This project deals with the design and implementation of the extensible programmable environment intended for the creation of various 3D simulations, specifically targeted for testing of the algorithms and creation of applications from the field of computer vision and robotics. Environment VISIMBOX was implemented in c# programming language and uses OpenGL as back-end for hardware accelerated rendering.

The Diploma thesis deals with geometry calculation and design tools for the functional parts to eliminate the spring-back of the irregular shaped sheet metal. In this thesis there is shown one of the possible ways for 3D modelling in the recent engineering company.

Electrochemical machining (ECM) is a non-conventional manufacturing process, which uses electrochemical dissolution to shape any conductive metal regardless of its mechanical properties and without leaving behind residual stresses or tool wear. Therefore, ECM can be an alternative for machining difficult-to-cut materials, complex geometries, and materials with improved characteristics, such as strength, heat-resistance or corrosion-resistance. Notwithstanding its great potential as a shaping tool, the ECM process is still not fully characterised and its research is an on-going process. Various phenomena are involved in ECM, e.g. electrodynamics, mass transfer, heat transfer, fluid dynamics and electrochemistry, which occur in parallel and this can lead to a different material dissolution rate at each point of the workpiece surface. This makes difficult an accurate prediction of the final workpiece geometry. This problem was addressed in the first part of the present thesis by developing a simulation model of the ECM process in a two-dimensional (2D) environment. A finite element analysis (FEA) package, COMSOL multiphysics® was used for this purpose due to its capacity to handle the diverse phenomena involved in ECM and couple them into a single solution. Experimental tests were carried out by applying ECM on stainless steel 316 (SS316) samples. This work was done in collaboration with pECM Systems Ltd® from Barnsley, UK. The interest of studying ECM on stainless steels (SS) resides on the fact that the application of ECM on SS typically results in various different surface finishes. The chromium in SS alloys usually induces the formation of a protective oxide film that prevents further corrosion of the alloy, giving the metal the special characteristic of corrosion resistance. This oxide film has low electrical conductivity; hence normal anodic dissolution often cannot proceed without oxide breakdown. Partial breakdown of the oxide film often occurs, which causes pits on the surface or a non-uniform surface finish. Therefore the role of the ECM machining parameters, such as interelectrode gap, voltage, electrolyte flow rate, and electrolyte inlet temperature, on the achievement of a uniform oxide film breakdown was evaluated in this work. Experimental results show that the resulting surface finish is highly influenced by the over-potential and current density, and by the characteristics of the electrolyte, flow rate and conductivity. The complexity of experimentally controlling these parameters emphasised the need for the development of a computational model that allows the simulation of the ECM process in full. The simulation of ECM in a three-dimensional (3D) environment is crucial to understand the behaviour of the ECM process in the real world. In a 3D model, information that was not visible before can be observed and a more detailed realistic solution can be achieved. Hence, in this work a computer aided design (CAD) software was used to construct a 3D geometry, which was imported to COMSOL Multiphysics® to simulate the ECM process, but this time in a 3D environment. This enhanced simulation model includes fluid dynamics, heat transfer, mass transfer, electrodynamics and electrochemistry, and has the novelty that an accurate computational simulation of the ECM process can be carry out a priori the experimental tests and allows the extraction of enough information from the ECM process in order to predict the workpiece final shape and surface finish. Moreover, this simulation model can be applied to diverse materials and electrolytes by modifying the input ECM parameters.

This work is concerned with the numerical simulation of percussion instruments based on physical principles. Three novel modular environments for sound synthesis are presented: a system composed of various plates vibrating under nonlinear conditions, a model for a nonlinear double membrane drum and a snare drum. All are embedded in a 3D acoustic environment. The approach adopted is based on the finite difference method, and extends recent results in the field. Starting from simple models, the modular instruments can be created by combining different components in order to obtain virtual environments with increasing complexity. The resulting numerical codes can be used by composers and musicians to create music by specifying the parameters and a score for the systems. Stability is a major concern in numerical simulation. In this work, energy techniques are employed in order to guarantee the stability of the numerical schemes for the virtual instruments, by imposing suitable coupling conditions between the various components of the system. Before presenting the virtual instruments, the various components are individually analysed. Plates are the main elements of the multiple plate system, and they represent the first approximation to the simulation of gongs and cymbals. Similarly to plates, membranes are important in the simulation of drums. Linear and nonlinear plate/membrane vibration is thus the starting point of this work. An important aspect of percussion instruments is the modelling of collisions. A novel approach based on penalty methods is adopted here to describe lumped collisions with a mallet and distributed collisions with a string in the case of a membrane. Another point discussed in the present work is the coupling between 2D structures like plates and membranes with the 3D acoustic field, in order to obtain an integrated system. It is demonstrated how the air coupling can be implemented when nonlinearities and collisions are present. Finally, some attention is devoted to the experimental validation of the numerical simulation in the case of tom tom drums. Preliminary results comparing different types of nonlinear models for membrane vibration are presented.

Le procédé de tournage galetage (CoTuB) est un traitement d'usinage innovant réalisant les procédés de tournage et de galetage à billes simultanément et sur la même machine-outil. L'objectif du procédé combiné est d'améliorer l'intégrité de surface et en même temps d'augmenter la productivité par rapport aux traitements conventionnels de surface et les procédés d'usinage. En adoptant un plan d’expérience, il a été démontré qu'une amélioration considérable de l’intégrité de surface pourrait être obtenue en utilisant le nouveau procédé combiné et en sélectionnant les paramètres appropriés. Pour effectuer une étude paramétrique, un ensemble d'expériences basées sur un plan d’expérience de type Taguchi complété par une analyse de la variance (ANOVA) a été réalisée. Le but de cette étude expérimentale est d'identifier les paramètres optimaux du tournage / galetage lors du traitement de l'acier 42 Cr Mo 4 permettant de donner une intégrité de surface optimale.Pour une meilleure compréhension des phénomènes impliqués lors du procédé combiné d'usinage / galetage, des approches et méthodologies numériques ont été développées afin de reproduire le procédé combiné. Une nouvelle approche numérique, appelée «Approche Mixte», est développée et utilisée afin de simplifier la simulation du procédé combiné. Cette approche combine des données expérimentales et numériques afin de déterminer la forme et de quantifier les chargements thermiques et mécaniques exercés par l'outil de coupe sur la surface usinée sur chaque zone de cisaillement. Cette nouvelle méthode a permis d'effectuer une simulation 3D du procédé de tournage-galetage combiné et permet de simuler plusieurs passages des outils autour de la surface usinée. La simulation permet de prédire les contraintes résiduelles induites par le procédé combiné et la comparaison révèle un bon accord entre les résultats numériques et expérimentaux. / The Combined Turning-Burnishing (CoTuB) process is an innovative machining treatment that performs turning and ball-burnishing processes simultaneously and on the same machine tool. The aim of performing the combined process is to enhance surface integrity and increase productivity at the same time when compare to conventional surface treatment and machining processes. Based on adopting design of experiments, it has been depicted that a considerable improvement in surface quality could be obtained meaning the new combined process by using the suitable process parameters. In order to carry out a parametric study, a set of experiments based on Taguchi method completed with a statistical analysis of variance (ANOVA) were performed. The aim of this experimental investigation is to identify the optimal turning/burnishing parameters when treating AISI 4140 steel. This helps to get an optimal surface integrity. For a better understanding of the phenomena involved during combined machining / burnishing processes, numerical approaches and methodologies for reproducing the combined turning-burnishing process have been performed. A new approach, called the "Mixed Approach", is developed and used in order to simplify the simulation of the combined process. This approach combines experimental and numerical data in order to determine shape and to quantify thermal and mechanical loadings exerted by the cutting tool on the machined surface on each shear zone. This new method allowed to perform a 3D simulation of combined turning-burnishing and allows to model several tool passages on the machined surface. The simulation allows to predict residual stresses induced by the combined process and the comparison reveals good agreements between numerical and experimental results.

To circumvent some inherent problems in the conventional ECG, this research reinvestigates an ‘unassisted’ approach which enables ECG measurement without the placement of leads on the body. Employed in this research is a widely accepted assumption that the electrical activity of the heart may be represented, largely, by a 3-D time-varying current dipole (3D-CD). From the PhysioBank database, mECG and fECG data were obtained, and Singular Value Decomposition (SVD) was performed to estimate the time-varying Vector ECG dipole. To determine the sensing matrix responsible for transforming the activity of the 3D-CD into the potential distribution on the surface of the medium, the ECG vector dipole signals are used to excite a 3D-CD in water medium of a specific shape-containing-ellipsoid model(s) in COMSOL tool. The sensing matrix thereby estimated is then utilized to reconstruct the 3D-CD signals from the signals measured by the probes on the surface of the medium. Fairly low NRMSEs (Normalized Root-Mean-Squared Errors) are attained. The approach is also successfully extended to the case of two ellipsoids, one inside the other, representing a pregnant female subject. Low NRMSEs (Normalized Root-Mean-Squared Errors) are again observed.

Les cartes électroniques modernes nécessitent des analyses avancées d’intégrité du signal (IS), d’intégrité de puissance (IP), et de compatibilité électromagnétique (CEM). Face aux complexités des circuits imprimés, les méthodes de calcul classiques ne permettent ni de poser le problème ni de l’analyser théoriquement. Cependant, l’analyse tensorielle des réseaux (ATR) basée sur la méthode de Kron complétée du modèle de Branin (KB) laisse entrevoir une capacité d’analyse plus avancée des PCB. L’ATR appliquée à l’espace des mailles conduit à une modélisation compacte et une expression lagrangienne directe des circuits imprimés. Cette thèse présente une approche sous l’ATR appliquée aux circuits imprimés d’IS, IP, CEM et multiphysique des circuits imprimés multicouches. Après la description de l’état de l’art, la méthodologie de base de l’approche par l’ATR est décrite à l’aide de la formulation des métriques tensorielles dans le domaine des fréquences. Après définition des éléments primitifs nécessaires pour les structures des circuits imprimés et l’introduction analytique de la méthode KB, le modèle sous l’ATR et des analyses de sensibilité sont comparées avec des simulations « 3D » en utilisant des outils commerciaux et des mesures expérimentales du régime continu jusqu’à des fréquences de quelques gigahertz. Ensuite, le modèle des circuits multicouches est originellement traduit totalement dans le domaine temporel (DT) en définissant les opérateurs temporels appropriés aux éléments dits « primitifs » sous l’ATR. La pertinence du modèle ATR en DT est vérifiée par des comparaisons avec des simulations é3D » et des mesures de circuits multicouches en prenant en compte des signaux de débits de l’ordre du gigabit par seconde. Dans la partie suivante, des modèles innovants élaborés via l’ATR pour la CEM en modes rayonnés des cartes multicouches sont étudiés en considérant des couplages entre champs électromagnétiques et cartes multicouches. La modèle élaboré sous l’ATR pour la CEM des modes rayonnés est validé avec un scénario composé de circuits imprimés multicouches avec une ligne d’interconnexion en forme de « Z » agressés par des rayonnements électromagnétiques émis dans différentes directions de propagation, et aussi avec un couplage rayonné entre un circuit microruban avec une ligne en forme de « I » et un circuit multicouche. Puis, une analyse multiphysique complètement originale d’un circuit multicouche sous agression de cycle thermique est développé toujours sous le formalisme de l’ATR en traitant des phénoménologies électromécaniques. Après avoir formulé l’expression des sous-systèmes monophysiques, la métrique multiphysique du circuit multicouche sous agression de cycle thermique est élaborée. La faisabilité de cette analyse multiphysique est vérifiée à l’aide d’une preuve de concept d’un circuit à quatre couches. La dernière partie de cette thèse est consacrée à la CEM en mode conduit d’un circuit imprimé composé d’interconnexions multicouches, de composants passifs et de circuits intégrés comme composants actifs. Il est démontré que l’approche par l’ATR permet d’hybrider des modèles analytiques, numériques, et les standards IC-EMC et IBIS afin de réaliser une analyse pertinente de la CEM des cartes multicouches. Ce modèle typiquement système permet de prédire des niveaux de bruits émis par des perturbations CEM liées aux courants de perturbation induits par des circuits intégrés, via une matrice impédance de transfert dans les domaines des fréquences et du temps. / The modern electronic printed circuit boards (PCBs) require challenging signal integrity (SI), power integrity (PI) and electromagnetic compatibility (EMC) analyses. The PCB analysis conventional computational methods do not allow to pose and to analyse theoretically most of problems. However, the Kron’s method completed by Branin’s one based tensorial analysis of networks (TAN) promises a complex PCB analyses possibility. The TAN formalism applied to mesh space allows the PCB compact modeling and direct Lagrangian expression. This thesis introduces multilayer PCBs SI, PI, EMC, and Multiphysic TAN approaches. After the state-of-the-art description, the TAN modelling basic methodology by the way of tensorial metric formulation applied to PCB analysis in the frequency domain is developed. After the definitions of primitive elements necessary to investigate the PCB structure and the KB method introduction, the TAN model is validated from DC to some gigahertz with commercial tool « 3D » EM full-wave simulations and experimental measurements added by sensitivity analyses. Then, the multilayer PCB TAN is originally translated into innovative direct time-domain (TD) model by defining the primitive element appropriate TD operators. The TD TAN model efficiency is verified with multilayer PCB 3D simulation and measuremet comparisons by considering multigigabits-per-second high-speed signals. In the next part, original multilayer PCB radiated EMC TAN models are investigated via EM field coupling onto the PCBs. The radiated EMC model is validated with a scenario consisted of « Z »-shape multilayer PCB aggressed by radiated EM plane waves in different propagation directions and radiated coupling between multilayer and « I »-shape line microstrip PCBs. Then, a completely original Multiphysics TAN of multilayer PCB under thermal cycle aggression is developed by dealing with electrothermomechanical phenomena. After formulating monophysics subsystem TAN expression, the Multiphysics metrics of multilayer PCB under thermal cycle aggression id elaborated. The TAN Multiphysics analysis feasibility is verified with a four-layer proof-of-concept. The last part of this thesis is devoted to conducted EMC TAN of PCB system comprised of multilayer interconnects, passive components and active integrated circuit (IC) elements. It is shown that the TAN approach enables to hybridize the analytical, numerical, IC-EMC and IBIS standard models to perform a multilayer PCB EMC relevant analysis. This system level model allows to compute the EMC noises induced by IC perturbation currents with an innovative transfer matrix impedance in both frequency and time domains.

In this study, a robotic software, which controls the robot, is developed. The robot considered is a six degree of freedom robot and it is designed and manufactured in METU. User can send the robot anywhere in space within its workspace, in any orientation. Forward and inverse kinamatics can be executed according to the needs. Simulation framework is embedded into the software for the 3D visualisation of the robot. Any movements can be simulated on the screen. Software also generates the path for the given points. Then generated path is simulated on the screen. All position, velocity and acceleration graphics of joints can be examined for the generated path.

The field of robotics is becoming increasingly more important and consequently, students need better tools to gain knowledge and experience with them. The University of Skövde was interested in developing a learning tool focused on a virtual simulation of mobile robots. Despite the fact that there are several programmes to create this tool, MATLAB was preferable because of its strong presence in educational institutions. The objectives were oriented towards testing different robot kinematics in an adjustable virtual 3D environment. Moreover, the simulation needed a part in which future users could design own algorithms in order to control the AGVs. Therefore, sensors such as LIDAR sensors were necessary to enable a possible interaction between the robot and the scenario created. This project was developed with a previous study and a comparison of some MATLAB projects and tools. After that, the scenario and the simulation were produced. As a result, a virtual simulation has been created emphasising that the user could modify and adapt multiple parameters such as the size of the AGV, the form of the virtual environment or the selection of forward or inverse kinematics in order to develop different types of algorithms. Other features can be adjusted manually such as the type or number of sensors as well as SLAM conditions. Finally, this thesis was conducted to give a basis about mobile robots and to be a first step for operating with real robots. The simulation also provides an easy to use interface in which students can keep working in it through the introduction of new applications related to image processing or more sophisticated algorithms and controllers.

I den här kandidatuppsatsen inom Designteknik ska passform på shorts utforskas. I rapporten undersöks grensömmars passform i komfort, visuellt och under fysiska avprovningar. Olika faktorer som påverkar grensömmars passformsproblem analyseras. Arbetet baseras på ett samarbete mellan ett företag där en fältstudie utfördes, där företaget producerar träningskläder. Kärnan till ämnet uppkom när man sett brister i passform runt grensömmen på byxor och shorts i vävda material under avprovningar på marknaden. I tidigare forskning instämmer en stor majoritet av författarna att grensömmen är en kritisk punkt. Framställning av byxor med en god passform i grensömmen kan vara förhållandevis komplext men det beror inte bara på arbetslivserfarenheten. Under projektet granskas fyra befintliga shorts från marknaden. Det som dokumenteras är passformen, grensömmen på provpersoner och genomskärning av grensömmen för att utvärdera likheter och olikheter. Två shortsmodeller konstrueras utifrån litteratur och annan sekundära data. En tabell för kroppsmått för dam från företaget och mätningar på de tilldelade shortsen används som referens. Shortsens passform provas fram i form av 3D- simulering och på levande modeller. Resultatet av avprovningarna visar likheter av placering av veckbildning och dragningar i 3D- simuleringen respektive de fysiska avprovningarna. Shortsen provas även av i tränings positioner, det resulterade i att shortsen kändes annorlunda runt grensömmen vid hukande gentemot stående position och att grenkurvan ändrade form. Shortsen vidareutvecklades utifrån tidigare prövningar och studier, det resulterade i ett grundmönster. Grundmönstret ska kunna vara till hjälp för flera företag i deras framtagning av byxor och shorts till dam och minimera tillverkning av fysiska prototyper.