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Dissertations / Theses on the topic 'Ultrasonic Sensor'
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Beadle, Brad Michael. "Fiber optic sensor for ultrasound." Diss., Georgia Institute of Technology, 2002. http://hdl.handle.net/1853/17869.
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Beadle, Brad Michael. "Fiber optic sensor for ultrasound." Thesis, Georgia Institute of Technology, 1999. http://hdl.handle.net/1853/19173.
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FILHO, WAGNER MUNDY VALVERDE. "DEVELOPMENT OF FIBER OPTIC ACOUSTIC SENSOR FOR ULTRASONIC FLOWMETER." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2001. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=19330@1.
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CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOAGÊNCIA NACIONAL DE PETRÓLEO
Nesta dissertação são relatadas as etapas que resultam na construção do protótipo de um receptor acústico a Fibra Óptica (RAFO). O trabalho faz parte de um projeto mais amplo visando o desenvolvimento de um medidor de vazão sônico baseado em fibras ópticas. Nesta fase inicial, os esforços foram voltados para a concepção, construção e testes do protótipo do transdutor, responsável pela deteção dos sinais sônicos emitidos por uma fonte, baseado em tecnologia de fibras ópticas. O uso de um sensor extrínseco foi a solução aqui empregada, que adota uma proposta de medição diferente da utilizada em medidores de vazão sônicos convencionais. O sistema de medição de vazão proposto na linha de pesquisa na qual este trabalho está inserido, baseia-se em medidas de tempo de transito para daí inferir a vazão volumétrica do fluido que escoa pelo duto. O sistema foi concebido para operar apenas numa banda estreita de frequências, casada com o sinal senoidal emitido pela fonte sonora. Neste trabalho um receptor acústico a fibra óptica foi projetado, montado e testado, tendo seu funcionamento sido demonstrado para freqüências de operação em torno de 3,2 kHz. A escolha desta faixa de frequências deveu-se basicamente a limitações do sistema de leitura optoeletronico utilizado nos testes de medição. Entretanto, uma vez que o princípio de funcionamento foi demonstrado com sucesso, não existem limitações para o re-dimensionamento do sensor de forma que este possa vir a operar em bandas de freqüência mais elevadas.
This thesis reports the steps that have led to the assemblage and testing of na optical fiber microphone. This is part of a greater effort directed towards the development a sonic flowmeter based on optical fiber technology. In this first phase of the project, focus has been placed on the conception, construction, and testing, of the acoustic receiver first prototype. This transducer will be responsible for capturing the acouustical signails sent by an emitter, also based on optical fiber technology, and which is yet to be developed. In constrast with conventional sonic flowmeters, in which time of flight of acoustical pulses is the measured quantity related to flow rate, we are proposing a system based on measurement of phase difference between emitted and received sinusoidal signals.Hence, the acoustic receiver has been conceived to operate in a narrow frequency band. In particular, the developed prototype has been designed to operate in a frequency band centered at 3.2 kHz. This choice has been dictated by the response of the optoeletronic circuit employed in tests performed with the receiver operating in air and water. Nevertheless, since the principle of operation has been measurement of acoustical signails in higher frequency bands.
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Kranz, Michael S. "Micro-mechanical sensor for the spectral decomposition of acoustic signals." Diss., Georgia Institute of Technology, 2011. http://hdl.handle.net/1853/39496.
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An array of electret-biased frequency-selective resonant microelectromechanical system (MEMS) acoustic sensors was proposed to perform analysis of stress pulses created during an impact between two materials. This analysis allowed classification of the stiffness of the materials involved in the impact without applying post-impact signal processing. Arrays of resonant MEMS sensors provided filtering of the incident stress pulse and subsequent binning of time-domain waveforms into frequency-based spectra. Results indicated that different impact conditions and materials yielded different spectral characteristics. These characteristics, as well as the resulting sensor array responses, are discussed and applied to impact classification. Each individual sensor element in the array was biased by an in situ charged electret film. A microplasma discharge apparatus embedded within the microsensor allowed charging of the electret film after all device fabrication was complete. This enabled electret film integration using high-temperature surface micromachining processes that would typically lead to discharge of traditionally formed electret materials. This also eliminated the traditional wafer-bonding and post-fabrication assembly processes required in conventional electret integration approaches. The microplasma discharge process and resulting electret performance are discussed within the context of the MEMS acoustic sensor array.
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Salido, Monzú David, and Sánchez Oliver Roldán. "Robot Positioning System : Underwater Ultrasonic Measurement." Thesis, Mälardalen University, School of Innovation, Design and Engineering, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:mdh:diva-5817.
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This document provides a description about how the problem of the detection of thecenter of a defined geometry object was solved.This named object has been placed in an experimental environment surrounded bywater to be explored using microwaves under the water, to try to find a possibletumor. The receiver antenna is fixed in the tip of the tool of an ABB robot.Due to this working method, it was necessary to locate the center of this object tomake correctly the microwave scanning turning always around the actual center. Thiswork not only consist in give a hypothetic solution to the people who gave us theresponsibility of solve their problem, it is also to actually develop a system whichcarries out the function explained before.For the task of measuring the distance between the tip of the tool where themicrowave antenna is, ultrasonic sensors has been used, as a complement of acomplete system of communication between the sensor and finally the robot handler,using Matlab as the main controller of the whole system.One of these sensors will work out of water, measuring the zone of the object which isout of the water. In the other hand, as the researching side of the thesis, a completeultrasonic sensor will be developed to work under water, and the results obtained willbe shown as the conclusion of our investigation.The document provides a description about how the hardware and software necessaryto implement the system mentioned and some equipment more which were essentialto the final implementation was developed step by step.
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Atkinson, David. "Evaluation of an active acoustic waveguide sensor for embedded structural monitoring." Thesis, University of Strathclyde, 2000. http://oleg.lib.strath.ac.uk:80/R/?func=dbin-jump-full&object_id=21138.
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This Thesis describes research aimed towards the realisation of an embedded ultrasonic monitoring system for operation in a smart structure environment. Alien fibres embedded within carbon fibre reinforced composite plates could be utilised to guide ultrasound to strategic release points for the interrogation of the test sample, with minimal structural degradation. In particular, an array of fibre waveguides could be utilised to deliver periodic stresses to a plate-type structure to excite Lamb wave propagation. With such a system several problems need to be addressed. Firstly, identification of an appropriate mode of propagation to transport the acoustic energy along the waveguide and meet the requirements of the system is required. Theoretical analysis of elastic wave propagation in cylinders is provided to establish the characteristics of the various supported modes. Subsequently, the longitudinal (axisymmetric) modes are highlighted as being the most appropriate for the proposed system. Ideally, such a mode should be singly generated to provide increased control on the coupling of ultrasound from the waveguide to the desired Lamb wave mode. Therefore, the transducer-fibre interface utilised for efficient single mode generation in the fibre waveguides is essential. This Thesis investigates a novel, cheap, simple, and robust coupling strategy, which employs a conical polymer bond to behave as a mechanical transformer efficiently coupling the lateral displacements of a piezoceramic transducer into longitudinal displacements in the waveguide. Theoretical and experimental analysis of this technique are described and design guidelines detailed. The Thesis then goes on to provide experimental and theoretical evidence of the fibre waveguide's ability to transport acoustic energy to and from plate-type structures for subsequent Lamb wave generation and detection. Initially, a surface mount strategy is adopted, whereby the ends of several thin cylindrical waveguides are bonded to the surface of aluminium plates to behave as a line array. Generation and detection of the fundamental symmetric (So) and asymmetric (A0) Lamb wave modes is demonstrated. Following this, the Thesis details considerations concerning the realisation of an embedded fibre waveguide monitoring system. Here, the choice of waveguide material and geometry is crucial to ensure the guided ultrasound does not leak into the structure at undesirable locations and that the structural integrity of the test sample is maintainable. Consequently, various waveguide configurations are investigated to establish an arrangement capable of meeting the system requirements. An embedded fibre waveguide Lamb wave system is then presented in a hard-setting polymer plate confirming the basic design methodology. Finally, So Lamb wave generation and detection in a carbon fibre reinforced composite plate is demonstrated utilising embedded acoustic waveguides sensors.
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Moisan, Jean-Francois. "Ultrasonic monitoring of die-casting process using clad buffer rod sensor." Thesis, McGill University, 2001. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=32968.
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In-line monitoring of die-casting of aluminum (A356, A357, 86S), magnesium (AZ91) and a metal matrix composite (Gra-NiRTM 6S:3G) will be monitored using the reflection coefficient obtained by using an ultrasonic technique, the pulse/echo. For each of the materials enumerated above, the average temperature of the mold through its thickness, the end of filling of the part, the solidification of the part in the cavity of the mold, the gap and/or the detachment of the part, the sound velocity and the attenuation of the material will be measured by this ultrasonic technique during the process.For the materials the melt temperature will not exceed 600°C because the casting is made at the semi-solid state, between the solidus and liquidus, of the materials. A novel high performance buffer rod with a cooling system is integrated into the die. Therefore, ultrasonic measurements can be carried out with high signal-to-noise ratio at elevated temperatures.
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Alzebda, Said Anwar. "Low-cost oscillating sensor for ultrasonic testing and monitoring of liquids." Thesis, University of Nottingham, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.546599.
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McLean, Jeffrey John. "Interdigital Capacitive Micromachined Ultrasonic Transducers for Microfluidic Applications." Diss., Georgia Institute of Technology, 2004. http://hdl.handle.net/1853/7625.
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The goal of this research was to develop acoustic sensors and actuators for microfluidic applications. To this end, capacitive micromachined ultrasonic transducers (cMUTs) were developed which generate guided acoustic waves in fluid half-spaces and microchannels. An interdigital transducer structure and a phased excitation scheme were used to selectively excite guided acoustic modes which propagate in a single lateral direction. Analytical models were developed to predict the geometric dispersion of the acoustic modes and to determine the sensitivity of the modes to changes in material and geometric parameters. Coupled field finite element models were also developed to predict the effect of membrane spacing and phasing on mode generation and directionality.
After designing the transducers, a surface micromachining process was developed which has a low processing temperature of 250C and has the potential for monolithically integrating cMUTs with CMOS electronics. The fabrication process makes extensive use of PECVD silicon nitride depositions for membrane formation and sealing. The fabricated interdigital cMUTs were placed in microfluidic channels and demonstrated to sense changes in fluid sound speed and flow rate using Scholte waves and other guided acoustic modes. The minimum detectable change in sound speed was 0.25m/s, and the minimum detectable change in flow rate was 1mL/min. The unique nature of the Scholte wave allowed for the measurement of fluid properties of a semi-infinite fluid using two transducers on a single substrate. Changes in water temperature, and thus sound speed, were measured and the minimum detectable change in temperature was found to be 0.1C. For fluid pumping, interdigital cMUTs were integrated into microchannels and excited with phase-shifted, continuous wave signals. Highly directional guided waves were generated which in turn generated acoustic streaming forces in the fluid. The acoustic streaming forces caused the fluid to be pumped in a single, electronically-controlled direction. For a power consumption of 43mW, a flow rate of 410nL/min was generated against a pressure of 3.4Pa; the thermodynamic efficiency was approximately 5x10-8%. Although the efficiency and pressure head are low, these transducers can be useful for precisely manipulating small amounts of fluid around microfluidic networks.
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Krsmanovic, Dalibor. "High temperature ultrasonic gas flow sensor based on lead free piezoelectric material." Thesis, University of Cambridge, 2011. https://www.repository.cam.ac.uk/handle/1810/245065.
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The review of current technologies for measurement of gas velocity in stack flow applications is undertaken and it is shown that the ultrasonic time-of-flight method is the most suitable and offers a number of advantages over alternatives. Weakness of current piezoelectric based transducers are identified as the inability to operate at temperatures above 400 °C due to limitation of piezoelectric materials used, and a case for development of an alternative high temperature material is put forward. A novel and highly enhanced, lead free piezoelectric material, suitable for continuous operation at temperatures above 400 °C has been engineered for ultrasonic gas velocity sensor applications. Structural modification of pure bismuth titanate (Bi4Ti3O12) or BIT compound, through multi-doping at the Ti-site, has been found to enhance piezoelectric properties accompanied with a mild reduction in Curie temperature, Tc. Initially, compounds doped with tungsten and chromium were found to increase the piezoelectric coefficient (d33) from around 5 pC N¯¹ in pure bismuth titanate, to above 20 pC N¯¹ in doped compounds. This increase is attributed to lower conductivity and improved poling conditions. Further increases in d33 (up to 35 pC N¯¹) were then realised through controlled grain growth and reduction in conductivity for niobium, tantalum and antimony doped compounds. The Curie temperature of the material with best properties is found to be 667 °C, which is a slight reduction from 675 °C for pure bismuth titanate ceramic. The enhancements in modified bismuth titanate achieved in present work allow the material to be considered as suitable for high temperature ultrasonic transducer applications. Integration of bismuth titanate material into a working high temperature transducer is then considered and the investigation of suitable, high temperature bonding method is undertaken. It is shown that reactivity of bismuth titanate with the titanium based fillers makes brazing unsuitable as a bonding method between piezo-ceramics and stainless steel. A novel assembly method, using liquid gallium as an electrically conductive bond, and a mechanical restraint for the piezo actuator is then presented as an alternative with the potential to reduce the negative effects of differences in thermal expansion coefficients between constituents of the transducer assembly.
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Ruscher, Thomas Hall. "A Compact Ultrasonic Airflow Sensor for Clinical Monitoring of Pediatric Tracheostomy Patients." Thesis, Virginia Tech, 2013. http://hdl.handle.net/10919/50143.
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Infants and young children with tracheostomies need better respiratory monitors. Mucus in the tracheostomy tube presents a serious choking hazard. Current devices indirectly detect respiration, often yielding false or delayed alarms. A compact ultrasonic time-of-flight (TOF) airflow sensor capable of attaching directly to the tracheostomy tube has been developed to address this need. The ultrasonic flow sensing principle, also known as transit time ultrasound, is a robust method that correlates the timing of acoustic signals to velocity measurement. The compact prototype developed here can non-invasively measure all airflow into and out of a patient, so that breath interruption can easily be detected.This paper concerns technical design of the sensor, including the transducers, analog/digital electronics, and embedded systems hardware/software integration. Inside the sensor\'s flow chamber, two piezoelectric transducers sequentially transmit and receive ping-like acoustic pulses propagating upstream and downstream of flow. A microcontroller orchestrates measurement cycles, which consist of the transmission, reception, and signal processing of each acoustic pulse. The velocity and direction of airflow influence transit time of the acoustic signals. Combining TOF measurements with the known geometry of the flow chamber, average air velocity and volumetric flow rate can be calculated. These principles have all been demonstrated successfully by the prototype sensor developed in this research.
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Sonbul, O., M. Byamukama, S. Alzebda, and A. N. Kalashnikov. "Autonomous intrusion detection information system." Thesis, Сумський державний університет, 2012. http://essuir.sumdu.edu.ua/handle/123456789/28777.
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Abstract – Implementation of security arrangements for insecure premises, for example, for temporary exhibitions or infrequent public events, usually results in substantial security personnel costs which can be potentially reduced by employing an easily installable ad hoc intrusion detection information system. In the paper we described the architecture, design and experimental results for a fully prototyped information system that utilizes ultrasonic sensors operating in the pulse echo mode for the perimeter control and ZigBee transceivers for wireless networking. The system consists of inexpensive autonomous sensor nodes with the component cost of less than £25 and a control terminal with a graphical user interface controlled by a touch screen. The nodes are programmed wirelessly to detect intrusion within any user set distance up to the operating distance of the node, and can operate unattended for days.
When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/28777
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Adeyemi, Gbenga Joshua. "Development of an external ultrasonic sensor technique to measure interface conditions in metal rolling." Thesis, University of Sheffield, 2017. http://etheses.whiterose.ac.uk/19393/.
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Metal rolling is by friction which develops at metal-to-roll interfaces during the rolling process. But, friction at the metal-to-roll interface during the metal rolling process can cause roll surface damage if not controlled. Over time, friction results in downtime and repair of the mill. Therefore, lubrication is essential to control the metal-to-roll interface coefficient of friction. It is important to understand the conditions at the metal-to-roll interface to minimize energy loss and improve the strip surface finish. In this work, a new method for measurement of metal-to-roll interface conditions, based on the reflection of ultrasound, is evaluated during the cold metal rolling operation. The method is a pitch-catch sensor layout arrangement. Here, a piezoelectric element generates an ultrasonic pulse which is transmitted to the metal-to-roll contact interface. This method is non-invasive to both roll and strip during the process. The wave reflection from the metal-to-roll interface is received by a second transducer. The amplitude of the reflected waves is processed in the frequency domain. The reflection coefficient values are used to study the metal-to-roll interface conditions at different rolling parameters like, roll speeds and rolling loads. The results show that the reflection coefficient increases with increasing roll speed. This is because of reduction in the roll-bite contact area or increase in the frictional resistance of interface during the roll speed increment. However, the reflection coefficient decreases with increasing rolling load due to either increase in the roll-bite contact area or pressure. The reflection coefficient determines the oil film thickness formation at the metal-to-roll interface. In-addition, the Time-of-Flight of the reflected wave obtained from this technique is used to estimate strip thickness and roll-bite length during the rolling process. The oil film thickness in the range of 1.25µm to 3.05µm was measured during the rolling process. The film thickness increases with increasing roll speed and reduces with increasing rolling load. The roll-bite value of 5.5mm was measured during the process. The results from this study show that this ultrasonic technique can measure the metal-to-roll interface conditions (roll-bite, oil film and strip thickness) during the rolling process. This ultrasonic technique has the advantage of minor roll modification. Additionally, the experimental roll condition values obtained from the ultrasonic reflection method agree with theoretical values. The technique shows promising results as a research tool, and with further development, could be used for lubricant monitoring. Also, it can be utilized in the control system of a working mill for reduction of friction losses in the metal rolling process.
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Jayabharath, Kumar Suri. "Sensor systems for positioning and identification in ubiquitous computing." Thesis, Linköping University, Department of Computer and Information Science, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-5767.
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Technologies for position sensing and identification are important to have in ubiquitous computing environments. These technologies can be used to track users, devices, and artefacts in the physical milieu, for example, locating the position of a cellular phone in av physical environment. The aim of this thesis was to survey and classify available technologies for location sensing and identification.
We have made a literature study on both commercial and research-oriented systems and technologies for use in indoor and outdoor environments. We compared the characteristics of the underlying sensing technologies with respect to physical size, sensing method, cost, and accuracy. We conclude the thesis with a set of recommendations to developers and discuss the requirements on future sensing technologies and their use in mobile devices and environments.
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Chou, Tsung-nan. "The integration of an ultrasonic phased array and a vision system for the 3D measurement of multiple targets." Thesis, University of Nottingham, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.362887.
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Wieneke, Jacob Daniel. "A feasibility assessment of using ultrasonic sensor position feedback for a ball-and-beam apparatus." Thesis, Kansas State University, 2010. http://hdl.handle.net/2097/6241.
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Master of ScienceDepartment of Mechanical and Nuclear Engineering
Warren N. White
This thesis describes the process of testing and implementing ultrasonic transducers for ball position feedback on a ball-and-beam apparatus. Also included are specifications for equipment to allow feedback and command signals to be wireless, not hardwired to the control computer. The author presents various ball-and-beam configurations as well as details about the specific configuration used for this work. These details include choices in sensors, materials, hardware, construction, and controller. After the apparatus has been described, the author provides information to support claims about system performance. The conclusions presented specify the necessary hardware to make the system wireless and indicate that acoustic sensors can complete a successful ball-on-beam balancing system.
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Cheema, Saad Saadat. "Design and Performance Analysis of a Sonar Data Acquisition System." University of Cincinnati / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1563874431553724.
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Paul, Sanjib. "Sensor karakterisering kring delaminering." Thesis, Mittuniversitetet, Institutionen för elektronikkonstruktion, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:miun:diva-41310.
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Dagens industrier håller på att bli allt mer automatiserade, smartare och effektivare, i samband med detta ökas kraven att man tar fram noggrannare och pålitligare sensorsystem som är även kostnadseffektiva. Målet med denna undersökning har varit tillsammans med Iggesund Pappersbruk är att karakterisera noggrannheten för sensorn Ultrasonic Double sheet moniter (DSM) och även ta fram riktlinjer för en ingående inline mätande prototyp. Studien använder sig av väldigt enkla metoder för att karakterisera resolutionen och även undersöka det minimala avståndet för flera seriekopplade sensorer utan att de ingriper och stör varandras inläsningar. De programvaror som används under studien är PACTware och Matlab. Undersökningen visar resultat på en trovärdig noggrannhet utav sensorn och man har även kunnat karakteriserat detektions arean runt om receivern för den framtida prototypen. Avslutningsvis går studien igenom synpunkter på DSM sensorn och en diskussion om att karakterisa olika destruktiva ytor men även om vad som kan förbättras eller förbyggas.Today's industries are becoming more automated, smarter and more efficient, and it requires high standards to develop more accurate and reliable sensor systems that are low-cost. The aim of this study was together with Iggesund Pappersbruk to characterize the accuracy of the Ultrasonic Double Sheet Monitor (DSM) sensor and to develop guidelines for an in-line measuring prototype. The study uses quite simple methods to characterize the resolution and investigate the minimum distance for several series-connected sensors without interfering with each other's readings. The software used during the study is PACTware and Matlab. The study shows results on a credible accuracy of the sensor and it has also been possible to characterize the detection area around the emitter for the future prototype. Finally, the study concludes with views on the DSM sensor and a discussion on how to characterize different destructive surfaces but also what can be improved or prevented.
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Trujillo, Victor Esteban. "Global Shipping Container Monitoring Using Machine Learning with Multi-Sensor Hubs and Catadioptric Imaging." W&M ScholarWorks, 2019. https://scholarworks.wm.edu/etd/1582642585.
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We describe a framework for global shipping container monitoring using machine learning with multi-sensor hubs and infrared catadioptric imaging. A wireless mesh radio satellite tag architecture provides connectivity anywhere in the world which is a significant improvement to legacy methods. We discuss the design and testing of a low-cost long-wave infrared catadioptric imaging device and multi-sensor hub combination as an intelligent edge computing system that, when equipped with physics-based machine learning algorithms, can interpret the scene inside a shipping container to make efficient use of expensive communications bandwidth. The histogram of oriented gradients and T-channel (HOG+) feature as introduced for human detection on low-resolution infrared catadioptric images is shown to be effective for various mirror shapes designed to give wide volume coverage with controlled distortion. Initial results for through-metal communication with ultrasonic guided waves show promise using the Dynamic Wavelet Fingerprint Technique (DWFT) to identify Lamb waves in a complicated ultrasonic signal.
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Maqueira, Benigno. "Robotic seam tracking of weld joints through the use of an ultrasonic sensor : system development and implementation." Thesis, Georgia Institute of Technology, 1986. http://hdl.handle.net/1853/15839.
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Veedhi, Carisma Catherin, and Vasantha Sai Darahas Yeedi. "Estimation of Altitude : using ultrasoinc and pressure sensors." Thesis, Blekinge Tekniska Högskola, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:bth-19950.
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This paper deals with the estimation of altitude of the drone for which the sensors like ultrasonic, barometric pressure sensors and their characteristics plays a major role. To estimate the altitude of the drone, we used the matlab software with Simulink. apart from the software and hardware description, we discuss several issues regarding the equipment,abilities and performance of the drone.
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Lilly, Bradford R. "A Novel System for Wireless Robotic Surgery Through the Use of Ultrasonic Tracking Coupled with Advanced Modeling Techniques." University of Toledo / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1333673350.
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Ottosson, Joachim, and Niklas Renström. "aMAZEing robot : A method for automatic maze solving." Thesis, KTH, Skolan för industriell teknik och management (ITM), 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-264491.
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The purpose of this report was to examine a method for automatic maze solving by developing a robot that can find a specific target within a maze. On this basis, a Arduino based robot was constructed. The steering mechanism was constructed in a way that supports differential steering which enables zero radius turns which is preferred in narrow spaces. The intersection detection as well as the method for defining which type of intersection occurring was based on three distance sensor mounted in front and on the left and right side of the robot. The target detection was based on a IR sensor. A feedback controller was applied on the left Ultrasonic sensor enabling the robot to keep a reference distance to the wall. The feedback system also enabled the robot to straighten up when taking to big or small turns. The robot was able to both detect and define what kind of intersection occurring as well as detect the specific target. The execution of the correct operation by detected intersection was calculated to 80% - 100% and the target was found 100% out of the test made. The definition of ”correct operation” in this report was when the robot detected a intersection, and executed the operation that was in accordance with the implemented algorithm. The rotational error, that is the quantity of degrees from the desired turn angle, occurring when the robot executed different operations was calculated to 3.5◦ - 9.5◦ . The robot started to oscillate due to angles grater than 19.5◦ when the left distance sensor was facing the wall which made the robot less able to follow a path and straighten up.Syftet med denna rapport var att undersöka en metod för automatiserad labyrintlösning genom att utveckla en robot som kan finna ett specifikt mål i en labyrint. På dessa grunder konstruerades en arduinobaserad robot. Styrmekanismen konstruerades på sådant sätt att differentialstyrning var möjlig vilket tillät svängar utan svängradie, vilket är att föredra vid trånga utrymmen. Vägkorsningsdetekteringen samt metoden för att bestämma vilken typ av vägkorsning som förekommer baserades på tre distansmätare. Dessa var monterade på robotens front samt på höger och vänster sida. Måldetekteringen var baserad på en IR sensor. Ett system medåterkoppling implementerades på den vänstra distansmätaren för att få roboten att hålla ett referensavstånd till väggen. Detta möjliggjorde även så att vägen kunde följas på ett optimalt sätt samt att roboten kunde rätas upp vid för stora eller för små tagna svängar. Roboten lyckades både detektera samt definiera vilken typ av vägkorsning som uppstod likväl som att detektera det specifika målet. Andelen utförda korrekta operationer vid detekterande av vägkorsning beräknades till 80% - 100% av fallen och målet detekterades 100% av gångerna vid det gjorda testerna. Definitionen av ”korrekt operaton ”i denna rapport var då roboten upptäckte en vägkorsning och utförde den operation som var i enlighet med den implementerade algoritmen. Rotationsfelet, det vill säga antalet grader från den önskade svängvinkeln, som uppstod vid de olika operationerna beräknades till 3.5◦ - 9.5◦ . Roboten började att oscillera vid vinklar större än 19.5◦ då den vänstra distansmätaren var vänd mot väggen vilket gjorde roboten mindre duglig att följa väggen samt att rätas upp.
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Persson, Annie, and Johanna Bergsten. "PlaCo : The plastic collecting robot." Thesis, KTH, Mekatronik, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-295807.
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The oceans are an essential global resource for all living organisms but especially for us humans. However, year after year we continue to neglect proper recycling of our waste, resulting in litter ending up in our oceans. The majority of said litter comes from single use plastic items. Through fragmentation and erosion, the plastic dissolves to smaller pieces, once they are no larger than 5 mm theyare classified as micro- and nanoplastics. Little is known about these small plastic particles impact on marine life and marine environment. As a step towards understanding this, the robot PlaCo was created. PlaCo stands for plastic collecting which is exactly what the robot does. With the help of three filters PlaCo gathers marine debris, such as plastic, from the water in which it operates. The filters have decreasing mesh size resulting in the microplastics being caught in the last one. Once emptied, the finds can be examined and logged for future referencing. With the help of a sensor, blockages of the filters can be monitored and if detected, notice will be given to the user through a LED. In order for PlaCo to move forward and for water to travel through the filters, the robot was provided with two DC motors. A microcontroller, Arduino Uno, was used to regulate PlaCo’s functions. The performance of two different sensors, an IR-sensorand an ultrasonic sensor, were investigated as well as the robot's water cleaning capacity. The results indicate that the latter of the two sensors would be preferable due to its high reliability. However, the robot’s water cleaning capacity could not be measured due to the chosen motors not being powerful enough. In future iterations of PlaCo, thiswould need to be rectified.Globalt sett är världens hav en viktig resurs för alla levande organismer men inte minst för människan. Trots detta fortsätter vi att, år efter år, försumma återvinningen av vårt avfall vilket resulterar i att skräp i stället hamnar i haven. Majoriteten av de sopor som hamnar där är resultatet av förbrukade engångsprodukter i plast. Genom sönderfall och erosion skapas allt mindre och mindre bitar av plast. Detta resulterar i att så kallade mikro- och nanoplaster skapas. De är mindre än 5 mm i bredd och om deras påverkan på det marina djurlivet och den marina miljön vet vi mycket lite om. För att minska kunskapsluckorna och för att få en bättre förståelse för deras påverkan har nu därför PlaCo konstruerats. Med hjälp av tre sorters filter kan PlaCo samla upp marintskräp, så som plast, i vattnet där den arbetar. Filtrens finhet varierar, där det första är mycket grovt medan det sista är fint nog att klara av att samla upp mikroplaster. När PlaCo sedan töms kan mikroplasterna undersökas och dokumenteras. När en tömning behöver göras indikeras detta för användaren med hjälp utav en LED. Roboten är försedd med en sensor som läser av hur fulla filtren är. För att driva PlaCo framåt och för att underlätta filtreringsprocessen är den också försedd med två 6 V DC-motorer. Allt detta styrs med hjälp av mikrokontrollern Arduino Uno. För att uppnå bästa tänkbara funktion hos roboten undersöktes två olika sensortyper, en IR-sensor och en ultraljudssensor. Det visade sig att ultraljudssensorn var betydligt mer pålitlig än IR-sensorn och därför valde man att använda denna. Det var även av intresse att ta reda på hur mycket vatten PlaCo kunde rena per sekund. Tyvärr skulle det visa sig att de valda motorerna inte var kraftfulla nog att driva PlaCo i vattnet. Det är därför något som behöver åtgärdas i en framtida version av PlaCo.
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Gentilini, Lorenzo. "Kalman Filters: Linear and Nonlinear applications in Sensor Fusion." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2019.
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Autonomous navigation is nowadays one of the hottest topic among engineering research fields and, as a matter of facts, the number of researches which are working on this field increased a lot in last years and it is expected to increase even more in future. One of the main problem, which can be encountered when facing with autonomous navigation, is the gathering of information coming from different sensors. The autonomous devices are, in fact, equipped with a large number of perception tools useful to build a model of the surrounding environment. The main question to which this dissertation aims to found an answer, is: how can this large number of data be combined in order to exploit all the available information and to obtain an improved, unique and more reliable estimation of the interesting variable?
Therefore, the objective of this dissertation is the study of different techniques of state estimation which can be used to build different data fusion algorithms. In particular the focus is on Kalman-based data fusion techniques, the theory behind this kind of algorithms is deeply analyzed and the performances of them are tested by means of a real application: a Kalman-based method is used to combine data coming from visual odometry, IMU, GNSS module and encoders in order to estimate the absolute position of a UGV within a semistructured environment, such as an orchard.
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Wei, Daniel Chin Min. "Método de desvio de obstáculos aplicado em veículo autônomo." Universidade de São Paulo, 2015. http://www.teses.usp.br/teses/disponiveis/3/3138/tde-17062016-142254/.
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A operação de veículos autônomos necessita de meios para evitar colisões quando obstáculos não conhecidos previamente são interpostos em sua trajetória. Algoritmos para executar o desvio e sensores apropriados para a detecção destes obstáculos são essenciais para a operação destes veículos. Esta dissertação apresenta estudos sobre quatro algoritmos de desvio de obstáculos e tecnologia de três tipos de sensores aplicáveis à operação de veículos autônomos. Após os estudos teóricos, um dos algoritmos foi testado para a comprovação da aplicabilidade ao veículo de teste. A etapa experimental foi a realização de um programa, escrito em linguagem de programação Java, que aplicou o algoritmo Inseto 2 para o desvio de obstáculos em uma plataforma robótica (Robodeck) com o uso de sensores ultrassônicos embarcados na referida plataforma. Os experimentos foram conduzidos em ambiente fechado (indoor), bidimensional e horizontal (plano), fazendo o Robodeck executar uma trajetória. Para os testes, obstáculos foram colocados para simular situações variadas e avaliar a eficácia do algoritmo nestas configurações de caminho. O algoritmo executou o desvio dos obstáculos com sucesso e, quando havia solução para a trajetória, ela foi encontrada. Quando não havia solução, o algoritmo detectou esta situação e parou o veículo.The operation of autonomous vehicles need means to avoid collisions when unforeseen obstacles are posed in its trajectory. Algorithms to perform the deviation and suitable sensors for detecting these obstacles are essential for the operation of such vehicles. This dissertation presents studies on four obstacle avoidance algorithms and technology of three types of sensors applicable to the operation of autonomous vehicles. After the theoretical studies, one of the algorithms has been tested for evidence of applicability to the test vehicle. The experimental phase was the implementation of a program written in Java programming language, which applied the Insect 2 algorithm for obstacle avoidance in a robotic platform (Robodeck) using ultrasonic sensors embedded in the platform. The experiments were conducted in a closed environment (indoor), two-dimensional and flat, making Robodeck perform a trajectory. For testing, obstacles were placed to simulate various situations and evaluating the algorithm efficacy for these path configurations. The algorithm successfully performed the deviation of obstacles and, when there was a solution to the trajectory, it was found. When there was no solution, the algorithm has detected this situation and stopped the vehicle.
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Tiller, Ben. "Surface acoustic wave streaming in a PDMS microfluidic system : effect of frequency and fluid geometry, &, A remote ultrasonic glucose sensor." Thesis, University of Glasgow, 2016. http://theses.gla.ac.uk/7670/.
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This thesis describes two separate projects. The first is a theoretical and experimental investigation of surface acoustic wave streaming in microfluidics. The second is the development of a novel acoustic glucose sensor. A separate abstract is given for each here. Optimization of acoustic streaming in microfluidic channels by SAWs Surface Acoustic Waves, (SAWs) actuated on flat piezoelectric substrates constitute a convenient and versatile tool for microfluidic manipulation due to the easy and versatile interfacing with microfluidic droplets and channels. The acoustic streaming effect can be exploited to drive fast streaming and pumping of fluids in microchannels and droplets (Shilton et al. 2014; Schmid et al. 2011), as well as size dependant sorting of particles in centrifugal flows and vortices (Franke et al. 2009; Rogers et al. 2010). Although the theory describing acoustic streaming by SAWs is well understood, very little attention has been paid to the optimisation of SAW streaming by the correct selection of frequency. In this thesis a finite element simulation of the fluid streaming in a microfluidic chamber due to a SAW beam was constructed and verified against micro-PIV measurements of the fluid flow in a fabricated device. It was found that there is an optimum frequency that generates the fastest streaming dependent on the height and width of the chamber. It is hoped this will serve as a design tool for those who want to optimally match SAW frequency with a particular microfluidic design. An acoustic glucose sensor Diabetes mellitus is a disease characterised by an inability to properly regulate blood glucose levels. In order to keep glucose levels under control some diabetics require regular injections of insulin. Continuous monitoring of glucose has been demonstrated to improve the management of diabetes (Zick et al. 2007; Heinemann & DeVries 2014), however there is a low patient uptake of continuous glucose monitoring systems due to the invasive nature of the current technology (Ramchandani et al. 2011). In this thesis a novel way of monitoring glucose levels is proposed which would use ultrasonic waves to ‘read’ a subcutaneous glucose sensitive-implant, which is only minimally invasive. The implant is an acoustic analogy of a Bragg stack with a ‘defect’ layer that acts as the sensing layer. A numerical study was performed on how the physical changes in the sensing layer can be deduced by monitoring the reflection amplitude spectrum of ultrasonic waves reflected from the implant. Coupled modes between the skin and the sensing layer were found to be a potential source of error and drift in the measurement. It was found that by increasing the number of layers in the stack that this could be minimized. A laboratory proof of concept system was developed using a glucose sensitive hydrogel as the sensing layer. It was possible to monitor the changing thickness and speed of sound of the hydrogel due to physiological relevant changes in glucose concentration.
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Šamánek, Radek. "Posouzení časových změn přesnosti vykazovaného průtoku a proteklého objemu u měřicích systémů využívajících vzdouvací objekty." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2019. http://www.nusl.cz/ntk/nusl-391943.
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The diploma thesis deals with monitoring of metrological characteristics of ultrasonic sensors located at the FAST and in-situ and the evaluation of the time development in the values of the discharge and the outflow volumes reported by the ultrasonic sensors.
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Ndao, Saliou. "Développement de capteurs interdigités à ondes acoustiques de surface pour l'estimation de l'humidité dans des structures en béton." Thesis, Valenciennes, Université Polytechnique Hauts-de-France, 2020. http://www.theses.fr/2020UPHF0005.
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Dans ce travail, nous avons développé des capteurs ultrasonores interdigités (IDT) d’humidité exploitant des ondes acoustiques de surface (SAW) de type Rayleigh. Ces capteurs SAWIDT sont destinés à suivre d’une part l’humidité ambiante dans les bétons du génie civil et d’autre part, le monitoring du séchage des bétons réfractaires à haute température (jusqu’à 450°C). Dans ce dernier cas, une évaporation brusque de l’humidité résiduelle lors d’une première mise en œuvre conduit à un endommagement de la structure d’où l’intérêt de s’assurer de l’absence d’humidité en fin de séchage de la structure. Ces deux applications imposent de développer de nouveaux capteurs d’humidité capables d’opérer à haute température et de détecter de faibles taux d’humidité relative dans le cadre des bétons réfractaires et de forts taux d’humidité relative dans le cadre des bétons du génie civil. Par ailleurs, la présence d’eau liquide ne doit pas avoir de conséquence sur le fonctionnement de ces capteurs. Pour ce faire, les capteurs SAW-IDT en mode ligne à retard ont été privilégiés. Ces derniers ont la particularité d’être très sensibles aux aspects environnementaux grâce au confinement de l’énergie des ondes à l’extrême surface (environ une longueur d’onde). De plus, dans la configuration de ces capteurs SAW-IDT, il est possible d’adapter les matériaux qui les composent (substrats piézoélectriques, couches sensibles à l’humidité et électrodes) en fonction de l’application visée. Au cours de cette thèse, des capteurs SAW-IDT opérant à 30 MHz sur substrat de niobate de lithium et fonctionnalisés avec une couche polymérique d’alcool polyvinylique (PVA) pour les applications basse température et d’oxyde de silicium pour celles à haute température ont été réalisés et optimisés. Des premiers tests in situ ont pu être menés. Il a été ainsi montré les potentialités de ces types de capteurs d’humidité aussi bien pour le monitoring de l’humidité ambiante dans les structures en génie civil que le suivi du séchage des bétons réfractairesIn this work, we have developed ultrasonic humidity interdigital (IDT) sensors exploiting Rayleigh type Surface Acoustic Waves (SAW). These SAW-IDT sensors are intended to monitor ambient humidity in civil engineering concretes and to monitor the refractory concretes drying at high temperatures (up to 450°C). In the latter case, a sudden evaporation of the residual humidity during a first implementation leads to a damage to the structure from which the interest to ensure the absence of humidity at drying end of the structure. These two applications require the development of new humidity sensors capable of operating at high temperatures and detecting low relative humidity levels in the context of refractory concretes and high relative humidity levels in the context of engineering concretes civil. In addition, the presence of liquid water must not have any effect on the operation of these sensors. To do this, SAW-IDT delay line sensors have been favored. The latter have the particularity of being very sensitive to environmental aspects thanks to the confinement of the acoustic waves energy at the near surface (approximately one wavelength). In addition, in the configuration of these SAW-IDT delay line sensors, it is possible to adapt the materials that compose them (piezoelectric substrates, humidity sensitive layers and electrodes) according to the intended application. In this work, SAW-IDT delay line sensors operating at 30 MHz on lithium niobate substrate and functionalized with a polymeric polyvinyl alcohol (PVA) layer for low temperature applications and silica layer for high temperature applications have been realized and optimized. First in situ tests could be conducted. It has been shown the potential of these types of humidity sensors both for the monitoring of ambient humidity in civil engineering structures and the monitoring of the refractory concrete drying
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Vengasandra, Srikanth G. "Studies on high power ultrasonic microembossing and organic light emitting diodes (OLEDs) for the creation of lab-on-CD devices for sensor related applications." [Ames, Iowa : Iowa State University], 2009. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:3396981.
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Takpara, Rafatou. "Développement de capteurs piézoélectriques interdigités flexibles pour la caractérisation ultrasonore des revêtements." Thesis, Valenciennes, 2015. http://www.theses.fr/2015VALE0041/document.
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Ce travail porte sur la réalisation de capteurs interdigités (IDT pour InterDigital Transducer) sur des supports piézoélectriques. L’enjeu est double puisqu’il s’agit premièrement de disposer de capteurs efficaces pour générer des ondes de surface acoustiques (SAW pour Surface Acoustic Wave) afin de caractériser la qualité des revêtements et des surfaces de structures. Le deuxième objectif de cette étude est de rendre ces capteurs IDT flexibles afin qu’ils puissent s’adapter non seulement aux différentes géométries planes ou non mais aussi pour qu’ils soient capables de supporter les déformations des structures au cours de leur utilisation. En général, les matériaux piézoélectriques sont rigides et le caractère souple des matériaux est souvent en opposition avec les performances piézoélectriques de ces derniers ; nous avons donc développé des matériaux qui répondent à ces deux exigences : la performance piézoélectrique et la souplesse. Enfin, nous avons privilégié des technologies relativement bon marché pour développer ces capteurs afin d’envisager par la suite, un contrôle continu des structures en intégrant ces capteurs à demeure sur ces dernièresThis work deals with the realization of interdigital sensors (IDT for InterDigital Transducer) on piezoelectric substrates. There is a dual challenge since firstly, the aim is to have efficient sensors to generate surface acoustic waves (SAW) in order to characterize the quality of the coatings and structure surfaces. The second objective of this study is to make these IDT sensors flexible so as to adapt to different geometries of structures and to be able to put up with the deformations of structures in use. Typically, piezoelectric materials are rigid and the flexible nature of the materials is often in opposition to the piezoelectric performance of the latter. We developed materials that meet these two requirements: piezoelectricity and flexibility. Finally, we gave greater importance to relatively cheap technologies to develop these sensors because this allows then to consider continuous monitoring (structural health monitoring) by incorporating these sensors permanently on the structures to be tested
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Alnakar, Raran, and Danilo Catovic. "Rotary parking system." Thesis, KTH, Mekatronik, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-295808.
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Automatic parking systems are intended to save a lot ofspace and create a more favourable parking experience. In this thesis the main goal was to create a functional and user-friendly rotary parking system. The system consistsof a framework, DC-motor, driveline, ultrasonic distance sensor and platforms. Most of the construction consists of plastic, the remaining parts are made of metal. The system was evaluated using two experiments, one that measured the speed of the system and the other one measuring the level of accuracy. After the first experiment, it was concluded that the system works well for the corresponding speed. The second experiment showed that improvements of the accuracy can be made.Automatiska parkeringssystem är avsedda att spara utrymme och skapa en bättre parkeringsupplevelse. I denna avhandling var huvudmålet att skapa ett funktionellt och användarvänligt roterande parkeringssystem. Systemet består av ett ramverk, likströmsmotor, drivlina, ultraljudssensor och plattformar. Majoriteten av konstruktionen består av plast, de återstående delarna är gjorda av metall. Systemet utvärderades med hjälp av två experiment, ett som mätte systemets hastighet och ett annat som mätte noggrannheten. Efter det första experimentet drogs slutsatsen att systemet fungerar bra för motsvarande hastighet. Det andra experimentet visade att förbättringar av noggrannheten kan göras.
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Alnakar, Rayan, and Danilo Catovic. "Rotary parking system." Thesis, KTH, Mekatronik, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-295808.
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Automatic parking systems are intended to save a lot ofspace and create a more favourable parking experience. In this thesis the main goal was to create a functional and user-friendly rotary parking system. The system consistsof a framework, DC-motor, driveline, ultrasonic distance sensor and platforms. Most of the construction consists of plastic, the remaining parts are made of metal. The system was evaluated using two experiments, one that measured the speed of the system and the other one measuring the level of accuracy. After the first experiment, it was concluded that the system works well for the corresponding speed. The second experiment showed that improvements of the accuracy can be made.Automatiska parkeringssystem är avsedda att spara utrymme och skapa en bättre parkeringsupplevelse. I denna avhandling var huvudmålet att skapa ett funktionellt och användarvänligt roterande parkeringssystem. Systemet består av ett ramverk, likströmsmotor, drivlina, ultraljudssensor och plattformar. Majoriteten av konstruktionen består av plast, de återstående delarna är gjorda av metall. Systemet utvärderades med hjälp av två experiment, ett som mätte systemets hastighet och ett annat som mätte noggrannheten. Efter det första experimentet drogs slutsatsen att systemet fungerar bra för motsvarande hastighet. Det andra experimentet visade att förbättringar av noggrannheten kan göras.
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Hradil, Jiří. "Měření průtoku kapalin." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2011. http://www.nusl.cz/ntk/nusl-219325.
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In my master’s thesis, I consider with flow measurement. In shortness is described principle of flow sensors functionality, its advantages and disadvantages. I designed and made device for practice measurement of flow. On this device are installed three flowmeters The characteristic of this flowmeters were measured and evaluated. I made program in LabVIEW to collect and analyze information from instaled flowmeters.
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Ljungberg, Sebastian, and Fredrik Schalling. "HAMMS : Managing a mix of human driven and autonomous vehicles in four-way intersections." Thesis, KTH, Maskinkonstruktion (Inst.), 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-226687.
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The purpose of this report is to improve the flow of trafficin intersections through the use of a dynamic algorithm.People spend on average more than six weeks commuting towork in Stockholm every year. A large part of the time thatis spent in traffic is due to the time delay in intersections.In this report, sensors that measure speed and distanceto the vehicle are used instead of detectors that only knowif a car is there or not. There are existing solutions that canoptimise the flow for autonomous cars but since the trafficmay consist of a mix of autonomous and human drivenvehicles during the upcoming 40 years those solutions arenot usable for some time.In this work, a system that can handle both autonomousand human driven vehicles is created. The limitation of thesystem is that it can only receive two cars coming from differentdirections simultaneously. The system does not workfor car queues. The system measures the speed of- and thedistance to the vehicles continuously.According to the simulations that were made the algorithmthat has been designed through this project is moretime efficient than the system that is in place today, assumingthat the assumptions that were made for the currentsystem are correct.The conclusion in this report is that it is possible tomake a system that is more time efficient than the one thatis in use today.Syftet med den här rapporten är att förbättra flödet ikorsningar genom en dynamisk algoritm. Människor sitterdrygt 6 veckor i bilköer varje år. En stor del av av denspenderande tiden i traffiken är på grund av att fordonbehöver stanna i korsningar.I den här rapporten har sensorer som mäter hastighetoch distans använts istället för dagens detektorer som endastkänner av om ett fordon kör över detektorn eller inte.Det finns andra rapporter med lösningar för att öka flödeti korsningar för självkörande bilar men om man kollar pådet kommande 40 åren kommer det troligtsvis att vara enblandning av självkörande och mänskligt körda bilar.I det här arbetet skapas ett system som kan interageramed både mänskligt körda och autonoma bilar. Begränsningarnai det här systemet är att systemet endast kan taemot två bilar som kommer från olika ingångar i korsningensamtidigt. Systemet fungerar inte för bilköer. Systemet mäterden nuvarande hastigheten och distansen på fordonen.Systemet fungerar för alla olika kombinationer av mänskligtoch självkörande bilar.Resultatet av den här rapporten är att en algoritm harutvecklats och är mer tidseffektivt än systemet som användsi Sverige idag, med våra antaganden om systemet som harutveklats i den här rapporten och systemet som användsidag. Resultatet är baserat på korsningar där bara två bilarmöts utan köer.Slutsatsen av den här rapporten är att det är möjligtatt göra ett system som är mer tidseffektivt än systemetvi använder oss av idag, men vi kan inte säkertsätlla attsystemet i den här rapporten är mer robus och driftsäkertän det som används i Sverige idag.
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Škůrek, Pavel. "Měření výkonu v ultrazvukových polích." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2010. http://www.nusl.cz/ntk/nusl-218716.
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This work is focused on the developement of a sensor, which enables to measure the ultrasonic power by heat effect of the mechanical Wales. The princip of two basic kinds of thermoacoustic sensor is descibed here – one level and two level sensor. This work also contains a proposition of these sensors with description of each parts and a trial to find suitable absorber. Achieved results, which support the function of the sensors are presented here by form of graphs and tables. Measuring by thermoacoustic sensors is confronted here with measuring of ultrasonic by hydrophone, which is used as reference measuring.
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Oliveira, Rômulo Muriel Mesquita de. "Desenvolvimento de sistema de segurança veicular a baixo custo contra acidentes por abertura de porta." Universidade Federal de Goiás, 2015. http://repositorio.bc.ufg.br/tede/handle/tede/6491.
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Made available in DSpace on 2016-11-10T17:42:47Z (GMT). No. of bitstreams: 2 Dissertação - Rômulo Muriel Mesquita de Oliveira - 2015.pdf: 7641184 bytes, checksum: b650ba6efa2c0aba74125271f293ebcc (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2015-02-20
The increasing number of accidents on roads and highways around the world is causing concern in many government agencies. Because of that, actions have been proposed to eradicate this reality, which claims the lives of millions annually. Within the different types of traffic accidents occurring, one specific has gained space in the media, which involves the door of a vehicle, improperly opened, causing collision with a cyclist, motorcyclist or other vehicle. The law states to be responsible for the accident the one who opened the door without taking proper precautions, however, due to physical and emotional factors that disturb each day more the society, lives in traffic can?t be under the responsibility of a person. Many assistive technologies that helps in decision making or even contributing to road safety, have been submitted to the automotive market, which once included in vehicles would save the lives of thousands. Aware of this, this paper proposes a technology that, through low cost ultrasonic sensor detects possibility of collision on the side of the vehicle and sends alerts to the driver so he or she does not open the door during the moment of risk. For development of this security system was necessary to define which ultrasonic sensor to use, to prepare the case for the hardware accommodation, to build the computer program, to analyze the positioning of the system in the vehicle and to execute experimental tests to validate the ADS (Avoiding Doored System), name given to the collision avoidance system
A elevação do número de acidentes em estradas e rodovias ao redor do mundo vem causando preocupação em muitos órgãos governamentais. Em função disso, ações vêm sendo propostas para erradicação dessa realidade, que tira a vida de milhões anualmente. Dentro os vários tipos de acidentes que ocorrem no trânsito, um muito específico vem ganhando espaço na mídia, aquele envolvendo a porta de um veículo, aberta indevidamente, causando colisão com um ciclista, motociclista ou mesmo outro veículo. A legislação determina ser responsável pelo acidente àquele que abriu a porta sem tomar as devidas precauções, no entanto, devido a fatores físicos e emocionais, que perturbam cada dia mais a sociedade, deixar vidas no trânsito sob responsabilidade de terceiros não é uma escolha prudente. Inúmeras tecnologias assistivas, que auxiliam na tomada de decisão ou mesmo que contribuem para segurança no trânsito, vêm sendo apresentadas ao mercado automobilístico, as quais, uma vez inclusa nos veículos, pouparia a vida de milhares. Nesse contexto, este trabalho apresenta uma proposta de tecnologia que, por meio de sensor ultrassônico de baixo custo, detecta possibilidade de colisão na lateral do veículo devido à abertura da porta e emite alerta ao condutor, de forma que este não abra a porta durante o instante de risco. Para tanto, foi necessário desenvolver um sistema de mapeamento do campo de atuação do sensor, de modo que fosse possível determinar o mais adequado para o desenvolvimento do sistema. Além disso, foi projetado e construído um “case” para acomodação dos periféricos do sistema, desenvolvido o software de controle do sistema e posteriormente foi analisado o posicionamento do sistema no veículo e aplicação de testes experimentais para avaliação funcional do ADS (Avoiding Doored System), assim nomeado o sistema que evita colisões por abertura da porta.
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Vandi, Damiano. "ADAS Value Optimization for Rear Park Assist: Improvement and Assessment of Sensor Fusion Strategy." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2021.
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The project for this thesis consists in an ADAS Value Optimization activity conducted during an internship in Maserati S.p.A. with the objective of removing the ultrasonic sensors used for the Rear Park Assist (RPA) ADAS feature, obtaining the same functionality and performance in the detection and signaling of obstacles behind the car through a new system based on a sensor fusion strategy between Rear View Camera (RVC) and Blind Spot Radars (BSD).
To achieve this goal, a study of the current RPA feature has been conducted, and starting from a previous implementation of the sensor fusion strategy for the new system, multiple updates and improvements have been implemented in order to achieve the functionality and performance required. Both hardware and software components of the system were updated and redesigned in the MATLAB/Simulink environment, and the final system obtained was tested through a standard validation procedure in a virtual simulation environment, obtaining encouraging results compatible with the RPA requirements and demonstrating the technical and economic feasibility of the developed RPA system based on a sensor fusion strategy between RVC and BSD which, after additional tests on the actual vehicle, could go into production.
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Dokur, Omkar. "Embedded System Design of a Real-time Parking Guidance System." Scholar Commons, 2015. http://scholarcommons.usf.edu/etd/5939.
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The primary objective of this work is to design a parking guidance system to reliably detect entering/exiting vehicles to a parking garage in a cost-efficient manner. Existing solutions (inductive loops, RFID based systems, and video image processors) at shopping malls, universities, airports etc., are expensive due to high installation and maintenance costs. There is a need for a parking guidance system that is reliable, accurate, and cost-effective. The proposed parking guidance system is designed to optimize the use of parking spaces and to reduce wait times. Based on a literature review we identify that the ultrasonic sensor is suitable to detect an entering/exiting vehicle. Initial experiments were performed to test the sensor using an Arduino based embedded system. Detection logic was then developed to identify a car after analyzing the initial test results. This logic was extended to trigger a camera to take an image of the vehicle for validation purposes. This system consists of Arduino, ultrasonic sensor, and a temperature sensor. It was installed and tested in Richard Beard Garage at the University of South Florida for five days. The test results of each trial are provided and average error for all the trials is calculated. The error cases occur due to golf carts, straddling cars on both entry/exit lanes, and people walking under the sensor. The average error of the system is 5.36% over five days (120 hrs). The estimated cost for one detector per lane is approximately $30.
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Dalkic, Yurdaer, and Zoubida Alshekhly. "Development and design of a prototype for monitoring the water level in water wells using LoRaWAN." Thesis, Malmö universitet, Fakulteten för teknik och samhälle (TS), 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:mau:diva-20667.
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En översvämning kan inträffa när som helst och var som helst i världen. En översvämning börjar när vattennivån ökar, särskilt i dagvattenbrunnar i stadsområden. Genom att utnyttja de olika moderna teknologier som Internet of Things (IoT), förluster som orsakas av en översvämning kan minskas. Därför behövs en IoT-lösning för att övervaka vattennivån i brunnarna.Syftet med denna avhandling är att undersöka hur man konstruerar och implementerar ett IoT-baserat system som övervakar vattennivån för att bygga en prototyp med LoRaWAN teknologi. Konstruktionen av prototypen utförs genom att följa stegen i en iterativ systemutvecklingsmetod. Prototypen använder ett offentligt Lora-nätverk, särskilt The Things Network (TTN). Prototypens funktioner är att mäta vattennivån med en ultraljudssensor, sända mätdata via LoRa till TTN och visualisera data på en visualiserings plattform "Cayenne" i realtid. Systemet är testad i en laboratoriemiljö. Resultaten av den konstruerade prototypen visar att den mäter vattennivån och skickar mätdata när vattennivåns tillstånd ändras. Dessutom visualiseras datan på visualiserings plattformen Cayenne.A flood may occur anytime and anywhere in the world. A flood starts when the water level increases, especially, in the wells in the urban areas. By taking advantage of the modern technology, such as Internet of Things (IoT), the losses caused by the flood can be reduced. Therefore, an IoT-solution is needed for monitoring the water level in the wells.The aim of this thesis is to investigate how to design and implement an IoT-based system that monitors the water level to build a prototype using LoRaWAN technology. Building the prototype is done by following the steps of an iterative system development method. The prototype uses a Lora public network, specifically The Things Network (TTN). The functions of the prototype are measuring the water level by an ultrasound sensor, sending the measurement data through LoRa to TTN, and visualizing the data on the "Cayenne" dashboard in real-time. The system is tested in a lab environment. The results of the constructed prototype show that the prototype measures the water level and sends the measurement data whenever the state of the water level is changed. Additionally, the data is visualized on the Cayenne dashboard.
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Janík, Vladimír. "Chytré čerpadlo na čerpání vody z nádrže." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2021. http://www.nusl.cz/ntk/nusl-442364.
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This thesis deals with the implementation of a system for measuring the amount of water in the tank using a 12V water pump. The whole system is controlled by the ESP32 microcontroller. The introduction deals with the theoretical analysis of various principles of measuring the level of liquids. The next part deals with the procedure of the construction of the measuring device and its theoretical analysis. The last part of the work deals with the control of the pump and the individual functions that provide this control. The ultrasonic distance sensor AJ-SR04M was chosen for the implementation of the device. The volume of water in the tank is calculated from its data. The ESP32 microcontroller provides system control via a web interface. The whole system was implemented and tested to measure the volume of water and its pumping in the IBC container.
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Gerlach, Gerald. "Dresdner Beiträge zur Sensorik." Technische Universität Dresden, 2017. https://tud.qucosa.de/id/qucosa%3A26134.
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Seit 1996 wird von Prof. Dr.-Ing. habil. Gerald Gerlach die Buchreihe „Dresdner Beiträge zur Sensorik“ herausgegeben, in der herausragende wissenschaftliche Beiträge der Technischen Universität Dresden, insbesondere auch des Institutes für Festkörperelektronik, publiziert werden. Zu den bisher vorliegenden Bänden sind seitdem weitere Bände hinzugekommen. Das Profil des Institutes wird durch folgende Forschungsgebiete geprägt: Thermische Infrarotsensoren, Piezoresistive Sensoren auf der Basis quellfähiger Hydrogele, Ultraschalltechnik, Funktionelle Dünnschichten, Nanoptische Sensoren. Mit der Berufung von Prof. Dr.-Ing. habil. Gerald Gerlach auf den Lehrstuhl für Festkörperelektronik zum 01.01.1996 wurde das Spektrum der Forschungsarbeiten insbesondere um die Fachgebiete der Siliziumsensoren für unterschiedliche Meßgrößen und des Entwurfs komplexer Sensor- und Aktor-Systeme in der Mikrosystemtechnik erweitert. Das Zusammenwirken von Physik, Elektronik und Technologie der Mikroelektronik bei Forschung, Entwicklung und Fertigung sowie Applikation leistungsfähiger Sensoren ist Gegenstand von Lehre und Forschung des IFE.Since 1996 the book series „Dresdner Beiträge zur Sensorik“ edited by Prof. Dr.-Ing. habil. Gerald Gerlach has been published. The aim of this series is the publication of outstanding scientific contributions of TU Dresden, especially of those compiled at the Institute for Solid-State Electronics. The Solid-State Electronics Laboratory (Institut für Festkörperelektronik - IFE) is one of 12 laboratories of the Electrical and Computer Engineering Department at Technische Universität Dresden. Together with the Semiconductor Technology and Microsystems Lab and several chairs of the Circuits and Systems and the Packaging Labs, the Solid-State Electronics Laboratory is responsible for the microelectronics specialization in the Electrical Engineering program. Research and teaching field of the Institute for Solid-State Electronics are dedicated to the interaction of physics, electronics and (microelectronics) technology in: materials research, technology, and solid state sensor operational principles, application of sensors for special measurement problems, design of sensors and sensor systems including the simulation of components as well as of complex systems, development of thin films and multilayer stacks for sensor applications, application of ultrasound for nondestructive evaluation, medical diagnostics and process measurement technology.
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Ara?jo, Neto Ary Torres de. "Desenvolvimento de prot?tipo de coletor autom?tico destinado ? coleta de amostras de ?gua em corpos aqu?ticos para an?lise em laborat?rio." Universidade Federal do Rio Grande do Norte, 2008. http://repositorio.ufrn.br:8080/jspui/handle/123456789/15949.
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Previous issue date: 2008-12-22Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico
The aim of this approach is to describe the design and construction of a low-cost automated water sampler prototype. In recent years, there is an increasing need on the use of automated equipments for hydro climatic variables to be use in urban and rural environments. Such devices are always used to provide measured information which is of crucial importance on the development of water resources strategies at watershed scale. Actually, many research and water public institutions have been using these kinds of equipments. In most of the cases, automated equipments are expensive and need to be imported, generating a situation of technologic dependency. The prototype is based on an electronic system which controls a peristaltic pump functioning, five solenoid valves and an ultrasonic sensor connected to a datalloger. An interface with the user allows communication with a PC, when the equipment functioning parameters can be provided. The equipment has a hydraulic module composed by a 12V peristaltic pump connected to a distribution circuit composed by five solenoid valves, one of them being used to clean the circuit before each sampling procedure. Samples are collected by four 1.95 polyethylene bottles. The sampler body was made of acrylic material, with a cylindrical shape, and dimensions 0.72 m and 0.38 m height and diameter, respectively. The weight of the equipment without samples is approximately 15 kg, which infers to its portability. The prototype development total cost budget was approximately US$ 1,560.00. Laboratory tests aimed to evaluate the equipment performance and functioning demonstrated satisfactory results
O objetivo deste estudo ? desenvolver e apresentar um prot?tipo de coletor autom?tico de amostras de ?gua. Nos ?ltimos anos, tem havido uma crescente necessidade no uso de equipamentos autom?ticos no monitoramento de vari?veis hidro-clim?ticas, tanto em ambientes rurais como urbanos. Esses equipamentos s?o normalmente usados para gerar informa??o de vital import?ncia no desenvolvimento de a??es em recursos h?dricos na bacia hidrogr?fica. Atualmente, v?rias institui??es p?blicas e de pesquisa t?m usado esses tipos de equipamentos. Na maioria dos casos, os equipamentos autom?ticos s?o caros e necessitam ser importados, gerando uma situa??o de depend?ncia tecnol?gica. O prot?tipo desenvolvido tem como base um sistema eletr?nico que controla o funcionamento de uma bomba perist?ltica, cinco v?lvulas solen?ides e de um sensor ultra-s?nico acoplados a um datalogger. Uma interface com o usu?rio permite comunica??o com um PC, quando os par?metros de funcionamento do equipamento podem ser introduzidos. O equipamento disp?e de um m?dulo hidr?ulico composto de uma bomba perist?ltica 12V acoplada a um circuito de distribui??o com cinco v?lvulas solen?ides, uma delas usada na limpeza do circuito antes de cada coleta de amostra. As amostras s?o coletadas em quatro garrafas de polietileno, capacidade 1,95 ml. A estrutura do equipamento ? feita em acr?lico, com um formato cil?ndrico, dimens?es 0,72 m e 0,38 m de altura e di?metro, respectivamente. O peso do equipamento sem as amostras ? de aproximadamente 15 kg, o que lhe confere portabilidade. O or?amento referente ao custo total de desenvolvimento do equipamento foi de aproximadamente 1.560 d?lares americanos. Testes em laborat?rio, realizados para avaliar seu desempenho e funcionamento, foram bastante satisfat?rios
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Likitkumchorn, Nutthavit. "Ice Prevention and Weather Monitoring on Cable-Stayed Bridges." University of Toledo / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1404393052.
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Zilic, Ada. "Signifikanta skillnader i spirometrivariabler observerad mellan en Jaeger MasterScreen och en Vyntus spirometer : En jämförelse studie mellan två olika lungfunktionsutrustningar." Thesis, Örebro universitet, Institutionen för hälsovetenskaper, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:oru:diva-84606.
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Introduktion: En av de vanligaste undersökningsmetoderna för att bedöma den respiratoriska funktionen är spirometri. Det är en undersökning som mäter lungvolymer och lungvolymsförändringar över tid. En fullständig lungfunktionsundersökning består av statisk och dynamisk spirometri samt mätning av diffusionskapacitet. Studiens syfte var att jämföra två olika utrustningar, en gammal (Jaeger MasterScreen Body och PFT) och en ny utrustning (Vyntus Body och One) om det fanns någon signifikant skillnad på mätresultatet mellan utrustningarna. Metod och material: Studien bestod av 24 testpersoner, 16 kvinnor och 8 män, alla undersökningar utfördes på Fysiologiska kliniken på Västerås sjukhus under februari och april 2020. Variablerna som undersöktes och bearbetades var vitalkapacitet (VK), forcerad vitalkapacitet (FVK), forcerad exspiratorisk volym på en sekund (FEV1), forcerad exspiratorisk volym uttryck i procent med vitalkapacitet (FEV%VK), total lungkapacitet (TLK), residualvolym (RV), mätning av diffusionskapacitet (DLCO) samt alveolär ventilation (VA). Resultat: Resultatet från studien visade att det förelåg en statistisk signifikant skillnad mellan utrustningarna Jaeger och Vyntus. Lungfunktionsutrustningen Vyntus påvisade ett lägre mätresultat på samtliga variabler. Att det förelåg en statistisk signifikant skillnad kan bero på att utrustningarna använder olika mätmetoder, Jaeger har en pneumotach medan Vyntus har en ultraljudssensor. Slutsats: Slutsatsen är att det föreligger systematisk skillnad på den nya utrustningen Vyntus. Vyntus visade lägre värden på samtliga variabler.Introduction: One of the most common measurements for assessment of pulmonary function is spirometry. It is a method that measures lung volumes and changes in lung volume over time. A complete lung function test consists of static and dynamic spirometry as well as measurement of diffusion capacity. The purpose of the study was to compare two different equipment, an older (Jaeger MasterScreen Body and PFT) and the contemporary (Vyntus Body and One) if there was any significant difference in the measurement result between the two equipment. Method and materials: The study consisted of 24 test subjects, 16 women and 8 men, all examinations were performed at the Physiological Clinic at Västerås Hospital between February and April 2020. The variables investigated and processed were vital capacity (VC), forced vital capacity (FVC), forced expiratory volume in one second (FEV1), forced expiratory volume expression as a percentage with vital capacity (FEV%VC), total lung capacity (TLC), residual volume (RV), diffusion capacity measurement (DLCO) and alveolar ventilation (VA). Result: The results of the study showed that there was a statistical significant difference between the two equipments Jaeger and Vyntus. The lung function equipment Vyntus showed a lower measurement result on all variables. This statistical significant difference may be due to the fact that the equipment uses different measurement methods. Jaeger has a pneumotach while Vyntus has an ultrasonic sensor. Conclusion: The conclusion is that there is a systematic difference in the new Vyntus equipment. Vyntus showed lower values for all variables.
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Henriksson, Tomas. "Driver Assistance Systemswith focus onAutomatic Emergency Brake." Thesis, KTH, Fordonsdynamik, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-121306.
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This thesis work aims at performing a survey of those technologies generally called DriverAssistance Systems (DAS). This thesis work focuses on gathering information in terms ofaccident statistics, sensors and functions and analyzing this information and shall thruaccessible information match functions with accidents, functions with sensors etc.This analysis, based on accidents in United States and Sweden during the period 1998 – 2002and two truck accident studies, shows that of all accidents with fatalities or sever injuriesinvolving a heavy truck almost half are the result of a frontal impact. About one fourth of theaccidents are caused by side impact, whereas single vehicle and rear impact collisions causesaround 14 % each. Of these, about one fourth is collision with unprotected (motorcycles,mopeds, bicycles, and pedestrians) whereas around 60 % are collision with other vehicles.More than 90 % of all accidents are partly the result of driver error and about 75 % aredirectly the result of driver error. Hence there exist a great opportunity to reduce the numberof accidents by introducing DAS.In this work, an analysis of DAS shows that six of the systems discussed today have thepotential to prevent 40 – 50 % of these accidents, whereas 20 – 40 % are estimated to actuallyhaving the chance to be prevented.One of these DAS, automatic emergency brake (AEB), has been analyzed in more detail.Decision models for an emergency brake capable to mitigate rear-end accidents has beendesigned and evaluated. The results show that this model has high capabilities to mitigatecollisions.
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Jiang, Li-Yin, and 江笠印. "Infrared -Sensor and Ultrasonic-Sensor Based Following Robot Design." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/41998207297762986043.
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碩士國立暨南國際大學
電機工程學系
105
Nowadays, the service-oriented robot industries have been the focus of the national development. e.g., cleaning robot, intelligent robot, mobile robot, etc. This paper focuses on mobile robots. Generally, human-following robots are mostly based on image recognition, but image recognition still has many unsolved problems. In the market products, image recognition mostly uses acceptance mistake system because recognition results cannot achieve one hundred percent accuracy so it cannot be applied to precision control machine. This thesis proposed a method to solve this problem. To use six ultrasonic sensors and eight infrared sensors. Ultrasonic sensors sense the values, and then compare the difference with each other sensors in order to decide which direction the mobile robot will move. When the robot is running the infrared sensors can detect obstacles, and the robot will avoid it. The experimental results proved the robot can effectively complete the task with five kilograms load and an emergent switch. In the future, these mobile robots can apply supervision-system, which will help our life easier and better.
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Tseng, Yu-Lun, and 曾郁倫. "Ultrasonic Techniques for Methanol Concentration Sensor." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/98444168228714551488.
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碩士國立臺灣大學
工程科學及海洋工程學研究所
95
Recently, fuel cell technology which has owned an important position in the emerging energy grows rapidly, especially the Direct Methanol Fuel Cell (DMFC). Due to the advantage of high energy density, DMFC is expected to be the major portable energy for the next generation. Since the performance of the DMFC is directly relevant to the density of methanol solution, in order to optimize the efficiency of DMFC, concentration changes must be monitored and controlled. This thesis uses ultrasound sensing to monitor methanol concentration. At the operating concentration range of 0 to 10wt% for DMFC, the resolution of 0.5wt% was expected for the ultrasound sensing module. Although the theoretical sound speed prediction model had been proposed by other researchers, it can’t be used as a sound speed-concentration conversion formula. Because the forces between the molecules vary a lot for polar liquid such as water which results in a large deviation between these prediction models and actual sound speed. In this research we intended to measure the actual sound speed of methanol solution under various concentrations, and establish the empirical conversion model through these experiment data. Besides, we estimate how propagation distance and sampling time affect on sound speed measuring by uncertainty analysis. Finally, we investigate the blind spot on ultrasound sensing because of the decreasing sensitivity. New parameters such as peak frequency shift and attenuation will be employed for the concentration sensing in the blind temperature range.
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Wu, Tsung-Tao, and 吳宗道. "Design of Non-Blind-Zone Ultrasonic Sensor." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/3w2x6a.
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碩士國立臺北科技大學
電機工程系所
102
The main focus of this research paper is to address the issue of ultrasonic sensing system can not be measured in a blind-zone distance. Generally it is not easy to measure the distance when ultrasonic sensing system as an obstacle within the blind-zone reverberation time. Mainly because of obstacles when entering the blind-zone, obstacle echo signals are superimposed with the reverberation time, accumulated reverberation signals together and made it impossible to measure the correct amount of real distance. Therefore, this paper proposed a blind-zone close range ultrasound sensing method can effectively detect obstacles in a correct position within the blind-zone. We design an actual design and implementation of the ultrasonic sensing system to prove the feasibility of this approach. In this paper, we design a very close range reflective ultrasonic sensing system without blind-zone. The system uses a single ultrasonic sensor, which can use as a transmitter and receiver. In addition, the use of ultrasound reflection signal delay time is able to measure the distance between the obstacle and sensors. We implement the use of piezoelectric materials as distance sensors, it will damp in the last end of the drive circuit reverberation stage using the ultrasound probe mechanical structural. The energy of the ultrasound signal will dissipate slowly. When the amplitude of echo signal’s energy is smaller than obstacle, sensing system will enter into normal echo signal and back to distance detection stage. The key to solve this problem is to find a suitable ultrasound probe mechanical damping structure to enable it in the suitable period, which can effectively inhibit the ultrasonic echo amplitude energy. This period is defined as the reverberation time. We are able to distinguish the reflected signals in the blind-zone of obstacles by taking the advantage of the proposed method; further, solving the issue of ultrasonic sensing system can not be measured in a blind-zone distance.
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Wu, Yung-Yi, and 吳勇毅. "Fast-response ultrasonic sensor system for piezoceramics." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/17314860876956268271.
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碩士國立臺灣大學
土木工程學研究所
94
A new digital-signal-processing method combining ultrasonic time-of-flight with phase detection estimation is presented. The method uses the digital pulse width modulation to acquire ultrasonic signal in order to accurately estimate the responding time of the echo. It is also possible to assure reduced bias and uncertainty in digital filtering measurements, such as those involving low measurement errors of echo signal. A number of numerical tests are conducted on simulated signals with the aim of the good performance when operating in real-time conditions. There are five topics in the thesis, including ultrasonic transducer, ultrasonic sensor, circuit simulation, circuit design, and signal process. Users could follow the steps in the chapter to realize the system working stage. Results attained in DPWM-based distance measurements will finally give the top reliability and max efficiency in the actual ultrasonic tests. The main contributions of this distance measurement system reduce the responded time and get powerful information in long distance. It is easily achieved by supersonic data stream model to build up the target.