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Dissertations / Theses on the topic 'Camber angle'
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Karanja, Bethuel, and Elin Skoog. "Experimental investigation of rolling losses and optimal camber angle." Thesis, KTH, Maskinkonstruktion (Inst.), 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-201599.
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This Bachelor thesis project is an experimental investigation of the effect of camber and toe angles on rolling resistance. The experiments are done on Sleipner, a Prototype car made by KTH students, which takes part in the Shell Eco Marathon competition in Rotterdam. In order to succeed in the competition it is crucial to reduce energy losses in order to get an as energy efficient vehicle as possible. The experiment involves tests where Sleipner is manually dragged across a flat floor and its position and the dragging force are logged with a pulse encoder and a load cell respectively. This is done ten times for each chosen wheel alignment (specific camber and toe angle), in order to be able to find the optimal setting with respect to minimization of rolling losses. The tests are performed in the Integrated Transport Research Lab at KTH. The obtained data is then used to calculate the magnitude of the rolling friction.It is found that the more negative the camber angle, the larger the rolling resistance. The smallest camber angle investigated is -3º which gives a coefficient of rolling friction (Cr) of 0.0052. The second camber angle is -5º giving a Cr value of 0.016 and the largest camber angle is -7º giving a Cr value 0.019. It was also found that, with the minimum camber angle, toe out gives a larger coefficient of rolling resistance than toe in; 0.0081 compared to 0.0052.The report also delves into additional effects of camber and toe angles on the vehicle’s behaviour while driving and it is found that negative camber angle gives better stability in the car when cornering and that toe in gives better stability in straight line driving.With these results it is concluded that Sleipner should have a slight camber angle of -3º and toe in of 0.5º so as to have the best results in the Shell Eco Marathon.Detta kandidatexamensarbete i maskinkonstruktion är en experimentell undersökning av hur camber och toe- vinkeln påverkar rullmotstånd. Testerna är gjorda på Sleipner, ett fordon utvecklats av studenter på KTH, som tävlar i Prototyp-klassen i Shell Eco Marathon som hålls i Rotterdam i maj. För att få ett så energisnålt fordon som möjligt är det naturligtvis av största vikt att minska alla olika typer av förluster så mycket som möjligt. En stor del av dessa förluster är förluster som sker för att överkomma rullmotstånd, som i sin tur är beroende av många olika faktorer. Målet med undersökningen var att kunna ge en rekommendation på den optimala vinkelinställningen på Sleipner inför årets tävling.Testerna som bedömdes ge det bästa resultatet var dragtest, då Sleipner drogs med handkraft över ett platt golv. Dragkraften registrerades med en kraftgivare fastsatt centrerat på ramen och en pulsgivare på bakaxel registrerade positionen. Den data som registrerades användes för att kunna räkna ut storleken på rullmotståndet. För varje vald inställd vinkel, både camber och toe, så drogs Sleipner tio gånger över golvet, fem gånger i varje riktning. Detta för att kunna räkna ut medelvärden och på så sätt minska osäkerheten i resultaten. Alla tester utfördes i Integrated Transport Lab på KTH.Resultaten visade att ju större negativ camber vinkel, desto större blev rullmotståndet. Den minsta camber vinkeln som undersöktes var -3º, vilket gav en rullmotståndskoefficient (Cr) på 0.0052. Nästa camber vinkel som prövades var -5º, vilket gav Cr till 0.016 och den sista vilken var -7º och det resulterade i Cr-värde på 0.019. När den bästa camber vinkeln funnits, så utfördes tester med toe out, vilket visade att toe out gav ett större värde på rullmotståndet än toe in, Cr på 0.0081 jämfört med 0.0052.Rapporten behandlar vidare andra effekter av camber och toe-vinklar, såsom inverkan på fordonet under körning. Det visar sig att negativ camber vinkel ger bättre stabilitet, speciellt vid kurvtagning, och toe in ger bättre stabilitet vid körning rakt fram. Med de resultat som erhölls resulterade i en rekommendation på att Sleipner skulle ha camber vinkel på -3º, och toe in på runt 0.5º för att kunna uppnå bästa resultat i tävlingen.
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Lego, Zachary Michael. "Analysis of High Angle of Attack Maneuvers to Enhance Understanding of the Aerodynamics of Perching." University of Dayton / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=dayton1355101333.
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Kroliczek, Václav. "Konstrukční návrh zavěšení předních kol závodního automobilu." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2017. http://www.nusl.cz/ntk/nusl-318525.
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This work deals with design of front trapezoidal suspension for racing car Škoda 130RS. The first part describes types of current suspensions and provides a review of important suspension parameters that have great influence to vehicle handling. The second part deals with kinematic analysis existing suspension, its modification and design of new type.
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Vojtěšek, Aleš. "Měření odklonu kola během jízdy." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2015. http://www.nusl.cz/ntk/nusl-231779.
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The subject of this master's thesis is design measurement and measure change wheel camber angle during driving. For this task were used parts from Corrsys-Datron and remaining elements needed to be manufactured. With complete system measurements were done and outputs data were displayed by Matlab and evaluated. Based on data evaluation is possible exactly determine relative position of the wheel to the road surface and to the body of vehicle.
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Vajdák, Martin. "Návrh souboru zařízení pro seřízení podvozku závodního automobilu." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2017. http://www.nusl.cz/ntk/nusl-318805.
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Diplomová práce se zabývá návrhem zařízení pro měření parametrů podvozku závodního vozidla (sbíhavost/rozbíhavost, příklon/odklon, světlá výška vozu, rozložení hmotnosti), které následně slouží pro jeho seřízení. Úvodní teoretická část uvádí přehled nejdůležitějších parametrů podvozku, které mají podstatný vliv na chování a ovladatelnost vozu a které jsou tak nejčastěji předmětem zájmu. Následující kapitola shrnuje metody a zařízení, které se dnes pro měření parametrů podvozku využívají a uvádí jejich výhody a nevýhody. Předposlední kapitola teoretické části je věnována obecným doporučením pro měření parametrů podvozku vozidla a jeho seřizování. Poslední kapitola teoretické části uvádí požadavky na zařízení, jehož návrh je předmětem této práce. Úvod praktické části práce je věnován popisu konstrukce dvou navržených variant pro měření parametrů podvozku vozidla. Následující kapitola pak popisuje přípravu a průběh měření s využitím navržených souborů zařízení. Další kapitola je věnována výběru snímačů a zařízení pro měření. Závěr této kapitoly pak shrnuje přibližné celkové náklady na výrobu obou navržených variant. Poslední kapitolou je napěťová a deformační analýza navržené podpěry automobilu, která podepírá automobil namísto jeho kol. Závěr diplomové práce shrnuje dosažené cíle a zároveň uvádí návrhy a doporučení dalšího vývoje navržených zařízení.
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Šťáva, Martin. "Návrh závodního vozidla kategorie T1." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2019. http://www.nusl.cz/ntk/nusl-401488.
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This diploma thesis deal with conceptual design of racing car of T1 category. Car consist of tubular frame, front and rear double wishbone suspension, braking system and conceptual design of the fairing. These are the basic of this thesis. For the completeness of the design, the location of the crew and the placement of the components inside the frame are also proposed. Adams Car 2016, Autodesk Inventor 2016, Ansys Workbench 18.1 were used for designing, testing, simulation and calculations. Designed T1 category race car meets International Automobile Federation (FIA) technical standards and safety regulatons.
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de, Laval Astrid. "Online Calibration of Camera Roll Angle." Thesis, Linköpings universitet, Datorseende, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-94219.
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Modern day cars are often equipped with a vision system that collects informa- tion about the car and its surroundings. Camera calibration is extremely impor- tant in order to maintain high accuracy in an automotive safety applications. The cameras are calibrated offline in the factory, however the mounting of the camera may change slowly over time. If the angles of the actual mounting of the cam- era are known compensation for the angles can be done in software. Therefore, online calibration is desirable. This master’s thesis describes how to dynamically calibrate the roll angle. Two different methods have been implemented and compared.The first detects verti- cal edges in the image, such as houses and lamp posts. The second one method detects license plates on other cars in front of the camera in order to calculate the roll angle. The two methods are evaluated and the results are discussed. The results of the methods are very varied, and the method that turned out to give the best results was the one that detects vertical edges.
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Chaura, Václav. "Přestavba zavěšení předních kol automobilu." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2019. http://www.nusl.cz/ntk/nusl-400428.
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This diploma thesis is focused on the design of the conversion of the car front suspension for racing purpose. Existing suspension solution is described by analyse static and kinematic quantities. Furthermore, a change of suspension is proposed to improve the driving characteristics of the vehicle, where the kinematic, dynamic and strength analysis of the newly designed suspension is performed. The conclusion summarizes the comparison of the original and the new suspension design.
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Knobel, Christian. "Optimal control allocation for road vehicle dynamics using wheel steer angles, brake, drive torques camber angles." Düsseldorf VDI-Verl, 2009. http://d-nb.info/992593425/04.
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Higham, David William. "Extracting field hockey player coordinates using a single wide-angle camera." Thesis, Sheffield Hallam University, 2018. http://shura.shu.ac.uk/21925/.
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Desenfans, Philip. "Aerodynamics of the Maple Seed." Aircraft Design and Systems Group (AERO), Department of Automotive and Aeronautical Engineering, Hamburg University of Applied Sciences, 2019. http://d-nb.info/1204982848.
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Purpose - The paper presents a theoretical framework that describes the aerodynamics of a falling maple (Acer pseudoplatanus) seed. --- Methodology - A semi-empirical method is developed that provides a ratio stating how much longer a seed falls in air compared to freefall. The generated lift is calculated by evaluating the integral of two-dimensional airfoil elements using a preliminary falling speed. This allows for the calculation of the definitive falling speed using Blade Element Momentum Theory (BEMT); hereafter, the fall duration in air and in freefall are obtained. Furthermore, the input-variables of the calculation of lift are transformed to require only the length and width of the maple seed. Lastly, the method is applied to two calculation examples as a means of validation. --- Findings - The two example calculations gave percentual errors of 5.5% and 3.7% for the falling speed when compared to measured values. The averaged result is that a maple seed falls 9.9 times longer in air when released from 20 m; however, this result is highly dependent on geometrical parameters which can be accounted for using the constructed method. --- Research limitations - Firstly, the coefficient of lift is unknown for the shape of a maple seed. Secondly, the approximated transient state is yet to be verified by measurement. --- Originality / Value - The added value of this report lies in the reduction of simplifications compared to BEMT approaches. In this way a large amount of accuracy is achieved due to the inclusion of many geometrical parameters, even though simplicity is maintained. This has been accomplished through constructing a simple three-step method that is fundamental and essentially non-iterative.
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O'Brien, Gillian. "Lord Camden in Ireland, 1795-8 : a study in Anglo-Irish relations." Thesis, University of Liverpool, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.269615.
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Holgersson, Jakob. "Camera impact on social impact games : Top down, third person and immersion." Thesis, Högskolan i Skövde, Institutionen för informationsteknologi, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:his:diva-13259.
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Raddatz, M., and H. J. Schönfeldt. "Ejection and impact angles of saltating particles measured with a high-speed camera." Universität Leipzig, 2010. https://ul.qucosa.de/id/qucosa%3A16374.
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3D and 2D trajectory data of sand grains saltating over a bed are presented from highspeed camera measurements. They were obtained at Zingst peninsula and in laboratory using a wind tunnel. Trajectories, calculated with a Runge-Kutta procedure, using values of the mean wind profile and the air flow were fitted to the measured ones. The trajectory with the lowest RMSE against the measured one was used to estimate the
grain diameter of the saltating grain. Also ejection and impact angle, ejection and impact speed of the grain were determined. The results confirm earlier findings that ejection angles decreases with increasing grain diameter. Ejection angles between 57° and 27° for fine (63-200 μm) and middle (200-630 μm) ejecta and between 38° and
20° for coarse grains (630-2000 μm) were found. The impact angle β increases with increasing grain diameter. Impact angles between 8° and 15° for fine impactors and between 12° and 36° for middle and coarse grains were found. Additionally the ratio between the mean ejection angle α and mean impact angle β, which decrease with
increasing grain diameter (Rice et al., 1995), could be confirmed. The ration between the ejection speed ue and impact speed ui was found nearly the same for all determined grain sizes, but the grains ejected from the bed had an average speed of one order of magnitude less than the impact speed.
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Fornasier, Sonia. "Mission Rosetta : caractérisation scientifique de la "Wide angle camera" et étude physique des petits corps du système solaire." Paris 7, 2002. http://www.theses.fr/2002PA077084.
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Algers, Björn. "Stereo Camera Calibration Accuracy in Real-time Car Angles Estimation for Vision Driver Assistance and Autonomous Driving." Thesis, Umeå universitet, Institutionen för fysik, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-149443.
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The automotive safety company Veoneer are producers of high end driver visual assistance systems, but the knowledge about the absolute accuracy of their dynamic calibration algorithms that estimate the vehicle’s orientation is limited. In this thesis, a novel measurement system is proposed to be used in gathering reference data of a vehicle’s orientation as it is in motion, more specifically the pitch and roll angle of the vehicle. Focus has been to estimate how the uncertainty of the measurement system is affected by errors introduced during its construction, and to evaluate its potential in being a viable tool in gathering reference data for algorithm performance evaluation. The system consisted of three laser distance sensors mounted on the body of the vehicle, and a range of data acquisition sequences with different perturbations were performed by driving along a stretch of road in Linköping with weights loaded in the vehicle. The reference data were compared to camera system data where the bias of the calculated angles were estimated, along with the dynamic behaviour of the camera system algorithms. The experimental results showed that the accuracy of the system exceeded 0.1 degrees for both pitch and roll, but no conclusions about the bias of the algorithms could be drawn as there were systematic errors present in the measurements.Bilsäkerhetsföretaget Veoneer är utvecklare av avancerade kamerasystem inom förarassistans, men kunskapen om den absoluta noggrannheten i deras dynamiska kalibreringsalgoritmer som skattar fordonets orientering är begränsad. I denna avhandling utvecklas och testas ett nytt mätsystem för att samla in referensdata av ett fordons orientering när det är i rörelse, mer specifikt dess pitchvinkel och rollvinkel. Fokus har legat på att skatta hur osäkerheten i mätsystemet påverkas av fel som introducerats vid dess konstruktion, samt att utreda dess potential när det kommer till att vara ett gångbart alternativ för att samla in referensdata för evaluering av prestandan hos algoritmerna. Systemet bestod av tre laseravståndssensorer monterade på fordonets kaross. En rad mätförsök utfördes med olika störningar introducerade genom att köra längs en vägsträcka i Linköping med vikter lastade i fordonet. Det insamlade referensdatat jämfördes med data från kamerasystemet där bias hos de framräknade vinklarna skattades, samt att de dynamiska egenskaperna kamerasystemets algoritmer utvärderades. Resultaten från mätförsöken visade på att noggrannheten i mätsystemet översteg 0.1 grader för både pitchvinklarna och rollvinklarna, men några slutsatser kring eventuell bias hos algoritmerna kunde ej dras då systematiska fel uppstått i mätresultaten.
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Collier, James Gordon. "Autobiographical Memory during Narrative Message Processing:The Role of Trait Empathy, Camera Angles, Scene Affect and Parasocial Interaction." The Ohio State University, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=osu1367501115.
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Schattschneider, Robert. "Accurate high-resolution 3D surface reconstruction and localisation using a wide-angle flat port underwater stereo camera: towards autonomous ship hull inspection." Thesis, University of Canterbury. Computer Science and Software Engineering, 2014. http://hdl.handle.net/10092/10063.
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The goal of this thesis is to scan a ship hull with high 3D accuracy and resolution using an underwater stereo camera so as to enable the future autonomous detection of invasive biofouling organisms with autonomous underwater vehicles (AUVs). However, turbidity in most harbours necessitates being within a metre of the hull and thus requires ultra wide-angle camera lenses. But such ultra wide-angle lenses embedded in an underwater housing with a flat port lead to significant distance dependent image distortions. Prior research in this area has only considered narrower fields of view and so has not solved for the significant image distortions arising from wide-angle high resolution flat port underwater cameras. This thesis proposes a solution to modelling and calibrating the underwater camera for accurate 2D imaging and 3D reconstruction, and additionally demonstrates an accurate underwater real-time pose estimation system required for future ship hull relative AUV navigation.
In this thesis an ultra wide-angle, short-baseline stereo camera is used, which is embedded in a flat port underwater housing. Flat port underwater housings represent a cost efficient way to use arbitrary in-air cameras underwater. However, the flat port of the underwater housing is subject to light refraction and causes distance dependent distortion, which is particularly visible at the large angles of the ultra wide-angle stereo camera used. To incorporate the effects of refraction, the thesis uses the well-known and accurate physics-based refractive underwater camera model. In contrast to the perspective camera-based underwater camera model, the refractive underwater camera model accurately describes the distance dependency of distortion.
In the beginning of this thesis, the effects of refraction caused by a thick flat port underwater housing are summarised and extended. In this context, the fundamental magnification function is proposed, which enables the description of numerous known and also newly discovered effects. An additional quantitative analysis is carried out in which the importance to model the thickness of the port and the wavelength of light is revealed.
In refractive geometry with a thick flat port, refractive forward projection represents a fundamental operation and describes where a 3D object point is observed in a 2D camera image. Refractive forward projection is required in numerous applications, such as refractive calibration, bundle adjustment, simultaneous localisation and mapping (SLAM) or image restoration. Unlike perspective projection in air, this operation is non-linear and computationally more expensive. This thesis compares existing and proposes new refractive forward projection methods and shows in contrast to previous research that refractive forward projection is efficient enough for real-time applications.
The thesis also investigates the impact of the port and the impact of the indices of refraction on the camera's projection and reconstruction accuracy. A novel investigation shows that the water pressure, water salinity, water temperature, air pressure and the wavelength of light significantly affect the projection and reconstruction accuracy of wide-angle flat port underwater stereo cameras and should not be neglected by standard refractive indices.
Moreover, this thesis proposes an accurate and efficient calibration method for thick flat port underwater stereo cameras. The proposed calibration method mainly achieves its high accuracy by the use of a significantly higher number of calibration images. In contrast to prior research, the computation of the reprojection error does not represent a bottleneck if the proposed refractive forward projection method is used. In this way, the calibration is similar to standard in-air camera calibration techniques and minimises the reprojection error.
In combination with the proposed more accurate indices of refraction and refractive calibration, the underwater reconstruction accuracy of the novel configuration of a wide-angle flat port underwater short baseline stereo camera is evaluated under real-world conditions. In this context, a method is proposed, which enables the evaluation of the accuracy of the reconstructed 3D object space.
Both chromatic aberration and pincushion distortion are effects of refraction and are particularly visible at the large angles of wide-angle underwater cameras.
In order to obtained distortion-free images with minimised chromatic aberration to texturize reconstructed 3D ship hull surfaces, this thesis proposes accurate real-time methods to minimise chromatic aberration and to correct the distortion in the underwater camera images.
The refractive camera model is based on image coordinates of images, which are distortion-free in air. But these in-air undistorted images are strongly distorted in-water by refraction, particularly at the large angles of wide-angle flat port underwater cameras. Image correspondence in these images is difficult. For that reason, this thesis proposes pseudo rectified images in which these distortions are minimised. Moreover, an accurate and efficient representation of epipolar curves is presented, which enables, for example, real-time constrained correspondence search or dense stereo.
This thesis concludes with the demonstration of a pose estimation system for future ship hull relative navigation. The proposed pose estimation system is the first underwater SLAM and visual odometry system, which is based on the more accurate refractive underwater camera model. This thesis shows that the proposed pose estimation system is very accurate in a water tank experiment and efficiently works in real-time, and thus is superior to prior underwater SLAM research, which is based on the less accurate perspective camera-based underwater camera model.
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Olgemar, Markus. "Camera Based Navigation : Matching between Sensor reference and Video image." Thesis, Linköping University, Department of Electrical Engineering, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-15952.
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an Internal Navigational System and a Global Navigational Satellite System (GNSS). In navigational warfare the GNSS can be jammed, therefore are a third navigational system is needed. The system that has been tried in this thesis is camera based navigation. Through a video camera and a sensor reference the position is determined. This thesis will process the matching between the sensor reference and the video image.
Two methods have been implemented: normalized cross correlation and position determination through a homography. Normalized cross correlation creates a correlation matrix. The other method uses point correspondences between the images to determine a homography between the images. And through the homography obtain a position. The more point correspondences the better the position determination will be.
The results have been quite good. The methods have got the right position when the Euler angles of the UAV have been known. Normalized cross correlation has been the best method of the tested methods.
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Amara, Ashwini. "Object Detection and Tracking Using Uncalibrated Cameras." ScholarWorks@UNO, 2010. http://scholarworks.uno.edu/td/1184.
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This thesis considers the problem of tracking an object in world coordinates using measurements obtained from multiple uncalibrated cameras. A general approach to track the location of a target involves different phases including calibrating the camera, detecting the object's feature points over frames, tracking the object over frames and analyzing object's motion and behavior. The approach contains two stages. First, the problem of camera calibration using a calibration object is studied. This approach retrieves the camera parameters from the known locations of ground data in 3D and their corresponding image coordinates. The next important part of this work is to develop an automated system to estimate the trajectory of the object in 3D from image sequences. This is achieved by combining, adapting and integrating several state-of-the-art algorithms. Synthetic data based on a nearly constant velocity object motion model is used to evaluate the performance of camera calibration and state estimation algorithms.
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Bandarupalli, Sowmya. "Vehicle detection and tracking using wireless sensors and video cameras." ScholarWorks@UNO, 2009. http://scholarworks.uno.edu/td/989.
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This thesis presents the development of a surveillance testbed using wireless sensors and video cameras for vehicle detection and tracking. The experimental study includes testbed design and discusses some of the implementation issues in using wireless sensors and video cameras for a practical application. A group of sensor devices equipped with light sensors are used to detect and localize the position of moving vehicle. Background subtraction method is used to detect the moving vehicle from the video sequences. Vehicle centroid is calculated in each frame. A non-linear minimization method is used to estimate the perspective transformation which project 3D points to 2D image points. Vehicle location estimates from three cameras are fused to form a single trajectory representing the vehicle motion. Experimental results using both sensors and cameras are presented. Average error between vehicle location estimates from the cameras and the wireless sensors is around 0.5ft.
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Jalovecký, Martin. "Analýza přesnosti výsledků astronomického určení polohy." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2012. http://www.nusl.cz/ntk/nusl-225609.
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This diploma thesis is focused on the analysis of results accuracy of astronomical positioning. It describes observation methods and the latest surveying systems used in geodetic astronomy. Further in the thesis there is the description of surveying system MAAS-1. Subject of the elaboration is the data obtained by measuring with this system. Testing is focused on digital camera. There is also an analysis of the results of geographical coordinates, depending on the accuracy of determining the angled pixel size and also on the accuracy of the input coordinates.
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Li, Qi. "Acoustic noise emitted from overhead line conductors." Thesis, University of Manchester, 2013. https://www.research.manchester.ac.uk/portal/en/theses/acoustic-noise-emitted-from-overhead-line-conductors(90a5c23c-a7fc-4230-bbab-16b8737b2af2).html.
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The developments of new types of conductors and increase of voltage level have driven the need to carry out research on evaluating overhead line acoustic noise. The surface potential gradient of a conductor is a critical design parameter for planning overhead lines, as it determines the level of corona loss (CL), radio interference (RI), and audible noise (AN). The majority of existing models for surface gradient calculation are based on analytical methods which restrict their application in simulating complex surface geometries. This thesis proposes a novel method which utilizes both analytical and numerical procedures to predict the surface gradient. Stranding shape, proximity of tower, protrusions and bundle arrangements are considered within this model. One of UK National Grid's transmission line configurations has been selected as an example to compare the results for different methods. The different stranding shapes are a key variable in determining dry surface fields. The dynamic behaviour of water droplets subject to AC electric fields is investigated by experiment and finite element modelling. The motion of a water droplet is considered on the surface of a metallic sphere. To understand the consequences of vibration, the FEA model is introduced to study the dynamics of a single droplet in terms of phase shift between vibration and exciting voltage. Moreover, the evolution of electric field within the whole cycle of vibration is investigated. The profile of the electric field and the characteristics of mechanical vibration are evaluated. Surprisingly the phase shift between these characteristics results in the maximum field occurring when the droplet is in a flattened profile rather than when it is ‘pointed’.Research work on audible noise emitted from overhead line conductors is reviewed, and a unique experimental set up employing a semi-anechoic chamber and corona cage is described. Acoustically, this facility isolates undesirable background noise and provides a free-field test space inside the anechoic chamber. Electrically, the corona cage simulates a 3 m section of 400 kV overhead line conductors by achieving the equivalent surface gradient. UV imaging, acoustic measurements and a partial discharge detection system are employed as instrumentation. The acoustic and electrical performance is demonstrated through a series of experiments. Results are discussed, and the mechanisms for acoustic noise are considered. A strategy for evaluating the noise emission level for overhead line conductors is developed. Comments are made on predicting acoustic noise from overhead lines. The technical achievements of this thesis are summarized in three aspects. First of all, an FEA model is developed to calculate the surface electric field for overhead line conductors and this has been demonstrated as an efficient tool for power utilities in computing surface electric field especially for dry condition. The second achievement is the droplet vibration study which describes the droplets' behaviour under rain conditions, such as the phase shift between the voltage and the vibration magnitude, the ejection phenomena and the electric field enhancement due to the shape change of droplets. The third contribution is the development of a standardized procedure in assessing noise emission level and the characteristics of noise emissions for various types of existing conductors in National Grid.
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Gavérina, Ludovic. "Caractérisation thermique de milieux hétérogènes par excitation laser mobile et thermographie infrarouge." Thesis, Bordeaux, 2017. http://www.theses.fr/2017BORD0012/document.
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De nos jours, les matériaux composites sont très largement utilisés dans l’industrie aéronautique et aérospatiale car ils ont de très bonnes tenues mécaniques, mais ces matériaux comportent de fortes hétérogénéités dues aux fibres et aux liants qui les constituent. Ainsi, depuis de nombreuses années, l’équipe TIFC «Thermal Imaging Fields and Characterization » du département TREFLE de l’institut I2M développe des méthodes de mesure des propriétés thermophysiques de matériaux hétérogènes dans le plan ou dans l’épaisseur. Ces méthodes sont très variées du point de vue des méthodes inverses (transformée intégrale, double décomposition en valeurs singulières, …) ou expérimentale (Flash, diode laser, …). Le faible coût des diodes lasers et des systèmes de déplacement de miroirs galvanométriques ont permis de développer un système complet de scanner optique laser, monté sur un banc de mesure. Il permet de revisiter les différents types de sollicitations thermiques et de réaliser une infinité de combinaisons spatiotemporelles d’excitations thermiques par méthode laser. Ceci est une des principales originalités de ce travail. De nouvelles méthodes inverses basées sur la réponse thermique au point source impulsionnel et sur la séparabilité des champs de température ont été proposées. Ces méthodes ont permis d’estimer le tenseur de diffusivité thermique selon les axes principaux d’anisotropie, mais aussi hors des axes du repère de l’image, où il est possible de déterminer l’orientation des axes d’anisotropie, lorsque le transfert de chaleur s’effectue hors des axes du repère de l’image. Ces méthodes ont permis d’obtenir des résultats intéressants comptetenu de leur simplicité. De plus, elles ont permis d’obtenir des cartographies de diffusivités thermiques dans le plan car, comparées aux autres méthodes, elles permettent d’obtenir des estimations du tenseur de diffusivité thermique localement grâce à l’obtention d’une cartographie de flux thermique surfacique via le scanner optique laserNowadays, composite materials are widely used in the aeronautic and aerospace industries because of their high mechanical resistance. However, they have a large heterogeneity due to the fiber and matrix they are made of. In this way, for many years, the TIC team «Thermal Imaging Fields and Characterization » from TREFLE department of I2M laboratory develops methods to measure thermal in-plane properties of heterogeneous materials such as inverses (integral transforms, double singular value decomposition…) or experimental (Flash, laser diode…) methods. The recent progress made in optical control, lasers and infrared (IR) cameras enables the development of a new scanning system (based on galvanometer-mirror) which allows the easy control of a laser hot spot spatial and temporal displacements over a plane surface. The low cost of laser diodes and optical control (galvanometric mirror) systems allows to develop a laser scanning system fixed on a test bench. We can revisit the different types of thermal excitation and realize infinite spatio-temporal combinations of thermal excitations by laser method. This is one of this thesis aims. New inverse methods based on the thermal response to an instantaneous point source heating, and temperature fields separability, have been proposed. These methods allow to estimate the thermal diffusivity tensor along the main axes of anisotropy, but also out of those axes, where it is possible to estimate the anisotropy axes orientation when the heat transfer takes place out of the image axes. These methods have produced interesting results in view of their simplicity. Moreover, they made it possible to obtain in-plane thermal diffusivities maps because, compared to the other methods, they allow to obtain, locally, thermal diffusivity tensor estimations by getting a surface heat flux map using the laser optical scanner
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Chuang, Chih-Yuan, and 莊智淵. "Study on Camber Angle Measurement for Vehicle Wheel Alignment by Accelerometer." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/42166110385605445384.
Full textAbstract:
碩士國立彰化師範大學
車輛科技研究所
104
This study is against to measure camber angle, use coordinate conversion principle from vehicles coordinates to camber coordinates, and then estimate the camber angle. To use accelerometer and MCU on this study is main, and display the value on LCD and APP, Is easier to viewing and operating by measurement. Moreover, to use algorithm on this study the direction of x axis didn’t close by vehicles coordinates and camber coordinates. The camber measure system which is first to use algorithm, it can automatic to correction the x axis of error angle, and avoid error by measurement. Use deviation method to confirm the accuracy of the measure. This study compare the aligner of visual-based and new camber measure system on vehicle, result of error value is less than 0.02o. This camber measure system have high accuracy、low price and easy to operating etc. It will developmental on measure the camber angle. Keywords: Accelerometer, Camber angle, Coordinate transformation, Wheel alignment
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Stewart, Brock. "Using a camera as an angle gauge in angle-count sampling." 2004. http://purl.galileo.usg.edu/uga%5Fetd/stewart%5Fbrock%5Ft%5F200408%5Fms.
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Kung, Shu-Cheng, and 龔書正. "Design and Study for Wide Angle Intraoral Camera." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/31058393062928526033.
Full textAbstract:
碩士國立交通大學
光電系統研究所
99
The wide angle intraoral camera we designed is for oral examination. The fabrication technology of camera module has greatly improved, and the lens module is lighter, smaller, and cheaper as before. On the other hand, the stereo technology is an ancient knowledge, but it has been improved significantly the image application in recent years. The governments and companies in the world also focus on stereo systems development. In this study, we use multiple lens modules to design a low wide angle view with low optical distortion. This result can let doctor observe the patients oral cavity more easily. And we can get a 3D oral image using multiple camera modules, which can produce stereo vision. This technology is expected to be used in the oral examination, photography and record. We believe that this design can help more people with health.
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Hsieh, Tzu-Chen, and 謝子宸. "Wireless Invisible Backup Camera with Adjustable View Angle." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/ryyzm5.
Full textAbstract:
碩士國立虎尾科技大學
光電與材料科技研究所
99
Many traffic accidents occur because of blind spots. With increased emphasis on driving safety, many people started to pay more attention to intelligent parking assist systems. To some drivers, double parking and backing-up may be problematic. However, with the aid of a parking assist system, which includes parking sensors and backup cameras, the drivers can not only judge the space behind the car and the location of the car with ease, but can also maneuver more precisely during backing up and parking. This thesis aims to improve on the traditional wired backup cameras for automobiles. As wireless devices have become increasingly prevalent and are used for a variety of purposes in modern society, the wireless backup cameras are designed with a user centric point of view. The benefits of using the wireless backup cameras are as follows: firstly, they are easy to install since they do not have the wires that require intricate installation. Secondly, they can be set up easily in remote areas as the cameras can be transferred from one car to another. Thirdly, the current design also used the cameras that have adjustable camera angles. For the user’s convenience, this model also can memorize the latest angle the user used. It can then help to reduce blind spots while backing up or parking. The working sample of the improved design not only is a study but also can be installed into a car to operate. This design wins silver medal award of Malaysia International Invention, Innovation and Technology Exhibition in 2011.
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Lin, Ting-Li, and 林庭立. "Traffic-Flow Detection System with Roadside Low-Angle Camera." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/12989020331630444672.
Full textAbstract:
碩士國立交通大學
電控工程研究所
100
Vehicle detection techniques in visual-based Intelligent Transportation System (ITS) have been studied for years. However, fragmented foreground and vehicle occlusion problem still cause serious errors and mistakes. How to reduce the influence of fragmented foreground and vehicle occlusion is our essential target. This study proposes a novel method and different from conventional processing on image plane. We transform image into bird-view image and collect foreground information from a cross-section by suitable sensing blocks. The data we obtain will transform into one-dimension feature sequence and represent the objects in future processes. This method will prevent fragmented foreground. Based on bird-view image and complete foreground we can design general conditions to detect occlusion cases and handle. Our system is capable of vehicle detection with roadside low-angle camera and with high speed moving objects. This method is sufficiently robust to detect vehicles at a high success rate of 97.4% in day and 97.07% in night. Our research is to reform fragmented foreground and handle vehicles that move in parallel occluding each other from the beginning to the end of the traffic image as a single region. And this study can provide a different concept from traditional background based method. Experimental results show the opportunity of tracking and counting systems and advanced applications.
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LO, CHIEN-WEI, and 羅健瑋. "A Design of Wide Angle Camera lens for Dashcam." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/2nb4jm.
Full textAbstract:
碩士國立雲林科技大學
電子工程系
106
In recent years, the dashboard camera has been widely used. Good dashboard camera can provide more image information with wide-angle lens. This paper uses optical software Zemax to design the wide-angle lens. The proposed wide-angle lens is designed to be 80-degree incident from half angle, which will reduce the imaging surface of the relative illumination. Control degree is very important in the process of optimization. Because the barrel distortion will cause the image surface to be extruded, F- theta distortion is used instead of optical distortion. The wide-angle lens uses five spherical glass lenses and a aspherical plastic lens in this study. A sensor with 2 million pixels is used. The half-angle incident light reaches 80 degrees, F/# is 2.4, and the lens length is 22.41 mm. Relative illumination is greater than 80% in the whole field of view, The transverse chromatic aberration is less than 1.75μm, and the MTF at the full field is more than 0.5 at 142lp/mm.
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Lin, Kun-Hsien, and 林坤賢. "Monitoring System of Hidden Wide-Angle Camera by Mirror." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/3snzpe.
Full textAbstract:
碩士國立虎尾科技大學
光電與材料科技研究所
102
This study aims at wide-angle lens around the corner of the roadside that is improved to coating wide-angle lens in combination with camera for an achievement of a hidden indoor wide-angle monitoring system in indoor public places. Traditional cameras have either no disguise or dead angle causing that the mob can choose photographic dead zone to use violence without evidences being able to collect afterwards. The difference between coating and normal traditional wide-angle lens is that the former uses dielectric coatings as material to reach confidentiality and imaging effect for camera installed inside. Two ordinary video cameras at 62° visual angle for the purpose of increasing shooting visual angle to comprehensively increase to 112° more than that of ordinary surveillance camera. For the promotion of stitched video quality, problems incurred from real scene stitch will be analyzed. The basic concept of using dynamic instant image stitching technology is to be realized on the basis of SIFT (Scale Invariant Feature Transform) algorithm, and distortion measurement between PSNR (Peak Signal-to-Noise Ratio) after being stitched and costing wide-angle lens after being installed is then compared. Keywords: Vacuum coating、Image stitching、SIFT、Measuring Angles、Solid works
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Rodriguez, Marisol. "Evaluation of scale placement and camera angle in footwear impression examination." Thesis, 2019. https://hdl.handle.net/2144/38710.
Full textAbstract:
Footwear impressions can be found at any type of crime scene. Footwear impressions are valuable pieces of physical evidence when discovered, properly documented and collected. Two-dimensional footwear impressions can be left behind when the outsole of a shoe comes into contact with a substance and then the substance is transferred to a surface, leaving a positive impression on that surface [1-3]. 2-D impressions can also occur when a shoe steps onto a dusty surface and the dust adheres to the tread elements, which take away the dust leaving behind a negative impression [2,3].
Footwear impression evidence may display class characteristics, such as the type, manufacturer, the approximate size and shape and general description of the shoes [2]. They are most commonly documented and collected through photography, specifically examination quality photographs. The value of the photographs taken depends on the quality of the images and requires the correct placement of the scale and angle of the camera. In order to ensure an accurate representation of the evidence, the camera should be parallel to the impression and a scale must be present in the same plane as the impression. Taking photographs at any other angle can distort the object in the photograph, resulting in incorrect measurements, which can hinder the comparison process between the photographed object and the physical object. Digital imaging applications and software can be used to calibrate images, meaning the scale is used to adjust, or calibrate, the photographed image into a 1:1 image or actual size. Forensic photography guidelines provided by SWGTREAD stress the importance of scale placement and the position of the camera lens, but research on how exact these two steps must be executed to accurately determine the physical size or dimensions of the shoe remains limited [3,4].
The goal of this project was to determine how the positioning of a scale in relationship to the footwear impression can potentially lead to possible distortion of the actual size of the photographed impression. This project seeks to evaluate the extent to which the depth of the scale and impression can vary before the size of the photographed impression becomes measurably distorted as well as evaluate the tolerable range of angle tilt of the scale allowed before the size of the photographed impression becomes distorted.
A left counterfeit Nike Air Jordan’s shoe from the Jordan Melo line, US adult size 7.5 was used to make several test impressions and then the best impression with the highest quality was chosen to be photographed. Examination quality photographs of the test impression with the scale in the same plane were taken, followed by an incremental increase in the height/distance (0-66.9 mm) of the scale from the ground and lastly, with an incremental increase in the angle (0-20 degrees) of the camera horizontally, vertically left and right. The photographs were then calibrated using Adobe® Photoshop® and actual size images were printed out. Based on the tread design, ten areas present on the outsole were examined through measurement.
The results indicated that if the scale was placed at a height within 5.7 mm of the height of the impression, then there would be no change in estimated shoe size. However, if the scale was placed a distance or height of 7.6 mm or greater from the bottom of the impression, then the image would result in a change of half a shoe size or more. Also, if the angle of the camera was greater than 8 degrees horizontally or greater than 14 degrees vertically to the left there was a change in the apparent shoe size. However, there was no change in the shoe size when the camera angle increased horizontally up to 8 degrees, vertically up to 20 degrees, and vertically up to 14 degrees.
It is important to be aware of discrepancies that can exist in size dimensions when the scale placement and camera angle are not in the correct plane and position. The distorted images may result in false measurements, which can lead to inaccurate size interpretations. This would be problematic when comparing a suspect’s shoe to the photographed footwear impression, possibly resulting in false inclusion or exclusion decisions of the questioned footwear impression.
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Li, Tzu-Yang. "A Visual Monitoring System Using Wide-Angle Cameras and Pan-Tilt Camera." 2004. http://www.cetd.com.tw/ec/thesisdetail.aspx?etdun=U0001-1307200409434800.
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Chiang, Sung-Chi, and 江松輯. "Kinematic Modeling and Camera Angle Control of an 8-DOF Endoscope Robot." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/7bxhk6.
Full textAbstract:
碩士國立臺灣大學
機械工程學研究所
106
In recent years, laparoscopic minimally invasive surgery has been extensively used in the medical field due to the small wounds, shorter recovery time and less suffering of patients. Combined with robotic technology, laparoscopic minimally invasive surgical robots can obtain higher surgical accuracy and expand the application of minimally invasive techniques. The main purpose of this paper is to design a force controller to achieve the angle control of an 8-DOF laparoscopic minimally invasive surgical robot. This article first introduces the design of the endoscope motor mechanism and deduces the kinematics and dynamic model of the manipulator arm and endoscope. Under the constraint of the celiac incision, a null-space matrix relative to the task space would be derived. Perspective space of the endoscope camera would be analyzed and a nullspace impedance control architecture would be constructed so that the endoscope-holding manipulator can provide images with different perspectives in the situation where the target object does not change its position in the picture and does not generate lateral force on the incision. Finally, the control algorithm would be implemented with the arm controller API and MATLAB model to verify the theoretical feasibility.
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Song, Yan-Bin, and 宋焱檳. "Research on Near-infrared-based Ego-positioning Algorithm with Wide-angle Camera." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/gn6gdf.
Full textAbstract:
碩士國立臺灣大學
資訊網路與多媒體研究所
106
Simultaneous Localization and Mapping(SLAM)is a generic method used to solve robot ego-positioning problems. At present, popular SLAM methods are mainly divided into direct methods and feature-based methods. The direct method is more sensitive to brightness information, and the feature-based method has been demonstrated more tolerance toward changes in brightness. In nighttime environment, information from normal camera become difficult to identify. Therefore, we propose to use near-infrared (NIR) cameras for ego-positioning of night robots. Images obtained by NIR light have different light intensities due to their distance from the infrared light sources, so SLAM is not suitable for direct methods. We used a feature-based method which is tolerant to light intensities to ego-positioning. This method combines ego-positioning and NIR with multi-wide-angle NIR cameras to not only solve the problem of capturing the feature points under low-light conditions, but also obtain more accurate ego-positioning results. This allows the robot to do SLAM even at night in low illumination indoor scenario. Therefore, this system has more robust results in different challenging situations.
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Li, Tzu-Yang, and 李子洋. "A Visual Monitoring System Using Wide-Angle Cameras and Pan-Tilt Camera." Thesis, 2004. http://ndltd.ncl.edu.tw/handle/86070699060278502538.
Full textAbstract:
碩士國立臺灣大學
資訊工程學研究所
92
Visual monitoring systems will play a more and more important role in our daily life. Traditional Close Circuit Television System (CCTV) sets cameras in many key positions, and need a guard to keep an eye on the videos of those cameras. In this work, we developed a fully automatic visual monitoring system that can be set up with a simple method. Utilize the properties of the wide-angle cameras and of the pan-tilt camera (PT-camera), i.e., large view field of wide-angle cameras and high-resolution images of PT-cameras, we can design a real-time visual monitoring system having high detection rate and clear target images. Important methods used in this system include the following: (1) Camera calibration: First, we estimate the intrinsic camera parameters using a camera calibration method that require simply placing a 2D calibration plane at different positions. Then, we use a cross rig having calibration markers, each marker with known 3D position, to estimate the extrinsic parameters between cameras. (2) Moving object detection: For the wide-angle cameras, Gaussian mixture is used to update the background model in real-time, which is then used to detect objects different from the background. (3) Object tracking: For the PT-camera, we use the mean-shift algorithm to keep track of the target. (4) Face detection: A cascade of boosted classifiers, working with Haar-like features, is used to obtain fast and accurate face detection. In the experiments, we combine the detection and tracking methods together to reliably fixate the PT-camera on the object. One single person can easily set up the whole system and calibrate all cameras. Our experiments showed that, when there is only one moving object in the monitoring area, our system could track the object successfully.
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Uys, Carli. "Mascelli's functional analysis of camera angles versus viewers' interpretations of unconventional camera angles in Avatar and The English Patient / Carli Uys." Thesis, 2014. http://hdl.handle.net/10394/12053.
Full textAbstract:
The primary research strategy of this study was to elicit meaningful answers from
viewers by means of a focus-group procedure; this is a method associated with
qualitative research (see Creswell, 1998; Berg & Lune, 2011) The group consisted of ten
adults, whose visual literacy in terms of narrative films, was described as high (they
frequently watch films at home, or in the theatre). The researcher acted as the
moderator; and a set of semi-structured questions, based on meanings attached to
camera-angle codes as defined by Mascelli, were answered by the participants.
The codification scheme of Mascelli was applied to the unconventional camera angles in
Avatar and The English Patient. These were compared with the viewers’ responses.
Finally, the results were interpreted, in order to establish whether a meaningful
relationship exists between the viewers’ responses and the interpretation of
unconventional camera angles by such a seminal figure as Joseph V. Mascelli. The
literature study focused on a media aesthetic explanation of cinematography, which
included media aesthetics theory, framing, and composition, as well as the general
codes and conventions relevant to cinematography.
The literature overview includes a study of books, academic articles, internet sources,
legislation, and training videos. A Nexus and EbscoHost search (Academic Search
Premier and Jstor) was conducted on cinematography in general, and on camera angles
in particular.
Chapter 5 indicates the viewers’ overall interpretations of the unconventional camera
angles used in Avatar and The English Patient. The graphs in Chapter 5 indicate that
the viewers found the unconventional camera angles used in the films to represent
the meaning of the shots appropriately, and that they understood why each unconventional camera angle had been used. The viewers’ responses correspond
with the meanings of the unconventional camera angles, as stated by Mascelli.
To ensure the effectiveness of a film and the accurate representation of the
meanings of camera angles and camera sizes, the way it is described by Mascelli
should ideally be taken into consideration by all future producers. Mascelli’s
descriptions of camera angles and camera sizes, combined with the media
aesthetics, as described by Zettl – when successfully applied – could lead to the
production of a good quality film and images within the film.MA (Communication Studies), North-West University, Potchefstroom Campus, 2014
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Shen, Hui-Kai, and 沈惠凱. "Wide angle camera in multi-channel architecture using microlenses on a curved surface." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/42140524635246427318.
Full textAbstract:
碩士國立臺灣大學
光電工程學研究所
102
In this paper, we proposed a multi-channel imaging system, which combines the principles of the insect compound eye and the human eye. The optical system enables the reduction of track length of the imaging device to achieve miniaturization. With the aid of optical engineering software ZEMAX, the multi-channel structure is simulated by a curved microlens array (MLA), and we used a Hypergon lens as the main lens to simulate the human eye, which can achieve the purpose of the wide field of view (FOV). With this architecture, each microlens of a MLA transmits a segment of the overall FOV. The partial images that are separately recorded in different channels are stitched together to form the final image of the whole FOV by software processing. This design is 2.70 mm thick, with 59 channels and 102&;#730;× 90&;#730; FOV is optimized using ZEMAX ray tracing software on a 5.63 mm × 3.69 mm image plane. Given recent progress in the fabrication of microlenses, this image system has potentials to be commercialized. Due to the microlenses are realized by state-of-the-art micro-optical fabrication techniques on a wafer level that are suitable for application in mobile phone camera in the future. Finally, we will discuss the simulation results of this system and compare with a mobile phone patent.
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Pan, Jun-Gu, and 潘俊谷. "Fabrication of multi-focal microlens array on curved surface for wide-angle camera module." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/837edw.
Full textAbstract:
碩士國立臺灣大學
光電工程學研究所
105
In this thesis, we presented a wide-angle and compact camera module that consists of microlens arrays with different focal lengths on curved surface. The design integrates the principle of an insect’s compound eye and the human eye. It contains a curved hexagonal microlens array and a spherical lens. The diameter of microlens is 400 µm, and we fabricate 4 groups different focal length of microlenses. The radius of curvature of curved surface is 2.45 mm and sag height is 1.08 mm. Compared with normal mobile phone cameras which usually need no less than four lenses, the proposed system use only one lens. Furthermore, the thickness of our proposed system is only 2.08 mm and full field of view is about 100 degrees. To make the critical microlens arrays, we used the inkjet printing to control the focal lengths of each microlens and use replication method to form curvature hexagonal microlens arrays.
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Chen, Yao-tung, and 陳耀東. "A Low-Cost Pipeline Architecture for Barrel Distortion Correction of Wide-Angle Camera Images." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/85963794458594662214.
Full textAbstract:
碩士國立成功大學
資訊工程學系碩博士班
95
Images captured with wide-angle cameras tend to have severe barrel distortions which pull points towards the optical center. To solve the problem, we can use a mathematical model based on polynomial equations to map the images from distorted image space to the corrected image space. This thesis focuses on the barrel distortion correction of wide-angle camera images. To perform barrel distortion correction, usually we need to identify the distance of the pixel to be corrected and the distorted center of the wide-angle camera. Besides, we need to calculate the angle between the distance and horizontal axis. The traditional method obtains the distance and angle by using the coordinate rotation digital computer (CORDIC) based hardware design. This correction flow requires extensive computational time and higher hardware cost. A new lower-complexity technique for barrel distortion correction is presented in this thesis. The proposed distortion-correction model is applied to several images captured from wide-angle lens camera. Simulation results show that our method outperforms the traditional one. Finally, a low-cost pipeline VLSI architecture for our method is presented. The VLSI architecture is designed with Verilog and implemented with Altera EP20K600EBC652-1X FPGA, respectively. Compared with the previous design, our chip achieves less hardware cost and higher clock rate.
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Lee, Chien-Chen, and 李建成. "Study on the glass defects measurements using the critical angle method and a CCD camera." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/2bn5mv.
Full textAbstract:
碩士國立虎尾科技大學
光電與材料科技研究所在職專班
99
The purpose of this thesis is to combine the critical angle method with CCD image capture technology for measuring the scratches on the LCD glass substrate. The panels of mobile phones, LCD TVs, digital cameras and tablet PCs etc with glass substrates are high-technique produces in modern life. The serious defects in or on the glass, like as, scratches, bubbles, or smudges, etc, will affect the image quality of display. In this method, when the expanded laser beam passes through the transparent component, the surface information is added in it. We use a rotating stage to control the incident angle of a parallelogram prism. Two incident angles, the critical angle and the angle of total internal reflection (TIR), are set to measure the image pattern of the glass using a CCD camera, respectively. Use the data of two patterns to calculate the reflectance profile and use the principle of the first-order geometrical optics to calculate the surface profile using the MATLAB program. From the surface profile results, how the quality of the glass is detected. The method has some merits, such as, simple structure, easy operation, high sensitivity, and it can measure a wide range of transparent surface defects.
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Lee, Chung-Yi, and 李重儀. "Construction of a Wide-Angle High-Resolution Visual Monitoring System Using a Multi-Resolution Dual-Camera System." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/08754277983661508358.
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Lin, Zhen-Chin, and 林振勤. "Study on the Surface Profile Measurement by Uses of the Critical Angle Method and a CCD Camera." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/v43376.
Full textAbstract:
碩士國立虎尾科技大學
光電與材料科技研究所
97
In this paper, we proposed a new method based on the critical angle method and the use of a CCD camera for surface profile measurement of a transparent component, a broaden beam was normally incident at a transparent test component, and the output beam was incident into a critical angle prism for angular detecting. If there are some points with some different heights on the surface, the light passing through these point will deviated a small angle in the output, then these light incident into a prism at a specific incident angle will be changed its intensity apparently because of the steep reflection varied near at the critical angle, the surface height is proportional to the deviation angle and the intensity of light. So, we could use this principle to measure the surface profile or the surface roughness. Using a CCD camera to catch and analyze the image is easier for us. The method has some merits, such as easy operation, large-range measurement, real-time detection, and high resolution.
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Tsai, Chun-Lung, and 蔡君龍. "Multiple Baseline Stereoscopic Visual Technique by Use of Singular Camera with View Angle of Horizontal and Rotational Plane." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/95749898904369672591.
Full textAbstract:
碩士國立中正大學
電機工程研究所
101
The thesis proposes a 3D information measuring system to realize a precise 3D information measuring results equivalent to that obtained from multiple cameras. In the system, based on the spatial invariant principle for an object, we use a rotational platform to drive a singular camera to rotate along a circle and generate multiple various horizontal view angle stereoscopic image to replace ordinary stereo vision system of single level view angle stereoscopic images. We further rectify the obtained multiple various horizontal view angle stereoscopic image, and calculate relative points of the multiple various horizontal view angle stereoscopic image, and through advantages of multiple view angle image to conduct inaccurate relative points removing and optimizing actions. Finally, by use of sum of squares to analyze the similarity of relative points and matched up with camera parameters and based on camera relative position weighted function integration and optimized multiple view angle image depth values, we achieve 3D information measuring effect with a single camera and acquires the 3D information which is wider than traditional single horizontal view angle stereoscopic vision system.
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Lee, Wen-Yung, and 李玟蓉. "How Camera Angle of Product and Ad Claims in Print Advertisement Affect Consumer Decision? The Application of Construal Level Theory." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/v69pnu.
Full textAbstract:
碩士國立政治大學
傳播學院傳播碩士學位學程
106
Much research has shown that when the upward-looking camera angle employed to depict a product, people generate more favorable attitude toward the product. The reverse is found when the product depicted by downward-looking angle. However, the existing literature seldom incorporates construal level ad slogan as a determining factor in the effectiveness of camera angle. According to construal level theory, power and construal level are bidirectional relationship. When the construal level of the ad message the same as consumers’ mental construal level leads to high processing efficiency and fit. As a result, we propose processing efficiency and power are the mediators of the interaction effect between camera angle and construal level ad slogan. We demonstrate across two experiments that there is interaction effect between camera angle and construal level ad slogan. Study 1 shows there is interaction effect between camera angle and desirability-feasibility ad slogan. Study 2 shows there is interaction effect between camera angle and promotion-focus and prevention-focus ad-slogan. Processing fluency and power are not the mediator of the interaction effect.
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Wen, Chi-Sin, and 温基信. "Verify Purpose and View Angle Coverage of Camera in Campus Corridor Safety-In Case of Campus Surveillance of National Taiwan University (Main Campus)." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/5dz3ck.
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碩士國立臺灣大學
工業工程學研究所
105
The security surveillance system implement is a top priority of solution when people consider the issue of campus safety maintenance. Society is as same as school, the key point is that people would like to do relational analysis and clarify the responsibility through reviewing historical video by security system.it is not difficult to co-work with an experienced vendor/partner to execute a security surveillance system under sufficient budget. However, none of these companies can guarantee the capability of the system that can achieve all requirements. Every initial planner should fully understand the purpose of security surveillance system more than the functions or cost. Therefore, this study is focus on the relation between purpose verification and view angle coverage of camera in campus corridor’s safety. Furthermore, as increase of surveillance range and quantities of CCTV. It is more difficult to evaluate effective of the purpose. In this research would be expected to find out a solution that is using an international indication standard and particularly points out ROTAKIN (BS ENS50132). it will be able to measure resolution, color, motion capture of CCTV Camera and then to ensure how security surveillance system meet the purpose. It also suggests how to calculate a reasonable number in a wide field. In final conclusion and the purpose of this research as well, would provide a simple procedure to implement a security surveillance system in a broad scope and remains safe. This consequence is not only useful to my previous security programs, but also assist more security program planners. Due to stable and reliable security surveillance system, it may stop some criminal motivation. In that case, not only in corridor safety but also whole society environment would be improved and safe.
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Tavares, Jose Brandao. "Automatic Diagnosis System for Human Gait Pathologies Using Computer Vision." Master's thesis, 2015. http://hdl.handle.net/10316/40411.
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