Dissertations / Theses on the topic 'Mechanically Actuated System'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 dissertations / theses for your research on the topic 'Mechanically Actuated System.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.
Sul, Onejae Washburn Michael Sean. "Thermally actuated mechanical systems." Chapel Hill, N.C. : University of North Carolina at Chapel Hill, 2006. http://dc.lib.unc.edu/u?/etd,392.
Full textTitle from electronic title page (viewed Oct. 10, 2007). "... in partial fulfillment of the requirements for the degree of Doctor of Philosophy in the Department of Physics and Astronomy." Discipline: Physics and Astronomy; Department/School: Physics and Astronomy.
Farahat, Waleed A. (Waleed Ahmed) 1975. "Optimal workloop energetics of muscle-actuated systems." Thesis, Massachusetts Institute of Technology, 2007. http://hdl.handle.net/1721.1/39898.
Full textIncludes bibliographical references (p. 117-122).
Skeletal muscles are the primary actuators that power, stabilize and control locomotive and functional motor tasks in biological systems. It is well known that coordinated action and co-activation of multiple muscles give rise to desirable effects such as enhanced postural and dynamic stability. In this thesis, we study the role of muscle co-activation from an energetics perspective: Are there situations in which antagonist co-activation leads to enhanced power generation, and if so, what is the underlying mechanism? The mechanical energetics of muscles are traditionally characterized in terms of workloop measures where muscles are activated against oscillating, zero-admittance motion sources. We extend these measures to more natural, "mid-range" admittance loads, actuated by multiple muscles. Specifically, we set up the problem of a second-order mechanical system driven by a pair of antagonist muscles. This is the simplest problem where the influences of load dynamics and muscle co-activation on the output energetics may be investigated. To enable experimentation, a muscle testing apparatus capable of real-time servo emulation of the load is developed and utilized for identification and workloop measurements.
(cont.) Using this apparatus, an experimentally identified model predicting muscle contractile force is proposed. Experimental data shows that with a simple Weiner structure, the model accounts for 74% (sigma = 5.6%) of the variance in muscle force, that force dependence on contraction velocity is minimal, and that a bilinear approximation of the output nonlinearity is warranted. Based on this model we investigate what electrical stimulation input gives rise to maximal power transfer for a particular load. This question is cast in an optimal control framework. Necessary conditions for optimality are derived and methods for computing solutions are presented. Solutions demonstrate that the optimal stimulation frequencies must include the effects of muscle impedances, and that optimal co-activation levels are indeed modulated to enable a pair of muscles to produce more work synergistically rather than individually. Pilot experimental data supporting these notions is presented. Finally, we interpret these results in the context of the familiar engineering notion of impedance matching. These results shed new light on the role of antagonist co-activation from an energetics perspective.
by Walled A. Farahat.
Ph.D.
Nahon, Meyer. "Optimization of force distribution in redundantly-actuated robotic systems." Thesis, McGill University, 1991. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=74596.
Full textFirstly, graph theory is used to characterize the kinematic structure of these systems and show that they can be decomposed into two subsystems, each with different properties. The contacts which occur between the constituent bodies in the system are then analyzed in order to determine the system's mobility (or number of degrees of freedom). It is found that this mobility varies during the task and that, at any given time, there will be more actuators active than are necessary.
The kinematic and dynamic equations governing the motion of these systems are then studied and compared to those of more conventional robotic systems. Although the inverse dynamics equations can be formulated in a number of ways, they always constitute an underdetermined system of linear equations. This allows their treatment as equality constraints in an optimization problem. In order to account for the limitations of passive contacts and actuator capabilities, inequality constraints are also considered.
The formulation of the optimization problem is then studied with emphasis on problems which are solvable in real-time and which produce time-continuous solutions. Quadratic programming is found to be a good choice of problem formulation. A quadratic-programming algorithm which efficiently includes both equality and inequality constraints is presented. A number of linear and quadratic objective functions which could be optimized are reviewed and the limitations of linear programming are made apparent through the use of numerical examples. Quadratic objective functions which minimize internal force, power consumption and solution discontinuities are examined. Finally, other applications of redundant actuation are briefly touched upon--the full dynamic balancing of linkages and the reduction of impact shocks in robotic systems.
Mohammadshahi, Donya. "Dynamics and control of cables in cable-actuated systems." Thesis, McGill University, 2013. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=119654.
Full textCette thèse présente une étude de la modélisation dynamique et commande d'un système actionné par câbles, celui-ci composé d'un effecteur attaché à une série de câbles actionnés. L'objectif de cette thèse est de développer un contrôleur qui positionne l'effecteur et diminue les vibrations des câbles. La dynamique du système est modélisée en utilisant la méthode de masses localisées. D'abord, deux algorithmes de commande, PID et LQG sont utilisés pour développer la command. Puis, nous étudions l'application de la commande passive sur le système actionné pas câbles. Les systèmes actionnés par câbles sont généralement non carré avec des actionneurs et des senseurs non colocalisés, ce qui limite généralement l'utilisation de la commande passive. Pour trouver une solution pour ces contraintes, premièrement, nous considérons une intégration dynamique, où un observateur est utilisé pour construire une nouvelle sortie qui donne un système passif. Deuxièmement, nous considérons une entrée-sortie alternative, où la sortie est une version réduit de la vitesse réelle de l'effectuer et l'entrée est une modification du couple de treuil.
Wongviriyawong, Chanikarn Mint. "Stable hopping of a muscle-actuated leg system using positive force feedback." Thesis, Massachusetts Institute of Technology, 2007. http://hdl.handle.net/1721.1/39725.
Full textIncludes bibliographical references (leaves 89-92).
In control of movement, two key components, which are pure mechanical response of the system and response due to sensory feedback, must be thoroughly understood. Recent studies suggest not only the existence of positive force feedback in vivo, but also the emergent property of positive force feedback in having a stabilizing effect on a dynamical system in the presence of disturbances. In this thesis, simulated environment of simple one-dimensional point mass hopping model with positive force feedback as well as experimental results of the same dynamical system are compared and studied in detail. Three important hypotheses are investigated. The first hypothesis involves positive force feedback and its stabilization property despite disturbances in the system. A system with positive force feedback control attains cyclic motion while system energy is being added or removed without changing its steady state system energy. Secondly, overall mechanical behavior of the leg becomes elastic in the existence of positive force feedback. In locomotion, elastic leg behavior is desired for a pertinent adaptation to physical properties of the environment and utilization of the locomotory performances.
(cont.) The last hypothesis investigated is the effect of feedback control parameters on closed loop system behavior, i.e. frequency of hopping, steady state hopping height, etc. Simulation and pilot experimental data are compared both qualitatively and quantitatively concerning all three hypotheses.
by Chanikarn Wongviriyawong.
S.M.
Abhijit, Upadhye. "Electrostatically actuated and bi-stable MEMS structures." Diss., Columbia, Mo. : University of Missouri-Columbia, 2007. http://hdl.handle.net/10355/6041.
Full textThe entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed on April 16, 2008) Includes bibliographical references.
Lichter, Matthew D. (Matthew Daniel) 1977. "Concept development for lightweight binary-actuated robotic devices, with application to space systems." Thesis, Massachusetts Institute of Technology, 2001. http://hdl.handle.net/1721.1/8546.
Full text"June 2001."
Includes bibliographical references (leaves 66-71).
Exploratory space missions of the future will require robotic systems to lead the way by negotiating and mapping very rough terrain, collecting samples, performing science tasks, and constructing facilities. These robots will need to be adaptable and reconfigurable in order to achieve a wide variety of objectives. Conventional designs using gears, motors, bearings, encoders, and many discrete components will be too complex, heavy, and failure-prone to allow highly-reconfigurable systems to be feasible. This thesis develops new concepts that may potentially enable the design of self-transforming space explorers. The vision of this research is to integrate compliant bistable mechanisms with large numbers of binary-actuated embedded smart materials. Compliant mechanisms are lightweight and robust. Binary actuation is the idea of using an actuator in a discrete on/off manner rather than in a continuous manner. A binary actuator is easy to control and robust, and by using tens or hundreds of binary actuators, one can approximate a continuous system, much like a digital computer can approximate an analog system. The first part of this thesis examines the fundamental planning issues involved with systems having large numbers of binary actuators. The notion of a workspace is described and applied to the optimization of a manipulator design. Methods for solving the forward and inverse kinematics are discussed in the context of this application. These methods are extended to the trajectory and locomotion planning problems. Methods for planning systems of substantial complexity are developed in the context of exploratory space robotics. The second part of this thesis presents experimental demonstrations that examine elements of the concept. The results of several design prototypes are discussed.
by Matthew D. Lichter.
S.M.
Selden, Brian A. 1980. "Segmented binary control of shape memory actuator systems." Thesis, Massachusetts Institute of Technology, 2005. http://hdl.handle.net/1721.1/30307.
Full textIncludes bibliographical references (p. 51).
A new approach to the design and control of shape memory alloy (SMA) actuators is presented. SMA wires are divided into many segments and their thermal states are controlled individually as a group of finite state machines. Instead of driving a current to the entire SMA wire and controlling the wire length based on the analogue strain-temperature characteristics, the new method controls the binary state (hot or cold) of individual segments and thereby the total displacement is proportional to the length of the heated segments, i.e. austenite phase. Although the thermo-mechanical properties of SMA are highly nonlinear and uncertain with a prominent hysteresis, Segmented Binary Control is robust and stable, providing characteristics similar to a stepping motor. However, the heating and cooling of each segment to its bi-stable states entail longer time and larger energy for transition. An efficient method for improving speed of response and power consumption is developed by exploiting the inherent hysteresis of SMA. Instead of keeping the extreme temperatures continuously, the temperatures return to intermediate "hold" temperatures closer to room temperature but sufficient to keep constant phase. Coordination of the multitude of segments having independent thermal states allows for faster response with little latency time even for thick SMA wires. Based on stress dependent thermo-mechanical characteristics, the hold temperature satisfying a given Stress Margin is obtained. The new control method is implemented using the Peltier effect thermoelectric devices for selective segment-by-segment heating and cooling. Experiments demonstrate effectiveness of the proposed method.
by Brian A. Selden.
S.M.
Rupinsky, Michael J. "Smart material electrohydrostatic actuator for intelligent transportation systems." The Ohio State University, 2006. http://rave.ohiolink.edu/etdc/view?acc_num=osu1391701972.
Full textWester, Brock Andrew. "Development and characterization of mechanically actuated microtweezers for use in a single-cell neural injury model." Diss., Georgia Institute of Technology, 2011. http://hdl.handle.net/1853/39645.
Full textHubbard, Neal B. "Dual-stage Thermally Actuated Surface-Micromachined Nanopositioners." Diss., CLICK HERE for online access, 2005. http://contentdm.lib.byu.edu/ETD/image/etd743.pdf.
Full textDe, Lillo Liliana. "A matrix converter drive system for an aircraft rudder electro-mechanical actuator." Thesis, University of Nottingham, 2006. http://eprints.nottingham.ac.uk/14034/.
Full textTorabzadeh-Tari, Mohsen. "Analysis of Electro-mechanical actuator systems in more electric aircraft applications /." Stockholm : Department of electrical engineering, Royal Institute of Technology, 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-255.
Full textKRUTZ, JILL E. "DESIGN OF A HYDRAULIC ACTUATOR TEST STAND FOR NON-LINEAR ANALYSIS OF HYDRAULIC ACTUATOR SYSTEM." University of Cincinnati / OhioLINK, 2001. http://rave.ohiolink.edu/etdc/view?acc_num=ucin990813095.
Full textGonthier, Yves. "Force task planning of robotic systems with limited actuator capabilities." Thesis, McGill University, 1996. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=27222.
Full textTo improve the force capabilities of a system, base mobility or redundancy can be employed. A planning algorithm is proposed which results in proper base positioning relative to large-force quasi-static tasks. Similarly, the Force Workspace can be used to position such tasks relative to a robotic system. An efficient numerical algorithm is proposed to generate the Force Workspace, based on the 2$ sp{n}$-tree decomposition of the Cartesian space. Its efficiency stems from the variable resolution nature of the Cartesian space representation, and also from the use of four test levels that restrict the search to valid regions of the Cartesian space only. Examples of Force Workspaces are given for redundant and non-redundant planar manipulators, and spatial manipulators.
Next, the case of tasks requiring the application of a wrench along a given path is considered. The Task Workspace, the set of Cartesian space locations that are valid starting positions for such tasks, is shown to be a subset of the Force Workspace.
To plan redundant manipulator postures during large force-tasks, a new method based on a mini-max optimization scheme is developed. (Abstract shortened by UMI.)
Anderson, Catherine J. (Catherine Jane). "The design of a compact actuator system for a robotic wrist/hand." Thesis, Massachusetts Institute of Technology, 1992. http://hdl.handle.net/1721.1/29546.
Full textThis electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Includes bibliographical references (p. 103-105).
by Catherine J. Anderson.
M.S.
Zhou, Junqiang. "CONTROL OF OVER-ACTUATED SYSTEMS WITH APPLICATION TO ADVANCED TURBOCHARGED DIESEL ENGINES." The Ohio State University, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=osu1420810533.
Full textRoan, Earl Taylor. "Design of an STM and EPL control system and linear actuator preload diaphragm." Thesis, Massachusetts Institute of Technology, 2007. http://hdl.handle.net/1721.1/40310.
Full textThis electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Includes bibliographical references (p. 53-54).
Increasing demand for nano-scale machining processes in the semiconductor industry necessitates new mechanisms for nano-machining. A system capable of nano-scale machining of conductive material via Electronic Pen Lithography (EPL) may fit this niche. The purpose of this research is to develop a system capable of EPL based on a HexFlex six axis nano-manipulator. The system will also be capable of Scanning Tunneling Microscopy (STM), which is will locate the surface with the precision necessary for EPL and also allow the user to confirm the machined features immediately after machining. The import of this work is the development of a low-cost and compact system for nano-machining and nano-scale imaging. The impact of this work may improve the process for manufacturing semiconductors including circuitry, MEMS, and NEMS. The continued development of full six axis machining techniques may allow for the construction of features hitherto impossible to fabricate. This segment of the project focuses on the integration of the HexFlex, a micron stepper motor, precision mounts, a preload diaphragm, and an advanced control system capable of automated EPL and STM verification. Steady electron tunneling is first demonstrated, followed by STM imaging functionality. However, high-speed, high-accuracy EPL machining techniques are reserved for future work.
by Earl Taylor Roan.
S.B.
Taylor, David Donald James. "Reducing booster-pump-induced contaminant intrusion in Indian water systems with a self-actuated, back-pressure regulating valve." Thesis, Massachusetts Institute of Technology, 2014. http://hdl.handle.net/1721.1/92062.
Full textThis electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Cataloged from PDF version of thesis.
Includes bibliographical references (pages 151-155).
Intermittently-operated water systems struggle to equitably and effectively distribute clean water to customers. One common customer response to intermittency is to supplement the water system's pressure by using a household, or residential, booster pump. When such booster pumps are directly connected to the water utility's supply pipe, without an underground isolation tank (sump), they often induce negative pressure in the supply pipe which increases the flow rate. Unfortunately, where leakage rates are high, this negative pressure also increases the risk of contaminant intrusion. This thesis presents the iterative design and field testing of a patent-pending, full-bore, back-pressure regulating valve. The valve's simple mechanism relies on a stabilized collapsing tube, or 'Starling Resistor,'which when installed at a customer's connection, controls the flow rate and prevents booster pumps from creating negative pressure in the supply pipe. In collaboration with the Delhi Jal Board and several private partners, the valve's performance was verified in two rounds of field trials in neighborhoods of New Delhi, India including Pitampura, Azad Market, Vivek Vihar, Malvia Nagar, and Vasant Vihar. Using a crossover study, the valve was found to reduce the total contamination risk across all 19 tested houses during supply times by a median of 80%. The valve prevented 96% of pressure below -1 meter and an average of 53 minutes per day, per connection of total negative pressure. In an estimated worst-case scenario for contaminant intrusion, the presence of the valve reduced the contamination risk by two orders of magnitude at six customer connections - enough to correspond to significant reductions in health risks.
by David Donald James Taylor.
S.M.
Huang, Xiaoyu. "Real-Time Parameter Estimations and Control System Designs for Lightweight Electric Ground Vehicles." The Ohio State University, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=osu1403261078.
Full textZhou, Su-Wei. "Coupled electro-mechanical system modeling and experimental investigation of piezoelectric actuator-driven adaptive structures." Diss., This resource online, 1994. http://scholar.lib.vt.edu/theses/available/etd-06062008-165825/.
Full textChen, Yan. "Energy-Efficient Control Allocation for Over-Actuated Systems with Applications to Electric Ground Vehicles." The Ohio State University, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=osu1366305314.
Full textBarragán, Patrick R. "An efficient drive, sensing, and actuation system using PZT stack actuator cells." Thesis, Massachusetts Institute of Technology, 2012. http://hdl.handle.net/1721.1/70462.
Full textCataloged from PDF version of thesis.
Includes bibliographical references (p. 81-82).
The PZT cellular actuator developed in the MIT d'Arbeloff Laboratory utilizes small-strain, high-force PZT stack actuators in a mechanical flexure system to produce a larger-strain, lower-force actuator useful in robotic systems. Many functionalities for these cellular actuators are developed which can have great impact on robotic systems and actuation itself. After initial exploration into other possible circuitry, a circuit is designed to recovery unused energy for the PZT cells. The circuit design is formed around a proposed method of distributed actuation using PZT cells which imposes that different PZT cells will be activated during different periods such that the charge from some cells can be transferred to others. If the application allows actuation which can conform to this criteria, the developed circuit can be used which, without optimization, can save ~41% of the energy used to drive the actuators with a theoretical upper limit on energy efficiency of 100%. A dynamic system consisting of multiple PZT actuators driving a linear gear is analyzed and simulated which can achieve a no load speed 2.4 m/s with minimal actuators. Then, the two-way transforming properties of PZT stack actuators are utilized to allow dual sensing and actuation. This method uses an inactive PZT cell as a sensor. With no additional sensors, a pendulum system driven by antagonistic groups of PZT cells is shown to find its own resonance with no system model. These functionalities of charge recovery, distributed actuation, and dual sensing and actuation set the PZT cellular actuator as an important contribution to robotic actuation and begin to illuminate the possible impacts of the concept. The design and analysis described reveals many possibilities for future applications and developments using the PZT cellular actuator in the fields of actuation and robotics.
by Patrick R. Barragán
S.M.
Secord, Thomas W. (Thomas William). "Design and application of a cellular, piezoelectric, artificial muscle actuator for biorobotic systems." Thesis, Massachusetts Institute of Technology, 2010. http://hdl.handle.net/1721.1/61612.
Full textCataloged from PDF version of thesis.
Includes bibliographical references (p. 219-227).
One of the foremost challenges in robotics is the development of muscle-like actuators that have the capability to reproduce the smooth motions observed in animals. Biological muscles have a unique cellular structure that departs from traditional electromechanical actuators in several ways. A muscle consists of a vast number of muscle fibers and, more fundamentally, sarcomeres that act as cellular units or building blocks. A muscle's output force and displacement are the aggregate effect of the individual building blocks. Thus, without using gearing or transmissions, muscles can be tailored to a range of loads, satisfying specific force and displacement requirements. These natural actuators are desirable for biorobotic applications, but many of their characteristics have been difficult to reproduce artificially. This thesis develops and applies a new artificial muscle actuator based on piezoelectric technology. The essential approach is to use a subdivided, cellular architecture inspired by natural muscle. The primary contributions of this work stem from three sequential aims. The first aim is to develop the operating principles and design of the actuator cellular units. The basic operating principle of the actuator involves nested flexural amplifiers applied to piezoelectric stacks thereby creating an output length strain commensurate with natural muscle. The second aim is to further improve performance of the actuator design by imparting tunable stiffness and resonance capabilities. This work demonstrates a previously unavailable level of tunability in both stiffness and resonance. The final aim is to showcase the capabilities of the actuator design by developing an underwater biorobotic fish system that utilizes the actuators for resonance-based locomotion. Each aspect of this thesis is supported by rigorous analysis and functional prototypes that augment broadly applicable design concepts.
by Thomas William Secord.
Ph.D.
Wang, Rongrong. "Fault-Tolerant Control and Fault-Diagnosis Design for Over-Actuated Systems with Applications to Electric Ground Vehicles." The Ohio State University, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=osu1365522537.
Full textSasaki, H., M. Shikida, and K. Sato. "A Novel Type of Mechanical Power Transmission Array for Switching Densely-Arrayed Actuator Systems." IEEE, 2006. http://hdl.handle.net/2237/9536.
Full textBaxter, Michael Scott. "An Open Architecture for Versatile Machine and Actuator Control." BYU ScholarsArchive, 2004. https://scholarsarchive.byu.edu/etd/793.
Full textLake, Melinda Ann. "Electrostatic curved electrode actuator for particle sorting at a microfluidic bifurcation." The Ohio State University, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=osu1560441199033201.
Full textArtho-Bentz, Samuel S. "Telescope Parallel Actuator Mount: Control and Testing." DigitalCommons@CalPoly, 2020. https://digitalcommons.calpoly.edu/theses/2242.
Full textLott, Christian D. "Electrothermomechanical Modeling of a Surface-micromachined Linear Displacement Microactuator." BYU ScholarsArchive, 2005. https://scholarsarchive.byu.edu/etd/306.
Full textLong, Fei. "Three-Dimensional Motion Control and Dynamic Force Sensing of a Magnetically Propelled Micro Particle Using a Hexapole Magnetic Actuator." The Ohio State University, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=osu1452093964.
Full textWroble, Daniel G. "Force Fight Study in a Dual Electromechanical Actuator Configuration." University of Dayton / OhioLINK, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=dayton1512641850024148.
Full textMason, Taylor William. "Design and Testing of an Electrostatic Actuator with Dual-Electrodes for Large Touch Display Applications." Miami University / OhioLINK, 2021. http://rave.ohiolink.edu/etdc/view?acc_num=miami1627087821308489.
Full textLiu, Taoming. "Design and Prototyping of a Three Degrees of Freedom Robotic Wrist Mechanism for a Robotic Surgery System." Case Western Reserve University School of Graduate Studies / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=case1283538593.
Full textLarson, John P. "Design of a Magnetostrictive-Hydraulic Actuator Considering Nonlinear System Dynamics and Fluid-Structure Coupling." The Ohio State University, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=osu1402566309.
Full textClause, Matthew. "SPARSE APERTURE SPECKLE INTERFEROMETRY TELESCOPE ACTIVE OPTICS CONTROL SYSTEM." DigitalCommons@CalPoly, 2015. https://digitalcommons.calpoly.edu/theses/1508.
Full textTorabzadeh-Tari, Mohsen. "Dimensioning Tools of MEA Actuator Systems, Including Modeling, Analysis and Technology Comparison." Doctoral thesis, Stockholm : Elektrotekniska system, Kungliga Tekniska högskolan, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-9727.
Full textGruenwald, Benjamin Charles. "Toward Verifiable Adaptive Control Systems: High-Performance and Robust Architectures." Scholar Commons, 2018. https://scholarcommons.usf.edu/etd/7676.
Full textBarnett, Street. "Laboratory Test Set-up to Evaluate Electromechanical Actuation System for Aircraft Flight Control." University of Dayton / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=dayton1429461885.
Full textCragun, Rebecca. "Thermal Microactuators for Microelectromechanical Systems (MEMS)." BYU ScholarsArchive, 2003. https://scholarsarchive.byu.edu/etd/54.
Full textKIESI, MIKKO, and SJÖBLOM ROBERT AXELSSON. "Model based design of an expiratory valve and voice-coil actuator and evaluation of complete expiratory system performance with a PI controller." Thesis, KTH, Maskinkonstruktion (Inst.), 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-193143.
Full textMekaniska ventilatorer är en utrustning inom intensivvården för assisterad andning för patienter med nedsatt andningsförmåga. Utandningsventilen är en kritisk komponent till ventilatorn då den kontrollerar lungtrycket hos patienten. Design processen för en ny utandningsventil är en tidskrävande process mycket på grund av den mängd olika design möjligheter som kan utforskas för både talspole aktuatorn samt membran ventilen som oftast används i ventilatorerna. I detta examensarbete utforskades möjligheterna till att skapa och använda analytiska modeller för modellbaserad utveckling för att accelerera de tidiga design stadierna för en utandningsventil. Huvudkomponenterna, talspole aktuatorn och membran ventilen är modellerade separat och experimentellt verifierade. En fullständig modell för hela utandningssystemet samt en hardware-in-the-loop test plattform är konstruerad för att utforska hur väl de dynamiska egenskaperna samt kontroll prestandan för en utandningsventil kan prediceras. Slutligen utforskas diverse frågor angående ventil designen och en ny design föreslås för att demonstrera möjligheterna med en modellbaserad metod. Den slutliga modellen för både talspole aktuatorn och membran ventilen kan betraktas som tillräcklig precisa för snabb utforskning inom de olika design möjligheterna, då en felprocent under 10% är uppnådd utan manuell finjustering för varje design.
Oliver, Danielle Simonette. "Power Requirements of Control Surface Actuators Towards Active Aeroelastic Control Using the Method of Receptances." Miami University / OhioLINK, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=miami159601703575348.
Full textWroblewski, Adam Christopher. "Health Monitoring of Cracked Rotor Systems using External Excitation Techniques." Cleveland State University / OhioLINK, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=csu1228312469.
Full textChakrabarti, Suryarghya. "Modeling of 3D Magnetostrictive Systems with Application to Galfenol and Terfenol-D Transducers." The Ohio State University, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=osu1322635954.
Full textSeung, Taehun. "Holistic-Lightweight Approach for actuation systems of the next generation aircraft." Universitätsverlag Chemnitz, 2017. https://monarch.qucosa.de/id/qucosa%3A34400.
Full textGegenwärtig konzentriert sich die Technologieentwicklung für Flugzeuge auf die Reduktion des Energieverbrauchs mehr denn je zuvor. Hierfür ist die Effizienz der an Bord befindlichen, nicht propulsiven Subsysteme neben der Wirkungsgradverbesserung der Triebwerke von zentraler Bedeutung. Laut vorangegangenen Untersuchungen und Studien ist die Vereinfachung bzw. Vereinheitlichung der Vielfalt der konventionellen Bordenergiesysteme durch ein adäquates Energiemanagement unter Verwendung von Elektrizität der aussichtsreichte Weg zur Effizienzverbesserung auf der Gesamtflugzeugebene. Durch die Elektrifizierung wurden die einzelnen Geräte zwar zuverlässiger und energieeffizienter als je zuvor aber gleichzeitig erheblich schwerer, sodaß ein signifikanter Verlust an Nutzlasten auf Gesamtflugzeugebene hervorgerufen wird. Das Hauptziel der vorliegenden Arbeit war es, ein Schwerlast-EHA-System mit mehrfachen Betätigungseinheiten durch Einführung von umfassenden Perspektiven zu optimieren. Durch Einführung der sog. ganzheitlichen Leichtbauweise demonstriert die Arbeit, wie das Subsystem mit mehreren Endgeräten ultimativ optimiert werden kann, ohne Abstriche an Gewichtsbilanz u/o Kompromiß mit der Energieeffizienz zu machen. Um eine wahrhaftige Optimierung, d.h. die Erreichung des ultimativen, Nonplusultra-Verbesserungslevels zu erreichen, wurden die Systemarchitektur, die Hardware und die Operationsmethode interaktiv kombiniert, wobei die besondere Aufmerksamkeit auf die interaktiven, zur Verbesserung führenden Einflüsse gelegt wurde. Die Minimierung des Energieverbrauchs und die ultimative Gewichtsoptimierung gleichzeitig können erreicht werden, wenn die physikalischen Zusammenhänge zwischen den involvierten Subsystemen verstanden und ihre verborgenen Potentiale ausgenutzt werden. Der einzige und vernünftige Weg zur Erreichung der ultimativen Optimierung eines Betätigungssystems ist eine allumfassende Betrachtung, also eine ganzheitliche Betrachtungs- bzw. Vorgehensweise.
Abid, Fatma. "Contribution à la robustesse et à l'optimisation fiabiliste des structures Uncertainty of shape memory alloy micro-actuator using generalized polynomial chaos methodUncertainty of shape memory alloy micro-actuator using generalized polynomial chaos method Numerical modeling of shape memory alloy problem in presence of perturbation : application to Cu-Al-Zn-Mn specimen An approach for the reliability-based design optimization of shape memory alloy structure Surrogate models for uncertainty analysis of micro-actuator." Thesis, Normandie, 2019. http://www.theses.fr/2019NORMIR24.
Full textThe design of economic system leads to many advances in the fields of modeling and optimization, allowing the analysis of structures more and more complex. However, optimized designs can suffer from uncertain parameters that may not meet certain reliability criteria. To ensure the proper functioning of the structure, it is important to consider uncertainty study is called the reliability analysis. The integration of reliability analysis in optimization problems is a new discipline introducing reliability criteria in the search for the optimal configuration of structures, this is the domain of reliability optimization (RBDO). This RBDO methodology aims to consider the propagation of uncertainties in the mechanical performance by relying on a probabilistic modeling of input parameter fluctuations. In this context, this thesis focuses on a robust analysis and a reliability optimization of complex mechanical problems. It is important to consider the uncertain parameters of the system to ensure a robust design. The objective of the RBDO method is to design a structure in order to establish a good compromise between the cost and the reliability assurance. As a result, several methods, such as the hybrid method and the optimum safety factor method, have been developed to achieve this goal. To address the complexity of complex mechanical problems with uncertain parameters, methodologies specific to this issue, such as meta-modeling methods, have been developed to build a mechanical substitution model, which at the same time satisfies the efficiency and the precision of the model
Guskey, Christopher R. "NEAR WALL SHEAR STRESS MODIFICATION USING AN ACTIVE PIEZOELECTRIC NANOWIRE SURFACE." UKnowledge, 2013. http://uknowledge.uky.edu/me_etds/27.
Full textMessenger, Robert K. "Modeling and Control of Surface Micromachined Thermal Actuators." Diss., CLICK HERE for online access, 2004. http://contentdm.lib.byu.edu/ETD/image/etd434.pdf.
Full textRoussel, Michael. "Intégration sur silicium et caractérisation de films minces de polyuréthane nanocomposite pour le développement de micro-actionneurs MEMS électrostrictifs." Thesis, Lyon, INSA, 2012. http://www.theses.fr/2012ISAL0135/document.
Full textThis thesis is part of the general development of MEMS microactuators, low cost and simple technology for future applications in the domain of microfluidics. The motivation of this work is to evaluate the feasibility of an electrostrictive microactuator based on electroactive nanocomposite polymer thin films. Polyurethane, loaded with carbon or iron carbide nanoparticles is chosen to be integrated in a conventional silicon MEMS process. The first chapter provides a state of the art of MEMS actuators, presents the different families of electroactive polymers and defines what is electrostriction. The second chapter is devoted to the integration of polyurethane thin films on silicon and to the development of different mechanical and electrical test structures. The emphasis is on identifying and overcoming technological barriers. Chapter three presents the mechanical and electrical characterization methods and the obtained results for pure and nanocomposites films. The fourth and final chapter concerns the realization and the static and dynamic characterizations of first MEMS demonstrators
Rydén, Gustav, and Fredrik Anarp. "Beräkningsmodell för slagtider av pneumatiska manöverdon : En experimentell och teoretisk studie av beteendet för pneumatiska cylindrar samt manöverdon." Thesis, Linköpings universitet, Fluida och mekatroniska system, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-166356.
Full textThis thesis work describes the development of a calculation model for stroke times of pneumatic cylinders and actuators. The stroke time of an actuator can be determined by experimental tests. To facilitate and reduce the time required in connection with the tests, a calculation model is created which presents theoretical values of the stroke time. This calculation model is qualitatively consistent with the experimental tests carried out in this work. The tests are first carried out on a simple pneumatic cylinder, which contributes to knowledge of stroke characteristics and stroke times. This knowledge is helpful for the development of the calculation model. During the tests the stroke time, chamber pressure and piston movement are measured in a variety of operating conditions. The tests show that one of the most critical parameters for the calculation model is the C value, a parameter that describes the flow characteristics of pneumatic components. To make the calculation model reliable, a reasonable C value need to be used. The calculation method consists largely of equations for filling and emptying of pneumatic volumes as well as pressure changes in the cylinder chambers during compression and expansion. With a combination of these equations it is possible to calculate the stroke time. Since the calculation model wants to be kept relatively simple, several assumptions are made about parameters in the system. These assumptions are evaluated according to their potential and impact on the stroke time. Validation experiments show that the calculation model generally works better at high supply pressures and critical flows. When the supply pressure is low and subcritical flow are obtained, the stroke time is affected by many more parameters, which lower the precision of the calculation model. This result is not entirely unexpected since the critical flow equations are relatively simple.