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Structuring Emperical Methods For Reuse And Efficiency In Product Development Processes, Marshall Edwin Bare Dec 2006

Structuring Emperical Methods For Reuse And Efficiency In Product Development Processes, Marshall Edwin Bare

Theses and Dissertations

Product development requires that engineers have the ability to predict product performance. When product performance involves complex physics and natural phenomena, mathematical models are often insufficient to provide accurate predictions. Engineering companies compensate for this deficiency by testing prototypes to obtain empirical data that can be used in place of predictive models. The purpose of this work is to provide techniques and methods for efficient use of empirical methods in product development processes. Empirical methods involve the design and creation of prototype hardware and the testing of that hardware in controlled environments. Empirical methods represent a complete product development sub-cycle ...


The Piezoresistive Effect In Microflexures, Gary K. Johns Dec 2006

The Piezoresistive Effect In Microflexures, Gary K. Johns

Theses and Dissertations

The objective of this research is to present a new model for predicting the piezoresistive effect in microflexures experiencing bending stresses. A linear model describing piezoresistivity exists for members in pure tension and compression. Extensions of this model to more complex loading conditions do not match experimental results. An accurate model of piezoresistivity in complex loading conditions would expand the design possibilities of piezoresistive devices. A new model to predict piezoresistive effects in tension, compression, and more complex loading conditions is proposed. The focus of this research is to verify a unidirectional form of this proposed model for microflexures in ...


A Dynamic Workflow Framework For Mass Customization Using Web Service And Autonomous Agent Technologies, Daniel J. Karpowitz Dec 2006

A Dynamic Workflow Framework For Mass Customization Using Web Service And Autonomous Agent Technologies, Daniel J. Karpowitz

Theses and Dissertations

Custom software development and maintenance is one of the key expenses associated with developing automated systems for mass customization. This paper presents a method for reducing the risk associated with this expense by developing a flexible environment for determining and executing dynamic workflow paths. Strategies for developing an autonomous agent-based framework and for identifying and creating web services for specific process tasks are presented. The proposed methods are outlined in two different case studies to illustrate the approach for both a generic process with complex workflow paths and a more specific sequential engineering process.


A Torque Based Power Input Model For Friction Stir Welding, Jefferson W. Pew Dec 2006

A Torque Based Power Input Model For Friction Stir Welding, Jefferson W. Pew

Theses and Dissertations

For decades models have been developed for predicting the size of the weld nugget and heat affected zones in fusion welded structures. The basis for these models is the welding heat input, which is fairly well understood for most arc welding processes. However, this traditional approach is not as straightforward for Friction Stir Welding (FSW). To date, there is no definitive relationship to quantify the heat input for FSW. An important step to establish a heat input model is to identify how FSW process parameters affect weld power. This study details the relationship between FSW process parameters and torque for ...


Large 3-D Deflection And Force Analysis Of Lateral Torsional Buckled Beams, Robert Parley Chase Dec 2006

Large 3-D Deflection And Force Analysis Of Lateral Torsional Buckled Beams, Robert Parley Chase

Theses and Dissertations

This thesis presents research on the force and deflection behavior of beams with rectangular cross-sections undergoing lateral torsional buckling. The large 3-D deflection path of buckling beam tips was closely approximated by circular arcs in two planes. A new chain algorithm element was created from pseudo-rigid-body segments and used in a chain calculation that accurately predicted the force deflection relationship of beams with large 3-D deflections.


Vision-Based Target Geo-Location Using A Fixed-Wing Miniature Air Vehicle, D. Blake Barber, Joshua D. Redding, Timothy W. Mclain, Randal W. Beard, Clark N. Taylor Dec 2006

Vision-Based Target Geo-Location Using A Fixed-Wing Miniature Air Vehicle, D. Blake Barber, Joshua D. Redding, Timothy W. Mclain, Randal W. Beard, Clark N. Taylor

Faculty Publications

This paper presents a method for determining the GPS location of a ground-based object when imaged from a fixed-wing miniature air vehicle (MAV). Using the pixel location of the target in an image, with measurements of MAV position and attitude, and camera pose angles, the target is localized in world coordinates. The main contribution of this paper is to present four techniques for reducing the localization error. In particular, we discuss RLS filtering, bias estimation, flight path selection, and wind estimation. The localization method has been implemented and flight tested on BYU’s MAV testbed and experimental results are presented ...


Defining A Model For Tool Consumption Rate On Asphalt Reclamation Machines, Matthew H. Taylor Nov 2006

Defining A Model For Tool Consumption Rate On Asphalt Reclamation Machines, Matthew H. Taylor

Theses and Dissertations

Asphalt and concrete reclamation machines are used to cut roadways when a repair is required. The performance of these machines can affect the quality of road repairs, and cost/profitability for both contractors and governments. We believe that several performance characteristics in reclamation machines are governed by the placement and pattern of cutting picks on the cutter head. Previous studies, focused on mining and excavation applications, have shown strong correlation between placement and wear. The following study employs a screening experiment (observational study) to find significant contributors to tool wear, in applications of asphalt milling or reclamation. We have found ...


Methods And Metrics For Human Control Of Multi-Robot Teams, Jeffrey D. Anderson Nov 2006

Methods And Metrics For Human Control Of Multi-Robot Teams, Jeffrey D. Anderson

Theses and Dissertations

Human-controlled robots are utilized in many situations and such use is becoming widespread. This thesis details research that allows a single human to interact with a team of robots performing tasks that require cooperation. The research provides insight into effective interaction design methods and appropriate interface techniques. The use of team-level autonomy is shown to decrease human workload while simultaneously improving individual robot efficiency and robot-team cooperation. An indoor human-robot interaction testbed was developed at the BYU MAGICC Lab to facilitate experimentation. The testbed consists of eight robots equipped with wireless modems, a field on which the robots move, an ...


Simulation Of A Carbon Nanotube-Based Compliant Parallel-Guiding Mechanism: A Nanomechanical Building Block, Martin L. Culpepper, Christopher M. Dibiasio, Robert M. Panas, Spencer P. Magleby, Larry L. Howell Nov 2006

Simulation Of A Carbon Nanotube-Based Compliant Parallel-Guiding Mechanism: A Nanomechanical Building Block, Martin L. Culpepper, Christopher M. Dibiasio, Robert M. Panas, Spencer P. Magleby, Larry L. Howell

Faculty Publications

The authors report the behavior of a nanoscale parallel-guiding mechanism wherein the compliant components are single-walled carbon nanotubes. Parallel-guiding mechanisms are often the building blocks of macro- and microscale mechanical systems. The authors present results that provide insight into the performance of a parallel-guiding mechanism for nanoscale devices. The device exhibits a range over 75% of the device size, i.e., 5.5 nm, when actuated with 6.4 nN. Below 3.6 nN, displacements are due to bulk elastic bending of the nanotubes. Above 5.2 nN, displacements are governed by the hingelike bending of kinks in the nanotubes ...


Characterization Of Black Liquor Sprays For Application To Entrained-Flow Processes, Andrew John Mackrory Nov 2006

Characterization Of Black Liquor Sprays For Application To Entrained-Flow Processes, Andrew John Mackrory

Theses and Dissertations

In this work the differences between and characteristics of water and high solids, heated black liquor sprays from air-assist atomizers are examined. Sprays were imaged with a high speed camera and the images analyzed with computer code to produce droplet size data and macroscopic spray characteristics such as mass distribution. Fluid flow rates were measured to allow relevant dimensionless groups for the spray to be calculated. A 1000 degree C tubular furnace was placed around the spray to determine the effect of industrially relevant temperatures on the droplet formation process, relative to room-temperature conditions. It was found that high solids ...


Active Minimization Of Acoustic Energy Density To Attenuate Radiated Noise From A Diesel Generator, Andrew J. Boone Nov 2006

Active Minimization Of Acoustic Energy Density To Attenuate Radiated Noise From A Diesel Generator, Andrew J. Boone

Theses and Dissertations

The focus of this thesis was to use active noise control (ANC) to globally minimize the tonal and broadband noise radiating from a diesel generator enclosure. The major goal of this research was to show that minimizing the noise within the enclosure can lead to an overall sound pressure level (SPL) reduction of radiated noise. The target levels for overall SPL reduction were at least 2 dBA. The control algorithms used in this research were based on a filtered-x LMS adaptive algorithm, which minimizes energy density (ED). Both feedforward and feedback control approaches were investigated. The noise spectrum produced by ...


An Evaluation Of Attributes And Competencies For Manufacturing Engineering Technology Graduates, Loni S. Williamson Oct 2006

An Evaluation Of Attributes And Competencies For Manufacturing Engineering Technology Graduates, Loni S. Williamson

Theses and Dissertations

The purpose of this study is to determine the required attributes and competencies required for a graduate from a manufacturing engineering technology baccalaureate program. A document called “Competencies of Manufacturing Engineering Technology Graduates” was compiled in October 2004. This document lists twelve attributes thought to be important for MET graduates: Leadership, Professionalism, Creativity and Problem Solving, Management, Materials, Processes, Quality, Systems, Design, Communication, Safety and Environmental Issues, and Global Awareness. Under each attribute is a list of five to seven competencies creating a total of seventy-three competencies for graduates of an MET baccalaureate program. This list of attributes and competencies ...


Agglomeration Of Bed Particles In Low-Temperature Black Liquor Gasification, Mark A. Woodruff Oct 2006

Agglomeration Of Bed Particles In Low-Temperature Black Liquor Gasification, Mark A. Woodruff

Theses and Dissertations

The increasing concern for emissions and pollutants from power generation plants has increased the desire for and the study of biomass fuels. Biomass combustion produces less carbon monoxide as well as other greenhouse gases. Black liquor is a byproduct from the Kraft process in making paper. Black liquor can be gasified and used as a fuel in recovery boilers and fluidized bed steam reformers. Recovery boilers have a low efficiency and are used today because of their reliability. Steam reformers have a much higher efficiency but they are a relatively new science and are not as reliable. One of the ...


Performance Of Algebraic Multigrid For Parallelized Finite Element Dns/Les Solvers, Gregory James Larson Sep 2006

Performance Of Algebraic Multigrid For Parallelized Finite Element Dns/Les Solvers, Gregory James Larson

Theses and Dissertations

The implementation of a hybrid spectral/finite-element discretization on the unsteady, incompressible, Navier-Stokes equations with a semi-implicit time-stepping method, an explicit treatment of the advective terms, and an implicit treatment of the pressure and viscous terms leads to an algorithm capable of calculating 3D flows over complex 2D geometries. This also results in multiple Fourier mode linear systems which must be solved at every timestep, which naturally leads to two parallelization approaches: Fourier space partitioning, where each processor individually and simultaneously solves a linear system, and physical space partitioning, where all processors collectively solve each linear system, sequentially advancing through ...


Numerical Simulation Of Plasma-Based Actuator Vortex Control Of A Turbulent Cylinder Wake, Nathan Keith Mcmullin Sep 2006

Numerical Simulation Of Plasma-Based Actuator Vortex Control Of A Turbulent Cylinder Wake, Nathan Keith Mcmullin

Theses and Dissertations

A numerical study has been performed to investigate the mechanics of the turbulent wake of a circular cylinder that is controlled by a plasma actuator. The numerical investigation implements a straightforward moving wall boundary condition to model the actuator's effects on the flow. Validations of the moving wall for this simulation are set forth with the understanding that the moving wall can model the plasma actuator bulk flow effects at a distance downstream and not in a region near or on the plasma actuator. The moving wall boundary condition is then applied to a circular cylinder at a Reynolds ...


Design And Fabrication Of Rotationally Tristable Compliant Mechanisms, Tyler M. Pendleton Sep 2006

Design And Fabrication Of Rotationally Tristable Compliant Mechanisms, Tyler M. Pendleton

Theses and Dissertations

The purpose of this research is to develop the tools necessary to create tristable compliant mechanisms; the work presents the creation of models and concepts for design and a demonstration of the feasibility of the designs through the fabrication of tristable compliant mechanism prototypes on the macro scale. Prior methods to achieve tristable mechanisms rely on detents, friction, or power input; disadvantages to these methods include a high number of parts, the necessity for lubrication, and wear. A compliant tristable mechanism accomplishes tristability through strain energy storage. These mechanisms would be preferable because of increased performance and cost savings due ...


Design Of Piezoresistive Mems Force And Displacement Sensors, Tyler Lane Waterfall Sep 2006

Design Of Piezoresistive Mems Force And Displacement Sensors, Tyler Lane Waterfall

Theses and Dissertations

MEMS (MicroElectroMechanical Systems) sensors are used in acceleration, flow, pressure and force sensing applications on the micro and macro levels. Much research has focused on improving sensor precision, range, reliability, and ease of manufacture and operation. One exciting possibility for improving the capability of micro sensors lies in exploiting the piezoresistive properties of silicon, the material of choice in many MEMS fabrication processes. Piezoresistivity—the change of electrical resistance due to an applied strain—is a valuable material property of silicon due to its potential for high signal output and on-chip and feedback-control possibilities. However, successful design of piezoresistive micro ...


Maximizing Miniature Aerial Vehicles, Stephen Griffiths, Jeffery Brian Saunders, Andrew Curtis, Blake Barber, Timothy W. Mclain, Randal W. Beard Sep 2006

Maximizing Miniature Aerial Vehicles, Stephen Griffiths, Jeffery Brian Saunders, Andrew Curtis, Blake Barber, Timothy W. Mclain, Randal W. Beard

Faculty Publications

Despite the tremendous potential demonstrated by miniature aerial vehicles (MAV) in numerous applications, they are currently limited to operations in open air space, far away from obstacles and terrain. To broaden the range of applications for MAVs, methods to enable operation in environments of increased complexity must be developed. In this article, we presented two strategies for obstacle and terrain avoidance that provide a means for avoiding obstacles in the flight path and for staying centered in a winding corridor.


Recovering Grain Boundary Inclination Parameters Through Oblique Double-Sectioning, Eric Richards Homer Aug 2006

Recovering Grain Boundary Inclination Parameters Through Oblique Double-Sectioning, Eric Richards Homer

Theses and Dissertations

A method for the retrieval of grain boundary inclination parameters of the grain boundary character distribution by oblique double-sectioning is proposed. The method, which is similar to the recovery of the orientation distributions from sets of incomplete pole-figures, is described along with a framework for implementation. The method directly measures grain boundary inclinations in a manner similar to serial sectioning while statistically sampling the microstructure comparably to stereological methods. Computer simulations of the method were used to confirm the mathematical framework. Additional simulations, where the grain boundary normal distributions were recovered by both oblique double-sectioning and stereological methods, showed that ...


Improved State Estimation For Miniature Air Vehicles, Andrew Mark Eldredge Aug 2006

Improved State Estimation For Miniature Air Vehicles, Andrew Mark Eldredge

Theses and Dissertations

Research in Unmanned Air Vehicles (UAV's) continues to push the limitations of size and weight. As technical advances have made UAV's smaller and less expensive, they have become more flexible and extensive in their roles. To continue using smaller and less expensive components while retaining and even enhancing performance requires more sophisticated processing of sensor data in order for the UAV to accurately determine its state and thereby allow the use of feedback in controlling the aircraft automatically. This work presents a three-stage state-estimation scheme for the class of UAV's know as Miniature Air Vehicles (MAV's ...


Preliminary Modeling, Control, And Trajectory Design For Miniature Autonomous Tailsitters, Nathan B. Knoebel, Stephen R. Osborne, Deryl Snyder, Timothy W. Mclain, Randal W. Beard, Andrew Mark Eldredge Aug 2006

Preliminary Modeling, Control, And Trajectory Design For Miniature Autonomous Tailsitters, Nathan B. Knoebel, Stephen R. Osborne, Deryl Snyder, Timothy W. Mclain, Randal W. Beard, Andrew Mark Eldredge

Faculty Publications

A tailsitter UAV has unique advantages over typical fixed wing aircraft or hovercraft. This paper highlights topics of interest in our preliminary research in developing a tailsitter UAV. An aerodynamic model and quaternion-based attitude and position control scheme is presented for controlling a tailsitter through hover maneuvers, with simulation results. Desired trajectories are also developed through feedback linearization of the dynamic equations, intended for quaternion-based attitude control. Finally, a hardware platform is proposed.


Modeling And Validation Of Tension-Element Based Mechanisms For Golf Ball-Club Impact, Aaron Robison Jul 2006

Modeling And Validation Of Tension-Element Based Mechanisms For Golf Ball-Club Impact, Aaron Robison

Theses and Dissertations

Previous work has systematically and numerically demonstrated feasibility and performance benefits of the tension-element concept in golf club heads; however, higher fidelity models needed to be created and validated for this concept. There is a need for more accurate models for this concept to further investigate its performance benefits. Performance is measured in terms of impact efficiency of the ball and head and is referred to as coefficient of restitution (COR). COR is affected by the dynamic effective face stiffness and mass properties of the club. This thesis creates and validates high-fidelity, non-linear, dynamic finite element models for the tension-element ...


Modeling The Mechanical Effects Of Liquid Mediated Adhesion Between The Human Vocal Folds, Gifford Zach Decker Jul 2006

Modeling The Mechanical Effects Of Liquid Mediated Adhesion Between The Human Vocal Folds, Gifford Zach Decker

Theses and Dissertations

The vocal folds are a complex self-oscillating biological system. In the current research, an equation was developed to model viscous adhesion forces that occur when the collision of the vocal folds results in the formation of a liquid bridge. The adhesion equation was validated using experimental data, and simplified to a one-dimensional approximation with an included correction factor that adjusted the predicted pressure in situations where the one-dimensional approximation was invalid. A non-oscillating vocal fold model with a modeled liquid bridge was used to study stress resulting from viscous adhesion. The vertical normal stress magnitude ranged from about 80 to ...


Contractor Variability In Construction Of Cement Treated Base Layers, Maile Anne Rogers Jul 2006

Contractor Variability In Construction Of Cement Treated Base Layers, Maile Anne Rogers

Theses and Dissertations

The primary purposes of this research were to identify construction factors most correlated to specific mechanical properties of cement-treated base (CTB) layers and to determine which construction factors exhibit comparatively high variability within individual construction sections of the two pavement reconstruction projects included in this study. In addition, differences between construction sections tested in this research were evaluated. The research focused on the construction of CTB layers in two pavement reconstruction projects in northern Utah, one along Interstate 84 (I-84) near Morgan and one along U.S. Highway 91 (US-91) near Richmond. The significant predictor variables associated with California bearing ...


A Solution For Commodity Field Hauling With Self-Unloading Semi-Trailers, Lee Pagens Wilkerson Jul 2006

A Solution For Commodity Field Hauling With Self-Unloading Semi-Trailers, Lee Pagens Wilkerson

Theses and Dissertations

Commodity hauling of bulk goods is a growing enterprise that has expanded from hauling agricultural products to hauling many other bulk products. Commodity trailers are used to haul agricultural products from storage facilities to processing plants. These trailers are designed for highway use but are frequently required to work in field conditions as well. In many cases this environment overstresses these trailers and results in permanent irreparable damage. In addition to the structural problems of these trailers, the current systems for unloading the bulk produce from these trailers have serious inadequacies. While functional, the currently used chain and non-chain driven ...


Design Of A Linear Ultrasonic Piezoelectric Motor, Scott L. Sharp Jul 2006

Design Of A Linear Ultrasonic Piezoelectric Motor, Scott L. Sharp

Theses and Dissertations

A new geometrically unique ultrasonic motor (USM) was designed using finite element modeling (FEM). A USM operates by vibrating a drive tip in an elliptical motion while it is in periodic contact with a driven surface. Piezoelectric elements are used to create the elliptical motions and are driven near a resonant frequency to create the needed displacements for the motor to operate. An idea for a motor frame was conceived that consisted of an arch, a center ground, and two piezoelectric elements connected to the center ground. End caps were added between the frame and the piezoelectric elements to reduce ...


Development Of A Variational Part Model Using In-Process Dimensional Measurement Error, Shane A. Carlson Jun 2006

Development Of A Variational Part Model Using In-Process Dimensional Measurement Error, Shane A. Carlson

Theses and Dissertations

To improve the geometric accuracy of CNC machined parts, dynamic machining errors due to on-line disturbances (tool deflection, tool wear, heat deformation, etc.) should be accounted for in some manner. Unless these on-line disturbances are properly handled, it is obvious that a high degree of geometric accuracy is difficult to achieve. Many attempts have been made to compensate for these on-line disturbances such as the development of engineering models; however, the models are not adequate enough for reflecting the real phenomenon and are dependent on continuous process monitoring using a variety of sensors. Closed-loop process control is a scheme for ...


Compliant Mechanism Suspensions, Timothy Melvin Allred Jun 2006

Compliant Mechanism Suspensions, Timothy Melvin Allred

Theses and Dissertations

This thesis has explored the use of compliant mechanisms in vehicle suspension systems, specifically where a compliant mechanism acts as part of the wheel locating mechanism and as the energy storage element. A compliant mechanism has the potential of reducing part count, joints, and manufacturing and assembly costs of a suspension system. Fatigue failure has been found to be a limiting design constraint which competes with space and weight constraints. Controlling wheel motion in response to control forces has also been shown to be an important functional requirement for a compliant suspension system. Vehicle applications that are best suited for ...


Vector Field Path Following For Small Unmanned Aerial Vehicles, Derek R. Nelson, D. Blake Barber, Timothy W. Mclain, Randal W. Beard Jun 2006

Vector Field Path Following For Small Unmanned Aerial Vehicles, Derek R. Nelson, D. Blake Barber, Timothy W. Mclain, Randal W. Beard

Faculty Publications

This paper presents a new method for unmanned aerial vehicle path following using vector fields to represent desired ground track headings to direct the vehicle onto the desired path. The key feature of this approach is that ground track heading error and lateral following error approach zero asymptotically even in the presence of constant wind disturbances. Methods for following straight-line and circularorbit paths, as well as combinations of straight lines and arcs, are presented. Experimental results validate the effectiveness of this path following approach for small air vehicles flying in high-wind conditions.


Vision-Based Target Localization From A Fixed-Wing Miniature Air Vehicle, Joshua D. Redding, Timothy W. Mclain, Randal W. Beard, Clark N. Taylor Jun 2006

Vision-Based Target Localization From A Fixed-Wing Miniature Air Vehicle, Joshua D. Redding, Timothy W. Mclain, Randal W. Beard, Clark N. Taylor

Faculty Publications

This paper presents a method for localizing a ground-based object when imaged from a small fixed-wing unmanned aerial vehicle (UAV). Using the pixel location of the target in an image, with measurements of UAV position and attitude, and camera pose angles, the target is localized in world coordinates. This paper presents a study of possible error sources and localization sensitivities to each source. The localization method has been implemented and experimental results are presented demonstrating the localization of a target to within 11 m of its known location.