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121	Model-Based Design of an Optimal Lqg Regulator for a Piezoelectric Actuated Smart Structure Using a High-Precision Laser Interferometry Measurement System Gallagher, Grant P 01 June 2022 (has links) (PDF) Smart structure control systems commonly use piezoceramic sensors or accelerometers as vibration measurement devices. These measurement devices often produce noisy and/or low-precision signals, which makes it difficult to measure small-amplitude vibrations. Laser interferometry devices pose as an alternative high-precision position measurement method, capable of nanometer-scale resolution. The aim of this research is to utilize a model-based design approach to develop and implement a real-time Linear Quadratic Gaussian (LQG) regulator for a piezoelectric actuated smart structure using a high-precision laser interferometry measurement system to suppress the excitation of vibratory modes. The analytical model of the smart structure is derived using the extended Hamilton Principle and Euler-Bernoulli beam theory, and the equations of motion for the system are constructed using the assumed-modes method. The analytical model is organized in state-space form, in which the effects of a low-pass filter and sampling of the digital control system are also accounted for. The analytical model is subsequently validated against a finite-element model in Abaqus, a lumped parameter model in Simscape Multibody, and experimental modal analysis using the physical system. A discrete-time proportional-derivative (PD) controller is designed in a heuristic fashion to serve as a baseline performance criterion for the LQG regulator. The Kalman Filter observer and Linear Quadratic Regulator (LQR) components of the LQG regulator are also derived from the state-space model. It is found that the behavior of the analytical model closely matches that of the physical system, and the performance of the LQG regulator exceeds that of the PD controller. The LQG regulator demonstrated quality estimation of the state variables of the system and further constitutes an exceptional closed-loop control system for active vibration control and disturbance rejection of the smart structure. Optimal Control Active Vibration Control Laser Interferometry Smart Structure Linear Quadratic Gaussian Control Kalman Filtering Acoustics, Dynamics, and Controls Ceramic Materials Controls and Control Theory Electro-Mechanical Systems Semiconductor and Optical Materials
122	Smarttelefon-sensorernas möjligheter - En studie om barometer-, GPS- och accelerometersensorer. The smartphone sensor possibilities - A case study featuring the barometer, GPS and accelerometer sensors Mylonas, Christos, Đulić, Samir January 2014 (has links) Denna rapport sammanfattar resultat av ett examensarbete på en högskoleingenjörsutbildningsom utfördes av två studenter på Malmö högskola.Arbetets syfte var att genomföra en mängd olika experiment med accelerometer, barometeroch GPS i en modern smarttelefon. Ett antal scenarier för en tänkbar sensoranvändning i applikationerformulerades för att vägleda olika experiment. Experimentdata dokumenterades noggrantoch analyserades med avsikten att skapa en databank med information för framtida studier.Analys av data inkluderar höjdbestämning i naturen och i byggnader med hjälp av barometersensor,geografisk position med hjälp av GPS, hastighet och acceleration under en hissfärdmed hjälp av accelerometer.Rapporten innehåller en omfattande litteraturstudie om användning av sensorer vid inomhuspositionering.Från analys av mätdata, kom vi fram till slutsatsen att är möjligt att beräkna höjdenfrån barometerdata med bra noggrannhet under optimala omständigheter. GPS höjdenfrån mätningarna har stor felmarginal jämfört med den verkliga höjden samt när den jämförsmed den beräknade höjden från barometern.Genom att utföra en numerisk integration på accelerometer-data kom vi fram till att det är möjligtatt beräkna ungefär hur långt man har färdats med en hiss, dock att vissa detaljer måste tasi beaktning. / This report summarizes the results of a degree Bachelor of engineering in Computer Scienceconducted by two students at Malmo University.Work aim was to conduct a variety of experiments with accelerometer, barometer and GPS in amodern smartphone. A number of scenarios for a possible sensor use in applications formulatedto guided experiments. Data is carefully documented and analyzed, with the intention tocreate a database of information for future studies. Analysis of the data includes the altitudedetermination in nature and in buildings using barometric sensor, geographic location usingGPS, speed and acceleration during an elevator journey with the help of accelerometer.The report contains a comprehensive literature review on the use of sensors for indoorpositioning.From our analysis of the measurement data, we conclude that it is possible to calculate thealtitude from barometric- information but good accuracy if there are optimum circumstances.GPS altitude from our measurements show faulty height by a large margin compared with theactual height and when it is compared with the calculated height of the barometer the barometricheight is closer to the actual height.By performing a numerical integration of the accelerometer data, the results show that it ispossible to calculate approximately how far you have traveled in meters in an elevator, howeverthere are some things that must be taken into consideration. barometer sensor Comma-separated value CSV Androsensor accelerometer Global Positioning System RSS Root Square Sum GPS SVM Signal Vector Magnitude PDR Pedestrian Dead-Reckoning system MEMS Micro-electro-mechanical systems LG Nexus 4 Android höjdberäkning Social Sciences Samhällsvetenskap
123	A Low Power Electrical Method for Cell Accumulation and Lysis Using Microfluidics Islam, Md. Shehadul 10 1900 (has links) <p>Microbiological contamination from bacteria such as <em>Escherichia coli</em> and Salmonella is one of the main reasons for waterborne illness. Real time and accurate monitoring of water is needed in order to alleviate this human health concern. Performing multiple and parallel analysis of biomarkers such as DNA and mRNA that targets different regions of pathogen functionality provides a complete picture of its presence and viability in the shortest possible time. These biomarkers are present inside the cell and need to be extracted for analysis and detection. Hence, lysis of these pathogenic bacteria is an important part in the sample preparation for rapid detection. In addition, collecting a small amount of bacteria present in a large volume of sample and concentrating them before lysing is important as it facilitates the downstream assay. Various techniques, categorized as mechanical, chemical, thermal and electrical, have been used for lysing cells. In the electrical method, cells are lysed by exposure to an external electric field. The advantage of this method, in contrast to other methods, is that it allows lysis without the introduction of any chemical and biological reagents and permits rapid recovery of intercellular organelles. Despite the advantages, issues such as high voltage requirement, bubble generation and Joule heating are associated with the electrical method.</p> <p>To alleviate the issues associated with electrical lysis, a new design and associated fabrication process for a microfluidic cell lysis device is described in this thesis. The device consists of a nanoporous polycarbonate (PCTE) membrane sandwiched between two PDMS microchannels with electrodes embedded at the reservoirs of the microchannels. Microcontact printing is used to attach this PCTE membrane with PDMS.</p> <p>By using this PCTE membrane, it was possible to intensify the electric field at the interface of two channels while maintaining it low in the other sections of the device. Furthermore, the device also allowed electrophoretic trapping of cells before lysis at a lower applied potential. For instance, it could trap bacteria such as <em>E. coli</em> from a continuous flow into the intersection between two channels for lower electric field (308 V/cm) and lyse the cell when electric field was increased more than 1000 V/cm into that section.</p> <p>Application of lower DC voltage with pressure driven flow alleviated adverse effect from Joule heating. Moreover, gas evolution and bubble generation was not observed during the operation of this device.</p> <p>Accumulation and lysis of bacteria were studied under a fluorescence microscope and quantified by using intensity measurement. To observe the accumulation and lysis, LIVE/DEAD BacLight Bacterial Viability Kit consisting of two separate components of SYTO 9 and propidium iodide (PI) into the cell suspension in addition to GFP expressed <em>E. coli</em> were used. Finally, plate counting was done to determine the efficiency of the device and it was observed that the device could lyse 90% of bacteria for an operation voltage of 300V within 3 min.</p> <p>In conclusion, a robust, reliable and flexible microfluidic cell lysis device was proposed and analyzed which is useful for sample pretreatment in a Micro Total Analysis System.</p> / Master of Applied Science (MASc) Cell Lysis Microfluidics Electrical Lysis Bacterial Lysis Electroporation Polycarbonate Membrane Biochemical and Biomolecular Engineering Bioimaging and biomedical optics Biological Engineering Biomedical Electro-Mechanical Systems Membrane Science Nanoscience and Nanotechnology Other Mechanical Engineering Biochemical and Biomolecular Engineering
124	Electromechanical fatigue properties of dielectric elastomer stretch sensors under orthopaedic loading conditions Persons, Andrea Karen 05 May 2022 (has links) Fatigue testing of stretch sensors often focuses on high amplitude, low-cycle fatigue (LCF) behavior; however, when used for orthopaedic, athletic, or ergonomic assessments, stretch sensors are subjected to low amplitude, high-cycle fatigue (HCF) conditions. As an added layer of complexity, the fatigue testing of stretch sensors is not only focused on the life of the material comprising the sensor, but also on the reliability of the signal produced during the extension and relaxation of the sensor. Research into the development of a smart sock that can be used to measure the range of motion (ROM) of the ankle joint during athletic practices and competitions using stretch sensors is ongoing at Mississippi State University. The current smart sock prototype utilizes StretchSense™ StretchFABRIC capacitive dielectric elastomer sensors. These sensors are no longer manufactured, and FlexSense stretch sensors are being investigated as a potential replacement. To assess the reliability of the signal of the StretchFABRIC sensors currently used in the prototype, two sensors were subjected to 25,000 cycles of fatigue, under with simultaneous capture of the capacitance. The capacitances of the fatigued sensors were then compared to the capacitance of an unfatigued StretchFABRIC sensor during participant trials. Participants completed four static movements and six dynamic gait trials using either the fatigued or unfatigued sensor. Following completion of the initial static and dynamic movements, the movements were repeated using the opposite sensor. Comparison of the fatigued sensor to the unfatigued sensor revealed an upward drift in the capacitance of the fatigued sensor for all trials. Two FlexSense sensors were then subjected to either 450,000 or 250,000 cycles of fatigue with simultaneous capture of the signal from the sensor. To assess the signal, the peak capacitance recorded during the fatigue test was compared to the peak stretch percentage produced by the sensor. The peak displacement remained tight about the mean, while the peak stretch percentage exhibited a high level of scatter. From a materials standpoint, the sensors conformed to the Rabinowitz-Beardmore model of polymer fatigue where an initial monotonic overload of the material is followed by a transition to cyclic stability of the material. high-cycle fatigue low-cycle fatigue Coffin-Manson Equation Basquin's Equation polymer polymer model ankle joint gait fatigue testing standards signal processing Biomechanics Electro-Mechanical Systems Engineering Mechanics Laboratory and Basic Science Research Polymer and Organic Materials Signal Processing
125	Challenges and signal processing of high strain rate mechanical testing Lamdini, Barae 13 May 2022 (has links) Dynamic testing provides valuable insight into the behavior of materials undergoing fast deformation. During Split-Hopkinson Pressure Bar testing, stress waves are measured using strain gauges as voltage variations that are usually very small. Therefore, an amplifier is required to amplify the data and analyze it. One of the few available amplifiers designed for this purpose is provided by Vishay Micro-Measurements which limits the user’s options when it comes to research or industry. Among the challenges of implementing the Hopkinson technology in the industry are the size and cost of the amplifier. In this work, we propose a novel design of a signal conditioning amplifier that provides the following functionalities: voltage excitation for strain gauges, wide gain range (1-1000), signal balancing, shunting, and filtering. The main objective is to make a smaller and cheaper amplifier that provides equivalent or better performance allowing larger application of the Hopkinson technology in the industry. Mechanical testing High strain rate testing Split Hopkinson pressure bar Signal conditioning amplifier Acoustics, Dynamics, and Controls Electrical and Electronics Electro-Mechanical Systems Mechanics of Materials Other Materials Science and Engineering Other Mechanical Engineering Signal Processing
126	Electromechanics of an Ocean Current Turbine Tzelepis, Vasileios 18 December 2015 (has links) The development of a numeric simulation for predicting the performance of an Ocean Current Energy Conversion System is presented in this thesis along with a control system development using a PID controller for the achievement of specified rotational velocity set-points. In the beginning, this numeric model is implemented in MATLAB/Simulink® and it is used to predict the performance of a three phase squirrel single-cage type induction motor/generator in two different cases. The first case is a small 3 meter rotor diameter, 20 kW ocean current turbine with fixed pitch blades, and the second case a 20 meter, 720 kW ocean current turbine with variable pitch blades. Furthermore, the second case is also used for the development of a Voltage Source Variable Frequency Drive for the induction motor/generator. Comparison among the Variable Frequency Drive and a simplified model is applied. Finally, the simulation is also used to estimate the average electric power generation from the 720 kW Ocean Current Energy Conversion System which consists of an induction generator and an ocean current turbine connected with a shaft which modeled as a mechanical vibration system. Ocean Current Turbine (OCT) Induction Generator (IG) Variable Frequency Drive (VFD) MATLAB Simulink® Controls and Control Theory Dynamics and Dynamical Systems Electrical and Computer Engineering Electrical and Electronics Electro-Mechanical Systems Engineering Mechanics Mechanical Engineering Ocean Engineering Power and Energy
127	Detecting Structural Defects Using Novel Smart Sensory and Sensor-less Approaches Baghalian, Amin 17 October 2017 (has links) Monitoring the mechanical integrity of critical structures is extremely important, as mechanical defects can potentially have adverse impacts on their safe operability throughout their service life. Structural defects can be detected by using active structural health monitoring (SHM) approaches, in which a given structure is excited with harmonic mechanical waves generated by actuators. The response of the structure is then collected using sensor(s) and is analyzed for possible defects, with various active SHM approaches available for analyzing the response of a structure to single- or multi-frequency harmonic excitations. In order to identify the appropriate excitation frequency, however, the majority of such methods require a priori knowledge of the characteristics of the defects under consideration. This makes the whole enterprise of detecting structural defects logically circular, as there is usually limited a priori information about the characteristics and the locations of defects that are yet to be detected. Furthermore, the majority of SHM techniques rely on sensors for response collection, with the very same sensors also prone to structural damage. The Surface Response to Excitation (SuRE) method is a broadband frequency method that has high sensitivity to different types of defects, but it requires a baseline. In this study, initially, theoretical justification was provided for the validity of the SuRE method and it was implemented for detection of internal and external defects in pipes. Then, the Comprehensive Heterodyne Effect Based Inspection (CHEBI) method was developed based on the SuRE method to eliminate the need for any baseline. Unlike traditional approaches, the CHEBI method requires no a priori knowledge of defect characteristics for the selection of the excitation frequency. In addition, the proposed heterodyne effect-based approach constitutes the very first sensor-less smart monitoring technique, in which the emergence of mechanical defect(s) triggers an audible alarm in the structure with the defect. Finally, a novel compact phased array (CPA) method was developed for locating defects using only three transducers. The CPA approach provides an image of most probable defected areas in the structure in three steps. The techniques developed in this study were used to detect and/or locate different types of mechanical damages in structures with various geometries. Structural Health Monitoring SHM Sensor-less SHM SSHM Sensor-free SHM Heterodyning Effect Guided Waves Defect Detection Loose Bolt Detection Crack Detection Beam Forming Phased Array Monitoring of Pipes Nonlinear Guided Waves Nonlinear Wave Modulation Spectroscopy NWMS Surface Response to Excitation SuRE Acoustics, Dynamics, and Controls Electro-Mechanical Systems Signal Processing
128	Binary Arithmetic for Finite-Word-Length Linear Controllers : MEMS Applications / Intégration sur électronique dédiée et embarquée du traitement du signal et de la commande pour les microsystemes appliqués à la microrobotique Oudjida, Abdelkrim Kamel 20 January 2014 (has links) Cette thèse traite le problème d'intégration hardware optimale de contrôleurs linéaires à taille de mot finie, dédiés aux applications MEMS. Le plus grand défi est d'assurer des performances de contrôle satisfaisantes avec un minimum de ressources logiques. Afin d'y parvenir, deux optimisations distinctes mais complémentaires peuvent être entreprises: en théorie de contrôle et en arithmétique binaire. Seule cette dernière est considérée dans ce travail.Comme cette arithmétique cible des applications MEMS, elle doit faire preuve de vitesse afin de prendre en charge la dynamique rapide des MEMS, à faible consommation de puissance pour un contrôle intégré, hautement re-configurabe pour un ajustement facile des performances de contrôle, et facilement prédictible pour fournir une idée précise sur les ressources logiques nécessaires avant l'implémentation même.L'exploration d'un certain nombre d'arithmétiques binaires a montré que l'arithmétique radix-2r est celle qui répond au mieux aux exigences précitées. Elle a été pleinement exploitée afin de concevoir des circuits de multiplication efficaces, qui sont au fait, le véritable moteur des systèmes linéaires.L'arithmétique radix-2r a été appliquée à l'intégration hardware de deux structures linéaires à taille de mot finie: un contrôleur PID variant dans le temps et à un contrôleur LQG invariant dans le temps,avec un filtre de Kalman. Le contrôleur PID a montré une nette supériorité sur ses homologues existants. Quant au contrôleur LQG, une réduction très importante des ressources logiques a été obtenue par rapport à sa forme initiale non optimisée / This thesis addresses the problem of optimal hardware-realization of finite-word-length(FWL) linear controllers dedicated to MEMS applications. The biggest challenge is to ensuresatisfactory control performances with a minimal hardware. To come up, two distinct butcomplementary optimizations can be undertaken: in control theory and in binary arithmetic. Only thelatter is involved in this work.Because MEMS applications are targeted, the binary arithmetic must be fast enough to cope withthe rapid dynamic of MEMS; power-efficient for an embedded control; highly scalable for an easyadjustment of the control performances; and easily predictable to provide a precise idea on therequired logic resources before the implementation.The exploration of a number of binary arithmetics showed that radix-2r is the best candidate that fitsthe aforementioned requirements. It has been fully exploited to designing efficient multiplier cores,which are the real engine of the linear systems.The radix-2r arithmetic was applied to the hardware integration of two FWL structures: a linear timevariant PID controller and a linear time invariant LQG controller with a Kalman filter. Both controllersshowed a clear superiority over their existing counterparts, or in comparison to their initial forms. Systemes linéaires Arithmétique Radix-2 Contrôleurs à Taille de Mot Finie Systemes Micro Electro Mécanique Multiplication by a variable Multiplication by a constant Linear systems Radix-2r arithmetic High-Speed and Low-Power Design Finite-Word-Length Controllers Micro Electro Mechanical Systems 629.8
129	MICROFLUIDIC DEVICES FOR NEMATODE-BASED BEHAVIOURAL ASSAYS USING ELECTROTAXIS Rezai, Pouya 04 1900 (has links) <p>Small nematode model organisms such as <em>Caenorhabditis elegans</em> are widely used in the fields of neurobiology, toxicology, drug discovery, etc. They are advantageous due to their fully characterized genomic and cellular system. Traditional screening methods involve the exposure of animals to chemicals/drugs inside multiwell-plates while its effects on growth, movement and other cellular/sub-cellular processes are monitored by visual inspection. Yet, these methods are time-consuming, low-throughput, expensive, tedious, difficult to control, hard to modulate instantaneously, prone to subjectivity and not suitable for movement-based behavioural assays. Hence, a method to induce and to quantify movement on-demand in a rapid, sensitive, precise and reversible manner would greatly facilitate biological studies. In this thesis, microfluidic engineering approaches have been utilized in nematode-based assays due to their potential to obtain high precision measurements in a low-cost, rapid and automated manner. Movement response of worms to a diverse range of electric signals has been quantitatively characterized. DC and pulse-DC electric fields have been shown to stimulate worms’ swimming towards the negative electrode inside a microchannel (electrotaxis). AC electric fields were used to inhibit movement on-demand. Animals’ movement has been characterized in terms of speed and range of motion, body-bend frequency and turning time. Electrotaxis was shown to be mediated by neuronal activities and correlations between animal’s behaviour and neuronal signalling has also been demonstrated. Using this basic understanding, multiple microfluidic components such as position sensors and electric immobilizers have been developed. Electrotaxis has then been applied as a technique to sort worms in accordance to their size/age and phenotype as well as to perform drug screening at a single-animal level. Integration of the techniques and components developed during this research is expected to have a significant impact on the development of an integrated microfluidic platform for high throughput automated behavioural screening of nematodes with applications in drug discovery, toxicology, neurobiology and genetics.</p> / Doctor of Philosophy (PhD) Nematode C. elegans Electrotaxis Microfluidic Movement Assay Drug Screening Immobilization Sorting Detection Localization Animal Sciences Behavioral Neurobiology Bioelectrical and neuroengineering Biological Engineering Biomechanical Engineering Biomechanics and biotransport Biomedical devices and instrumentation Biotechnology Electro-Mechanical Systems Animal Sciences
130	Vision Beyond Optics: Standardization, Evaluation and Innovation for Fluorescence Microscopy in Life Sciences Huisman, Maximiliaan 01 April 2019 (has links) Fluorescence microscopy is an essential tool in biomedical sciences that allows specific molecules to be visualized in the complex and crowded environment of cells. The continuous introduction of new imaging techniques makes microscopes more powerful and versatile, but there is more than meets the eye. In addition to develop- ing new methods, we can work towards getting the most out of existing data and technologies. By harnessing unused potential, this work aims to increase the richness, reliability, and power of fluorescence microscopy data in three key ways: through standardization, evaluation and innovation. A universal standard makes it easier to assess, compare and analyze imaging data – from the level of a single laboratory to the broader life sciences community. We propose a data-standard for fluorescence microscopy that can increase the confidence in experimental results, facilitate the exchange of data, and maximize compatibility with current and future data analysis techniques. Cutting-edge imaging technologies often rely on sophisticated hardware and multi-layered algorithms for reconstruction and analysis. Consequently, the trustworthiness of new methods can be difficult to assess. To evaluate the reliability and limitations of complex methods, quantitative analyses – such as the one present here for the 3D SPEED method – are paramount. The limited resolution of optical microscopes prevents direct observation of macro- molecules like DNA and RNA. We present a multi-color, achromatic, cryogenic fluorescence microscope that has the potential to produce multi-color images with sub-nanometer precision. This innovation would move fluorescence imaging beyond the limitations of optics and into the world of molecular resolution. microscopy nanoscopy fluorescence cryogenic cryo-fluorescence cryoFM FM 3DSPEED SPEED standardization PSF PSF engineering achromatic dichroic multi-color super-resolution imaging imaging standard optics adaptive optics meta-data meta MetaMax calibration characterization back-projection image reconstruction pseudo-tomography model-based reconstruction chromatic aberrations cryogenic imaging 4D-PSF calibration tool Bioimaging and Biomedical Optics Biological Engineering Biomedical Devices and Instrumentation Biophysics Computer-Aided Engineering and Design Electrical and Electronics Electromagnetics and Photonics Electro-Mechanical Systems Engineering Physics Molecular Biology Nanoscience and Nanotechnology Numerical Analysis and Computation Optics Other Engineering Systems and Integrative Engineering

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