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On Robotic Peg-in-Hole Assembly: Chamfer Positions and Double Peg InsertionTung, Ying-Tse 30 August 2004 (has links)
Both position and angular errors during the insertion process, which cannot be easily predicted because of indeterminate collision situations, may cause failure of the assembly. One of the frequently applied strategies is to use a passive remote center compliance. We break the insertion problem down in to two phases: chamfer-crossing, and inserting (after chamfer-crossing)phase. In this article, the relationship between the position and angular errors during chamfer-crossing with different chamfer size and locality are thoroughly analysis. We also try to design a technological processes of minimizing the angular errors during chamfer-crossing. Besides single round peg insertion, two dimensional dual peg-in-hole insertion problems are briefly analysis.
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Large scale audience interaction with a Kinect sensorSamini, Ali January 2012 (has links)
We present investigation and designing of a system that interacts with big audience, sitting in a dimmed theater environment. The goal is to automatically detect audiences and some of their actions. Test results indicate that because of low light condition we can’t rely on RGB camera footage in a dimmed environment. We use Microsoft Kinect Sensor to collect data from environment. Kinect is designed to be used with Microsoft Xbox 360 for gaming purposes. It has both RGB and Infrared depth camera. Change in amount of visible light doesn’t affect data from depth camera. Kinect is not a strong camera so it has limitations that we should deal with. Viewing angles of both cameras and depth range of Infrared camera are limited. Viewing angles of depth camera are 43° vertical and 57° horizontal. Most accurate range of depth camera is 1 meter to 4 meters from camera. Non-infrared reflective surfaces cause gaps in depth data. We evaluate possibility of using Kinect camera in a large environment with big audience. “Dome 3D theater” in Norrkoping Visualization Center C, is selected as environment to investigate and test the system. We ran some tests to find the best place and best height for camera to have most coverage. Our system works with optimized image processing algorithms that use 3D depth data instead of regular RGB or Grayscale image. We use “libfreenect”, Open Kinect library to get Kinect sensor up and running. C++ and OpenGL are used as programing languages and graphics interface, respectively. Open GLUT (OpenGL Utility Toolkit) is used for system’s user interface. It was not possible to use Dome environment for every test during the programming period so we recorded some depth footage and used for later tests. While evaluating the possibility of using Kinect in Dome environment, we realized that implementing a voting system would make a good demonstration and test application. Our system counts votes after audiences raise their hands to vote for something.
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Stanovení pozice objektu / Detection of object positionBaáš, Filip January 2019 (has links)
Master’s thesis deals with object pose estimation using monocular camera. As an object is considered every rigid, shape fixed entity with strong edges, ideally textureless. Object position in this work is represented by transformation matrix, which describes object translation and rotation towards world coordinate system. First chapter is dedicated to explanation of theory of geometric transformations and intrinsic and extrinsic parameters of camera. This chapter also describes detection algorithm Chamfer Matching, which is used in this work. Second chapter describes all development tools used in this work. Third, fourth and fifth chapter are dedicated to practical realization of this works goal and achieved results. Last chapter describes created application, that realizes known object pose estimation in scene.
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AvaliaÃÃo de tensÃes residuais de soldagem em chapas planas do aÃo estrutural ASTM A516 g70 / Welding residual stress evaluation in flat samples of structural ASTM A516 G70 steelGeorge Luiz Gomes de Oliveira 15 January 2009 (has links)
Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico / O objetivo principal desse trabalho foi avaliar o efeito do procedimento de soldagem empregado, com foco na energia de soldagem, no tipo de chanfro empregado e na tÃcnica de soldagem utilizada, sobre o nÃvel e a distribuiÃÃo das tensÃes residuais resultantes em junta submetida à soldagem multipasse. Foi avaliado tambÃm o efeito da corrente e da velocidade de soldagem de forma isolada sobre estas tensÃes, bem como a correlaÃÃo desses resultados com a microestrutura e dureza encontrada. As tensÃes residuais foram medidas utilizando a tÃcnica de difraÃÃo de raios-x, atravÃs de um minidifratÃmetro para mediÃÃo em campo. As anÃlises metalogrÃficas foram realizadas na seÃÃo transversal da junta, atravÃs de microscopia Ãtica e microscopia eletrÃnica de varredura. Foram levantados os perfis de microdureza na seÃÃo transversal da junta. Os resultados mostraram que as tensÃes residuais originadas da soldagem multipasse na superfÃcie das amostras analisadas sÃo compressivas no metal de solda e trativas da ZAC. As tensÃes residuais encontradas na raiz das amostras analisadas se mostraram trativas tanto no metal de solda quanto na ZAC. A energia de soldagem apresentou uma relaÃÃo nÃo linear com as tensÃes residuais encontradas, sendo encontrado que o parÃmetro que apresentou maior influÃncia foi a velocidade de soldagem, o que representa um problema, pois geralmente tal parÃmetro à o menos controlado nas soldagens manuais. As amostras chanfradas em meio-v foram as que apresentaram os menores nÃveis de tensÃes residuais, devido a alÃvios de tensÃo gerados por deformaÃÃes plÃsticas geradas durante a soldagem, fato que nÃo ocorre nas amostras chanfradas em X. A tÃcnica da dupla camada mostrou-se uma ferramenta bastante Ãtil à soldagem do aÃo ASTM A516 Gr70, pois alÃm de promover o refinamento e revenimento da ZAC-GG das amostras soldadas, acrescentou tensÃes residuais compressivas ao longo de toda a superfÃcie analisada das amostras. As microestruturas e durezas encontradas nas juntas foram bem similares para todas as amostras, sendo a ferrita acicular encontrada no metal de solda uma das provÃveis causas da caracterÃstica compressiva das tensÃes residuais encontradas / The main aim of this work was to evaluate the employed welding procedure effect on the level and profile of the final residual stresses on a multipass joint, with emphasis in the welding energy, chamfer and used welding technique. It was also evaluated the effect of the welding current and speed on these stresses, as well as it was correlated the results with microstructure and microhardness. The residual stress measurement was accomplished through X-ray diffraction, using a minidiffractometer for measurement in field. Metallographic analysis was accomplished in the transverse section of the welded joint, using optic microscopy and scanning electron microscopy. It were determined the microhardness profiles in the traverse section of the welded joint. The results showed that the multipass welding residual stresses on the surface of the analyzed samples are compressive in the weld metal and tensile in the HAZ. In the weld root, the welding residual stresses are tensile as in the weld metal as in the HAZ. The welding energy showed a non-linear relationship with the founded residual stresses and it was observed that the most influential parameter was the welding speed, what can be a trouble, since this parameter is the less controlled in manual weldings. The semi-v chamfered samples were the ones that present the fewer levels of residual stresses, due to the stress relief created by plastic deformations during the welding, what do not occur in the X chamfered samples. The double layer technique showed that it can be used in the welding of ASTM A516 Gr70 steel, because, besides promote a refinement and a drawing back of the CG-HAZ, it increased compressive residual stress in the whole surface of the analyzed samples. The founded microstructures and microhardness were similar for all samples and it has believed that the acicular ferrite founded in the weld metal was one of the the main causes for the compressive characteristics of the welding residual stresses in the joints
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Plnicí potrubí s proměnným průřezem pro 16V motor / Variable Intake manifold for 16V EngineKonečný, Lukáš January 2014 (has links)
Aim of the diploma thesis is to design intake ducting with variable cross-section for 16V diesel engine consisting from divided intake manifold and divided ejector. Cross-section variability is ensured by a swirl flap placed in the divided ejector. Next aim of thesis is to provide drawing documentation for production of samples. For designing was used PTC Creo system and software GeomCaliper. Also was taken account of manufacturing of the parts with sand-casting, especially to guarantee trouble-free taking out of models from the moulds, and taking out of cores from core moulds, and also for machinability of some elements. Introduction of thesis is focused on diesel engine emissions and ways of their reduction.
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