Kaunis Iron är ett gruvföretag som utvinner järnmalm i Kaunisvaara och producerade cirka 2,3 miljoner ton finkornigt järnmalmskoncentrat under 2022, vilket även går under benämningen slig. Företaget har planer på att öppna två nya dagbrott inom en snar framtid för att öka årsproduktionen till 3 miljoner ton. Som en global aktör betjänar Kaunis Iron kunder över hela världen, vilket kräver effektiva och väl fungerande transporter för att säkerställa hög leveranssäkerhet och nöjda intressenter. Syftet med denna studie var att analysera leveranskedjan utifrån dess kvalitet, kostnadseffektivitet och produktivitet för att identifiera eventuella flaskhalsar som påverkar leveranssäkerheten. Studien använde problemlösningsmetodiken DMAIC och genomfördes som ett Six Sigma-projekt med hjälp av simulering och försöksplanering. Faktorerna antal chaufförer per skiftlag, antal lastbilar, tillgänglighet lastbilar, tillgänglighet chaufförer, fastfrysningar och lagerkapacitet i Pitkäjärvi undersöktes genom en optimal design i två separata scenarier. Det första scenariot baserades på Kaunis Irons nuvarande årsproduktion på 2,3 miljoner ton, medan det andra scenariot utgick från en framtida årsproduktion på 3 miljoner ton. Totalt genomfördes 100 delförsök i det första scenariot och 120 delförsök i det andra. Resultaten från dessa två scenarierna användes sedan för att optimera transporten av slig för respektive scenarion, med fokus på att öka leveranssäkerheten och därmed minska den totala kostnaden. Studiens slutsats var att samtliga undersökta faktorer hade en viss påverkan på förseningstiderna och de totala kostnaderna för hela värdeflödet, för respektive scenario. Resultaten antyder att det nuvarande transporten av slig inte är optimal. Efter analys och optimering för respektive scenario är våra rekommendationer att använda 37 chaufförer/skift och 33 lastbilar för scenario 1 samt 46 chaufförer/skift och 39 lastbilar för scenario 2. Om tillgänglighet på lastbilar och chaufförer ökas samt att det sker en effektivisering av cykeltiden på grund av minskning av fastfrysningar, blir de optimala inställningarna 34 chaufförer/skift och 31 lastbilar för scenario 2,3 miljoner ton samt 42 chaufförer/skift och 39 lastbilar för scenario 3 miljoner ton. För scenariot 3 miljoner ton rekommenderas en utbyggnad av lager i Pitkäjärvi till alternativet 70 000 ton. En ytterligare slutsats från studien är att det inte alltid är ekonomiskt fördelaktigt att helt eliminera förseningstiderna. I scenariot med 2,3 miljoner ton visade det sig att den optimala lösningen innefattar en viss förseningskostnad (1 993 tkr), vilket ändå resulterade i ett kostnadseffektivare system. Baserat på kostnadsöversikterna i control-avsnittet går det att dra slutsatsen att det är mer ekonomiskt fördelaktigt för Kaunis Iron att använda sin egen personal och lastbilar för att uppnås en hög leveranssäkerhet. / Kaunis Iron is a mining company that extracts iron ore in Kaunisvaara and produced approximately 2,3 million tons of fine-grained iron ore concentrate, also known as slig, in 2022. The company plans to open two new open-pit mines in the near future to increase annual production to 3 million tons. As a global player, Kaunis Iron serves customers worldwide, which requires efficient and well-functioning transportation to ensure high delivery reliability and satisfied stakeholders. The purpose of this study was to analyze the supply chain in terms of its quality, cost-effectiveness, and productivity to identify any bottlenecks that affect delivery reliability. The study used the DMAIC problem-solving methodology and was conducted as a Six Sigma project using simulation and experimental design. The factors of the number of drivers per shift team, the number of trucks, truck availability, driver availability, freezing issues, and storage capacity in Pitkäjärvi were examined through an optimal design in two separate scenarios. The first scenario was based on Kaunis Iron's current annual production of 2,3 million tons, while the second scenario assumed a future annual production of 3 million tons. A total of 100 sub-experiments were conducted in the first scenario and 120 sub-experiments in the second. The results from these two scenarios were then used to optimize the transportation of slig for each scenario, with a focus on increasing delivery reliability and thus reducing the overall cost. The study concluded that all the factors examined had some impact on the delay times and total costs for the entire value stream, for each scenario. The results suggest that the current transportation of slurry is not optimal. After analysis and optimization for each scenario, our recommendations are to use 37 drivers/shift and 33 trucks for scenario 1, and 46 drivers/shift and 39 trucks for scenario 2. If truck and driver availability is increased and cycle time is improved due to reduced freezing issues, the optimal settings would be 34 drivers/shift and 31 trucks for the 2,3 million-ton scenario, and 42 drivers/shift and 39 trucks for the 3 million-ton scenario. For the 3 million-ton scenario, expanding the storage capacity in Pitkäjärvi to the 70 000 ton option is recommended. Another conclusion from the study is that it is not always economically advantageous to completely eliminate delay times. In the 2,3 million-ton scenario, it was found that the optimal solution includes a certain delay cost (1 993 tkr), which still resulted in a more cost-effective system. Based on the cost overviews in the control section, it can be concluded that it is more economically advantageous for Kaunis Iron to use its own personnel and trucks to achieve high delivery reliability.

Detab is a company in Jönköping that develops systems for feeding parts for robots and packaging processes. To control the flow of parts on their vibratory feeders, Detab uses different carpets with angled straws. The two mainly used carpets have been discontinued and must now be replaced. A newly emerged option is a contender in replacing one of the carpets. The new white carpet is completely additively manufactured. To compare the old carpet and the new carpet, data is needed to show how different settings affect the flow of the parts. Through design of experiments and response surface methods, tests can be performed in a systematic and mathematical way compare the performance of different settings. Some basic parameters were defined to begin the investigation of which design of experiments method would be used to best compare the carpets. The parameters defined where the parts that would be used in the tests, the factors that were to be adjusted during the tests, the maximum and minimum values of the selected factors and how the results would be measured. Different methods were tested, and finally optimal design was chosen and executed using the program Design-Expert. The completed tests resulted in response surfaces that were constructed using Design-Expert. These response surfaces were analyzed and several similarities and differences between the different carpets were observed. Primarily, it was found that the green carpet had more settings that resulted in a flow above 0 parts/minute. Using Design-Expert, the response surfaces could be analyzed to find the optimal settings and their expected response. These points and more were then compared with tests performed afterwards to see if the expected values matched reality. It turned out that there were some uncertainties in how well the surfaces could predict the response in comparison with reality. Based on the experiments carried out, recommendations were made on how the company should proceed to be able to assess whether the new carpet is worth using in future construction of their machines.

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no / In this work, a model based MINLP (mixed integer nonlinear programming) optimisation framework is developed for evaluating boron rejection in a reverse osmosis (RO) desalination process. A mathematical model (for the RU process) based on solution diffusion model and thin film theory is incorporated in the optimisation framework. A superstructure of the RU network is developed which includes two passes: (a) seawater pass containing normal two-stage RU system housing seawater membrane modules and (b) the brackish water pass (BW) accommodating brackish water membrane modules. For fixed freshwater demand, the objective of this work is to demonstrate the effectiveness of the MINLP approach for analyzing and optimizing the design and operation of RU network while attaining desired limit on boron concentration in the freshwater produced. The effect of seasonal variation in seawater temperature and pH on boron removal efficiency is also discussed.

Design problems involve finding optimal plans that minimize cost and maximize information about the effects of changing experimental variables on some response. Information is typically measured through statistically meaningful functions, or criteria, of a design's corresponding information matrix. The most common criteria implicitly assume equal interest in all effects and certain forms of information matrices tend to optimize them. However, these criteria can be poor assessments of a design when there is unequal interest in the experimental effects. Morgan and Wang (2010) addressed this potential pitfall by developing a concise weighting system based on quadratic forms of a diagonal matrix W that allows a researcher to specify relative importance of information for any effects. They were then able to generate a broad class of weighted optimality criteria that evaluate a design's ability to maximize the weighted information, ultimately targeting those designs that efficiently estimate effects assigned larger weight. This dissertation considers a much broader class of potential weighting systems, and hence weighted criteria, by allowing W to be any symmetric, positive definite matrix. Assuming the response and experimental effects may be expressed as a general linear model, we provide a survey of the standard approach to optimal designs based on real-valued, convex functions of information matrices. Motivated by this approach, we introduce fundamental definitions and preliminary results underlying the theory of general weighted optimality. A class of weight matrices is established that allows an experimenter to directly assign weights to a set of estimable functions and we show how optimality of transformed models may be placed under a weighted optimality context. Straightforward modifications to SAS PROC OPTEX are shown to provide an algorithmic search procedure for weighted optimal designs, including A-optimal incomplete block designs. Finally, a general theory is given for design optimization when only a subset of all estimable functions is assumed to be in the model. We use this to develop a weighted criterion to search for A-optimal completely randomized designs for baseline factorial effects assuming all high-order interactions are negligible. / Ph. D.

Noise has become a main nuisance in urban areas to the point that according to the World Health Organization 40% of the European population is exposed to excessive noise levels, mainly due to ground transportation. There is therefore a need to find new ways to mitigate noise in urban areas. In this work, a possible device to achieve this goal is studied: a low-height noise barrier. It consists of a barrier typically less than one meter high placed close to a source, designed to decrease the noise level for nearby pedestrians and cyclists. This type of device is studied both numerically and experimentally. Tramway noise barriers are especially studied since the noise sources are in this case very close to the ground and can therefore be attenuated efficiently. The shape and the surface treatment of the barrier are optimized using a gradient-based method coupled to a 2D boundary element method (BEM). The optimization variables are the node coordinates of a control mesh and the parameters describing the surface impedance. Sensitivities are calculated efficiently using the adjoint state approach. Numerical results show that the shapes generated by the optimization algorithm tend to be quite irregular but provide a significant improvement of more than 5 dB (A) compared to simpler shapes. Utilizing an absorbing treatment on the source side of the barrier is shown to be efficient as well. This second point has been confirmed by scale model measurements. In addition, a full scale low height noise barrier prototype has been built and tested in situ close to a tramway track in Grenoble. Measurements show that the device provides more than 10 dB (A) of attenuation for a close receiver located at the typical height of human ears. These results therefore seem to confirm the applicability of such protections to efficiently decrease noise exposure in urban areas

Ce travail de thèse constitue le prolongement direct des travaux de thèse Chachuat (2001) sur l'optimisation dynamique et la commande optimale des stations de traitement de petite taille. L'objectif est d'aller plus loin en s'intéressant aux dimensionnement et fonctionnement optimaux des stations de traitement des eaux usées de toute taille. Ainsi, dans une première étape, l'optimisation des stations de traitement de petite taille a été abordée. Contrairement à ce qui a été fait jusqu'à maintenant : (i) l'aération n'est plus alternée, mais continue, (ii) le décanteur n'est plus considéré comme parfait, mais son fonctionnement est modélisé à l'aide d'une série de 10 couches de décantation, (iii) la méthode d'optimisation développée est fondée sur la méthode des sensibilités implémentée au sein du logiciel de simulation et optimisation dynamiques gProms, utilisé dans toute la thèse. L'influence du modèle du décanteur sur la minimisation de l'énergie d'aération a été particulièrement analysée. Dans une deuxième étape, les stations de traitement de grande taille sont considérées. Plus spécifiquement, le modèle benchmark développé par le réseau européen COST a été utilisé pour décrire leur fonctionnement. Un « foreignobject » a été développé pour que la simulation et l'optimisation du fonctionnement de ces stations soient possibles sous gProms. L'optimisation a notamment montré que la consommation d'énergie d'aération pouvait être réduite d'au moins de 30% par rapport au fonctionnement actuel de ces stations. Dans une troisième étape, l'optimisation du dimensionnement des stations de traitement de grande taille a été étudiée. Une superstructure a ainsi été définie avec plusieurs (cinq) réacteurs et un décanteur. Toutes les possibilités de recyclage et de court-circuit entre les réacteurs d'une part et entre les réacteurs et le décanteur d'autre part sont prises en compte. L'objectif était de déterminer la meilleure structure et les valeurs optimales des volumes des réacteurs qui permettent de minimiser le coût total tout en respectant les contraintes réglementaires sur les rejets.Par ailleurs, une optimisation multicritère de la station optimale résultante a été réalisée. Elle a permis de déterminer l'ensemble de Pareto des solutions qui minimisent la consommation énergétique (d'aération et de pompage) et maximisent la qualité de l'effluent. La quatrième et dernière partie de ce travail s'intéresse à la modélisation, simulation et optimisation de la station de traitement de Verulam près de Durban en Afrique du Sud. Des mesures expérimentales ont été réalisées sur cette station et le modèle ASM1 a été utilisé pour décrire son fonctionnement. Une analyse d'estimabilité des paramètres a été d'abord réalisée pour déterminer les paramètres du modèle qui peuvent être estimés à partir des mesures expérimentales disponibles. Les paramètres estimables ont ensuite été identifiés à l'aide de gProms. Le modèle ainsi identifié a été validé et ensuite utilisé pour optimiser le fonctionnement énergétique de cette station / This work is a direct extension of the PhD thesis of Chachuat (2001) on dynamic optimization and optimal control of small size wastewater treatment plants. The objective is to go further by focusing on optimal design and operation of wastewater treatment plants of any size. Thus, in a first part, optimization of small size wastewater treatment plants was studied. Contrary to what has been done so far: (i) the aeration is no longer alternating, but continuous, (ii) the settler is not considered perfect, but its operation is modeled using a series of 10 sedimentation layers, (iii) the optimization approach developed is based on the method of sensitivities implemented wthin the dynamic simulation and optimization software gProms, used throughout this work. The influence of the settler model on the minimization of aeration energy was particularly investigated. In a second part , the large size treatment plants are considered . More specifically, the benchmark model developed by the European network COST was used to describe their operation. A "foreign object" was developed in order to make the simulation and optimization of these plants possible using gProms. The optimisation showed that the aeration energy consumption could be reduced by at least 30 % compared to the current operation of these plants . In a third part, the optimization of the design of the wastewater treatment plant was studied. A superstructure has been defined with several (five) reactors and a settler. All the possibilities of recycling and by-passes between the reactors on the one hand and between the reactors and the settler on the other are considered. The objective was to determine the best structure and the optimal values of the reacter volumes that minimize the net present value while respecting the regulatory constraints. On the other hand, a multi-objective optimization problems of the treatment plant was carried out. It allawed to determine the Pareto set of solutions that minimize the energy consumption (pumping and aeration) and maximize the effluent quality. The fourth and last part of this work focuses on modeling, simulation and optimization of the treatment plant of the city of Verulam in the area of Durban in South Africa. Experimental measurements were carried out on the plant and the ASM1 model was used to describe its operation. An estimability analysis was first performed in order to determine the model parameters that can be estimated from the available experimental measurements . The estimable parameters were then identified using gProms . The identified model was validated and then used to optimize the energy function of this plant

Les grandes entreprises ferroviaires intègrent au niveau du matériel roulant une grande variété de systèmes complexes qui se doivent d’être fiables et ce, dès le démarrage du service commercial. Ce travail de thèse propose une méthodologie expérimentale pour l’amélioration de la robustesse d’un système prédominant, à savoir l’accès voyageurs. L'objectif est d'améliorer sa fiabilité intrinsèque dans un laps de temps raisonnable dans le cadre de projet industriel contraint par le temps. La méthodologie expérimentale proposée s’appuie sur la méthode des essais aggravés et accélérés de fiabilité, et se veut être optimisée grâce à l’utilisation de plans d’expériences D-optimaux. Après une analyse bibliographique, suivie d’une étude sur l’utilisation des plans d’expériences D-optimaux, ce travail expose les méthodes et moyens expérimentaux mis en place pour utiliser les plans d’expériences dans un contexte industriel. La dernière partie de cette thèse contient les résultats quantitatifs et qualitatifs issus des expérimentations réaliséessur le banc d'essais du système accès voyageurs développé par Bombardier. / The train manufacturer companies handle a large number of complex systems in their trains. These systems must be reliable to ensure reliability of the final product as soon the entry into commercial services. This thesis provides an experimental solution to improve robustness of a predominate system, namely passengers access system. The goal is to improve inherent reliability in a reasonable amount of time to be integrated in a project phase. This experimental method is based on testing aggravated and accelerated method temporally optimized with using of D-optimal design of experiment. After a literature review, followed by a focus on the definition and use of experimental design D-optimal, this work will present experimental methods and means used to set up the experimental design in an industrial context. The last part of this thesis contains quantitative and qualitative results performed on the passenger’s access test bench developed by Bombardier.

Les robots parallèles à câbles sont une variante originale des robots parallèles. L'utilisation de câbles en lieu et place des segments rigides procure à ce type de robots un espace de travail potentiellement très grand car des longueurs importantes de câbles peuvent être déroulées. Toutefois, dans la plupart des études sur les robots à câbles, un modèle de câble sans masse non élastique est utilisé. Si dans le cas de robots de faibles dimensions soumis à de faibles efforts, ce modèle est valide, lorsque l'on considère des applications de très grande dimension pour lesquels la masse des câbles et l'élasticité ne peuvent plus être négligées, ces modèles simples ne sont plus valables. Ces travaux de thèse proposent des nouvelles méthodes d'étude des robots parallèles à câbles de grande dimension. Dans un premier temps, des tests de traction réalisés sur différents câbles permettent de proposer différents modèles élastiques. La modélisation d'un câble par une caténaire élastique est ensuite rappelée, et l'erreur importante obtenue en négligeant la masse des câbles est mise en exergue. La modélisation par caténaire élastique bien que précise, nécessite la résolution d'un système d'équations couplées non-linéaires. Un modèle simplifié de câble pesant est alors présenté. Il permet, sous l'hypothèse de faible déflection du câble, de simplifier la résolution de l'équilibre statique d'un robot à câble. Ce modèle permet également de développer des outils utiles à la détermination de l'ensemble des torseurs d'efforts admissibles à la plate-forme d'un robot parallèle à câbles. La vérification de l'inclusion de l'ensemble des torseurs nécessaires à la réalisation d'une tâche dans l'ensemble des torseurs admissibles est finalement utilisée comme critère d'optimisation pour une méthode de conception de robots à câbles de grandes dimensions. / Cable-driven robot is an original variation of parallel robots. Replacing rigid bodies by cables provides new capabilities to these robots, and particularly large-size workspaces, since long cable lengths can be deployed. In the literature, cables are usually supposed to be inextensible and massless. If this modeling is valid for small robots with moderate payloads, this cable model is not accurate enough to be used for large dimension cable-driven robots. The work presented here focuses on the modeling of such large cable robots. First, from a set of traction tests applied to various cables, elastic models are proposed. Then, the well-know elastic catenary model is recalled, and its effects on the modeling of large dimension cable robots is shown. However, when using this cable model, solving the platform static equilibrium require the resolution of a non-linear coupled equation system. Assuming a low sagging of the cable, some simplifications can be made to this model. The resulting simplified hefty cable model is then presented and the new expression of the static equilibrium is shown to be close to the one obtained with the massless cable model. Thus, it allows us to determine the set of admissible mobile platform wrenches at a given pose. By comparing this set to the set of required wrenches for a specific task a cost function is finally defined and used in a design procedure dedicated to large dimension cable-driven robots.

In the present study, the optimal design of feeding system in steel sand-mold castings is considered. The first part of this research includes fundamental studies on the physics of shrinkage defect formation during the casting process. The results of these studies lead to new findings on the mechanism of shrinkage defect formation, effect of melt quality on the distribution of defects within the castings and the connection between shrinkage and gases defects. The theoretical analysis of thermal criterion functions for the prediction of shrinkage defects in castings and introducing new criterion function with fewer shortcomings can be accounted as the other finding of this part. A new model was introduced in the second part of this research for the purpose of optimal design of feeding system in the shape casting processes. In this model the optimal design problem is formulated as a point-wise constrained topology optimization problem. Unlike alternative methods, the presented method does not require any predesigned feeding system as an initial guess. Using the functional analysis on the infinite-dimensional function spaces, a numerically efficient method was introduced to solve the optimal design problem in this study. By using extensive numerical experiments, capabilities and limitations of the presented method were studied in the last part of this research.