Dissertations / Theses on the topic 'Optical measuring systems'
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Zobrist, Tom L. "Application of laser tracker technology for measuring optical surfaces." Diss., The University of Arizona, 2009. http://hdl.handle.net/10150/195326.
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The pages of this dissertation detail the development of an advanced metrology instrument for measuring large optical surfaces. The system is designed to accurately guide the fabrication of the Giant Magellan Telescope and future telescopes through loose-abrasive grinding. The instrument couples a commercial laser tracker with an advanced calibration technique and a set of external references to mitigate a number of error sources. The system is also required to work as a verification test for the GMT principal optical interferometric test of the polished mirror segment to corroborate the measurements in several low-order aberrations. A set of system performance goals were developed to ensure that the system will achieve these purposes. The design, analysis, calibration results, and measurement performance of the Laser Tracker Plus system are presented in this dissertation.
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Berglund, Martin. "Optical measuring system using a camera and laser fan-out for narrow mounting on a miniaturized submarine." Thesis, Uppsala University, Ångström Space Technology Centre, ÅSTC, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-112681.
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The aim was to develop, manufacture and evaluate diffractive lenses, or diffractive optical elements (DOE), for use in correlation with a camera to add perspective in pictures. The application is a miniaturized submarine developed in order to perform distant exploration and analysis in harsh and narrow environments. The idea is to project a laser pattern upon the observed structure and thereby add geometrical information to pictures acquired with an onboard CMOS camera. The design of the DOE-structures was simulated using the optimal rotational angle method (ORA). A set of prototype DOEs were realized using a series of microelectromechanical system (MEMS) processes, including photolithography, deposition and deep reactive-ion etching (DRIE). The projected patterns produced by the manufactured DOEs were found to agree with the simulated patterns except for the case where the DOE feature size was too small for the available process technology to handle. A post-processing software solution was developed to extract information from the pictures, called Laser Camera Measurement (LCM). The software returns the x, y and z coordinate of each laser spot in a picture and provides the ability to measure a live video stream from the camera. The accuracy of the measurement is dependent of the distance to the object. Some of the patterns showed very promising results, giving a 3-D resolution of ~0.6 cm, in each dot, at a distance of 1 m from the camera. Lengths can be resolved up til 3 m distance from the submarine.
Tillämpningen finns i en miniatyriserad ubåt framtagen för utforskning och analys av svåråtkomliga och trånga håligheter. Målet var att designa, tillverka och utvärdera en diffraktiv lins (DOE) för användning tillsammans med en kamera för att skapa perspektiv i bilder. Idén var att projicera ett lasermönster på objektet och därmed lägga till geometrisk information till bilderna tagna med CMOS kameran. Utformningen av DOE-strukturerna simulerades med the optimal rotational angle method (ORA). En uppsättning av prototyp DOE-linser tillverkades med hjälp av en serie mikrostrukturteknikprocesser, bland annat fotolitografi, deponering och plasmaetsning. Mönster projicerade med de tillverkade DOE-linserna stämde väl överens med önskade mönster, med undantag för de DOEs där strukturstorleken underskred processens begränsningar. En programvara, kallad Laser Camera Measurement (LCM), utvecklades för att extrahera information från bilderna. Programvaran returnerar x, y, och z koordinaterna för varje laserpunkt i en bild och ger möjlighet att mäta i en kontinuerlig videoström från kameran. Mätosäkerheten är beroende av avståndet till objektet. Vissa mönster gav mycket lovande resultat, med en 3-D upplösning på ~0.6 cm, i varje punkt, på ett avstånd av 1 m från kameran. Längder kan upplösas upp till 3 m från kameran där ett så kallat far-field uppstår.
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Godun, Rachel M. "Beam splitting mechanisms for a caesium atom interferometer." Thesis, University of Oxford, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.343474.
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He, Zaiqian. "Investigation of a multi-purpose optical measurement system /." View abstract or full-text, 2005. http://library.ust.hk/cgi/db/thesis.pl?IEEM%202005%20HE.
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Ingraham, John. "Model automatic focusing system for linewidth measuring instruments /." Online version of thesis, 1985. http://hdl.handle.net/1850/11372.
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Maldonado, Alejandro V. "High Resolution Optical Surface Metrology with the Slope Measuring Portable Optical Test System." Diss., The University of Arizona, 2014. http://hdl.handle.net/10150/337294.
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New optical designs strive to achieve extreme performance, and continually increase the complexity of prescribed optical shapes, which often require wide dynamic range and high resolution. SCOTS, or the Software Configurable Optical Test System, can measure a wide range of optical surfaces with high sensitivity using surface slope. This dissertation introduces a high resolution version of SCOTS called SPOTS, or the Slope measuring Portable Optical Test System. SPOTS improves the metrology of surface features on the order of sub-millimeter to decimeter spatial scales and nanometer to micrometer level height scales. Currently there is no optical surface metrology instrument with the same utility. SCOTS uses a computer controlled display (such as an LCD monitor) and camera to measure surface slopes over the entire surface of a mirror. SPOTS differs in that an additional lens is placed near the surface under test. A small prototype system is discussed in general, providing the support for the design of future SPOTS devices. Then the SCOTS instrument transfer function is addressed, which defines the way the system filters surface heights. Lastly, the calibration and performance of larger SPOTS device is analyzed with example measurements of the 8.4-m diameter aspheric Large Synoptic Survey Telescope's (LSST) primary mirror. In general optical systems have a transfer function, which filters data. In the case of optical imaging systems the instrument transfer function (ITF) follows the modulation transfer function (MTF), which causes a reduction of contrast as a function of increasing spatial frequency due to diffraction. In SCOTS, ITF is shown to decrease the measured height of surface features as their spatial frequency increases, and thus the SCOTS and SPOTS ITF is proportional to their camera system's MTF. Theory and simulations are supported by a SCOTS measurement of a test piece with a set of lithographically written sinusoidal surface topographies. In addition, an example of a simple inverse filtering technique is provided. The success of a small SPOTS proof of concept instrument paved the way for a new larger prototype system, which is intended to measure subaperture regions on large optical mirrors. On large optics, the prototype SPOTS is light weight and it rests on the surface being tested. One advantage of this SPOTS is stability over time in maintaining its calibration. Thus the optician can simply place SPOTS on the mirror, perform a simple alignment, collect measurement data, then pick the system up and repeat at a new location. The entire process takes approximately 5 to 10 minutes, of which 3 minutes is spent collecting data. SPOTS' simplicity of design, light weight, robustness, wide dynamic range, and high sensitivity make it a useful tool for optical shop use during the fabrication and testing process of large and small optics.
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Palásek, Vítězslav. "Souřadnicové měřicí stroje (CMM) s optickým snímacím systémem a optické CMM." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2009. http://www.nusl.cz/ntk/nusl-228384.
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This graduation work is about co-ordinal measuring machines (CMM) with optical reader system and optical CMM. In accordance with submission and in terms of survival well known contactless systems the direction is to make methodology objective classification of rating with granting summary of these systems. The first part contains optical principles for visual scanner in CMM and optical CMM. Ist is described there principle of contactless obtaining steric digital version of measured object with using laser and optical facilities. The second part contains brief makes survey of these contactless systems and their component which are used for co-ordinal measuring. The survey is devided into optical readers, which are put on CMM brake or on mobile measuring brake and on optical CMM, which localize position measuring/sensing head in the space or they read measured object from specific distance – fotogrammetric. Characteristic of offered systems and chart with technical data are mentioned with each maker. The third and fourth part is about submission methodology for objective choice suitable sort of reader, optical CMM in target of characteristic reader system quality. And from this methodology is given the choice of suitable exponent stationary measuring machine with contact and contactless way of reading and their comparison.
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Wang, Na 1982. "System of measuring mechanical properties of colloidal gels with optical tweezers." Thesis, McGill University, 2006. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=101662.
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Due to the unique rheological properties of colloidal gels, gelation of colloidal suspensions has become increasingly important to fundamental investigations, as well as to technological applications. Recent experimental approaches are mainly focused on the bulk properties of colloidal gels, using methods of static and dynamic light scattering and shear rheometry. This thesis describes the development of a system for measuring the mechanical properties of colloidal gels with optical tweezers.We make colloidal gels out of polystyrene beads of two different sizes, diameters of 3.5mum or 62nm respectively. Investigation of the colloidal gels under the light microscope shows the fractal nature of the gel structure while macroscopic study confirms that the gelation process of the smaller polystyrene beads is faster than that of the bigger polystyrene beads. We were also able to generate a phase diagram of the gelation process.
We successfully assembled the main instrument, a time-sharing single beam optical tweezers, and calibrated the lateral stiffness of the optical trap. Our optical tweezers setup is used to study the polystyrene gel and it has many more applications in colloidal samples. The strong 3D optical trapping highlights the optical tweezers as a powerful technique suitable for further investigation of colloidal samples.
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Al-Rjoub, Bashar Ahmed. "Structured light optical non-contact measuring techniques : system analysis and modelling." Thesis, Liverpool John Moores University, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.438765.
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Gedemer, L. A. "A new method for measuring and calibrating cinema audio systems for optimal sound quality." Thesis, University of Salford, 2017. http://usir.salford.ac.uk/42005/.
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The aim of this research is to utilize new methodologies and technology in order to gain insight into how the modern cinema audio system could be calibrated to provide improved audio performance. To this end, both objective and subjective measurements were developed to better understand the audio preferences of listeners, the requirements of the audio systems inclusive of the acoustic environment, and how the two are related. Part of the data for this research was derived from a survey of re-recording mixers regarding their use and opinion of the current SMPTE standard. The survey confirmed anecdotal information suggesting that re-recording mixers use high-end pre-emphasis to compensate for the severe roll-off induced by the SMPTE X-curve. It is also noted that the re-recording mixers' opinions of how well their mix translates from dub-stage to cinema is correlated to how many years they have spent in the industry. The aim of this research is to utilize new methodologies and technology in order to gain insight into how the modern cinema audio system could be calibrated to provide improved audio performance. To this end, both objective and subjective measurements were developed to better understand the audio preferences of listeners, the requirements of the audio systems inclusive of the acoustic environment, and how the two are related. Part of the data for this research was derived from a survey of re-recording mixers regarding their use and opinion of the current SMPTE standard. The survey confirmed anecdotal information suggesting that re-recording mixers use high-end pre-emphasis to compensate for the severe roll-off induced by the SMPTE X-curve. It is also noted that the re-recording mixers' opinions of how well their mix translates from dub-stage to cinema is correlated to how many years they have spent in the industry. To further understand listener preference to in-room responses curves, a series of listening tests utilizing the BRS system were conducted using various sized cinemas, seating positions within the cinemas, audio tracks (including those mixed on a SMPTE calibrated dub-stage) and target curves. The overwhelming outcome was that regardless of cinema size, seating position or audio track utilized; the "curve" that listeners preferred is a relatively flat 0.9dB/octave slope with a 6.5dB bass boost below 105Hz and a -2.5dB roll off above 2.5kHz. Of the 5 target curves presented, the SMPTE X-curve place fourth with scores very near the low-rated perceptual anchor. This calls into question the notion of the X-curve providing "ideal" translation between dub-stage and cinema and in fact, challenges the concept of translation all together. Research was completed in an effort to identifying the number of microphone positions required, along with their placement, in order to accurately capture a cinema's response for calibration purposes. A novel experiment utilizing anechoic loudspeaker data as a guideline for xxi analysis demonstrated that, with proper data, the number of microphones and their positions plays a less critical factor in determining the room response. The collected data shows that even with as few as 4 microphones at varied positions, the resultant room response will trend towards the anechoic data above 1kHz. From around 300Hz to 1kHz, there is evidence of seat effects that may be resolved through randomizing the microphone heights. Below 300Hz, the room becomes the dominating factor and more than 5 microphone positions will be required to properly identify any problems.
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Moore, Andrew Clay. "An improved system for measuring optically the surface dynamics of a sample." Thesis, Georgia Institute of Technology, 1997. http://hdl.handle.net/1853/16334.
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Stan, Nikola. "Complete Measurement System for Measuring High Voltage and Electrical Field Using Slab-Coupled Optical Fiber Sensors." BYU ScholarsArchive, 2018. https://scholarsarchive.byu.edu/etd/7053.
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A slab-coupled optical fiber sensor (SCOS) falls into a narrow class of all-dielectric optical fiber electric field sensors, which makes it a perfect candidate for measurements of high electric fields in environments where presence of conductors is highly perturbing to the system under test. Its nonlinear response to high fields requires a new nonlinear calibration technique. A nonlinear calibration method is explained and demonstrated to successfully measure high electric fields, as well as high voltages with dynamic range up to 50 dB. Furthermore, a SCOS can be fitted into narrow spaces and make highly localized measurements due to its small size. This allows a SCOS to be integrated inside a standard high voltage coaxial cable, such as RG-218. Effects of partial discharge and arcing is minimized by development of a fabrication method to avoid introduction of impurities, especially air-bubbles, into the cable during SCOS insertion. Low perturbation of the measured voltage is shown by simulating the introduced voltage reflections to be on the order of –50 dB. It is also shown that a SCOS can be inserted into other cables without significant perturbation to the voltage. A complete high voltage and high electric field measurement system is built based on the high-voltage modifications of the SCOS technology. The coaxial SCOS is enhanced for robustness. Enhancements include packaging a SCOS into stronger ceramic trough, strengthening the fiber with kevlar reinforced furcation tubing and protecting the sensor with metal braces and protective shells. The interrogator is protected from electromagnetic interference with an RF-shielded box. Reduction in power losses introduced by the new PANDA-SCOS technology allows interrogator bandwidths to be increased up to 1.2 GHz. The whole measurement process is streamlined with dedicated software, developed specifically for high voltage and electric field measurements with support for the nonlinear calibration.
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Crolla, Paul. "On a dual wavelength optical sensor system for measuring strain and temperature simultaneously in tokamak port plug." Thesis, University of Strathclyde, 2014. http://oleg.lib.strath.ac.uk:80/R/?func=dbin-jump-full&object_id=24278.
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A large variety of sources will provide energy, including nuclear fusion energy from tokamak type reactors; still at a research stage of development to produce 500 MW of energy. The reactor's structure will be affected by temperature changes and ionising radiation (neutrons produced by the burning plasma); it is therefore necessary to instrument the structure with long lasting, accurate, temperature and strain monitoring devices. This thesis demonstrates that using electrical sensors in the supporting structures of a fusion reactor for measuring strain and temperature will be strongly affected by the ionising radiation and the electromagnetic fields. This is because it was found that errors of over 100% can be present on the measurements due to combined electromagnetic and radiation effects. An optical fibre sensor was constructed to a strain resolution of ±10uε and temperature resolution of ±5°C. The fibre sensor is an off the shelf solution dual-wavelength fibre Bragg grating. The thesis proposes a method of coating the fibre in layers of silver and copper to protect this sensor. A new method of embedding the fibre in a stainless steel piece is described using a silver solder to couple the fibre with the steel increasing its temperature and strain sensitivity by approximately three times, with the solder melted using an induction heater. To measure the temperature and strain response from the fibre Bragg grating a broadband optical filter was used as a real-time interrogation system. Data capture and analysis software solution was created running at 30Hz and ~1pm resolution; temperature and strain requirements were met. This work describes a method of performing measurements of strain and temperature not subject to electromagnetic interference, with good electrical isolation possible and capable of operating in a near vacuum. The sensor package provides a robust, weldable solution for connecting the sensor to the port plug structure and/or plasma instrumentation equipment that will provide regular repeatable measurements of strain and temperature.
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Tesfaldet, Mogos Tseletu. "Evaluation of the validity of IMU sensors measuring wrist angular velocity by comparison with an optical motion tracking system." Thesis, KTH, Skolan för kemi, bioteknologi och hälsa (CBH), 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-283787.
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There is a need for objective methods for wrist angular velocity measurements for accurate risk assessments because there is a high frequency of musculoskeletal disorder in workers. The goal of this project was to validate the accuracy of inertial measurement unit sensors to measure the angular velocity. More specifically, the purpose of this master thesis project was to apply an alternative algorithm to compute the markers velocity, other than the one from the optical system that Jenny Wingqvist, and Josephine Lantz used. The project used an experimental data of 10 participants from the previous project done by Jenny Wingqvist and Josephine Lantz. To validate the accuracy, the data of angular velocity of the sensors was compared with the data of angular velocity of markers. The lowest mean value of the root mean square differences value was 23.5 degrees/s during flexion and deviation standard movements at 40 BPM (Beats Per Minute) and the maximum value was 110.5 degrees/s at 140 BPM. The mean value of the correlation coefficients between markers and sensors angular velocities in standard movements of flexion and deviation were 0.85, 0.88, and 0.89 at 40 BPM, 90 BPM, and 140 BPM, respectively. The smallest and the largest mean value of the absolute difference in 50th percentile was found in 40 BPM (19.4±11.3), and 140 BPM (51.2±28.5) respectively. The decorrelation coefficient between the subjects 50th percentile of the angular velocity was 0.91 for the standard movements. The upper limit of agreement for the standard movements was 78.36 degrees/s, while the lower limit of agreement was -13.76 degrees/s. The results show that the error was too large, so there is a need of further research to measure the wrist angular velocity using IMU sensors.
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Shayegan, Salek Mir Farrokh. "Simultaneous Optical and MR Imaging of Tissue Within Implanted Window Chamber: System Development and Application in Measuring Vascular Permeability." Diss., The University of Arizona, 2013. http://hdl.handle.net/10150/308901.
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Simultaneous optical imaging and MRI of a dorsal skin-fold window chamber mouse model is investigated as a novel methodology to study the tumor microenvironment. Simultaneous imaging with two modalities allows for cross-validation of results, integration of the capabilities of the two modalities in one study and mitigation of invasive factors, such as surgery and anesthesia, in an in-vivo experiment. To make this investigation possible, three optical imaging systems were developed that operated inside the MRI scanner. One of the developed systems was applied to estimate vascular kinetic parameters of tumors in a dorsal skin-fold window chamber mouse model with simultaneous optical and MRI imaging. The target of imaging was a molecular agent that was dual labeled with both optical and MRI contrast agents. The labeling of the molecular agent, characteristics of the developed optical systems, the methodologies of measuring vascular kinetic parameters using optical imaging and MRI data, and the obtained results are described and illustrated.
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Pernikář, Václav. "Přesnost měření na dílenských mikroskopech." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2008. http://www.nusl.cz/ntk/nusl-227877.
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This thesis deals with the performance of the measurement accuracy in the optical measuring systems. The first part describes basic principles of metrology and the guidelines of the expression of uncertainty and the factors which influence measurement result. The second part classifies optical measuring systems and describes some measuring principles of them. The final part compares two optical gauges and the evaluation of some of their characteristics through the use of very simple experiments.
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Opravil, Jan. "Systém pro optické měření." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2012. http://www.nusl.cz/ntk/nusl-219684.
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This diploma thesis deals with the creation and testing of optical measurement system. There are basic parts of computer vision. Some ways of image preprocessing and templates matching are discussed. Everything is directed to a particular practical task. Selected methods for templates matching are the Correlation Method, the Classical and Hybrid Hausdorff Distance, Radial and Circular Sampling Space. These methods are programmed in C++ and they are compared with function for searching templates from specific library.
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Schneider, Tobias [Verfasser]. "Optisches Messverfahren zur gleichzeitigen Erfassung von Absolutdrehwinkel und Drehmoment an Wellen : Optical system for measuring simultaneously the absolute angle of rotation and the torque of shafts / Tobias Schneider." Hannover : Gottfried Wilhelm Leibniz Universität Hannover, 2020. http://d-nb.info/1220422649/34.
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Luong, Marie. "Conception optimale de l'architecture d'un systeme d'instrumentation sous contraintes de diagnostic, de fiabilité et de disponibilité." Vandoeuvre-les-Nancy, INPL, 1996. http://www.theses.fr/1996INPL155N.
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L’objectif de ce mémoire concerne, d'une part, l'analyse structurelle et quantitative d'un processus et, d'autre part, la conception optimale d'une architecture d'instrumentation permettant de définir la position, le nombre et la précision des capteurs. Cette conception doit satisfaire à de nombreuses contraintes dont les principales sont la disponibilité de la valeur des variables nécessaires, la détectabilité et l'isolabilité des capteurs défaillants, la précision de l'estimation, le coût, la fiabilité et la disponibilité du systeme d'instrumentation. Pour ce qui est l'analyse structurelle et quantitative, nous avons développé des méthodes permettant de caractériser le processus selon le critère d'observabilité, le degré de redondance des variables, la détectabilité et l'isolabilité des capteurs défaillants, la précision de l'estimation de l'état du processus, la fiabilité et la disponibilité de son systeme d'instrumentation. Quant à la conception optimale d'un systeme d'instrumentation, elle a été résolue en trois étapes: i) définir la position et le nombre de capteurs sous contraintes d'observabilité, de degré de redondance, de détectabilité et d'isolabilité des capteurs défaillants, de non-mesurabilité et d'obligation de mesurer des variables. En utilisant les cycles et la formulation en termes de programmation linéaire en nombres entiers, une solution optimale est proposée soit en minimisant le coût à fiabilité imposée, soit en maximisant la fiabilité à coût imposé, ii) déterminer la précision des capteurs de façon à garantir une précision imposée de l'estimation, en se basant sur un algorithme à itération directe, iii) déterminer le taux de réparation des capteurs pour obtenir une disponibilité donnée pour le systeme d'instrumentation. Ces méthodes ont été testées sur une partie d'une plate-forme pétrolière de la société ELF
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Derner, Petr. "Měření zkrutné tuhosti karosérie s využitím fotogrammetrického zařízení TRITOP." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2009. http://www.nusl.cz/ntk/nusl-228710.
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This master's thesis deals with measurement of torsional rigidity of a vehicle body with the application of TRITOP optical measuring system. The measurement was made in dynamic test-room of Škoda Auto a.s. together with a methodology used by this company. In the light of the objective comparison of both measuring methods and their accuracy, the optimal method of measurment and evaluation was made.
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Poizat, Jean-Philippe. "Réalisation et caractérisation de mesures quantiques non-destructives en optique." Phd thesis, Université Paris Sud - Paris XI, 1993. http://pastel.archives-ouvertes.fr/pastel-00714222.
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L'objectif d'un dispositif de mesure qnd est de contrôler l'action en retour, imposée par la mécanique quantique, qui se produit sur un système soumis a une mesure. Il est, en effet, possible de rejeter cette perturbation entièrement sur l'observable complémentaire de celle mesurée, laissant cette dernière inchangées. Nous présentons ici, de manière détaillée, un ensemble de critères quantitatifs permettant d'évaluer les performances d'un dispositif mesurant l'intensité d'un faisceau lumineux. Ces critères permettent en particulier de séparer clairement des domaines classique et quantique de fonctionnement d'un tel dispositif. La première expérience realisee utilise le couplage par effet kerr croise de deux faisceaux laser dans un milieu non linéaire. Ce milieu est compose d'un jet atomique de sodium place dans une cavite optique doublement résonnante. Nous avons effectue une analyse théorique complète des proprietes de bruit quantique d'un tel système. Nous avons identifie un régime de paramètres, base sur des effets de déplacement lumineux, pour lequel il existe un transfert efficace d'information du faisceau incident vers la voie de mesure, sans dégradation appréciable du signal. Ces prévisions théoriques ont ensuite été vérifiées dans notre expérience. Nous présentons également une deuxième expérience utilisant la détection puis la réémission de la lumière par des composants optoélectroniques a semi-conducteur. Nous montrons que lorsque les taux de conversion photon-électron pour les photodiodes et électron-photon our les diodes electro-luminescentes sont proches de l'unité, ce dispositif permet de mesurer puis de recréer les fluctuations quantiques du faisceau incident. La démonstration de principe que nous avons realisee laisse présager des applications possibles dans le domaine des réseaux de télécommunication optique.
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kulkarni, Milind Anant. "Small Angle Measurement Using Optical Caustics From Hollow Cylinders - Few Investingations." Thesis, 2007. http://hdl.handle.net/2005/621.
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‘Optical Caustics’ represent some of the most visually striking patterns of the light in nature.They occur when light rays from a source, such as the sun, get refracted, or reflected by curved media so as to bend and alter their path. They are ubiquitous and signify the regions of space in which many rays intersect to form bright singularities along a two-or a three-dimensional surface. The associated 2-D patterns (caustic patterns) could be simple or complex in ‘shape and size’ depending upon the optical arrangement used to produce them. Such patterns exhibit either a static or a dynamic behavior which can be controlled sensitively by the medium or the device used to produce them. The present thesis concerns with a few novel contributions in utilization of such optical caustics for the measurement of small angular rotation/tilt of objects.
Utilizing a ‘hollow cylinder’ as a novel device for the generation of the optical caustics, the author proposed and demonstrated three new schemes of realizing a position-dependent-behavior of ‘Optical Caustic Patterns’. The said behavior is investigated both analytically as well as experimentally. The results of the investigation are then utilized to propose and demonstrate three methods of magnifying angular displacement of the hollow cylinder. The salient feature of the principle behind each of the said methods is illustrated in the figures below.
The patterns in each of the above pictures correspond to two different positions of the hollow cylinder-the pattern in white color corresponds to the initial position while that in red color corresponds to new angular position of the cylinder. Defining S1 = ƒ (LΔΦ), S2= ƒ(TΔΦ) and S3= ƒ(ξ ΔΦ) as new signals from the proposed methods, it has been shown that each of them represent a magnified measure of the change in the angular position of the cylinder ΔΦ. Further, if a plane mirror is used in place of cylinder in the proposed methods, the corresponding signal S for the same change in the angular position ΔΦis represented by ΔD. For a chosen set of the experimental conditions, it is shown that for unit change in ΔΦ, the values of S1, S2 and S3 change 30, 37 and 62 times faster than ΔD. The investigations clearly demonstrate that hollow cylinders can be advantageously used as position-magnifying angle-sensing devices. The results of the investigations also suggest that in application areas such as auto collimation, torsion pendulum and design of motion control stages, this device is expected to bring in new advances.
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Lih-Wuu, Chang, and 張立武. "Optical interferometer and signal processing in optical measuring system." Thesis, 1998. http://ndltd.ncl.edu.tw/handle/58926460410483474257.
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Ji, Hong. "Development of a novel optical contact probing system for nano-CMM." 2008. http://arrow.unisa.edu.au:8081/1959.8/79344.
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This thesis describes the development and the verification of a novel micro probe system for high accurancy downscaled Coordinate Measuring Machines (CMMs).Thesis (PhD)--University of South Australia, 2008.
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Du, Plessis Jan Harm. "An all-fibre laser distance measurement system utilising figure-eight fibre lasers with electro-optic amplitude modulation." Thesis, 2010. http://hdl.handle.net/10210/3417.
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M.Ing.The aim of this project is to research the feasibility of an all-fibre laser distance measurement device that utilises a figure-eight fibre laser (F8L), in the nonlinear amplifying loop mirror (NALM) configuration, as a light source and implements pulse compression to improve the accuracy and signal-to-noise ratio of the system. A figure-eight fibre laser in the NALM configuration for use in a laser distance measurement device is described. The theory of fibre lasers is discussed, including mode-locking and Qswitching, and the characteristics of a NALM loop are analysed. By varying the length of the NALM loop from 500 m to 2000 m or inserting highly nonlinear dispersion shifted fibre, a variety of pulses in the picosecond to nanosecond range can be produced. The lengths of the pulses depend on the length of the NALM loop, the pump power and the setting of the polarisation controllers. The figure-eight fibre laser is pumped with a 980 nm laser diode up to 550 mA, which corresponds to 320 mW. Distance measurements are done with short unmodulated and long modulated pulses. Distance measurement with short unmodulated pulses is discussed only briefly and tested with a simple experiment. The focus of this project is distance measurement with long modulated pulses. A low autocorrelated binary sequence is modulated onto one of the long pulses produced by the figure-eight fibre laser by an electro-optic amplitude modulator. The long pulse gives the proposed system a good signal-to-noise ratio (SNR), while the modulation improves the accuracy. A Barker code of length 13 is proposed as modulation code because of its good autocorrelation properties. The Barker code will improve the accuracy 13-fold, with a corresponding increase in SNR. An electro-optic amplitude modulator is used to implement the modulation. The modulated long pulse is then sent to a target. After reflection, the signal is detected and cross-correlated to obtain the time-of-flight for the pulse. The code generation and cross-correlation are implemented with an FPGA via VHDL programming. The distance to a target can be calculated by knowing the time-of-flight and the speed of light in the propagation medium. In this project the resolution, single-shot precision, accuracy, linearity, repeatability and maximum unambiguous distance of the proposed all-fibre laser distance measurement device are examined.
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Chien, Chih-Lin, and 簡志霖. "The Development of Optical Dynamic Gait Pressure Measuring System." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/yyms5d.
Full textAbstract:
碩士國立臺北科技大學
製造科技研究所
102
The main purpose of this research is to construct a low-cost optical dynamic gait pressure measuring system. The phenomenon of image deformation as well as the intensity uniformity is the key issue to the measurement system. The correction algorithms have been developed. A webcam is used to capture the measuring image and followed by image processing to obtain the gait pressure distribution information. This components used in this research are chosen from off-the-shelf components. The main structure is made by aluminum bar and acrylic. The webcam will catch the movement who walk on the measurement platform and the gait pressure will show on the image files. The image combines the color identify table to show the pressure measurement diagram. The size of foot pressure gait machine is 900 × 660 × 280 mm, the maximum measuring range is 840 × 600 mm and the resolution is 10.8 sensors/cm2.
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LV, CHENG-ZHANG, and 呂承璋. "Design of a multi-function optical power measuring system." Thesis, 1990. http://ndltd.ncl.edu.tw/handle/50802571780530239414.
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Lin, Ming-Shan, and 林明山. "Astigmatic Measuring Optical Measurement System Optimized Anti-drift Circuit." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/97096274583665083190.
Full textAbstract:
碩士中華科技大學
電子工程研究所碩士班
102
Optical Pickup Unit (OPU) is the main component of CD-ROM. It can be used to read data from CD. Because astigmatic pickup head have nanoscale measurement technology and milliarcsecond resolution, many high precision measurement system apply digital multifunctional DVD to do research as a key component. For example, Astigmatism-based Multi-functional Atomic Force Microscopes, Resonance frequency investigation system and astigmatic optical interferometer measurement…etc. Although optical pickup unit can have nanoscale measurement, small variety of environment temperature and mechanical stress can cause tiny deformation. These will cause the drift of measurement signal and reduce the degree of accuracy. Continuing drift will let the signal exceed the normal measurement range and interrupt system. Such drift can be compensating through Voice Coil Motor (VCM) and let the measurement maintain in reasonable region. These researches use the optimal circuit to realize auto alignment and Anti-drift Negative Feedback Circuit. It can reduce the drift phenomenon causing from environment, improve the OPU stability, keep the measurement in the steepest linear region, reduce the error and improve the working efficiency.
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Ma, Sheng-Ju, and 馬聖茹. "System for Measuring Optical Admittance of a Thin Film Stack." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/00338854950897065431.
Full textAbstract:
碩士國立中央大學
光電科學研究所
96
A new method based on polarization interferometry is demonstrated. An optical system is built to obtain the phase and magnitude of reflection coefficient, as well as the optical admittance at normal incidence. We use Twyman Green interferometer to induce phase difference between two beams which have orthogonal polarizations and the Fizeau cavity makes interference happen. The refractive index and thickness of single layer thin film can be analytically found without numerical fitting. In addition,, we can use numerical fitting to get the refractive and index, thickness for multilayer film stack. In this article, the validity of the above characteristics will be examined theoretically and experimentally. There are two parts in this study. The first part of the experiments is the framework and discussion and the second part is the second kind of framework and experimental results.
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Lyu, You-Ru, and 呂侑儒. "Implementation of Surface Characteristics Measuring System for Optical Thin Films." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/20711570854427585275.
Full textAbstract:
碩士逢甲大學
產業研發碩士班
94
We proposed a measurement system for the surface characteristics of the optical thin films including the relative surface flatness, thickness, surface contour and internal stress. The experimental technique was based on the Twyman-Green interferometry. The wavelets transform, gray-level co-occurrence matrix and entropy were used to evaluate the surface flatness. The proposed method can also be used for recognizing the human’s iris. In this thesis, we used the Wiener filter to reduce the noise of the image, then processed it by thinning interference fringes to recognize the shift of the fringe spacing and step height automatically. According to the spatial carrier frequency, we can use the fast Fourier transform to divide the information of the phase and the intensity. To reconstruct the surface contour, the curve fitting of coating surface was performed. After calculating the curvatures before and after film deposition, the stress of thin films can be determined by using the Stoney’s formula. We have developed a measurement system for evaluating the surface characteristics of optical thin films. This system has several advantages such as multi-function, accuracy and fast measurement.
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Lima, Bruna Cristina Sérgio. "Time-gated system for measuring optical parameters of dispersive media." Master's thesis, 2019. http://hdl.handle.net/10316/87832.
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Dissertação de Mestrado Integrado em Engenharia Física apresentada à Faculdade de Ciências e TecnologiaO objetivo deste projeto foi implementar e testar uma ferramenta capaz de mediras propriedades ópticas de meios turvos, baseada na aproximação de difusão. Esta técnica foi testada a partir de dados adquiridos com um sistema time−gated, atravésde uma geometria de transiluminação. A instrumentação implementada é baseada num dı́odo laser pulsado e numa câmera intensificada com gating. Foi desenvolvida uma ferramenta de ajuste de dados para medir as propriedades ópticas de uma amostra. Uma superfı́cie de um meio difuso é iluminada com um laser pulsado. Os perfis temporais dos pulsos, emergentes na superfı́cie oposta, são ajustados pela ferramenta desenvolvida, a um modelo teórico que descreve a propagação de luz para meios homogéneos difusos. Realizámos vários estudos com fantomas lı́quidos e sólidos.Estes fantomas foram criados de forma a reproduzir as propriedades ópticas detecidos biológicos e a satisfazer os requisitos inerentes à instrumentação utilizada.Foi medida a função de resposta do instrumento (IRF) do sistema time − gated,e esta foi tida em conta pela ferramenta de ajuste de dados experimentais. Em suma, o sistema e a técnica implementados foram capazes de medir o coeficiente de absorção e de dispersão reduzido destes fantomas. A partir dos resultados obtidos,podemos concluir que parece existir um posicionamento para o qual os detectores criados no plano da imagem apresentam um melhor desempenho. No entanto, esta afirmação não pode ser validada sem recorrermos a uma técnica de referência. As medições efectuadas mostram linearidade entre a variação do coeficiente de dispersão reduzido e a concentração de Intralipid presente nos fantomas. É detectado um efeito de redução nas medições do coeficiente de dispersão. Conclui-se que este efeito está relacionado com a presença de agar nos fantomas, como já tinha sido relatado em estudos publicados.
The goal of this project was to implement and test a diffusion approximation model-based technique capable of extracting the optical properties of turbid media - absorption and reduced scattering coefficients - using data obtained from a time-gated detection system, using a trans-illumination geometry. We implemented time-gated instrumentation based on a pulsed diode laser and a gated intensified CCD camera and developed a data fitting tool for measuring the optical properties of a slab. The measurement technique is based on the fitting of the temporal profile of the light pulses, acquired at the output of a medium, illuminated on the opposite face with a short laser pulse, with a theoretical light propagation model for homogeneous media. Several studies were performed using liquid and solid phantoms designed to mimic the optical properties of biological tissues and to satisfy the requirements inherent to the instrumentation used. The instrument response function (IRF) of the time-gated system was measured and took into account when fitting experimental data.The implemented system and technique was able to measure the absorption and the reduced scattering coefficient of the tested phantoms. From the results obtained, we can conclude that it seems to exist an optimal positioning of the detectors on the image plane, although this statement cannot be fully confirmed without using a reference technique to validate the accuracy of the technique. The measurements show linearity regarding the variation of the reduced scattering coefficient with the concentration of IL in the phantoms. It also detected an agar-related reduction of the scattering coefficient that was reported in similar published studies.
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Du, Pei-Qin, and 杜佩芩. "Design and fabrication of diffraction optical elements for stereoscopic measuring system." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/39156321494224890673.
Full textAbstract:
碩士國立中興大學
機械工程學系所
102
The Kinect is a stereoscopic sensor which can sense the depth and position information of objects. Its recording method is called the light coding. The principle is to project a light pattern with speckles into the space and generate different speckle distribution at each position in the space. That is to mark each position in the space. Generally, the Kinect stereoscopic sensor was used to capture body’s actions in game applications. Because the human body is of big range area, it doesn’t need high dense speckle patterns to capture body’s actions. However, if we want to apply the light coding technology to the high-precision measuring systems, it is necessary to increase the density of speckle so that the profile of objects can be measured more precisely. The purpose of this study is to design the phase-only binary diffractive optical element (DOE) which can generate speckle patterns with higher density. The algorithm for achieving this element is the same as that for designing a computer generated hologram (CGH). It adopts the Fourier transform and inverse Fourier transform to iteratively calculate the wavefront distribution between input plane (element plane) and output plane (diffractive plane) and sets different constrains in each plane. In the input plane, the amplitude of input wavefront amplitude was set to be 1 and the phase was binarized. In the output plane, the wavefront amplitude was changed into the goal pattern values. The phase among the whole calculating process was not changed. After several iterations, the diffractive pattern generated by the element after being calculated using the algorithm would be close to the goal pattern. It is called the iterative Fourier transform algorithm (IFTA). During the IFTA process, the goal pattern was made by Excel software to produce finer speckle distribution. The spot size of a speckle was 4?4 pixels. There are goal patterns of 400?400, 210?210, 1000?1000 pixel matrices designed with speckle spacing of 2, 3, and 5 pixels, respectively. The designed speckle patterns occupied only half area of the overall goal patterns. The reason is that the two-leveled quantified element would generate a conjugate image in the diffractive pattern. Both diffractive images finally constitute the whole speckle distribution. The designed goal patterns were substituted into the IFTA to count the phase mapping of the speckle elements. These calculated phase mappings were then sent into the spatial light modulation (SLM) for observing whether the diffractive patterns would compliance with the design or not. The designed CGHs were vectorized by the WinTopo software, modified by the AutoCAD software, and drawn into the photo masks. Finally, the speckle elements were fabricated by the technologies of photolithography and etching processes for verifying the properties. The original speckle element of the Kinect stereoscopic sensor can produce a diffractive light field with the dimension of about 68?54cm at the distance of 240cm from the element. The spacings between spots are from 0.6cm to 3cm. The elements designed in this study can generate the regular speckle pattern with the spot spacing of 0.7cm at the same distance. The result shows that the way to design the speckle element can indeed improve the spot density.
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Chang, Hsuan-Tzu, and 張軒慈. "Development of a Gear Measuring System by Diffractive Optical Element Technology." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/em8686.
Full textAbstract:
碩士國立中央大學
機械工程學系
105
Most of the traditional gear measurements use contact probes, but such contact measurements are restricted by a number of factors, including, but not limited to probe sizes, gear materials and measuring speeds. Therefore, an innovative optical measuring technology is developed by this research for gear measurements, during which, the laser beams are projected to the surface of the gear to be measured by diffractive optical elements (DOEs), while CCDs are used to capture the resulting images for analysis in order to determine the errors for gear topography, tooth profile and lead. The measuring system developed by this study uses the images captured by two CCDs to perform calibrations, alignments and corrections, and a 3D coordinate system is established, from which, the coordinate values for the laser beams projected by the DOEs on the surface of the gear is determined. In order to determine the accuracy of the measuring system developed by this research, the measurement data obtained by 3D measuring devices are used as the reference and its corresponding distribution pattern is established. The perpendicular distance between a coordinate value of laser beam projected on the surface of the gear and the distribution pattern is determined. The distribution pattern of the data generated from such distance determination is established and compared with an ideal distribution in order to determine the errors for gear topology, gear profile and lead. The results of experiments show that the accuracy of the system developed by this research is up to 0.0651mm, which confirms the reliability of the system for 3D gear surface measurement. It is expected further improvement of DOEs and CCDs may enhance the resolution of the measuring system to satisfy the requirements for industrial use. The technology developed by this research is an efficient non-contact optical measurement system for gears, which performs comparisons against ideal values and determine errors by using DOEs, laser projections, the images captures by CCDs, computer vision and the corresponding distribution patterns of data obtained.
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Lung, Chun-Lin, and 龍俊霖. "Stereoscopic measuring system based on the holographic optical element and spatial frequency." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/94242586424354668933.
Full textAbstract:
碩士國立中興大學
機械工程學系所
101
This study replaces the two-dimensional diffractive optical element (DOE) of the Kinect stereoscopic sensor with the holographic optical element (HOE) for achieving the optical projection with uniform distribution and uses the dependence of object depth on the spatial frequencies of laser speckle distribution to propose a novel stereoscopic measuring system configuration. In comparison with the commercial Kinect stereoscopic sensor which adopts the two-dimensional DOE and generates a distorted optical projection, this system can provide uniform optical projection according to the measuring target of specific distribution with the HOE features of binarization and free-form surface. First, the HOE was divided into nine divisions. The optical design software was used to the optimization of the coefficients of the phase polynomial in each division for obtaining the uniform optical projection and aberration correction. The curve-fitting was then adopted to generate the photo mask pattern design. The photolithography and etching technologies of processes were applied to the device fabrication. Furthermore, the fabricated HOE was combined with the optical speckle component. It was verified by using the infrared laser light source of wavelength 808 nm to realize the optical projection in accordance with the distribution of the optical simulation result. Finally, the projected image with speckles was converted by the fast Fourier transform (FFT) to get the spatial frequency distribution. The results show that the distribution will be corresponsive to the change of object depth. The measuring accuracy can be at least less than 3.3 cm. It demonstrates the concept of the novel stereoscopic measuring system.
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林漢傑. "Optical Coating Design and Measuring System Development for Anti-Blue Light Ophthalmic Lens." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/jk4jhg.
Full textAbstract:
碩士逢甲大學
光電能源與視覺科技碩士在職專班
104
We present the spectra measurement analysis and optical coating design of anti-UV and anti-blue light ophthalmic lens by using the Macleod optical thin film design software. Two design cases of (MgF2 /TiO2)xMgF2 and (SiO2/Ta2O5)xSiO2 multilayer coatings are compared with commercial anti-Blue light lenses. The multilayer structures use a non-quarter wavelength design with 15-layer and 23-layer film stacks. The results show that the 23-layer design of (MgF2/TiO2)11MgF2 multilayer can meet the market requirement for anti-UV bandwidth. For the anti-blue light measurement system, the spectral response region of the photo detector in the 320 nm to 1100 nm, that is visible to near infrared region. The measurement system composed by three units, it consists of a transmitting circuit, a receiving circuit and a signal processing circuit. The proposed system can measure the wavelength range of 400 nm ~ 700nm, the working voltage of 5V. After completion of the system development, the wavelength of 470 nm blue-light passing through the anti-blue light ophthalmic lens was used to measure the transmittance to verify the anti-blue light ophthalmic lens performance.
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WANG, ZE-YAN, and 王澤彥. "Design of optical system for measuring thickness and refractive index of transparent plate." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/zutbb5.
Full textAbstract:
碩士國立中正大學
機械工程系研究所
105
In this thesis, we design a novel optical system for simultaneously measuring the thickness and the refractive index of a transparent plate with two optical paths. In the structure of the proposed optical system, the light beam emitted from a laser light source passes through a mounted calcite beam displacer, which split laser into two separate polarizing light beams. The two light beams are then passed through two beam splitters (BSs), a triplet achromatic lens, and a transparent sample, and incident on a first reflective mirror surface. The two light beams reflect into a polarizing beam splitter (PBS) and separate into two optical paths to two CCDs, respectively. The centroids of laser spots on the sensors would change when the thickness d or refractive index n of sample is changed. To determine the measurement of the thickness and the refractive index of the transparent sample, the two optical paths are combined using a self-written signal processing algorithm in order to achieve a rapid measuring capability and a high measuring accuracy. The proposed optical system is based on astigmatic methods with a simpler structure and lower cost. Also, we verify the feasibility of the proposed optical system with qualitative and quantitative analysis respectively. In the qualitative analysis, the architecture of the proposed optical system is established in the optical simulation software ZEMAX to observe the characteristics of the proposed optical system. In the quantitative analysis, to accurately and efficiently analyze the relation between light spot position information and the individual thickness d and the refractive index n, the laser beam progression in the proposed optical system is tracked using a homogeneous coordinate transformation matrix and the skew-ray tracing method. Finally, the validity of the proposed optical system was verified by means of a laboratory-built prototype compareing with the commercial instrument, the measured errors of the thickness d and the refractive index n for the proposed optical system are less than 0.019% and 0.007%, respectively, with the transparent plant (thickness of 2 mm).
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Hsueh-LiangHuang and 黃學良. "Development of a high precise optical measuring system for the linear moving stage." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/73494086487842801276.
Full textAbstract:
博士國立成功大學
工程科學系碩博士班
98
In recent years, the linear moving stage is a main part of the high precise equipment. Because of the increasing requirement of precise equipment and the improvement of the manufacturing precision, the research of measurement systems for linear moving stages has become a main task. The errors of multi-degree-of-freedom for linear moving stages are always caused by the assembling process and component qualities. Thus, the researches based on the errors of multi-degree-of-freedom and on the measurement of component quality are developed at the objectives of high accuracy, high efficiency and low cost. In the multi-degree-of-freedom measurement, the researches focus on measuring the multi-degree-of-freedom errors of the linear moving stage. The three measuring systems based on multi-degree-of-freedom errors measurement for the linear moving component have been proposed, such as (a) a three-degree-of-freedom laser linear encoder for error measurement of a high precision stage, (b) a high resolution three-degree-of-freedom motion error measuring system for a single-axis linear moving stage and (c) a DVD pickup-based four-degree-of-freedom motion error measuring system for a single-axis linear moving stage. The proposed systems can be applied for measuring linear motion errors of linear guideways, CMM, machine tools, high precision X-Y stage and etc. in the future. In the quality measurement, the research is developed for measuring the quality of ballscrews which is one of the key components of linear moving stages, and a novel laser-based measuring system for the thread profile of ballscrews has been proposed. The proposed system can be applied for manufacturing process and for matching up the traditional contact method. The proposed system also exhibits some advantages, such as real-time, high-speed and high precision. The proposed method based on optical design, signal process and mathematical analysis can be used not only for measuring the linear motion equipment of precision machines, electro-optical and semiconductor industry but also for improving the development ability for both the technology and the equipment of high precision measurement.
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Chen, Jyun-yu, and 陳俊宇. "Design and Verification of Diffuse Optical Measuring System Assisting in X-ray Mammography." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/19508158159776962698.
Full textAbstract:
碩士國立中央大學
光機電工程研究所
98
This study is to develop a diffuse optical measuring instrument to be incorporated with an X-ray mammography system for the aid of obtaining functional images to detect breast tumors. It is expected to use the dual modality imaging system for enhancing the diagnosis of breast tumors. In this thesis, a dual-direction scanning device to project illuminated NIR light with a multiple-channel switching for both sources and detectors was designed and constructed. The device is handled to compress breast-like phantoms by two slabs to shorten the distance between sources and detectors that may enhance the detection of system. Thus the measured intensity and even phase are used to reconstruct optical-property images. For obtaining reliable measurement data, a two-phase procedure was employed to calibrate each detection channel of the system. Three types of inhomogeneous phantoms by varying contrast, size and location of inclusions to background were prepared and tested to investigate the differentiation of measured NIR power with using the constructed instrument. As known, the mammography and the diffuse optical tomography are based upon various physics models, the former using X-ray to distinguish density, and the later using NIR to tell between different optical properties of tissues. Matrix-type phantoms were made and tested by a mammographic system and our constructed diffuse optical measuring instrument respectively to justify the dual-modality imaging system.
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Chen, Jian-Hong, and 陳建宏. "Design/Implementation and Verification of NIR Electro-optical Measuring System for Medical Application." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/01468186713894498394.
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碩士國立中央大學
機械工程研究所
93
This thesis describes the design, implementation and verification of the near infra-red (NIR) diffuse optical tomography electro-optical measuring system which uses single rotating source/detector scanning mechanism and is suited for the purpose of medical diagnostics. The fibers connected to the source and detector are driven by stepping motors to achieve scanning operation. Therefore, the measuring system based on rotational motion possesses a high degree of spatial flexibility. The data acquisition system is based on continued-intensity scheme to acquire output radiance signals. System verification is performed using both homogeneous and heterogeneous phantoms. Judging form the measured results, this measuring system is able to differentiate the optical properties which are different in the homogeneous and heterogeneous phantoms. Normalization processes such as input power are also presented. Moreover, both simulated radiance power and reconstructed optical-property image are performed using the modified Beer-Lambert law and back projection imaging method, respectively. The obtained image is comparable to the reconstructed image using the finite element inverse computation scheme.
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CHEN, CHUN-LIN, and 陳俊霖. "Optical interference system for measuring thickness and refractive index of slim transparent plate." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/7z3b5j.
Full textAbstract:
碩士國立中正大學
機械工程系研究所
107
In this thesis, we design a novel optical interference system for measuring thickness and refractive index of slim transparent plate with two optical paths. In the structure of the proposed optical system, the laser beam passing through the sample is affected by the thickness and refractive index , which causes a change in the optical path difference from the reference beam and the measuring beam to the sensor, and then calculate sample parameters (refractive index n, thickness d) by using the different optical path difference variations of two optical paths. Also, we verify the feasibility of the proposed optical system with qualitative and quantitative analysis respectively. In the qualitative analysis, the architecture of the proposed optical system is established in the optical simulation software ZEMAX to observe the characteristics of the proposed optical system. In the quantitative analysis, to accurately and efficiently analyze the relation between interference fringe information and the individual thickness d and the refractive index n, the optical path difference is calculated by interference fringe.
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Chen, Kuan-Lung, and 陳冠龍. "The Building up of High Contrast Image for the Optical Foot Pressure Measuring System." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/88n2je.
Full textAbstract:
碩士國立臺北科技大學
製造科技研究所
99
This study is focusing on developing a high contrast image of an innovated optical foot pressure measuring system. Once the high contrast image has been captured, the foot pressure information can be read out easily. There are three parts taken in this study. The first is the optical foot pressure measuring system construction. The resulting system is only 105mm height. The second is the high contrast image taken while the background is white and the area with pressure is black. The resulting quality indication value of the contrast image can reach q=2.176. The third is the high contrast image taken while the background is black and the area with pressure is white. The resulting quality indication value of the contrast image can reach q=12.167. Moreover, the double reflection image caused by the bottom mirror can be limited by this black background design.
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FA-HSUAN, CHU, and 朱法軒. "Development of an Optical Inspection System Used for Measuring Dimension of Bonded Microfluidic Chips." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/6wuvc6.
Full textAbstract:
碩士國立臺灣科技大學
機械工程系
106
This study aims to develop an automated optical inspection system for measuring microchannel dimension. Research about microfluidic chip has flourished in recent years. There will be more and more related products which are important for dimension appearing. Therefore we developed a non-destructive and non-contact measurement for bonded microfluidic chip to verify whether the microchannel dimension meets the tolerance specification. The data measured with measurement system we’ve developed is compared with the reference value measured with toolmaker microscope. The error obtained after comparing reaches ± 2 %.
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Chang, Jiun-Yao, and 張軍堯. "Establishing the optimal process of tooth color measuring with the Munsell Color System and three tooth color measuring machines." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/96651702175691378785.
Full textAbstract:
博士高雄醫學大學
牙醫學研究所
101
As we pay increasing attention to dental aesthetics, tooth color matching has become an important part of daily dental practice. But measuring tooth color with dental shade guides by human eyes is not stable because of the inadequate design of the dental shade guide and the poor reliability of human eyes. The tooth color measuring machines provides another choice when dentists make the shade selection, but the accuracy of these machines is still controversial. The aim of this study is to combine the usage of the proper tools and conclude method which enhances the accuracy of tooth color measuring. The Munsell color tabs within the range of natural human teeth color were measured by three tooth color measuring machines (ShadeEye NCC, VITA EasyShade, DeguDent Shadepilot). The results showed when Chroma was higher than 6, and Value was lower than 4, the mean ΔE measured by ShadeEye NCC was significantly higher than the clinical acceptable range. When Hue located in 7.5YR and 10YR,Value was higher than 7, the mean ΔE measured by EasyShade was significantly higher than the clinical acceptable range. The measuring results of Degudent Shadepilot showed no significant different with Hue, Chroma, and Value, but when Hue located between 10YR to 10Y, Value located between 5 to 7 and Chroma was 2 and 6, Degudent Shadepilot showed better accuracy. As we know the limit of each dental color measuring machine by the procedure in this study, we could combine the usage of each machine and help us to achieve the optimal tooth color measuring result in daily dental practice.
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Shen, Wen-Chon, and 諶文中. "The characteristics measuring of the microbending optical fiber sensor system and applications on human physiology." Thesis, 1996. http://ndltd.ncl.edu.tw/handle/04944112495622398742.
Full textAbstract:
碩士國立臺灣大學
電機工程研究所
84
The fiber-optic-based sensor has excellent characteristics including small size, light weight, electromagnetic wave interference-immunity, high sensitivity, etc. Hence, the fiber- optic-based sensor is quite suitable for biomedical signal measurement. The microbending fiber-optic sensor, based on the intensity modulation, is valuable to medical applications due to its simple mechanism, good performance on electric safety, electromagnetic wave interference-immunity and high sensitivity. The long term purpose of our project is to develop an microbending optical fiber system, and to detect weak physiological signals, such as heart sound. In the present study , we tried to establish a multi-mode microbending fiber-optic sensor system, and made a profound investigation about it. There are five parts in our experiment : designing and manufacturing the microbending deformer and developing the system, statistical measurement, measuring noise in the system, dynamic measurement an on on human. The results of our experiments are not bad, and we can know that the sensor is a low pass sensor. The applications on human, including the vibration of the chest and the glottis, are not bad,too. What we need to do for improving the system is to enhance the stability of the system and to decrease the noise. In the future, based on the results of our experiment, we hope to enhance the whole system configuration to make it more suitable for detecting physiological signal.
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Lin, Bo-Jian, and 林伯堅. "Evaluation of Patients Bearing Medial Knee Joint Osteoarthritis by Using Optical Foot Pressure Measuring System." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/50288012013296206553.
Full textAbstract:
碩士中原大學
生物醫學工程研究所
105
The purpose of this study is to measure plantar dynamic and static parameters, to build a model to predict knee osteoarthritis, and to discuss changes of foot pressure parameters associated with degenerative arthritis. 30 patients with medial knee osteoarthritis were enrolled to the experiment group while 35 non-symptomatic healthy individuals were enrolled to the control group. The present study used the optical foot pressure measurement system to collect the path of the center of foot pressure in the gait cycle, to measure the travel time and offset angle of plantar pressure changes between gait cycle, and to estimate the static pressure of the plantar six districts along with the measurement of other clinical parameters and information. The results show that the mid-stance phase time of the left foot of osteoarthritis patients (0.20 seconds) is significantly longer than that of the control group (0.12 seconds) (p<0.05), and yet the mid-stance phase time of the right foot of osteoarthritis patients (0.19 seconds) is also significantly longer than that of the control group (0.15 seconds) (p<0.05). The individuals in the control (healthy group) prefer early toe-off in terminal stage of gait cycle and the toes used less force to finish the gait cycle. The center of pressure progression of the individuals in the control group is biased toward the big toe, while that of the osteoarthritis group tends to be biased toward the second toe. At the terminal stage of gait cycle, the metatarsal head stress distribution of osteoarthritis group tends to move to big toe, and the individuals in the control group tend to move to fifth toe. The independent-samples t-test compared the means of pressure of six districts regions of plantar area between two groups. It was found that the left foot medial longitudinal arch area, the lateral heel region and the inner heel region of the control group are significant different. The statistics of the modified balance line also showed obvious differences in the left side of the foot, but the right side of the foot was not statistically significant. This finding may be related to pain compensation of standing posture. SPSS was used to reduce three variables of the foot pressure in the six districts regions using the principal component analysis, and then mid-stance phase period, body mass index and center of pressure excursion index variables were included for logistic regression model. The analysis resulted in 90% of the positive predictive logistic regression and a negative predictive value of 88.6% indicating that the static and dynamic plantar pressure variables are statistically different between two groups. Therefore, it is concluded that the optic foot pressure measuring system combined with physical measurements of body height and weight measurements can predict whether the individual is bearing medial knee osteoarthritis or not.
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Chen, Yi-Chi, and 陳翊齊. "The Study on Protein Dynamic Measuring System With Optical Fiber Based on Surface Plasmon Resonance." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/84878701852713250752.
Full textAbstract:
碩士銘傳大學
電子工程學系碩士班
101
Optical fiber Surface Plasmon Resonance (SPR) sensors have high sensitivity, compact size, remote-detectable and easily-fabricate advantages with less vulnerable to environmental interference. Such sensors can be applied for the biological molecules detection of enzymes, antigens, antibodies, proteins, and other micro substances in the biological medicine realm. In the study, we made the optical fiber SPR sensors by side-polished method to measure the bovine serum albumin and build the dynamic measuring system. We use sulfide to modify the thin gold film surface on optical fiber sensor to enhance the protein bonding. To verify the SPR performance of the device, we measured the resonance wavelength moved from 621.8nm to 637.2nm by OSA (Optical Spectrum Analyzer), changed 15.4nm. The variation is 4.9%. We also use popular molecules detection instrument (QCM, Quartz Crystal Microbalance) in the market to measure the same protein bonding. The resonance frequency changed from -3074.8Hz to -3155.3Hz (based on 900 KHz). The variation is 0.15%. In this study, our dynamic measuring system can identify an around 400mV voltage change after protein bonding. The variation is 10.05%., the change rate of our dynamic measuring system is twice and 67 times than the previous two detection methods respectively. Obviously, our measuring performance is better. In addition, our dynamic measuring system can get 10 data per second, far faster than the OSA and QCM measurement. Because of dropping expensive OSA and QCM, which need long measuring time, we use lower-cost LD and PD. So it should have commercializing potential.
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Lin, Kuan-yu, and 林冠宇. "Optical triangular measurement system for the study of measuring the surface curvature of the lens." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/66761218918936850642.
Full textAbstract:
碩士國立中央大學
照明與顯示科技研究所
101
This paper applies laser structure light to measure 3D lens surface curvature , The aim is to develop a cheaper as well as quick measurement of the non-contact measurement method, using program to monitor the shape changes of the laser rays on the lens surface . Take advantage of optical measurement, the system is non-destructive, non-contact, quick and easy to set up. Compared with the shade law of the measurement, laser light can do the long distances measurement, which intensity is more strength and the constraints of the distance and the space is relatively small. Optical Triangular Laser detection system of lens includes a special acrylic-made platform, a one dollar coin, red structure laser light, a CMOS image sensors, two lenses and PC. The resolution of CMOS image sensor is 640*480 pixel sizes and per second 30 frame. CMOS image sensor captures video information into MATLAB for analysis, converts the video into image frames, makes image binarization, laser triangulation method, optical centroid, and then we analyze the pixel as the principles. Therefore we can know the initial distribution of the laser line on the lens surface. And through the optical triangulation principle and the correction of resolution, we can get the real position and the real size of the lens from the horizontal direction view. Finally, matlab fit the curve we get above and calculate the radius of curvature as well as do 3D lens surface plots, and complete the lens measurement.
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Li, Jiun-Wei, and 李俊瑋. "Study on the Measurement Accuracy of Optical Coordinate Measuring System with a Single Vertical Moving CCD." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/95283474792976922313.
Full textAbstract:
碩士大同大學
機械工程學系(所)
98
n this research, a revised similar triangle algorithm based upon the pinhole imaging principle was proposed to establish a 3D optical measurement system with a vertical moving CCD. Although the algorithm can be applied to obtain 3D-information by using simple linear relationships, the precision of measurement can’t achieve an anticipative target. In this study, methods to correct the perpendicularity of the optical axis, enhance the resolution of capture image, and a statistics analysis method were proposed to improve measurement accuracy the measuring system. The experimental results show that the correction y the perpendicularity of the optical axis and the enhancement of capture image resolution can not improve the measurement accuracy, especially Z coordinate values of data. The statistics analysis method can be used to overcome the error due to hardware and to improve the measuring accuracy.
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CHEN, Yan Hua, and 陳彥華. "The study of a precise optical measuring system for the detection of wear of grinding wheel." Thesis, 1997. http://ndltd.ncl.edu.tw/handle/42634171765114135139.
Full textAbstract:
碩士國立臺灣大學
機械工程學系
85
In this research,image processing theory andtechnology are implemented to develop a preciseoptical measuring system for the detection of wear ofgrinding wheel. Thesholding,edge detection( LoGmask)and subpixel technologies are applied to find outthe edge of grinding wheel.A mask for cameracalibration is proposed to calibrate the dimension ofCCD image and the lens distortion. It can help to solvethe relationship between pixel coordinate and worldcoordinate.An index is then followed to judge whetherthe grinding wheel profile is necessary for grinding process.This optical measuring system is conductedsuccessfully for this project.
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Liu, Yu-jie, and 劉雩潔. "The Study of the Measurement Accuracy of 3D Optical Coordinate Measuring System with a Single Camera." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/13412948143007024044.
Full textAbstract:
碩士大同大學
機械工程學系(所)
99
In this research, a revised similar triangle algorithm based upon the pinhole imaging principle is proposed to conduct a 3D optical measurement system with a vertical moving camera, The algorithm can be applied to obtain 3D-information by using simple linear relationships, in the beginging ,the measurement results can’t achieve the desired value of z coordinate values. By using the tiangle algorithm , the relationship of the height of the object can be infered. This study focus on the datas which is collected from the position on the target that we interest in, at the mean time, the accuracy can be improved by using these datas to find the main factor that effecting the measuring result.