Engineering Commons^™

Design Of A Passive Ankle Prosthesis With Powered Push-Off Using A Cam Timing Mechanism, Jacob J. Rice

Master's Theses (2009 -)

This thesis presents the design and simulation results of the CamWalk, a novel passive prosthetic ankle that has mechanical behavior similar to that for a natural ankle. The CamWalk uses a compression spring network that allows coupling between two degrees of freedom; one for translation along the leg and another for rotation about the ankle joint. When walking, potential energy from the person's weight is stored in the spring network in deflection along the leg. The energy is released by the network as rotation of the foot. The amount of translational work that is converted to rotational work about the …

Determination Of A Predictive Stiffness Model For A 1 Dof Human Inspired Robotic Joint, Michael Boyarsky

Master's Theses (2009 -)

In order to facilitate more natural and intuitive interaction for human users, robots need to move in a more human-like manner as compared to current robots. This change would enable humans to better anticipate robot movements (which would allow humans to better avoid collisions if necessary) and also improve safety in the context of a collision between a robot and a human. The goal of this thesis was to analyze experimental data of human motion to gain an understanding of how human motion and robot motion differ. From this understanding, a neuro-motor model (NMM) of a human elbow (previously established …

A One-Dimensional Model Of A Closed-Loop Refrigeration Test Block For Centrifugal Compressors, Paul D. Gessler

Master's Theses (2009 -)

The increasingly competitive building equipment and control industry pushes manufacturers to continually improve the performance and efficiency of their products to develop and maintain a competitive edge. Compressor development is an expensive endeavor, but the cost and time required for testing can be minimized by developing a model of the compressor test block to predict its behavior with a given prototype compressor at specified operating conditions. This thesis presents a thermodynamic model of a hot gas bypass test block used to evaluate centrifugal compressor performance at a compressor development facility. The test block uses cooling towers to reject the heat …

The Derivation Of Euler's Equations Of Motion In Cylindrical Vector Components To Aid In Analyzing Single Axis Rotation, James J. Jennings

Master's Theses (2009 -)

The derivation of Euler's equations of motion in using cylindrical vector components is beneficial in more intuitively describing the parameters relating to the balance of rotating machinery. Using the well established equation for Newton's equations in moment form and changing the position and angular velocity vectors to cylindrical vector components results in a set of equations defined in radius-theta space rather than X-Y space. This easily allows for the graphical representation of the intuitive design parameters effect on the resulting balance force that can be used to examine the robustness of a design. The sensitivity of these parameters and their …

An Investigation Of Phase-Change Effects During Rapid Compression Machine Experiments, Colin Banyon

Master's Theses (2009 -)

Rapid compression machines (RCMs) are well characterized laboratory scale devices capable of achieving internal combustion (IC) engine relevant thermodynamic environments. These machines are often used to collect ignition delay times as targets for gas-phase chemical kinetic fuel autoigntion models. Modern RCMs utilize creviced piston(s) to improve charge homogeneity and allow for an adequate validation of detailed chemistry mechanisms against experiments using computationally efficient, homogeneous reactor models (HRMs). Conventionally, experiments are preformed by introducing a premixed gas of fuel + oxidizer + diluent into the machine, which is compressed volumetrically via a piston. Experiments investigating low-vapor pressure fuels (e.g. diesels, biodiesels, …

Effects Of Bit Type On Maximum Torque And Axial Force Using Manual Screwdrivers, Mark Hickok

Master's Theses (2009 -)

The screwdriver is a tool that has been among the most widely used hand tools for decades and continues to be used in the workplace to perform a variety of fastening tasks. Advancements in fastener technology have been complemented by the development of new types of screwdriver bits. While designs may vary, so do the force application requirements placed on the tool user. The primary objective of this experiment is to analyze the relationship between user torque and screwdriver bit design. A further objective is to utilize the results to develop an effort metric by which bits of different designs …

Numerical Simulation Model On Irreversibility Of Shock-Wave Process, Longhao Huang

Master's Theses (2009 -)

The objective of this research is to develop a better understanding of the irreversibilities associated with the shock compaction of matter, especially as a result of impact. Due to complex shock processes, experimentation alone cannot fix the material state, since properties such as internal energy, entropy as well as the shock process are not measurable. Thus, in addition to experimentation, analytical and numerical methods are also used to completely characterize the shock process, although they are restricted by underlying constitutive assumptions. Instead of using artificial irreversibility, such as artificial viscosity to simplify and stabilize the numeric shock model, this work …

Admittance Selection For Force Guided Assembly With Optimal Motion, Fernando Rodriguez Anton

Master's Theses (2009 -)

t

Current robots lack the precise relative positioning necessary to complete automatic assembly tasks. Several solutions have been proposed. Some approaches use complex vision and force sensing systems to generate corrective motion if misalignment is present in the assembly task. Other solutions rely on generating elastic behavior, known as compliance, between the end eector and the held movable part. This compliant mechanism helps guide the movable part of the assembly into its proper position. The project focuses on designing a process by which passive compliant systems can achieve successful assembly for a range of misalignment and generate error-reducing motion that …

Dynamic Modeling Of A Belt Driven Electromechanical Xy Plotter Cutter, Joseph V. Prisco

Master's Theses (2009 -)

Current industrial XY plotter cutters that use a belt driven gantry for the X motion and media feed for the Y motion sometimes have performance issues in cutting out high quality shapes. Mathematical models for these plotter cutters are not publicly available and thus the parameters critical to cut quality are not well understood. This thesis develops a dynamic, electromechanical model for the gantry arm and media feed using first principles and a non-linear friction model. These models are independently simulated and experimentally verified. In order to verify the effectiveness of the individual models, they are combined with a control …

Flame Temperature Imaging Of A Low Nox Burner Via Laser Rayleigh Scattering, Nicholas A. Smith

Master's Theses (2009 -)

Federal and global legislation are requiring increasingly stringent emission regulation on household appliances and in particular water heater burners. Emissions like NOx (NO and NO2) are a growing concern due to their adverse health effects and contribution to tropospheric ozone, acid rain, and smog formation. As NOx is more closely controlled, appliance manufacturers are developing low emission burners for use in water heaters.

Flame temperature is strongly correlated to NOx production. Hence, characterizing flame temperatures in new burners is a key part of improving upon burners used today and the development of future burners. Temperature measurements applied to a new, …

A Multi-Scale Approach To A Greater Understanding Of The Behavior Of Heterogeneous Materials Under Dynamic Loading, Andrew J. Van Vooren

Master's Theses (2009 -)

The penetration of granular materials is of interest to a variety of different fields, and is an active area of research. The objective of this project is to gain understanding of the dynamics of a projectile penetrating into a granular material. To do this, experiments were run and a numerical model was created.

A dart gun was used to accelerate an aluminum dart to velocities around 100 m/s, which then impacted a target tank filled with Ottawa sand. The dart flew along a view window, which allowed for a recording of the penetration event using a high speed camera. Pressure …

Powered Transtibial Prosthetic Device Control System Design, Implementation And Testing, Jinming Sun

Master's Theses (2009 -)

A powered lower limb prosthesis, which consists of a four bar mechanism, a torsional spring and a brushed DC motor, was previously designed and fabricated. To regulate the motor power input, a two level controller was proposed and built. The control algorithm includes a higher level finite state controller and lower level PID controllers. To implement the control system, a digital signal processor (DSP) control board and MATLAB Simulink were used to realize the higher level control and a DC motor controller was used to realize the lower level PID control. Sensors were selected to provide the required feedback. The …

Ergonomic Design Of An Aerial Bucket For Ingress And Egress, Bianca M. Bain

Master's Theses (2009 -)

Electric utility companies across the US have been using aerial bucket trucks for line work and troubleshooting for decades. The use of these trucks eliminates the need for workers to climb utility poles in order to repair or maintain lines. Poor ingress and egress design can lead to acute injuries (slips and falls) as well as cumulative injury (musculoskeletal disorders (MSDs)). Utility companies want to know the best combination of steps and handlebars for aerial bucket ingress and egress that would minimize the risk of injury. American National Standards Institute (ANSI) standard – ANSI/SIA A92.2-2009, sets design requirements for aerial …

Investigation Of Aluminum Equation Of State Generation, Aaron Ward

Master's Theses (2009 -)

There are many forms and methods to construct equations of state, EOSs. These methods are usually tailored for the particular problem of interest. Here, the EOSs of interest are those used in modeling shock responses. These EOSs cover a wide range of physical characteristics such as detonation and explosions, armor and anti-armor materials, and space structures protection. Aluminum will be the primary focus of this work. Aluminum was chosen because it has been studied in great length in the shock regime and is a common component in shock experiments and space type vehicles.

Droplet Behavior In Dense, Low Velocity Aerosols, Alexander Polley

Master's Theses (2009 -)

Rapid compression machines (RCM) are laboratory devices used to measure gas-phase fuel reactivity at conditions relevant to combustion engines. Test mixtures are generally prepared by rapidly compressing a gas phase fuel+oxidizer+diluent mixture to high pressure and temperature (e.g., 10-50 bar, 650-1000 K). It is extremely challenging to utilize diesel-relevant liquid fuels in these devices due to their involatility. One proposed method involves the delivery of an aerosol of suspended fuel droplets (∼ 0.1 mL_fuel/L_gas at stoichiometric fuel loading) to the machine. The compression stroke of the RCM subsequently heats the gas phase of the aerosol thereby achieving …

Surface Preparation Of Naval Ship Construction Steel (Abs-A And Ah-36) Via Bristle Blasting Process, Jorge Andres Martinez

Master's Theses (2009 -)

Bristle blasting is a new and unique corrosion-removal process that is rapidly gaining widespread acceptance among engineers and practitioners in the corrosion/ surface preparation community. Engineers from the ship construction and repair industries face a constant corrosive threat to ships' steel infrastructure and welded joints. To this end, great care is exercised in protecting the vessels' structural integrity and longevity, while maintenance engineers in the ship-building industry seek new methods to improve surface preparation that will not compromise the surface cleanliness and anchor profile required for proper adhesion of paints and coatings.

In this study, the cleanliness and texture of …

Heat And Mass Transfer Correlations For Steam Methane Reforming In Non-Adiabatic, Process-Intensified Catalytic Reactors, Adam Stephen Kimmel

Master's Theses (2009 -)

Because of its high energy density, hydrogen is a desirable energy source for the achievement of a renewable energy landscape. Though production methods like thermolysis, electrolysis and biomass conversion, among others, are thought to be long term renewable solutions, catalytic steam methane reforming (SMR) is currently the predominant mechanism to produce hydrogen on an industrial scale. The highly endothermic, transport-limited reforming process has also been scaled down through process intensification to create efficient small-scale hydrogen-generating systems. One proposed geometry utilizes a catalytic finned cylinder that provides a manufacturable solution to enable high-efficiency heat exchange and SMR reaction. An accurate representation …

Optimal Mobile It Location Based On Ergonomics, Kyle Saginus

Master's Theses (2009 -)

U.S. and Canadian electric utility companies are in the process of integrating mobile computers into their fleet vehicle cabs. The placement of the mobile computer in the vehicle cab could have a significant effect on biomechanical loading, performance, and subjective assessment. The objective of this research is to determine the best location to place a mobile computer in a truck cab.

In this experiment, four locations of mobile computers in a truck cab were selected and tested in a laboratory study to determine how location affected muscle activity of the lower back and shoulders; joint angles of the shoulders, elbows, …

Method Of Tolerance Allocation To Maintain Rotary Balance Of Multi-Component Bodies, Lindsay Louise Rogers

Master's Theses (2009 -)

Vibration of rotating machinery caused by mass imbalance is the most frequent source of unwanted disturbing forces and also the most preventable. In the case of a CT scanner, unwanted vibration in the equipment causes artifacts to the X-ray image, and therefore all measures are taken to eliminate imbalance. The CT scanner is a multi-component rotating body, therefore making it a challenge to account for many discrete components, each with unique variation. This research developed the equations for static and dynamic balance including considerations for inertia. The variation of the components was studied using two models: a sensitivity analysis and …

One-Dimensional Strain Initiated By Rapid Compaction Of A Heterogenous Granular Mixture Consisting Of Cu, Fe, Sio2, C, Mos2, And Sn, Cullen Braun

Master's Theses (2009 -)

The dynamic compaction of metal powders is of great interest to the metallurgical and military communities. The compaction of a heterogeneous granular mixture consisting of copper, iron, silica, graphite, molybdenum-disulde, and tin predominately used in aviation break-pad creation is presented. The initial density of the material was on average 2.756 g/cm3 . The research also required developing a working projectile velocity measurement system and a proper target assembly for pressure measurements. Manganin gages were used to record the shock wave transit time and the pressure of the transmitted waveform into the powder mixture. An impedance matching technique was utilized to …

A Novel Approach To The Part Orientation Problem For Robotic Assembly Applications, Brian James Slaboch

Master's Theses (2009 -)

SCARA (Selective Compliant Assembly Robot Arm) type robots are the most common type of assembly robots. These robots have four degrees of freedom (three rotational and one translational). Typically these robots are used for assembly tasks that take place along a vertical axis. Many times, however, assembly tasks take place along a non-vertical axis. To account for non- vertical axis assembly, parts must be fed in a proper orientation to allow for correct assembly. Parts feeders and specialized end-effectors are typically used to feed parts in their proper orientation. This thesis investigates a novel end-effector that can be used to …

Mechatronic Tools For The Modeling And Design Of Servo Motor Actuated Belt Driven Motion Systems, Robert William Copsey

Master's Theses (2009 -)

Mechatronics is defined as the synergistic integration of physical systems, electronics, controls, and computers through the design process, from the very start of the design process, thus enabling complex decision making. This definition reveals the elements involved yet it eludes to the complexity and the constant balance of tradeoffs which are prevalent in the context of applying Mechatronics to a successful design process. This work pursues the use of various tools for the application of Mechatronics to the modeling and design of a servo motor driven motion system.

The use of Mechatronics is pervasive in and among today's highly integrated …

A Fast Nir Spectrometer For Examining Explosive Events: Emission Of Petn Based Explosives And H2O Absorption Method Feasibility, Scott Piecuch

Master's Theses (2009 -)

The chemical dynamics and decomposition pathways of explosive materials are not entirely known. Measurements of chemical transients during explosive events can lead to enhanced knowledge of the detailed chemistry and eventually control of the end products; however, these measurements are often difficult to obtain due to fast time scales and harsh environments. Optical diagnostics present fast-response, minimally invasive methods for resolving properties in detonation environments and previous fast spectroscopic measurements have been recorded in the ultra-violet and visible regions. This work extends the range of such measurements to the near-infrared (NIR) through the development of a fiber-coupled NIR spectrometer utilizing …

Mesoscale Behavior Of An Aluminum-Manganese Dioxide-Epoxy Mixture Under Shock Loading: From Milli To Nano-Sized Aluminum Particles, Andrew Fraser

Master's Theses (2009 -)

The main focus of this thesis is to explore the dynamic shock compaction of multiple component mixtures, specifically Al-MnO₂-Epoxy. This will be facilitated by initially simulating the bulk dynamic response in a mesoscale configuration and then comparing these results to experimental data. The mesoscale simulations were performed in the shock code CTH. The first section will discuss the matching of experimental data to computational results. With the goal of determining the bulk shock Hugoniot, a one-dimensional flyer plate configuration was created while using a grain-geometry imported from an scanning electron microscope (SEM) micrograph of the mixture. Both the …

The Aerodynamics Of The Knuckleball Pitch: An Experimental Investigation Into The Effects That The Seam And Slow Rotation Have On A Baseball, Michael Patrick Morrissey

Master's Theses (2009 -)

There has been plenty of research on the fluid dynamic effects on different spheres, including sports balls, such as baseballs. Baseball pitches have different velocities, rotation rates and orientations which will cause the baseball to move in different directions. There has also been plenty of research on the aerodynamics of curveballs, but not nearly as much on knuckleballs. The difference between the two is that the knuckleball has a much slower rotation rate and a different initial orientation. This causes the baseball to "knuckle," or moving erratically. This pitch in baseball is one of the hardest to pitch, hit, catch, …

The Effect Of Office Chair Backrest Design On The Body's Metabolic Response To Office Work, Stephen H. Freier

Master's Theses (2009 -)

Most office chairs have a backrest that is wider at the shoulders than at the hips. Recently, a new office chair was developed that has a backrest that is narrower at the shoulders and wider at the hips (upwardly tapered backrest). The upwardly tapered backrest should allow users to increase their ventilatory efficiency, compared to a conventional, wide backrest. This new backrest design will hypothetically allow a user to retract their scapulae, increase expansion of the chest cavity, thus allowing the lungs more space to expand. Specific measures of improved ventilatory efficiency are an increase in tidal volume (V_{t …}

Reconfigurable End Effector Allowing For In-Hand Manipulation Without Finger Gaiting Or Regrasping, Jacob Ames Ziesmer

Master's Theses (2009 -)

The goal of this thesis is to move a step towards the solution of the bin picking problem. A novel metamorphic end effector is proposed, tested for proof of concept and analyzed using standard techniques of degrees of freedom and graph theory as well as a classical dynamic analysis. Once proof of concept was achieved, the results from the analysis were formed into an optimization program with the hope of finding a more stable, predictable mechanism.

A Mixed-Dimensionality Modeling Approach For Interaction Of Heterogeneous Steam Reforming Reactions And Heat Transfer, Jeroen Valensa

Master's Theses (2009 -)

Hydrogen is most often produced on an industrial scale by catalytic steam methane reforming, an equilibrium-limited, highly endothermic process requiring the substantial addition of heat at elevated temperatures. The extent of reaction, or conversion efficiency, of this process is known to be heat transfer limited. Scaling the industrial process equipment down to the size required for small, compact fuel cell systems has encountered difficulties due to increased heat losses at smaller scales. One promising approach to effectively scale down the reforming process is to coat the catalyst directly onto the heat exchange surfaces of an integrated reactor/heat exchanger. In this …

Development Of A Velocity Metric For Rigid-Body Planar Motion, Luis Ernesto Criales Escobar

Master's Theses (2009 -)

Two motions of motion quality have been developed for planar motion. They are the "best motion measure" and the "velocity metric". The "best motion measure" identifies the best motion for a given displacement. The "velocity metric" quantifies the discrepancy between two planar motions for the same rigid body.

The best motion measure compares the motion of each particle on the body to an "ideal", but usually unobtainable, motion. This ideal motion moves each particle from its current position to its desired position on a straight-line path. Although the ideal motion is not a valid rigid body motion, this does not …

Development And Implementation Of Novel Bristle Tool For Surface Treatment Of Metallic Components, Piyush Khullar

Master's Theses (2009 -)

Despite advances in paints and coatings technology, protective coatings are prone to eventual corrosion, degradation and/or failure. Consequently, a corrosive layer will develop that can undermine the performance and integrity of structural components. Therefore, both the corrosive layer and defunct coating must be periodically removed, and an acceptable level of surface cleanliness and texture must be obtained prior to the reapplication of new paint. Currently, an array of processes and equipment are used for efficiently cleaning and conditioning metallic surfaces, such as grit blasting, needle guns, and a variety of non-woven and coated abrasive tools.

This research investigates the method …