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Articles 61 - 90 of 321
Full-Text Articles in Mechanical Engineering
Investigation Of Extremum Seeking Control For Adaptive Exercise Machines, Brahm T. Powell
Investigation Of Extremum Seeking Control For Adaptive Exercise Machines, Brahm T. Powell
ETD Archive
Many muscle rehabilitation regimens are non-adaptive and recommended subjectively by physicians. While there are advantages to having the feedback of a qualified physician, utilizing real-time muscle performance feedback could be beneficial. An extremum seeking control design is proposed to fulfill the need for an automated, load-varying exercise machine that can optimize muscle performance.
Several steps are outlined to contribute to the realization of this goal. First, the extremum seeking control scheme is discussed. Second, the Hill muscle model will be described. Theoretical muscle effort extrema will be derived for selected optimization cases, namely maximizing average squared power by varying load …
P2: Construction Of Weather Station For Measuring Wind Using A Hovering Drone Network, Adam Stead, Mark Travis, Rishi Maheshwari
P2: Construction Of Weather Station For Measuring Wind Using A Hovering Drone Network, Adam Stead, Mark Travis, Rishi Maheshwari
Undergraduate Research Posters 2017
Our research aims to build and test the effectiveness of the Sparkfun® Weather Station in its ability to record meaningful data while streaming to a remote device in real-time. This is motivated by our plans to utilize a hovering-drone system to collect meteorological data, such as wind speed, wind direction, humidity, pressure, and temperature. This data is essential to evaluate the wind profiles of a given area and assess available wind resource. The weather station was first calibrated by comparing measurements of the cup anemometer against a standard pitot tube in the lab. We found that the measured wind speed …
Development And Verification Of A Mechanical Loading Device For Microfluidics, Stefan Habean, Erin Tesny
Development And Verification Of A Mechanical Loading Device For Microfluidics, Stefan Habean, Erin Tesny
Undergraduate Research Posters 2017
Establishing the role that mechanics play in nerve cell (e.g. neurons) function requires experimental testing. Microfluidic based experiments are commonly used to study neuron growth and function, and studies have found mechanics to play an important role in neuron health. External loads can be applied to a microfluidic device using a motor, which presumably influences the mechanical environment of the cells. While a motor can easily apply known displacements, a “load cell” is necessary to measure corresponding forces. In an existing prototype microfluidic loading device, a load cell was integrated and verified. The manufacturer's calibration of the load cell was …
P1: Measuring Wind Using A Hovering Drone Network: Met-Masts On The Go, Mohamad Khattab, Hassan Jaroudi
P1: Measuring Wind Using A Hovering Drone Network: Met-Masts On The Go, Mohamad Khattab, Hassan Jaroudi
Undergraduate Research Posters 2017
Renewable energy has grown considerably over the past years, with a projected growth of $460 billion per year by 2030. One of these renewable energies is deploying wind turbines to harvest wind energy. Knowledge of wind speed and direction is critical to determine the appropriate site to place wind turbines. The current method of collecting wind data primarily by installing stationary meteorological towers is expensive and limited, because met masts are fixed once built. This research aims at using a network of hovering drones as a platform to measure wind speed, direction, temperature and humidity at multiple elevations, which could …
Piv Analysis Of Wake Structure Of Real Elephant Seal Whiskers, Joseph Antun Bunjevac
Piv Analysis Of Wake Structure Of Real Elephant Seal Whiskers, Joseph Antun Bunjevac
ETD Archive
Seals are able to accurately detect minute disturbances in the ambient flow
environment using their whiskers, which is attributed to the exceptional capability of
their whiskers to suppress vortex-induced vibrations in the wake. To explore potential applications for designing smart flow devices, such as high-sensitivity underwater
flow sensors and drag reduction components, researchers have studied how the role
of some key parameters of whisker-like morphology affect the wake structure. Due to
the naturally presented variation in size and curvature along the length of whiskers,
it is not well understood how a real whisker changes the surrounding flow and the
vortex …
Design And Control Of A Powered Rowing Machine With Programmable Impedance, Jose Humberto De La Casas Zolezzi
Design And Control Of A Powered Rowing Machine With Programmable Impedance, Jose Humberto De La Casas Zolezzi
ETD Archive
Due to the rise of obesity, diabetes and cardiovascular disease, research in human performance and physical activity has received increased attention. Rowing machines are used for performance improvements through concentric exercises, however a combination of concentric and eccentric actions is known to improve the effectiveness of training. In this work, a conventional rowing machine was modified to include an electric motor and a robust impedance control system, enabling programmable impedance with concentric and eccentric capabilities. Eccentric exercises are known to contribute significantly to the efficacy of training and to diminish the detrimental effects of humans operating in microgravity for long …
Transcutaneous Electrical Stimulation For The Production Of Functional Motion Of A Human Arm, Kyra Ruby
Transcutaneous Electrical Stimulation For The Production Of Functional Motion Of A Human Arm, Kyra Ruby
Undergraduate Research Posters 2017
Persons with tetraplegia experience little to no function in their arms and are therefore unable to perform reaching tasks without assistance. While functional electrical stimulation (FES) has shown promise for restoring motion to paralyzed limbs, it is limited by issues such as muscle fatigue and atrophy. A control strategy robust enough to overcome these issues has yet to be developed and some motions are not feasible even with the most sophisticated FES control strategy. In theory, a powered exoskeleton could be used in concert with an FES system to increase the accuracy of control and assist the arm when motions …
Human-Like Rewards To Train A Reinforcement Learning Controller For Planar Arm Movement, Kathleen M. Jagodnik, Philip S. Thomas, Antonie J. Van Den Bogert, Michael S. Branicky, Robert F. Kirsch
Human-Like Rewards To Train A Reinforcement Learning Controller For Planar Arm Movement, Kathleen M. Jagodnik, Philip S. Thomas, Antonie J. Van Den Bogert, Michael S. Branicky, Robert F. Kirsch
Mechanical Engineering Faculty Publications
High-level spinal cord injury (SCI) in humans causes paralysis below the neck. Functional electrical stimulation (FES) technology applies electrical current to nerves and muscles to restore movement, and controllers for upper extremity FES neuroprostheses calculate stimulation patterns to produce desired arm movement. However, currently available FES controllers have yet to restore natural movements. Reinforcement learning (RL) is a reward-driven control technique; it can employ user-generated rewards, and human preferences can be used in training. To test this concept with FES, we conducted simulation experiments using computer-generated ``pseudohuman{''} rewards. Rewards with varying properties were used with an actor-critic RL controller for …
Walking Simulator Mechanism, Titus Lungu, Igor Tachynskyy, Omri Tayyara
Walking Simulator Mechanism, Titus Lungu, Igor Tachynskyy, Omri Tayyara
The Downtown Review: An Interdisciplinary Journal Written and Peer-Reviewed by Mandel Honors College Students at Cleveland State University
This paper presents the design, simulation, and kinematic evaluation of a mechanism aimed at simulating both the motion and ground reaction forces produced by a human foot while walking. Such a mechanism can be used to test the durability of shoes through life cycle analysis. In attempting to mimic the physical motion of the human foot as closely as possible, the forces experienced by the human foot were also accurately replicated through the incorporation of a non-stationary testing platform. As is shown in the paper, this testing environment allows for simple adjustments to be made in order to simulate different …
Experimental Investigation Of Turbulent Flow Induced By New-Generation Wind Fences With Multi-Scale Fractal Structure, Sarah M. Mcclure
Experimental Investigation Of Turbulent Flow Induced By New-Generation Wind Fences With Multi-Scale Fractal Structure, Sarah M. Mcclure
ETD Archive
Understanding and controlling atmospheric boundary-layer flows with engineered structures, such as porous wind fences or windbreaks, has been of great interest to the fluid mechanics and wind engineering community. Previous studies found that the regular mono-scale grid fence of 50% porosity and a bottom gap of 10% of the fence height are considered to be optimal over a flat surface. Significant differences in turbulent flow structure have recently been noted behind multi-scale fractal wind fences, even with the same porosity. In this study, wind-tunnel tests on the turbulent flow and the turbulence kinetic energy transport of 1D and 2D multi-scale …
A Simulation And Experimental Study Of Active Disturbance Rejection For Industrial Pressure Control, Xiaoxu Li
A Simulation And Experimental Study Of Active Disturbance Rejection For Industrial Pressure Control, Xiaoxu Li
ETD Archive
The quality of control loop is very important in hydraulic machineries, where pressure must be accurately regulated in the presence of various disturbances. Proportional-Integral-Derivative (PID) control has dominated the industry for a long time and it is by far the most popular general purpose controller for pressure control. The purpose of this study is to conduct a simulation and experimental study comparing PID with an emerging new technology, namely active disturbance rejection control (ADRC). For the purpose of this study, an experimental testbed similar to those used in industry settings is used; its mathematic model is derived and used in …
Characterization Of Performance Of A 3d Printed Stirling Engine Through Analysis And Test, Julie Vodhanel
Characterization Of Performance Of A 3d Printed Stirling Engine Through Analysis And Test, Julie Vodhanel
ETD Archive
This thesis involves the fusion of two technologies, Stirling engines and additive
manufacturing. The project began by building a Stirling engine primarily out of 3D printed parts. Methods to measure the power output were designed and built with a combination of 3D printed and off the shelf parts. The Stirling engine was tested to see if there was a correlation to analysis results, and a regenerator was installed to determine the effect on performance for this relatively low temperature engine. Finally, variations in test operation and the use of heat sinks were used to find a combination that will allow …
An Elaborate Data Set On Human Gait And The Effect Of Mechanical Perturbations, Jason K. Moore, Sandra K. Hnat, Antonie J. Van Den Bogert
An Elaborate Data Set On Human Gait And The Effect Of Mechanical Perturbations, Jason K. Moore, Sandra K. Hnat, Antonie J. Van Den Bogert
Mechanical Engineering Faculty Publications
Here we share a rich gait data set collected from fifteen subjects walking at three speeds on an instrumented treadmill. Each trial consists of 120 s of normal walking and 480 s of walking while being longitudinally perturbed during each stance phase with pseudo-random fluctuations in the speed of the treadmill belt. A total of approximately 1.5 h of normal walking (>5000 gait cycles) and 6 h of perturbed walking (>20,000 gait cycles) is included in the data set. We provide full body marker trajectories and ground reaction loads in addition to a presentation of processed data that …
Analytical And Numerical Validation Of Nozzle Spray Measurement Data Obtained From A Newly Developed Production System, Iddrisu Seidu
Analytical And Numerical Validation Of Nozzle Spray Measurement Data Obtained From A Newly Developed Production System, Iddrisu Seidu
ETD Archive
A newly developed production test stand for measuring the spray angle of a pressure swirl atomizer was constructed and used to measure a product line of these pressure swirl atomizers -- the macrospray atomizer. This new test stand, utilizing constant temperature hot wire anemometers, captures the spray angle data based on the voltage drop the hot wire probes see as they traverse the spray cone of the atomizer and as fluid droplets impinge upon the wire. Datasets acquired from the experiments are compared and correlated with computational fluid dynamics (CFD) simulation data. In addition, angles obtained from another type of …
Dynamic Model Of A Non-Linear Pneumatic Pressure Modulating Valve Using Bond Graphs, Christopher L. Brubaker
Dynamic Model Of A Non-Linear Pneumatic Pressure Modulating Valve Using Bond Graphs, Christopher L. Brubaker
ETD Archive
This research develops a mathematical model of the dynamic pressure response to a variable travel input of a pneumatic pressure modulating valve intended for use in a vehicle air brake system. Generically, the valve is a multi-domain system consisting of a mechanical portion and a pneumatic portion. Included in the mechanical portion of the model are compliance of the springs, inertia of the components, and resistance of the sliding components. The pneumatic portion of the model includes capacitance due to the compressibility of the gas, flow resistance through connected plumbing, and flow resistance through the valve control orifices. The development …
Optimal Design And Control Of A Lower-Limb Prosthesis With Energy Regeneration, Holly E. Warner
Optimal Design And Control Of A Lower-Limb Prosthesis With Energy Regeneration, Holly E. Warner
ETD Archive
The majority of amputations are of the lower limbs. This correlates to a particular need for lower-limb prostheses. Many common prosthesis designs are passive in nature, making them inefficient compared to the natural body. Recently as technology has progressed, interest in powered prostheses has expanded, seeking improved kinematics and kinetics for amputees. The current state of this art is described in this thesis, noting that most powered prosthesis designs do not consider integrating the knee and the ankle or energy exchange between these two joints. An energy regenerative, motorized prosthesis is proposed here to address this gap. After preliminary data …
Real-Time Simulation Of Three-Dimensional Shoulder Girdle And Arm Dynamics, Edward K. Chadwick, Dimitra Blana, Robert F. Kirsch, Antonie J. Van Den Bogert
Real-Time Simulation Of Three-Dimensional Shoulder Girdle And Arm Dynamics, Edward K. Chadwick, Dimitra Blana, Robert F. Kirsch, Antonie J. Van Den Bogert
Mechanical Engineering Faculty Publications
Electrical stimulation is a promising technology for the restoration of arm function in paralyzed individuals. Control of the paralyzed arm under electrical stimulation, however, is a challenging problem that requires advanced controllers and command interfaces for the user. A real-time model describing the complex dynamics of the arm would allow user-in-the-loop type experiments where the command interface and controller could be assessed. Real-time models of the arm previously described have not included the ability tomodel the independently controlled scapula and clavicle, limiting their utility for clinical applications of this nature. The goal of this study therefore was to evaluate the …
Numerical Evaluation Of Paris-Regime Crack Growth Rate Based On Plastically Dissipated Energy, Parag G. Nittur, Anette M. Karlsson, Leif A. Carlsson
Numerical Evaluation Of Paris-Regime Crack Growth Rate Based On Plastically Dissipated Energy, Parag G. Nittur, Anette M. Karlsson, Leif A. Carlsson
Mechanical Engineering Faculty Publications
The crack growth rate during cyclic loading is investigated via numerical simulations. The crack advancement is governed by a propagation criterion that relates the increment in plastically dissipated energy ahead of the crack tip to a critical value. Once this critical value is satisfied, crack propagation is modeled via a node release scheme. Thus, the crack growth rate is an output from the numerical simulation. The crack growth rate predicted by the proposed scheme is compared with published experimental crack growth data in the Paris-regime for selected metals. A good match is found between the experimentally observed crack growth rates …
Relationship Between Jump Landing Kinematics And Peak Acl Force During A Jump In Downhill Skiing: A Simulation Study, D. Heinrich, Antonie J. Van Den Bogert, W. Nachbauer
Relationship Between Jump Landing Kinematics And Peak Acl Force During A Jump In Downhill Skiing: A Simulation Study, D. Heinrich, Antonie J. Van Den Bogert, W. Nachbauer
Mechanical Engineering Faculty Publications
Recent data highlight that competitive skiers face a high risk of injuries especially during off-balance jump landing maneuvers in downhill skiing. The purpose of the present study was to develop a musculo-skeletal modeling and simulation approach to investigate the cause-and-effect relationship between a perturbed landing position, i.e., joint angles and trunk orientation, and the peak force in the anterior cruciate ligament (ACL) during jump landing. A two-dimensional musculo-skeletal model was developed and a baseline simulation was obtained reproducing measurement data of a reference landing movement. Based on the baseline simulation, a series of perturbed landing simulations (n=1000) was generated. Multiple …
Multi-Muscle Fes Force Control Of The Human Arm For Arbitrary Goals, Eric M. Schearer, Yu-Wei Liao, Eric J. Perreault, Matthew C. Tresch, William D. Memberg, Robert F. Kirsch, Kevin M. Lynch
Multi-Muscle Fes Force Control Of The Human Arm For Arbitrary Goals, Eric M. Schearer, Yu-Wei Liao, Eric J. Perreault, Matthew C. Tresch, William D. Memberg, Robert F. Kirsch, Kevin M. Lynch
Mechanical Engineering Faculty Publications
We present a method for controlling a neuroprosthesis for a paralyzed human arm using functional electrical stimulation (FES) and characterize the errors of the controller. The subject has surgically implanted electrodes for stimulating muscles in her shoulder and arm. Using input/output data, a model mapping muscle stimulations to isometric endpoint forces measured at the subject’s hand was identified. We inverted the model of this redundant and coupled multiple-input multiple-output system by minimizing muscle activations and used this inverse for feedforward control. The magnitude of the total root mean square error over a grid in the volume of achievable isometric endpoint …
Expressing The Joint Moments Of Drop Jumps And Sidestep Cutting In Different Reference Frames – Does It Matter?, Eirik Kristianslunda, Tron Krosshauga, Kam-Ming Mok, Scott Mclean, Antonie J. Van Den Bogert
Expressing The Joint Moments Of Drop Jumps And Sidestep Cutting In Different Reference Frames – Does It Matter?, Eirik Kristianslunda, Tron Krosshauga, Kam-Ming Mok, Scott Mclean, Antonie J. Van Den Bogert
Mechanical Engineering Faculty Publications
Joint moments help us understand joint loading and muscle function during movement. However, the interpretation depends on the choice of reference frame, but the different reference frames have not been compared in dynamic, high-impact sporting movements. We have compared the magnitude and the resulting ranking of hip and knee joint moments expressed in the laboratory coordinate system, the local system of the distal segment and projected or decomposed to the Joint Coordinate System (JCS) axes. Hip and knee joint moments of drop jumps and sidestep cutting in 70 elite female handball players were calculated based on recordings from an eight-camera …
Development Of Chatter Attenuation Robust Control For An Amb Machine Spindle, Alexander Hans Pesch
Development Of Chatter Attenuation Robust Control For An Amb Machine Spindle, Alexander Hans Pesch
ETD Archive
No abstract provided.
Development Of Test Methodology For Evaluation Of Fuel Economy In Motorcycle Engines, Alexander Michlberger
Development Of Test Methodology For Evaluation Of Fuel Economy In Motorcycle Engines, Alexander Michlberger
ETD Archive
Rising fuel costs and concerns over fossil fuel emissions have resulted in more stringent fuel economy and emissions standards globally. As a result, motor vehicle manufacturers are constantly pushed to develop more efficient engine and drivetrain systems. Along with advances in hardware, the development of highly fuel efficient engine oils and driveline lubricants can have a significant impact on total system efficiency. Recently motorcycle fuel economy and emissions have come under increased scrutiny. While the passenger vehicle and heavy duty vehicle industries employ a variety of American Society for Testing and Materials (ASTM) standardized tests to measure fuel economy and …
Numerical Investigation Of Boiling In A Sealed Tank In Microgravity, Sonya Lynn Hylton
Numerical Investigation Of Boiling In A Sealed Tank In Microgravity, Sonya Lynn Hylton
ETD Archive
NASA's missions in space depend on the storage of cryogenic fluids for fuel and for life support. During long-term storage, heat can leak into the cryogenic fluid tanks. Heat leaks can cause evaporation of the liquid, which pressurizes the tank. However, when the tanks are in a microgravity environment, with reduced natural convection, heat leaks can also create superheated regions in the liquid. This may lead to boiling, resulting in much greater pressure rises than evaporation at the interface between the liquid and vapor phases. Models for predicting the pressure rise are needed to aid in developing methods to control …
Semiactive Virtual Control Method For Robots With Regenerative Energy-Storing Joints, Hanz Richter, Daniel J. Simon, Antonie J. Van Den Bogert
Semiactive Virtual Control Method For Robots With Regenerative Energy-Storing Joints, Hanz Richter, Daniel J. Simon, Antonie J. Van Den Bogert
Mechanical Engineering Faculty Publications
A framework for modeling and control is introduced for robotic manipulators with a number of energetically self-contained semiactive joints. The control approach consists of three steps. First, a virtual control design is conducted by any suitable means, assuming a fully-actuated system. Then, virtual control inputs are matched by a parameter modulation law. Finally, the storage dynamics are shaped using design parameters. Storage dynamics coincide with the system's internal dynamics under exact virtual control matching. An internal energy balance equation and associated self-powered operation condition are given for the semiactive joints. This condition is a structural characteristic of the system and …
Time-Dependent Mechanical Behavior Of Proton Exchange Membrane Fuel Cell Electrodes, Zongwen Lu, Michael H. Santare, Anette M. Karlsson, F. Colin Busby, Peter Walsh
Time-Dependent Mechanical Behavior Of Proton Exchange Membrane Fuel Cell Electrodes, Zongwen Lu, Michael H. Santare, Anette M. Karlsson, F. Colin Busby, Peter Walsh
Mechanical Engineering Faculty Publications
The electrodes used for Proton Exchange Membrane Fuel Cells (PEMFCs) are typically painted or sprayed onto the membrane during manufacturing, making it difficult to directly characterize their mechanical behavior as a stand-alone material. An experimental-numerical hybrid technique is devised to extract the electrode properties from the experimentally measured properties of Nafion® 211 membrane1 and a membrane electrode assembly (MEA) based on Nafion® 211 membrane at various temperatures, humidities, and strain rates. Within the linear regime, the rule-of-mixtures assuming an iso-strain condition is used to calculate the rate-dependent Young's modulus of the electrodes. Beyond the linear regime, reverse …
On The Uniqueness And Sensitivity Of Indentation Testing Of Isotropic Materials, J. K. Phadikar, T. A. Bogetti, Anette M. Karlsson
On The Uniqueness And Sensitivity Of Indentation Testing Of Isotropic Materials, J. K. Phadikar, T. A. Bogetti, Anette M. Karlsson
Mechanical Engineering Faculty Publications
Instrumented indentation is a popular technique to extract the material properties of small scale structures. The uniqueness and sensitivity to experimental errors determine the practical usefulness of such experiments. Here, a method to identify test techniques that minimizes sensitivity to experimental erros is in indentation experiments developed. The methods are based on considering “shape functions,” which are sets of functions that describe the force–displacement relationship obtained during the indentation test. The concept of condition number is used to investigate the relative reliability of various possible dual indentation techniques. Interestingly, it was found that many dual indentation techniques can be as …
Implementation Of A Plastically Dissipated Energy Criterion For Three Dimensional Modeling Of Fatigue Crack Growth, Parag G. Nittur, Anette M. Karlsson, Leif A. Carlsson
Implementation Of A Plastically Dissipated Energy Criterion For Three Dimensional Modeling Of Fatigue Crack Growth, Parag G. Nittur, Anette M. Karlsson, Leif A. Carlsson
Mechanical Engineering Faculty Publications
Fatigue crack growth is simulated using three dimensional elastic-plastic finite element analysis. The crack extension per load cycle, da/dN, as well as crack front profile changes (crack tunneling) under cyclic loading is not specified as an input but evaluated based on a condition that relates plastically dissipated energy to a critical value. Simulation of cyclic crack propagation in a middle-crack tension M(T) specimen using this implementation captures the well established, experimentally obtained crack growth rate reduction accompanying a single overload event. The analysis predicts that the single overload also affects the crack front profile, where a tunneling crack propagates with …
Conical Indentation Of A Viscoelastic Sphere, J. K. Phadikar, T. A. Bogetti, V. N. Kaliakin, Anette M. Karlsson
Conical Indentation Of A Viscoelastic Sphere, J. K. Phadikar, T. A. Bogetti, V. N. Kaliakin, Anette M. Karlsson
Mechanical Engineering Faculty Publications
Instrumented indentation is commonly used for determining mechanical properties of a range of materials, including viscoelastic materials. However, most—if not all—studies are limited to a flat substrate being indented by various shaped indenters (e.g., conical or spherical). This work investigates the possibility of extending instrumented indentation to nonflat viscoelastic substrates. In particular, conical indentation of a sphere is investigated where a semi-analytical approach based on “the method of functional equations” has been developed to obtain the force–displacement relationship. To verify the accuracy of the proposed methodology selected numerical experiments have been performed and good agreement was obtained. Since it takes …
Time-Dependent Mechanical Response Of A Composite Pfsa Membrane, Narinder S. Khattra, Zongwen Lu, Anette M. Karlsson, Michael H. Santare, F. Colin Busby, Thomas Schmiedel
Time-Dependent Mechanical Response Of A Composite Pfsa Membrane, Narinder S. Khattra, Zongwen Lu, Anette M. Karlsson, Michael H. Santare, F. Colin Busby, Thomas Schmiedel
Mechanical Engineering Faculty Publications
The mechanical response of a composite fuel cell membrane, made from layers of reinforced and unreinforced PFSA material, is investigated via both experimental and numerical means. First, the time-dependent mechanical properties for the reinforced layers are measured for a range of environmental and loading conditions. A three-network, viscoelastic-plastic constitutive model is developed to characterize the mechanical response of this reinforced membrane material. This constitutive model is then used in finite element simulations of a fuel cell unit (consisting of composite membrane, electrodes, gas diffusion layer and bipolar plates) where the effect of relative humidity (RH) cycling on the stress response …