Global ETD Search

51	Smart Sensing System for a Lateral Micro Drilling Robot Jose Alejandro Solorio Cervantes (11191893) 28 July 2021 (has links) The oil and gas industry faces a lack of compact drilling devices capable of performing horizontal drilling maneuvers in depleted or abandoned wells in order to enhance oil recovery. The purpose of this project was to design and develop a smart sensing system that can be later implemented in compact drilling devices used to perform horizontal drilling to enhance oil recovery in wells. A smart sensor is the combination of a sensing element (sensor) and a microprocessor. Hence, a smart sensing system is an arrangement that consists of different sensors, where one or more have smart capabilities. The sensing system was built and tested in a laboratory setting. For this, a test bench was used as a case study to simulate the operation from a micro-drilling device. The smart sensing system integrated the sensors essential for the direct operational measurements required for the robot. The focus was on selecting reliable and sturdy components that can handle the operation Down the Hole (DTH) on the final lateral micro-drilling robot. The sensing system's recorded data was sent to a microcontroller, where it was processed and then presented visually to the operator through a User Interface (UI) developed in a cloud-based framework. The information was filtered, processed, and sent to a controller that executed commands and sent signals to the test bench’s actuators. The smart sensing system included novel modules and sensors suitable for the operation in a harsh environment such as the one faced in the drilling process. Furthermore, it was designed as an independent, flexible module that can be implemented in test benches with different settings and early robotic prototypes. The outcome of this project was a sensing system able to provide robotic drilling devices with flexibility while providing accurate and reliable measurements during their operation. Circuits and Systems Control Systems, Robotics and Automation Industrial Electronics Signal Processing Automation and Control Engineering Petroleum and Reservoir Engineering Engineering Instrumentation Sensing Technology Data Aquistion Industrial internet of things Oil Drilling robotics system Instrumentation micro-robotics user interface node-red Internet of things (IoT) microelectronics applications
52	Electromagnetic Physical Security: Addressing Exploitation Risks and Building Trust Md Faizul Bari (20373786) 10 December 2024 (has links) <p dir="ltr">Unintentional electromagnetic emission (called emanation) from electronic devices and cables contains a significant correlation with the source signal and can be used to recover otherwise confidential data. In our work, EM emanation has been exploited to recover keystrokes from USB keyboards. Also, such emission has been utilized to form a covert channel for data exfiltration from air-gapped devices without being detected by IDS. To protect sensitive information, an automated emanation detection system has been proposed by developing two emanation detection algorithms (CNN-based and harmonic-based) through the characterization of emanation signals from a wide range of devices. Apart from emanation, data theft can happen due to the failure of access control methods. Traditional wireless devices are susceptible to various spoofing attacks as they only use digital signature-based authentication systems, ignoring the physical signatures completely. To circumvent that, RF-PUF was proposed to use device-specific signatures to be used for trust augmentation in traditional methods. By forming an extensive experimental dataset, we established RF-PUF as a strong PUF with a low-power overhead that outperformed the state-of-the-art methods and is robust against typical attacks. For real-time authentication, we proposed DIRAC, which forms dynamic device clusters and incrementally learns as more device data becomes available. Since our root of trust is in the physical signature of the ICs, they also need to be secured. However, counterfeited ICs may jeopardize that goal. We have proposed RF-PSF, which uses device-specific physical properties to authenticate its process technology which is a big part of the cloned IC detection.</p> Circuits and systems Engineering electromagnetics Hardware security System and network security EM Emanation RF-PUF RF-PSF Side Channel Analysis Covert Channel Data exfiltration PWM Keystroke Recovery authentication security Incremental learning Dynamic Clusters Counterfeit IC Computational Harmonic Detector Emanation Compromising Emanation TEMPEST investigators
53	RELIABLE SENSING WITH UNRELIABLE SENSORS: FROM PHYSICAL MODELING TO DATA ANALYSIS TO APPLICATIONS Ajanta Saha (19827849) 10 October 2024 (has links) <p dir="ltr">In today’s age of information, we are constantly informed about our surroundings by the network of distributed sensors to decide the next action. One major class of distributed sensors is wearable, implantable, and environmental (WIE) electrochemical sensors, widely used for analyte concentration measurement in personalized healthcare, environmental monitoring, smart agriculture, food, and chemical industries. Although WIE sensors offer an opportunity for prompt and prudent decisions, reliable sensing with such sensors is a big challenge. Among them, one is uncontrolled outside environment. Rapidly varying temperature, humidity, and target concentration increase noise and decrease the data reliability of the sensors. Second, because they are closely coupled to the physical world, they are subject to biofouling, radiation exposure, and water ingress which causes physical degradation. Moreover, to correct the drift due to degradation, frequent calibration is not possible once the sensor is deployed in the field. Another challenge is the energy supply needed to support the autonomous WIE sensors. If the sensor is wireless, it must be powered by a battery or an energy harvester. Unfortunately, batteries have limited lifetime and energy harvesters cannot supply power on-demand limiting their overall operation.</p><p dir="ltr">The objective of this thesis is to achieve reliable sensing with WIE sensors by overcoming the challenges of uncontrolled environment, drift or degradation, and calibration subject to limited power supplies. First, we have developed a concept of “Nernst thermometry” for potentiometric ion-selective electrodes (ISE) with which we have self-corrected concentration fluctuation due to uncontrolled temperature. Next, by using “Nernst thermometry,” we have developed a physics-guided data analysis method for drift detection and self-calibration of WIE ISE. For WIE sensor, wireless data transmission is an energy-intensive operation. To reduce unreliable data transmission, we have developed a statistical approach to monitor the credibility of the sensor continuously and transmit only credible sensor data. To understand and monitor the cause of ISE degradation, we have proposed a novel on-the-fly equivalent circuit extraction method that does not require any external power supply or complex measurements. To ensure an on-demand power supply, we have presented the concept of “signal as a source of energy.” By circuit simulation and long-term experimental analysis, we have shown that ISE can indefinitely sense and harvest energy from the analyte. We have theoretically calculated the maximum achievable power with such systems and presented ways to achieve it practically. Overall, the thesis presents a holistic approach to developing a self-sustainable WIE sensor with environmental variation correction, self-calibration, reliable data transmission, and lifelong self-powering capabilities, bringing smart agriculture and environmental sensing one step closer to reality.</p> Electrical circuits and systems Electronic sensors Electrochemical sensor reliable sensing data analysis concept statistical analysis temperature correction self calibration drift detection
54	Development of Novel Wearable Sensor System Capable of Measuring and Distinguishing Between Compression and Shear Forces for Biomedical Applications Dimitrija Dusko Pecoski (8797031) 21 June 2022 (has links) <p>There are no commercially available wearable shoe in-sole sensors that are capable of measuring and distinguishing between shear and compression forces. Companies have already developed shoe sensors that simply measure pressure and make general inferences on the collected data with elaborate software [2, 3, 4, 5]. Researchers have also attempted making sensors that are capable of measuring shear forces, but they are not well suited for biomedical applications [61, 62, 63, 64]. This work focuses on the development of a novel wearable sensor system that is capable of identifying and measuring shear and compression forces through the use of capacitive sensing. Custom hardware and software tools such as materials test systems and capacitive measurement systems were developed during this work. Numerous sensor prototypes were developed, characterized, and optimized during the scope of this project. Upon analysis of the data, the best capacitive measurement system developed in this work utilized the CAV444 IC chip, whereas the use of the Arduino-derived measurement system required data filtering using median and Butterworth zero phase low pass filters. The highest dielectric constant reported from optimization experiments yielded 9.7034 (+/- 0.0801 STD) through the use of 60.2% by weight calcium copper titanate and ReoFlex-60 silicone. The experiments suggest certain sensors developed in this work feasibly measure and distinguish between shear and compressional forces. Applications for such technology focus on improving quality of life in areas such as managing diabetic ulcer formation, preventing injuries, optimizing performance for athletes and military personnel, and augmenting the scope of motion capture in biomechanical studies.</p> Biomechanical engineering Biomedical instrumentation Medical devices Circuits and systems Microelectronics Composite and hybrid materials Wearables Wearable Sensors Sensors Biomedical Engineering Mechanical Engineering Electrical Engineering Biomechanics Disease Management Diabetic Neuropathy Ulcer Prevention Athlete Injury Prevention Human Performance Optimization Motion Capture Analysis Optimization Sensor Development Capacitive Sensing Sensor Performance Characterization Dielectric Materials Composites Measurement Systems Instrumentation Mechanical Testing Materials Testing System Sensor Design Sensor Materials Sensor Manufacturing Sensor Data Analysis Custom Hardware and Software Development Sensor Systems Capacitive Sensor Modeling Biomechanical Engineering Biomedical Instrumentation Circuits and Systems Composite and Hybrid Materials Medical Devices Microelectronics and Integrated Circuits
55	Capacitorless Power Electronics Converters Using Integrated Planar Electro-Magnetics Haitham M Kanakri (18928150) 03 September 2024 (has links) <p dir="ltr">The short lifespan of capacitors in power electronics converters is a significant challenge. These capacitors, often electrolytic, are vital for voltage smoothing and frequency filtering. However, their susceptibility to heat, ripple current, and aging can lead to premature faults. This can cause issues like output voltage instability and short circuits, ultimately resulting in catastrophic failure and system shutdown. Capacitors are responsible for 30% of power electronics failures.</p><p dir="ltr">To tackle this challenge, scientists, researchers, and engineers are exploring various approaches detailed in technical literature. These include exploring alternative capacitor technologies, implementing active and passive cooling solutions, and developing advanced monitoring techniques to predict and prevent failures. However, these solutions often come with drawbacks such as increased complexity, reduced efficiency, or higher upfront costs. Additionally, research in material science is ongoing to develop corrosion-resistant capacitors, but such devices are not readily available.</p><p dir="ltr">This dissertation presents a capacitorless solution for dc-dc and dc-ac converters. The proposed solution involves harnessing parasitic elements and integrating them as intrinsic components in power converter technology. This approach holds the promise of enhancing power electronics reliability ratings, thereby facilitating breakthroughs in electric vehicles, compact power processing units, and renewable energy systems. The central scientific premise of this proposal is that the capacitance requirement in a power converter can be met by deliberately augmenting parasitic components.</p><p dir="ltr">Our research hypothesis that incorporating high dielectric material-based thin-films, fabricated using nanotechnology, into planar magnetics will enable the development of a family of capacitorless electronic converters that do not rely on discrete capacitors. This innovative approach represents a departure from the traditional power converter schemes employed in industry.</p><p dir="ltr">The first family of converters introduces a novel capacitorless solid-state power filter (SSPF) for single-phase dc-ac converters. The proposed configuration, comprising a planar transformer and an H-bridge converter operating at high frequency, generates sinusoidal ac voltage without relying on capacitors. Another innovative dc-ac inverter design is the twelve step six-level inverter, which does not incorporate capacitors in its structure.</p><p dir="ltr">The second family of capacitorless topologies consists of non-isolated dc-dc converters, namely the buck converter and the buck-boost converter. These converters utilize alternative materials with high dielectric constants, such as calcium copper titanate (CCTO), to intentionally enhance specific parasitic components, notably inter capacitance. This innovative approach reduces reliance on external discrete capacitors and facilitates the development of highly reliable converters.</p><p dir="ltr">The study also includes detailed discussions on the necessary design specifications for these parasitic capacitors. Furthermore, comprehensive finite element analysis solutions and detailed circuit models are provided. A design example is presented to demonstrate the practical application of the proposed concept in electric vehicle (EV) low voltage side dc-dc power converters used to supply EVs low voltage loads.</p> Circuits and systems Electrical circuits and systems Electrical machines and drives Engineering electromagnetics Solid-state power filter (SSPF) capacitorless topology active output power filter planar transformer electrolytic capacitor lifetime wear-out mechanisms notch resonant filter LLC-resonant converter calcium copper titanate (CCTO) intra capacitance Miniaturizing EV Chargers Multilevel inverters twelve-step inverter three-phase inverter six-level output voltage planar transform design Finite Element Analysis (FEA) Ansys Maxwell Ansys PEmag Ansys PExpert Ansys Simplorer Ansys Twin Builder planar electromagnetic buck-boost converter integrated magnetic hybrid LC filter high-power density converters CaCu3Ti4O12 electric vehicle chargers Nano graphene layer heat sink IGBT thermal response composite substrate planar transformer circuit models h-parameter voltage gradient dual transformer LLC resonant converter DC-DC Buck converter fundamental harmonic analysis power quality Total harmonic distortion (THD)
56	Performance enhancement techniques for low power digital phase locked loops Elshazly, Amr 16 July 2014 (has links) Desire for low-power, high performance computing has been at core of the symbiotic union between digital circuits and CMOS scaling. While digital circuit performance improves with device scaling, analog circuits have not gained these benefits. As a result, it has become necessary to leverage increased digital circuit performance to mitigate analog circuit deficiencies in nanometer scale CMOS in order to realize world class analog solutions. In this thesis, both circuit and system enhancement techniques to improve performance of clock generators are discussed. The following techniques were developed: (1) A digital PLL that employs an adaptive and highly efficient way to cancel the effect of supply noise, (2) a supply regulated DPLL that uses low power regulator and improves supply noise rejection, (3) a digital multiplying DLL that obviates the need for high-resolution TDC while achieving sub-picosecond jitter and excellent supply noise immunity, and (4) a high resolution TDC based on a switched ring oscillator, are presented. Measured results obtained from the prototype chips are presented to illustrate the proposed design techniques. / Graduation date: 2013 / Access restricted to the OSU Community at author's request from July 16, 2012 - July 16, 2014 Phase locked loops Delay locked loops Supply noise mitigation background calibration Digital PLL Supply noise Time to digital converter TDC Switched ring oscillator SRO-TDC Digital circuits Low power Area efficient Digitally controlled oscillator Performance enhancement techniques Integrated circuits Frequency synthesizers Clock multipliers Integrated circuits Microelectronics Analog and mixed Circuits and systems Analog Digital Solid state circuit Phase-locked loops Electronic noise -- Prevention Low voltage systems Frequency synthesizers

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