rotating environment with large oscillatory loads and icing conditions. In the case of airframe icing, special attention needs to be paid to …
Ultrasonic Nondestructive Evaluation Of Metal Additive Manufacturing.,
2018
University of Louisville
Ultrasonic Nondestructive Evaluation Of Metal Additive Manufacturing., Venkata Karthik Nadimpalli
Electronic Theses and Dissertations
Metal Additive Manufacturing (AM) is increasingly being used to make functional components. One of the barriers for AM components to become mainstream is the difficulty to certify them. AM components can have widely different properties based on process parameters. Improving an AM processes requires an understanding of process-structure-property correlations, which can be gathered in-situ and post-process through nondestructive and destructive methods. In this study, two metal AM processes were studied, the first is Ultrasonic Additive Manufacturing (UAM) and the second is Laser Powder Bed Fusion (L-PBF). The typical problems with UAM components are inter-layer and inter-track defects. To improve the …
Active Permanent Magnet Attitude Control For Cubesats Using Mu-Metal Shielding,
2018
University of Arkansas, Fayetteville
Active Permanent Magnet Attitude Control For Cubesats Using Mu-Metal Shielding, Maxwell Martin
Mechanical Engineering Undergraduate Honors Theses
Cube-Satellites (CubeSats) are nanosatellites composed of cube shaped units, each nominally 10cm to a side and around 1kg in mass. Due to their inherent size and weight limitations, it is often impractical to use conventional attitude, or rotational, control methods such as thrusters on these small satellites. Several methods, including magnetorquer rods and small reaction wheels, are often used instead of traditional methods to work around the size and weight limitations. As a new alternative to these methods, a permanent magnet mounted on a rotatable shaft could be used to achieve attitude control. In much the same way that a …
