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Pavliš, Jakub. "Využití optického odměřovacího systému Renishaw pro snímače a komparátory." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2020. http://www.nusl.cz/ntk/nusl-417745.
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The diploma thesis deals with the description of selected optical systems in length metrology. The main benefit of this work is the design and implementation of a sensor with the VIONiCplus optical system and the application of this measuring system to length comparators. The work contains experimental verification of the use of an optical system with a resolution of 2.5 nm for sensors and length comparators with recommendations for practical use.
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Kinney, Stuart. "The development of an optical position sensor." Virtual Press, 1998. http://liblink.bsu.edu/uhtbin/catkey/1115421.
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A theoretical study of an electrically passive, loss-compensated, optical position sensor is the goal of this project. Optical fiber sensors exploit light as the information carrier. Fiber-optic sensors consist of a constant light source launched into an optical fiber and transmitted to another point at which a measurement is made.In the proposed optical position sensor, a Light Emitting Diode (LED) produces a constant beam of light, which is channeled through an optical fiber to a Graded Index (GRIN) lens. This lens makes all the light rays parallel to one another, a process called collimation. The light then enters a polarizer which is a lens that further orders the light rays in a process called polarization.Then the light enters a chamber in which a doubly refracting (birefringent) crystal is situated. The crystal is a wedge, and thus has a varying thickness throughout its length. The light beam strikes the crystal, sending a spectrum, or spectral signature, that is distinct to the particular thickness of the crystal. That signature goes directly from the chamber housing the crystal into a lens called an analyzer which orders the light again through polarization. Then the light goes into another GRIN lens, and this GRIN lens focuses the light onto an optical fiber, which transmits the particular spectral signature of this light to an optical spectrum analyzer (OSA). The OSA uses a Photodiode Array to accept the incoming light, a device that takes in light and redistributes it to a monitor for display by the user. Such a device is called a detector. The thickness of the crystal that the light travels through is determined by the crystal's position.If the crystal rests on a platform which is connected to an object whose position must always be monitored, then the crystal will move as the object moves. The different spectral signatures shown on a monitor reveal different thicknesses of the crystal, which reveal different positions of the monitored object. The object whose position is measured is the measurand.The selected crystal is quartz. It has a 12.5-mm length, a width of 10.8-mm at its thinnest end, and a taper angle to the thickest end of only 0.008 degrees, which corresponds to a 0.17-micron difference between the two. This angle is called the polishing angle of the quartz. The quartz itself is called the active cell. The Photodiode Array Detector receives the spectral signature from the optical fiber, and that signature is projected on an OSA, which is software built-in to the computer. A mathematical program is used to evaluate the signature, and the position of the measurand is thereby revealed. How accurate the measurement is can be revealed by use of a control device. If the quartz crystal is moved by a measuring device, such as a micrometer, the distance that the crystal moved may be measured by the micrometer, as well as by the OSA. By comparing the two, the accuracy of the spectrograph, and the position it reveals, can be known.Department of Physics and Astronomy
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Wong, Francis Yee-Hon. "Inductive position/velocity sensor design and servo control of linear motor." Thesis, Massachusetts Institute of Technology, 1995. http://hdl.handle.net/1721.1/36084.
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Mäkynen, A. (Anssi). "Position-sensitive devices and sensor systems for optical tracking and displacement sensing applications." Doctoral thesis, University of Oulu, 2000. http://urn.fi/urn:isbn:9514257804.
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Abstract
This thesis describes position-sensitive devices (PSDs) and optical sensor systems suitable for industrial tracking and displacement sensing
applications. The main application areas of the proposed sensors include automatic pointing of a rangefinder beam and measuring the lateral
displacement of an object.
A conventional tracking sensor is composed of a laser illuminator, a misfocused quadrant detector (QD) receiver and a corner cube retroreflector
(CCR) attached to the target. The angular displacement of a target from the receiver optical axis is detected by illuminating the target and
determining the direction of the reflection using the QD receiver. The main contribution of the thesis is related to the modifications proposed
for this conventional construction in order to make its performance sufficient for industrial applications that require a few millimetre to
submillimetre accuracy. The work includes sensor optical construction modifications and the designing of new types of PSDs.
The conventional QD-based sensor, although electrically very sensitive, is not considered optimal for industrial applications since its precision
is severely hampered by atmospheric turbulence due to the misfocusing needed for its operation. Replacing the CCR with a sheet reflector is found
to improve the precision of the conventional sensor construction in outdoor beam pointing applications, and is estimated to allow subcentimetre
precision over distances of up to 100 m under most operating conditions. Submillimetre accuracy is achievable in close-range beam pointing
applications using a small piece of sheet reflector, coaxial illumination and a focused QD receiver. Polarisation filtering is found to be
effective in eliminating the main error contributor in close-range applications, which is low reflector background contrast, especially in cases
when a sheet reflector has a specularly reflecting background.
The tracking sensor construction is also proposed for measuring the aiming trajectory of a firearm in an outdoor environment. This time an order
of magnitude improvement in precision is achieved by replacing the QD with a focused lateral effect photodiode (LEP). Use of this construction in
cases of intermediate atmospheric turbulence allows a precision better than 1 cm to be achieved up to a distance of 300 m. A method based on
averaging the positions of multiple reflectors is also proposed in order to improve the precision in turbulence-limited cases.
Finally, various types of custom-designed PSDs utilising a photodetector array structure are presented for long-range displacement sensing
applications. The goal was to be able to replace the noisy LEP with a low-noise PSD without compromising the low turbulence sensitivity achievable
with the LEP. An order of magnitude improvement in incremental sensitivity is achievable with the proposed array PSDs.
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Mateen, Mala. "Development and Verification of the non-linear Curvature Wavefront Sensor." Diss., The University of Arizona, 2015. http://hdl.handle.net/10150/581277.
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Adaptive optics (AO) systems have become an essential part of ground-based telescopes and enable diffraction-limited imaging at near-IR and mid-IR wavelengths. For several key science applications the required wavefront quality is higher than what current systems can deliver. For instance obtaining high quality diffraction-limited images at visible wavelengths requires residual wavefront errors to be well below 100 nm RMS. High contrast imaging of exoplanets and disks around nearby stars requires high accuracy control of low-order modes that dominate atmospheric turbulence and scatter light at small angles where exoplanets are likely to be found. Imaging planets using a high contrast corona graphic camera, as is the case for the Spectro-Polarimetric High-contrast Exoplanet Research (SPHERE) on the Very Large Telescope (VLT), and the Gemini Planet Imager (GPI), requires even greater wavefront control accuracy. My dissertation develops a highly sensitive non-linear Curvature Wavefront Sensor (nlCWFS) that can deliver diffraction-limited (λ/D) images, in the visible, by approaching the theoretical sensitivity limit imposed by fundamental physics. The nlCWFS is derived from the successful curvature wavefront sensing concept but uses a non-linear reconstructor in order to maintain sensitivity to low spatial frequencies. The nlCWFS sensitivity makes it optimal for extreme AO and visible AO systems because it utilizes the full spatial coherence of the pupil plane as opposed to conventional sensors such as the Shack-Hartmann Wavefront Sensor (SHWFS) which operate at the atmospheric seeing limit (λ/r₀). The difference is equivalent to a gain of (D/r₀)² in sensitivity, for the lowest order mode, which translates to the nlCWFS requiring that many fewer photons. When background limited the nlCWFS sensitivity scales as D⁴, a combination of D² gain due to the diffraction limit and D² gain due to telescope's collecting power. Whereas conventional wavefront sensors only benefit from the D² gain due to the telescope's collecting power. For a 6.5 m telescope, at 0.5 μm, and seeing of 0.5", the nlCWFS can deliver for low order modes the same wavefront measurement accuracy as the SHWFS with 1000 times fewer photons. This is especially significant for upcoming extremely large telescopes such as the Giant Magellan Telescope (GMT) which has a 25.4 m aperture, the Thirty Meter Telescope (TMT) and the European Extremely Large Telescope (E-ELT) which has a 39 m aperture.
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Labicane, Robert Edward. "Position control of a two massed linear actuator used in an optical disk drive system." Thesis, The University of Arizona, 1988. http://hdl.handle.net/10150/276878.
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This study develops the foundation of a digitally implemented control system for the radial positioning of the read/write heads of an optical disk drive system. Topics addressed are: sample rate selection, state reconstruction, closed-loop system response, disk track-following filters, and measurement noise filters. Consideration is given to the unmodeled dynamic's influence on system performance, system sensitivity to parameter variations, and a one sample computational delay. What has been concluded from this work is that the system must be further desensitized to parameter variations, and, at this stage of the development of the control scheme, neither a computational delay nor the unmodeled dynamics degrade system performance significantly.
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Sargeant, Ramon Bradley. "A multi-axial optical fibre and linear polarizer based force and torque sensor for dexterous robotic fingertips." Thesis, King's College London (University of London), 2014. http://kclpure.kcl.ac.uk/portal/en/theses/a-multiaxial-optical-fibre-and-linear-polarizer-based-force-and-torque-sensor-for-dexterous-robotic-fingertips(a9c419a3-901e-4a56-9b02-00648539d17e).html.
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As robots play a more pervasive role in our everyday activities more and more research emphasis is being placed on having robots interact directly with humans, whether in terms of taking care of the elderly, medical interventions or performing dangerous or hazardous tasks. Another trend is for robots to use existing human tools to perform desired actions since it is also not always possible or cost effective to design special tools for every robot. This trend has led to the development of anthropomorphic dexterous manipulators that can perform equally or better than the human hand. Thus the accelerating trend is not only to design a dexterous manipulator but to focus on its ability to grasp and manipulate different and sometimes unknown objects. One of the most researched types of grasp is the precision grasp which accounts for over 80 % of the grasps performed by humans on a daily basis. Precision grasps are grasps involving the fingertips and are generally used for tasks that require fine manipulation skills. Fingertip sensors are therefore important for dexterous manipulators since humans can identify salient properties of an object and formulate effective manipulation strategies solely by grasping the object. This PhD project focuses on developing fingertip sensors, specifically force and torque fingertip sensors that can be integrated into the fingertip of an existing dexterous manipulator and gather contact force and torque information during a grasping event. Another goal is to make the sensor magnetic resonant (MR) compatible so that it can be used in high magnetic environments, as in the case of medical, magnetic resonance imagining applications. To accomplish these goals two sensors were developed based on light intensity modulation and novel sensing structures. Optical sensing schemes were chosen because they are not susceptible to magnetic interference, the sensor and its light source can be separated by long distances without significant signal attenuation and the size and weight of the actual sensing element can be reduced since the processing electronics can be positioned far from the sensing structure. The first sensor developed, as part of this PhD work, was a 2-DOF sensor which used a combination of axially-aligned fibres and linear polarizers to modulate the light to measure the applied force and torque respectively. The use of linear polarizers as the main sensing technique for force and torque sensing is a new area of research since linear polarizers have a defined response curve and can be easily cut into any desired shape and size. The experiments conducted with the 2-DOF sensor showed that the linear polarizer response was superior to traditional axially-aligned and reflective techniques and it was tolerant of small deviations and twists in the sensing structure. The second sensor improved on the first sensor by increasing the number of degrees of freedom from two to six by using a parallel-type 3-UPS (Universal Prismatic Spherical) sensing structure to allow measuring six degrees of movement. All of the joints of the sensing structure were made of nitinol flexures to reduce friction and all of the links were made of plastic and bonded together to produce a flexible but light and strong structure. Another improvement was that all of the optical modulation sensors on the sensing structure were based on linear polarizers thereby reducing the possibility of misalignment errors caused by the transmitting and receiving fibres moving out of axial alignment. The new sensor therefore satisfies the design requirements and the experiments conducted showed that Light Intensity Modulation (LIM) using linear polarizers and an appropriate sensing structure can produce an accurate and versatile force and torque sensor.
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Jesus, Sidney Nogueira Pereira de. "Controlador de posição linear hidro-pneumático." Universidade de São Paulo, 2008. http://www.teses.usp.br/teses/disponiveis/3/3151/tde-30052008-125213/.
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Nessa pesquisa é apresentada uma inovação tecnológica em aplicações de controle de posição em máquinas e/ou dispositivos: o Controlador de Posição Linear Hidro- Pneumático. Para os casos nos quais têm-se grandes esforços combinados com pequenos deslocamentos, normalmente esse trabalho é feito com o uso de Sistemas Servo-Hidráulcos nos quais, devido às características mencionadas do nicho de mercado visado pela presente proposta, representam um custo elevado quando comparado com a solução Hidro-Pneumática aqui descrita. Salienta-se a simplicidade da infra-estrutura requerida para a instalação dessa alternativa, e também a redução do desperdício energético com relação à tecnologia tradicional com a Servo-Hidráulica. Observou-se nos testes com o protótipo, um excelente desempenho do sistema em termos de rapidez de resposta, como ainda no quesito resolução de posicionamento cujos valores encontrados apresentam-se na casa de 0,05 segundos e 0,01 mm, respectivamente. O pequeno tamanho físico obtido com essa nova tecnologia é outro item relevante, permitindo-se o seu emprego em locais de reduzido espaço disponível. . Resultados de simulações numéricas e de testes experimentais são apresentadas, bem como perspectivas de desenvolvimentos futuros.This research presents a technological innovation for applications in machine / device position control: the Hydro-Pneumatic Linear Position controller. In cases where great efforts are combined with small dislocations, this task is normally accomplished by means of Servo Hydraulic Systems that, due to particular characteristics of the market envisaged by the present proposition, represent elevated costs, when compared to those of the hydro-pneumatic solution described here. This work presents an analytical numerical model for the devise as well as an experimental prototype. It worth noting the infra-structure simplicity required for this alternative implementation, and also the reduction in energy waste when compared to the traditional servo-hydraulic technology. The prototype experimental tests demonstrated the system excellent behavior in what concerns answer speed and position resolution whose values were respectively in range 0.05 s and 0,01 mm. The small physical size obtained with this technology is another relevant item, which allows the device use in places of reduced available space. Numerical simulation and experimental test results are presented as well as perspectives of future developments
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Bergenblad, Jonas. "Validation study of a portable accelerometer to measure muscular power output : Correlation between the Beast Sensor and the linear encoder MuscleLab." Thesis, Högskolan i Halmstad, Akademin för ekonomi, teknik och naturvetenskap, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:hh:diva-34823.
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Abstract Background: The ability to produce a high power output can be the deciding factor in determining which athlete wins or loses in a sporting event. Power output can be measured in an exercise like the squat or bench press. The use of a force plate, or a force plate paired with a linear position transducer is considered the gold standard when measuring power output in an exercise like the squat or bench press. Linear position transducers or linear encoders have also been considered valid methods. Power output can also be measured by accelerometers. Purpose: The purpose of this study was to test the concurrent validity of the accelerometer Beast Sensor by measuring average power in explosive squatting and bench pressing at 40 % and 80 % of one repetition maximum (1RM). The linear encoder MuscleLab was used as criterion. Methods: 17 test subjects, five women and 12 men (average age 28 years) were recruited. Fifteen of the subjects completed two test sessions. The first session determined their 1RM. The second session took place 7-14 days later and measured average power output during two sets of three repetitions at 40 % and 80 % of the subjects 1RM in explosive squats and bench presses. The average power output of the repetitions was measured simultaneously by Beast Sensor and MuscleLab. For the Beast Sensor to be considered valid, a correlation coefficient of 0.9 or higher needed to be reached. Results: Beast Sensor demonstrated high or very high correlations with MuscleLab for average power output of explosive squats at 40 % of 1RM (rs = 0.91), and for explosive bench presses at 40 % (rs = 0.86) and 80 % of 1RM (rs = 0.74). However, for explosive squats at 80 % of 1RM, the correlation was low (rs = 0.42). All correlations were statistically significant with p-values of < 0.01. Beast Sensor was considered valid for squats at 40 % of 1RM, but neither at 80 % of 1RM in squats, nor at 40 % or 80 % of 1RM in bench presses. Conclusion: Beast Sensor showed high or very high correlations with the criterion MuscleLab in three of the four assessed data variables. Only the correlation for average power output of the explosive squats at 40 % of the subject’s 1RM reached the required correlation coefficient of 0.9 or higher for the Beast Sensor to be considered valid. Except for at 40 % of 1RM in squats, Beast Sensor missed a substantial amount of repetitions. Further studies examining the reliability of the Beast Sensor are therefore needed.Abstrakt Bakgrund: Förmågan att producera hög effektutveckling (power) kan avgöra vilken idrottare som vinner eller förlorar en tävling. Effektutveckling kan mätas i övningar som knäböj och bänkpress. Detta kan göras med hjälp av en kraftplatta, eller en kraftplatta parad med en linear position transducer. Dessa metoder anses vara ”gold standard”, men linear position transducers eller linear encoders har också ansetts vara valida metoder. Effektutveckling kan även mätas med hjälp av en accelerometer. Syfte: Syftet med denna studie var att mäta samtidig validitet hos accelerometern Beast Sensor genom att mäta genomsnittlig effektutveckling i explosiva knäböj och bänkpressar vid 40 % och 80 % av en repetition max (1RM). MuscleLab, en linear encoder, användes som referensvärde. Metod: 17 försökspersoner, fem kvinnor och tolv män (medelålder 28 år) rekryterades. Femton av försökspersonerna fullföljde deltagande. Vid det första testtillfället mättes 1RM. Det andra tillfället ägde rum 7-14 dagar senare och mätte genomsnittlig effektutveckling i explosiva knäböj och bänkpressar vid 40 % och 80 % av försökspersonernas uppmätta 1RM. Två set av tre repetitioner mättes vid 40 % och 80 % av 1RM i både knäböj och bänkpress. Repetitionerna mättes samtidigt av MuscleLab och Beast Sensor. För att Beast Sensor skulle anses vara valid behövde en korrelationskoefficient på 0.9 eller högre uppnås. Resultat: Beast Sensor uppvisade höga eller väldigt höga korrelationer med MuscleLab för genomsnittlig effektutveckling i explosiva knäböj vid 40 % av 1RM (rs = 0.91) och explosiva bänkpressar vid 40 % (rs = 0.86) och 80 % av 1RM (rs = 0.74). Dock uppmättes en låg korrelation för de explosiva knäböjen vid 80 % av 1RM (rs = 0.42). Alla korrelationer var statistiskt signifikanta med p-värden på < 0.01. Beast Sensor ansågs vara valid för att mäta effektutveckling vid 40 % av 1RM i knäböj, men varken vid 80 % av 1RM i knäböj, eller vid 40 % eller 80 % av 1RM i bänkpressar. Slutsats: Beast Sensor visade höga eller väldigt höga korrelationer med referensvärdet från MuscleLab för tre av de fyra uppmätta variablerna. Endast korrelationen för genomsnittlig effektutveckling i explosiva knäböj vid 40 % av 1RM uppnådde den korrelationskoefficient på 0.9 eller högre som krävdes för att Beast Sensor skulle anses vara valid. Förutom vid 40 % av 1RM i knäböj, missade Beast Sensor en väsentlig andel repetitioner. Därför finns det ett behov av fler studier som undersöker reliabiliteten hos Beast Sensor.
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Dikmen, Serkan. "Development of Star Tracker Attitude and Position Determination System for Spacecraft Maneuvering and Docking Facility." Thesis, Luleå tekniska universitet, Rymdteknik, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-60166.
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Attitude and position determination systems in satellites are absolutely necessary to keep the desired trajectory. A very accurate, reliable and most used sensor for attitude determination is the star tracker, which orient itself in space by observing and comparing star constellations with known star patterns. For on earth tests of movements and docking maneuvers of spacecrafts, the new Spacecraft Maneuvering and Docking (SMD) facility at the chair of Aerospace Information Technology at the University of Würzburg has been built. Air bearing systems on the space ve- hicles help to create micro gravity environment on a smooth surface and simulate an artificial space-like surrounding. A new star tracker based optical sensor for indoor application need to be developed in order to get the attitude and position of the vehicles. The main objective of this thesis is to research on feasible star tracking algorithms for the SMD facility first and later to implement a star detection software framework with new developed voting methods to give the star tracker system its fully autonomous function of attitude determination and position tracking. Furthermore, together with image processing techniques, the software framework is embedded into a controller board. This thesis proposes also a wireless network system for the facility, where all the devices on the vehicles can uniquely communicate within the same network and a devel- opment of a ground station to monitor the star tracker process has also been introduced. Multiple test results with different scenarios on position tracking and attitude determination, discussions and suggestions on improvements complete the entire thesis work.
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Gunnam, Kiran Kumar. "A DSP embedded optical naviagtion system." Thesis, Texas A&M University, 2003. http://hdl.handle.net/1969/13.
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Pavlica, Jiří. "Lineární jednotka s hydraulickým pohonem pro robot s paralelní kinematickou strukturou." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2014. http://www.nusl.cz/ntk/nusl-231232.
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This thesis describes the design of linear units with hydraulic drive for the robot with parallel kinematic structure. The theoretical part deals with the historical development of parallel kinematic structures, its design proposals for individual structural elements and a comparison of parallel and serial kinematics. The main aim of the work is developing design of hydraulic drive, hydraulic circuit, creating a 3D model using Solid Edge software, and the development of design documentation for the designated parts.
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Uncajtik, Petr. "Měření polohy a rychlosti objektů pomocí řádkových optických snímačů." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2008. http://www.nusl.cz/ntk/nusl-217684.
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The objective of Master’s Thesis is to research the utilization of line optical sensors for object location´s and speed measurement in cooperation with PROTOTYPA company. At the beginning of the Thesis there is an explanation of CCD sensor components and photodiods working principals. Further are discussed particular methods of object sensing. There are schematics of different sensor locations and flying object. The other step deals with introduction to the question of ray impact on sensor in the way of using different light sources and optical systems. In the other part of the Thesis are presented two sensors, which have been chosen by PROTOTYPA company workers. Final part of the Thesis deals with description of executed experimental measurement with LCCD 2048S-14 type of sensor. Experiments are aimed for statical and dynamical processes. In statical part was checked displaying of fixed objects on CCD sensor in internal spaces on the assumption that changing of object-lens focalization, object´s high and shape. For the evaluation was used of MATLAB program. Dynamical part of measurement is aimed for moving objects.
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Vintr, Pavel. "Lineární jednotka s hydraulickým pohonem pro robot s paralelní kinematickou strukturou." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2013. http://www.nusl.cz/ntk/nusl-230468.
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This Master thesis deals with the design of linear unit with hydraulic actuator for the robot with parallel kinematic structure. One of the objectives is to get an overview of the differences related to characteristics of design and construction between serial and parallel kinematic structure (PKS) of the industrial robots, as a new type of technical objects in robotics. In addition the aim is to create an original structural design of linear unit, as the basic constructional assembly and operational node of robot with PKS, according to the specified input values, such as power, pressure, speed and stroke, important for the design of linear hydraulic actuator.
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Raniel, Thiago. "Desenvolvimento e implementação de um sistema de controle de posição e velocidade de uma esteira transportadora usando inversor de frequência e microcontrolador /." Ilha Solteira : [s.n.], 2011. http://hdl.handle.net/11449/87040.
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Orientador: Jozué Vieira FilhoBanca: Carlos Antonio Alves
Banca: Tony Inácio da Silva
Resumo: A automação de esteiras rolantes é algo comum e importante em sistemas industriais, mas problemas práticos ainda representam desafios. Um dos desses desafios é manter a precisão em sistemas que exigem paradas sistemáticas, pois folgas mecânicas tendem a provocar variações nas posições de paradas ao longo do tempo. A aplicação de motores de indução têm se tornado comum e soluções eficientes e de baixo custo têm sido pesquisadas. Neste trabalho foi desenvolvido e implementado um sistema de controle de posição e velocidade aplicado em esteiras transportadoras utilizando inversor de frequência, microcontrolador, encoder óptico incremental e sensor indutivo. O movimento da esteira transportadora é efetuado por um motor de indução trifásico, que é acionado pelo conjunto microcontrolador - inversor de frequência. Este conjunto impõe uma frequência no estator do motor através de uma troca de mensagens entre microcontrolador e inversor de frequência (Sistema Mestre-Escravo). Para o envio e recebimento das mensagens, utilizou-se o protocolo de comunicação serial USS® (Universal Serial Interface Protocol) através do padrão RS-485. Os controles de posição e velocidade de rotação do eixo do motor fundamentam-se no sinal gerado pelo encoder óptico incremental, responsável por informar a posição do eixo do motor ao longo da trajetória, e no sensor indutivo que determina uma referência externa importante para a esteira transportadora. Para o funcionamento automático da esteira, elaborou-se um software em linguagem de programação C. Como resultado obteve-se um sistema de controle de posição e velocidade do eixo do motor de indução trifásico que apresenta bons resultados
Abstract: Automated conveyors system have been largely used in industrial applications. However, there are still practical issues to be overcome. One of them is due to the system mechanical limitation which can lead to low accuracy for applications based on "stop-and-go" movements. Induction motors have been largely used in such applications and low costs solutions have been searched. In this work it was developed and implemented a system of positioning and velocity control applied to conveyors which is based on frequency inverter, microcontroller, optical incremental encoder and inductive sensor. The conveyor's movement is made by means of a three-phase induction motor, which is driven by the couple microcontroller-frequency inverter. There are messages exchange between the microcontroller and the frequency inverter (Master - Slave configuration) which is based on the communication serial protocol USS through the RS-485 standard. The position and velocity of the motor spindle are controlled using an optical incremental encoder, which is responsible to provide the position of the trajectory, and an inductive sensor which determines the initial reference to the conveyor. The software used to control the system was developed in C language. The results show a low cost system with good results
Mestre
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Santos, Weslley Queiroz. "Viabilidade de sistemas dopados e co-dopados com Yb3+ e Nd3+ para aplicações fotônicas - lasers e termometria óptica." Universidade Federal de Alagoas, 2015. http://www.repositorio.ufal.br/handle/riufal/1682.
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In this work, we investigated the spectroscopic characteristics of Nd3+ and Yb3+ doped/co-doped materials for potential applications in photonic devices, particularly lasers emitting in the IR and visible (blue) and thermal sensing operating in the first and second biological windows. For such purposes, we used the fluorescence spectroscopy technique in steady state and time resolved. Initially we investigated the spectroscopic characteristics of the Yb3+ doped oxyfluoride glass, analyzing three important effects present in Yb3+ doped systems: Radiation Trapping (RT), Self-Quenching (SQ), and Cooperative Luminescence (CL). We show that the effects of RT and SQ affect substantially the line shape of Yb3+ emission spectrum, thereby inducing miscalculations of the emission cross section, overestimation of the laser level lifetime, as well as errors in non-radiative decay rates. On the other hand, we show that the strong presence of RT favors the CL effect between Yb3+ ions, which configures an advantageous feature for the generation of blue light via CL. In the thermal sensing context, we carried out a study on application of Nd3+ single doped materials for optical temperature sensors based on Fluorescence Intensity Ratio (FIR) using the 4F3/2, 4F5/2 and 4F7/2 Nd3+ energy levels, more precisely, Nd3+ doped Q-98 phosphate glass, where we showed that the investigated phosphate glass present good perspectives for applications in optical thermometer, being its thermal sensitivity and the maximum thermal range, strongly dependent on the considered energy levels. Following the studies on thermal sensing, we investigated the effects of structure core and core@shell of lanthanum fluoride nanocrystals (LaF3) doped/co-doped with Nd3+ and Yb3+ for temperature sensor based on energy transfer (ET). For this, LaF3 nanocrystals in structural configurations LaF3:Nd (only core), LaF3:Nd/Yb (only core), LaF3 :Nd@LaF3:Yb (Nd3+ in core and Yb3+ in shell), and LaF3:Yb@LaF3:Nd (Yb3+ in core and Nd3+ in shell) were synthesized. We evaluated the FIR of the emission from Yb3+ (2F5/2→2F7/2 at ~990 nm) and Nd3+ (4F3/2→4I13/2 at ~1060 nm) against the temperature and we concluded that their sensitivities are strongly dependent on the structural configurations, i.e., we get control the ET processes and their temperature dependence. In addition, we show that FIR, using 990 and 1330 nm emissions present thermal sensitivity at least one order of magnitude greater that the other FIR’s.Conselho Nacional de Desenvolvimento Científico e Tecnológico
Neste trabalho investigamos as características espectroscópicas de materiais dopados/co-dopados com os íons terras-raras Nd3+ e Yb3+ para potenciais aplicações em dispositivos fotônicos, particularmente lasers emissores no infravermelho e visível (azul) e sensoriamento térmico operando na primeira e segunda janelas biológicas. Para tais propósitos, usamos a técnica de espectroscopia de fluorescência no estado estacionário e resolvida no tempo. Inicialmente investigamos as características espectroscópicas do vidro oxifluoreto dopado com Yb3+, analisando três importantes efeitos presentes em sistemas dopados com Yb3+: Radiation Trapping (RT), Self- Quenching (SQ) e Luminescência Cooperativa (LC). Mostramos que os efeitos de RT e SQ afetam de forma substancial a forma de linha do espectro de emissão do Yb3+, induzindo, assim, cálculos errôneos na seção de choque de emissão, superestimação do valor do tempo de vida do nível laser emissor, bem como erros nas taxas de decaimentos não-radiativos. Por outro lado, mostramos que a forte presença dos efeitos de RT observados favorece o processo de LC entre íons Yb3+, o que de certa forma constitui uma característica vantajosa para a geração de luz azul via processo de LC do Yb-Yb. Já no âmbito de sensoriamento térmico, realizamos um estudo sobre a aplicação de materiais mono-dopados com Nd3+ em sensores ópticos de temperatura baseados na Razão de Intensidade de Fluorescência (RIF) dos níveis de energia 4F3/2, 4F5/2 e 4F7/2 do Nd3+, mais precisamente, vidro fosfato Q-98 dopado com Nd3+, onde mostramos que o vidro fosfato investigado apresenta boas perspectivas para aplicações em termômetro óptico, sendo sua sensibilidade térmica, bem como o intervalo de temperatura de máxima sensibilidade, fortemente dependente dos níveis de energia considerados. Continuando os estudos sobre sensoriamento térmico, investigamos os efeitos da estrutura core e core@shell de nanocristais de fluoreto de lantânio (LaF3) dopados/co-dopados com Nd3+ e Yb3+ para sensor térmico por Transferência de Energia (TE). Para tanto, nanocristais de LaF3 nas configurações estruturais de LaF3: Nd (somente core), no LaF3: Nd/Yb (somente core), LaF3: Nd@LaF3: Yb (com Nd3+ no core e Yb3+ no shell) e LaF:Yb@LaF3:Nd (com Yb3+ no core e Nd3+ no shell) foram sintetizados. Nós avaliamos as RIF das emissões do Yb3+ (2F5/2 → 2F7/2 em ~990 nm) e do Nd3+ (4F3/2→4I13/2 em ~1060 nm) com a temperatura e concluímos que suas sensibilidades são fortemente dependentes das configurações estruturais, ou seja, conseguimos controlar os processos de TE e a dependência destes com a temperatura. Adicionalmente, mostramos que o sensor de RIF, usando as emissões em 990 nm e 1330 nm, apresenta uma sensibilidade térmica de pelo menos uma ordem de grandeza maior que os demais RIF’s.
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Komár, Michal. "Určení pozice mobilního zařízení v prostoru." Master's thesis, Vysoké učení technické v Brně. Fakulta informačních technologií, 2013. http://www.nusl.cz/ntk/nusl-236173.
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This thesis focuses on the current localization options of the Android mobile phone platform. It explores the possibilities of locating mobile devices not only with the use of inertial sensors, but also the possibility of localization using integrated video camera. The work describes the measurements done with available inertial sensors, introduces visual localization algorithm and design a system using these two approaches.
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Raniel, Thiago [UNESP]. "Desenvolvimento e implementação de um sistema de controle de posição e velocidade de uma esteira transportadora usando inversor de frequência e microcontrolador." Universidade Estadual Paulista (UNESP), 2011. http://hdl.handle.net/11449/87040.
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raniel_t_me_ilha.pdf: 1815527 bytes, checksum: 2b9558bcbd56601c8cbb627feda891cf (MD5)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
A automação de esteiras rolantes é algo comum e importante em sistemas industriais, mas problemas práticos ainda representam desafios. Um dos desses desafios é manter a precisão em sistemas que exigem paradas sistemáticas, pois folgas mecânicas tendem a provocar variações nas posições de paradas ao longo do tempo. A aplicação de motores de indução têm se tornado comum e soluções eficientes e de baixo custo têm sido pesquisadas. Neste trabalho foi desenvolvido e implementado um sistema de controle de posição e velocidade aplicado em esteiras transportadoras utilizando inversor de frequência, microcontrolador, encoder óptico incremental e sensor indutivo. O movimento da esteira transportadora é efetuado por um motor de indução trifásico, que é acionado pelo conjunto microcontrolador – inversor de frequência. Este conjunto impõe uma frequência no estator do motor através de uma troca de mensagens entre microcontrolador e inversor de frequência (Sistema Mestre-Escravo). Para o envio e recebimento das mensagens, utilizou-se o protocolo de comunicação serial USS® (Universal Serial Interface Protocol) através do padrão RS-485. Os controles de posição e velocidade de rotação do eixo do motor fundamentam-se no sinal gerado pelo encoder óptico incremental, responsável por informar a posição do eixo do motor ao longo da trajetória, e no sensor indutivo que determina uma referência externa importante para a esteira transportadora. Para o funcionamento automático da esteira, elaborou-se um software em linguagem de programação C. Como resultado obteve-se um sistema de controle de posição e velocidade do eixo do motor de indução trifásico que apresenta bons resultados
Automated conveyors system have been largely used in industrial applications. However, there are still practical issues to be overcome. One of them is due to the system mechanical limitation which can lead to low accuracy for applications based on “stop-and-go” movements. Induction motors have been largely used in such applications and low costs solutions have been searched. In this work it was developed and implemented a system of positioning and velocity control applied to conveyors which is based on frequency inverter, microcontroller, optical incremental encoder and inductive sensor. The conveyor’s movement is made by means of a three-phase induction motor, which is driven by the couple microcontroller–frequency inverter. There are messages exchange between the microcontroller and the frequency inverter (Master – Slave configuration) which is based on the communication serial protocol USS through the RS-485 standard. The position and velocity of the motor spindle are controlled using an optical incremental encoder, which is responsible to provide the position of the trajectory, and an inductive sensor which determines the initial reference to the conveyor. The software used to control the system was developed in C language. The results show a low cost system with good results
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Imbrosciano, Sébastien. "Flots et chemins contraints : applications aux réseaux de télécommunications." Thesis, Aix-Marseille, 2014. http://www.theses.fr/2014AIXM4001/document.
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Dans cette thèse, nous nous sommes intéressés à l'analyse et la conception de réseaux étudiés sont les réseaux de fibres optiques et les réseaux de capteurs. Les problématiques étudiées sont: pour les réseaux de fibres optiques, minimiser le coût de déploiement et assurer la qualité de service; dans les réseaux de capteurs, garantir la sécurité des transmissions et l'énergie consommée par le routage des communications. Pour résoudre ces problèmes nous utilisons des techniques de théorie des graphes, de complexité, de programmation linéaire. Le premier problème consiste à concevoir un plan d'installation de fibres optiques de coût minimal permettant de connecter un ensemble de clients à un noeud de raccordement via un ensemble de coupleurs en respectant les contraintes technologiques imposées par la norme. Nous proposons une modélisation de ce problème ainsi qu'une méthode de résolution. Le deuxième problème est un problème de flot avec contrainte de délai où le délai pour traverser une liaison est proportionnel à la quantité de flot quicircule sur celle-ci. Nous proposons une preuve de NP-complétude dans le cas général, un algorithme d'approximation facteur 2 dans le cas où le graphe support est un chemin et une heuristique évaluée de façon expérimentale qui calcule en un temps raisonnable de bonnes solutions pour des instances de tailles réelles. Enfin, nous proposons deux protocoles concernant les réseaux de capteurs. Le premier, basé sur un algorithme distribué, calcule un ensemble de chemins disjoints entre les terminaux. Le second maximise la durée de vie d'un réseau de capteurs alimentés par batteries. Des résultats s'expérimentations numériques sont présentésIn this thesis, we study some optimization problem applied to telecommunication networks. We study fiber optical networks and sensor networks. We are interested to analysis and design for these types of networks. The issues studied are: for fiber optic networks, minimize the cost of deployement and ensure quality of service; for sensors network, ensure the safety of transmissions and the energy consumed. To solve these problems we use techniques as graphs theory, complexity, linearprogramming, generalized flows and paths with resource constraints. The first problem is to minimize the cost to deploy a fiber optical network which connect a set of customers to a connection node through a set of splitter and deal about technological constraints imposed by the standard. We propose a model and a method of resolution for this problem. The second problem is a flow problem with delay constraint where time to cross a edge is proportional to the amount of flow that flows thereon. We offer a proof of NP-completeness in the general case, an approximation algorithm factor 2 in the case where the support graph is a path and an estimated experimentally an heuristic that calculates good solutions for instances of real sizes. Finally, we propose two protocols for sensor networks, which resulted in two patents. The first, based on a distributed algorithm, calculates a set of disjoint paths between terminals. The second maximizing the lifetime of sensors powered by batteries. The results of numerical experiments are also presented
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Manecy, Augustin. "Stratégies de guidage visuel bio-inspirées : application à la stabilisation visuelle d’un micro-drone et à la poursuite de cibles." Thesis, Université Grenoble Alpes (ComUE), 2015. http://www.theses.fr/2015GREAT050/document.
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Les insectes sont capables de prouesses remarquables lorsqu’il s’agit d’éviter des obstacles,voler en environnement perturbé ou poursuivre une cible. Cela laisse penser que leurs capacités de traitement, aussi minimalistes soient-elles, sont parfaitement optimisées pour le vol. A cela s’ajoute des mécanismes raffinés, comme la stabilisation de la vision par rapport au corps, permettant d’améliorer encore plus leurs capacités de vol.Ces travaux de thèse présentent l’élaboration d’un micro drone de type quadrirotor, qui ressemble fortement à un insecte sur le plan perceptif (vibration rétinienne) et reprend des points structurels clés, tels que le découplage mécanique entre le corps et le système visuel. La conception du quadrirotor (de type open-source), son pilotage automatique et son système occulo-moteur sont minutieusement détaillés.Des traitements adaptés permettent, malgré un très faible nombre de pixels (24 pixels seulement), de poursuivre finement du regard une cible en mouvement. A partir de là, nous avons élaboré des stratégies basées sur le pilotage par le regard, pour stabiliser le robot en vol stationnaire, à l’aplomb d’une cible et asservir sa position ; et ce, en se passant d’une partie des capteurs habituellement utilisés en aéronautique tels que les magnétomètres et les accéléromètres. Le quadrirotor décolle, se déplace et atterrit de façon autonome en utilisant seulement ses gyromètres, son système visuel original mimant l’oeil d’un insecte et une mesure de son altitude. Toutes les expérimentations ont été validées dans une arène de vol, équipée de caméras VICON.Enfin, nous décrivons une nouvelle toolbox qui permet d’exécuter en temps réel des modèles Matlab/Simulink sur des calculateurs Linux embarqués de façon complètement automatisée (http://www.gipsalab.fr/projet/RT-MaG/). Cette solution permet d’écrire les modèles, de les simuler, d’élaborer des lois de contrôle pour enfin, piloter en temps réel, le robot sous l’environnement Simulink. Cela réduit considérablement le "time-to-flight" et offre une grande flexibilité (possibilité de superviser l’ensemble des données de vol, de modifier en temps réel les paramètres des contrôleurs, etc.)Insects, like hoverflies are able of outstanding performances to avoid obstacles, reject disturbances and hover or track a target with great accuracy. These means that fast sensory motor reflexes are at work, even if they are minimalist, they are perfectly optimized for the flapping flight at insect scale. Additional refined mechanisms, like gaze stabilization relative to the body, allow to increase their flight capacity.In this PhD thesis, we present the design of a quadrotor, which is highly similar to an insect in terms of perception (visual system) and implements a bio-inspired gaze control system through the mechanical decoupling between the body and the visual system. The design of the quadrotor (open-source), itspilot and its decoupled eye are thoroughly detailed. New visual processing algorithms make it possible to faithfully track a moving target, in spite of a very limited number of pixels (only 24 pixels). Using this efficient gaze stabilization, we developed new strategies to stabilize the robot above a target and finely control its position relative to the target. These new strategies do not need classical aeronautic sensors like accelerometers and magnetometers. As a result, the quadrotor is able to take off, move and land automatically using only its embedded rate-gyros, its insect-like eye, and an altitude measurement. All these experiments were validated in a flying arena equipped with a VICON system. Finally, we describe a new toolbox, called RT-MaG toolbox, which generate automatically a real-time standalone application for Linux systems from a Matlab/Simulink model (http://www.gipsalab.fr/projet/RT-MaG/). These make it possible to simulate, design control laws and monitor the robot’s flight in real-time using only Matlab/Simulink. As a result, the "time-to-flight" is considerably reduced and the final application is highly reconfigurable (real-time monitoring, parameter tuning, etc.)
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Vestin, Albin, and Gustav Strandberg. "Evaluation of Target Tracking Using Multiple Sensors and Non-Causal Algorithms." Thesis, Linköpings universitet, Reglerteknik, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-160020.
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Today, the main research field for the automotive industry is to find solutions for active safety. In order to perceive the surrounding environment, tracking nearby traffic objects plays an important role. Validation of the tracking performance is often done in staged traffic scenarios, where additional sensors, mounted on the vehicles, are used to obtain their true positions and velocities. The difficulty of evaluating the tracking performance complicates its development. An alternative approach studied in this thesis, is to record sequences and use non-causal algorithms, such as smoothing, instead of filtering to estimate the true target states. With this method, validation data for online, causal, target tracking algorithms can be obtained for all traffic scenarios without the need of extra sensors. We investigate how non-causal algorithms affects the target tracking performance using multiple sensors and dynamic models of different complexity. This is done to evaluate real-time methods against estimates obtained from non-causal filtering. Two different measurement units, a monocular camera and a LIDAR sensor, and two dynamic models are evaluated and compared using both causal and non-causal methods. The system is tested in two single object scenarios where ground truth is available and in three multi object scenarios without ground truth. Results from the two single object scenarios shows that tracking using only a monocular camera performs poorly since it is unable to measure the distance to objects. Here, a complementary LIDAR sensor improves the tracking performance significantly. The dynamic models are shown to have a small impact on the tracking performance, while the non-causal application gives a distinct improvement when tracking objects at large distances. Since the sequence can be reversed, the non-causal estimates are propagated from more certain states when the target is closer to the ego vehicle. For multiple object tracking, we find that correct associations between measurements and tracks are crucial for improving the tracking performance with non-causal algorithms.
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Hong, Chi-Fu, and 洪麒富. "Design and Analysis of Inductive Reluctance Linear Position Sensor." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/9m99mj.
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Huang, Yan-Sheng, and 黃彥勝. "Optical Sensor for Measuring Position and Slanting Direction of Flat Surface." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/5kntga.
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碩士國立中正大學
機械工程學系暨研究所
103
The conventional auto-collimator can only measure the tilt of the sample surface, however, it is unable to measure the distance from the sample. Therefore, this paper presents a non-contact optical measuring system for an inclined surface, which can measure the defocusing amount (δ) and the tilt (α, β) of the sample surface. Consequently, the scope of application of this system will be more extensive. In this thesis, we verify the feasibility of the proposed system with qualitative and quantitative analysis respectively. In the qualitative analysis, the architecture of the proposed measurement system is established in the optical simulation software ZEMAX to observe the characteristics and trends of the proposed system. In the quantitative analysis, a complete mathematical model of the proposed system is established by using homogeneous transformation matrix (HTM) and using the skew ray-tracing method to derive the actual laser light transfer within the proposed measurement system. After completing the above analysis, we measure the performance of the proposed system using a laboratory-built prototype. Finally the experimental results are analyzed and compared to verify the feasibility of the proposed system. Keyword：
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Hsieh, Shih-Ho, and 謝是合. "A Magnetic Dipole Position and Direction Linear Estimation and Tri-axes Sensor Array Localization Method." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/5864na.
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Lee, Chun-Hua, and 李浚華. "A High Speed USB Measurement and Analysis System Designed for High Precision Optical Position Sensor." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/93230140524179888859.
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碩士龍華科技大學
電子系碩士班
94
The purpose of the study was to design a measurement and data acquisition system for Quadrant Detectors (QD). This designed system include two parts—analog processing circuit module and high speed data acquisition card. The analog processing circuit module was developed to reduce circuit noises and to acquire signals of quadrant detector. The other high speed data acquisition card adopted a USB 2.0 chipset as the transmission interface to PC and the data acquisition applied the Complex Programmable Logic device (CPLD) component to simplify the related peripheral circuits. In addition, the CPLD was to provide 8 A/D channels and acquires 4 set of sensor signals at one time. The result of the experiment reveals that the residual error of the system was within ±1μm, and its resulation was 0.3μm. The designed USB measurment and analog systems not only meet the requirements of high precision optical position, but also equipped with the integrated capability to other related systems.
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Morris, Julie Anne. "Design of an active stereo vision 3D scene reconstruction system based on the linear position sensor module." 2006. http://etd.utk.edu/2006/MorrisJulie.pdf.
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Pan, Po-Wei, and 潘伯威. "Towards Maximizing Measuring Accuracy of a Optical Blood Pressure Non-invasive Cuffless Array Sensor via Radial Artery Position Detection and Analog Signal Processing." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/m3we37.
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碩士國立交通大學
電控工程研究所
106
A new optical PPG sensor for continuous blood pressure (BP) monitoring is successfully developed by this thesis. BP device introduces the principle of photoplethysmography (PPG) to detect intravascular blood volume changes and calculate blood pressure. The real-time system adopts LEDs with muti-wavelength of 530, 660 and 940 nm. The analog front end (AFE) circuit includes a preamplifier, a band-pass filter, a programmable gain amplifier (PGA), LED driver, a microprocessor unit (MCU), and a wireless module. The pass-band frequency of filter is from 0.3 to 7.2 Hz. The PGA of adjustable gain has 8 channels to adjust. A computer is also used to display the continuous BPs, detect the pulse position and record statistical analysis/results for users. As results, 10 subjects in the experimental validation, in which the obtained BPs are compared with the results from a commercial BP monitor by OMRON HEM-7310. The maximum error of experimental results is ± 6 mmHg, which is less than ±8 mmHg conforming to the requirement by the Association for the Advancement of Medical Instrumentation (AAMI).