Most manufacturing processes produce parts that can only be correctly measured after the process cycle has been completed. Even if in-process measurement and control is possible, it is often too expensive or complex to practically implement. In this paper, a simple control scheme based on output measurement and input change after each processing cycle is proposed. It is shown to reduce the process dynamics to a simple gain with a delay, and reduce the control problem to a SISO discrete time problem. The goal of the controller is to both reduce mean output errors and reduce their variance. In so doing the process capability (e.g. Cpk) can be increased without additional investment in control hardware or in-process sensors. This control system is analyzed for two types of disturbance processes: independent (uncorrelated) and dependent (correlated). For the former the closed-loop control increased the output variance, whereas for the latter it can decrease it significantly. In both cases, proper controller design can reduce the mean error to zero without introducing poor transient performance. These finding were demonstrated by implementing Cycle to Cycle (CtC) control on a simple bending process (uncorrelated disturbance) and on an injection molding process (correlated disturbance). The results followed closely those predicted by the analysis. / Singapore-MIT Alliance (SMA)

The diploma paper is devoted to verification the application of SPC methods and performs evaluation of statistical stability and process eligibility of steel stampings in the real production process. In the second part is the author of the paper trying to design the optimal form of SPC methods for its use in a specified manufacturing process.

This work deals with documentation of produce of electrotechnical components in focus of quality and effeciency.

This master`s thesis is focused on the application of statistic process control in engineering production and it is focused on comparison with method Beta correction. The aim of the diploma thesis is to find suitable regulation of the producing process with respect to provision of sufficiently high level of quality of products at the process of achievement of adequate costs conneced with process monitoring. The basic principles of both methods are solved in the theoretical part of this diploma thesis. Both methods are compared in particular producing process in the practical part of the thesis. Conclusions and suggestions are done on the base of gained data.

This graduation thesis is concerned with implementing the SPC (Statistical process control) to the process plan. The aim of this thesis is an analysis of present status of manufacture laths bending and a selection of useful methods, which is possible to apply in a company processes. The main reason for SPC implementation is continual improvement of quality in manufacturing concern. The theoretical part of thesis consist of bending description, control of process quality, quality control instruments and errors in measurement. In practical part is described an actual status of manufacture and a solution of query.

<p>The objective of this research was to work with industrial partners to develop and apply innovative and intelligent improvement to their production processes in order to achieve a higher level of productivity and quality while lowering cost.</p> <p>Two projects were completed and are discussed in this work. The first project was focused on improving tooling in a milling process of high value parts by varying coatings and geometries of the tooling. The second project involved implementing statistical process control (SPC) using control charts and process capability metrics through customized software.</p> <p>In the first project, the industrial partner was experiencing rapid wear of tools when milling NiCrMoV steel. A detailed material characterisation study revealed the likely cause was the presence of un-tempered martensite having high hardness. Cutting tools were then chosen to compare the performance of tools with varying rake angle and coating; where all other geometry/features were identical. It was found that the best performing tooling had a relatively more aggressive rake angle at 16º, and a PVD coating consisting of TiAlN + Al₂O₃+ ZrN; showing a tool life 300% greater than the baseline tooling. Inspection of the worn tools by SEM, EDX, and Raman spectroscopy revealed that the Al₂O₃ and ZrN coating layers detached long before the failure.</p> <p>In the second project, software was developed collaboratively with an industrial partner for a CNC turning process. The process was semi-automated, and used 100% inspection of parts. Part measurement data was recorded by the software, allowing for SPC to be applied to identify common-cause sources of variation. The software was then able to make offset recommendations in real-time to correct for variation. Providing process history for quality assurance (QA) also allowed for identifying of several areas for improvement in the process which were corrected, considerably reducing variability.</p> / Master of Applied Science (MASc)

Actuellement, il existe deux types de peintures anti-salissures marines sur le marché : - Les Self-Polishing Coatings (SPC), revêtements auto-polissants à base de liants polymères hydrolysables, efficaces par relargage de biocides dans le milieu marin mais toxiques pour l’environnement ; - Les Fouling Release Coatings (FRC), revêtements hydrophobes à base de silicone, sans biocides, qui limitent la force d’adhésion des salissures mais ne sont pas efficaces en mode statique.L’objectif de cette étude est d’élaborer des peintures anti-salissures marines hybrides FRC/SPC. Pour ce faire, des polymères diblocs à la fois hydrolysables et présentant une faible énergie de surface ont été synthétisés et caractérisés puis utilisés en tant que liants dans la formulation de peintures anti-salissures marines.Le procédé de polymérisation RAFT a été employé afin de synthétiser des polymères avec une architecture et une masse molaire contrôlée. Deux approches ont été abordées :- Des polymères ont été synthétisés à base de monomères de faible énergie de surface et hydrolysables (le méthacrylate de (heptaméthyl-trisiloxy)diméthylsilyle et le méthacrylate de bis(triméthylsilyloxy)méthylsilyle) avec un co-monomère méthacrylate de méthyle ou méthacrylate de butyle. Il a notamment pu être montré que les copolymères de structure dibloc présentent une énergie de surface plus faible que les copolymères statistiques.- Des polymères ont été synthétisés à partir de monomères hydrolysables tel que le méthacrylate de tert-butyldiméthylsilyle et de monomères de faible énergie de surface tel que le méthacrylate de poly(diméthyl-siloxane).Les propriétés d’érosion (type SPC) et d’énergie de surface (type FRC) ont été étudiées pour les liants seuls et les peintures formulées, avant et pendant leur immersion en eau de mer artificielle. L’efficacité anti-salissures marines des peintures formulées a été évaluée lors de leur immersion in-situ en Mer Méditerranée. / Two main types of antifouling coatings are present on the market: - The Self-Polishing Coatings (SPC): they are based on hydrolysable polymer binders and their antifouling efficiency relies on the release of biocides in the marine surrounding. Unfortunately, they are toxic for the marine environment- The Fouling Release Coatings (FRC): these hydrophobic silicone-based coatings limit the adhesion strength of fouling organisms and are biocide-free. Nevertheless, they are not efficient during idle periods.The aim of this study is to develop FRC/SPC hybrid antifouling coatings. Thus, diblock polymers both hydrolysable and with a low surface energy have been synthesized and characterized, then used as binders for the formulation of antifouling coatings.Polymerization by the RAFT process has been used to synthesize well-architectured polymers with controlled molecular weights. Two different approaches have been considered:- Polymers have been synthesized from low surface energy and hydrolysable monomers ((heptamethyl-trisiloxy)dimethylsilyl methacrylate and bis(trimethylsilyloxy)methylsilyl methacrylate) and a co-monomer of methyl or butyl methacrylate. It has been demonstrated that the diblock copolymers exhibit a lower surface energy than the statistical copolymers.- Polymers have been synthesized from hydrolysable monomers (tert-butyldimethylsilyl methacrylate) and low surface energy monomers (poly(dimethylsiloxane) methacrylate).The erosion properties (SPC-type) and the hydrophobicity (FRC-type) have been studied for both the binders and the formulated coatings, before and during their immersion in artificial seawater. The antifouling efficiency of the formulated coatings has been evaluated during their in-situ immersion in the Mediterranean Sea.

L’objectif de ces travaux est de synthétiser des copolymères diblocs et triblocs à base d'unités monomères méthacrylate de tert-butyldiméthylsilyle et diméthylsiloxane. Le choix de ces unités monomères repose sur l'élaboration de films polymères hydrolysables dans le milieu marin et de faible énergie libre de surface, respectivement. Ces polymères ont été caractérisés puis utilisés comme liants dans la formulation de peintures anti-salissures marines SPC/FRC hybrides. Les performances des revêtements obtenus ont alors été comparées aux deux types de revêtements anti-salissures marines disponibles sur le marché : - les revêtements auto-polissants (Self-polishing copolymer, SPC), à base de liants polymères hydrolysables, efficaces par relargage de biocides dans le milieu marin et par érosion, mais toxiques pour l’environnement ; - les revêtements Fouling Release" (FRC), hydrophobes à base de silicone, et non toxiques, qui limitent la force d’adhésion des salissures mais sans efficacité en mode statique.Le procédé de polymérisation RAFT a été employé afin de synthétiser des polymères avec des architectures, des compositions et des masses molaires contrôlées. Des macro-agents de transfert de chaîne à base de poly(diméthylsiloxane)s ont été préalablement synthétisés à partir de poly(diméthylsiloxane)s mono et di-hydroxylés, de masses molaires 1000 , 5000 et 10000 g.mol-1. Trois séries de copolymères ont été préparées avec des masses molaires allant de 12000 à 60000 g.mol-1 et des teneurs en unités diméthylsiloxanes allant de 3% à 57%.Les propriétés de prise en eau, d'érosion (type SPC) et de mouillabilité (type FRC) ont été étudiées pour les liants seuls et les revêtements formulés avec et sans biocides. L'évolution de l'hydrophobie de surface des revêtements pendant leur immersion en eau de mer artificielle a été suivie. L'efficacité anti-adhésion bactérienne d'une série de copolymères, sous forme de vernis et de revêtements formulés, a été étudiée vis-à-vis de deux souches de bactéries marines. Enfin, l’efficacité anti-salissure marine des vernis et des revêtements formulés avec et sans biocides a été évaluée lors d'une immersion in-situ en Mer Méditerranée pendant 16 mois au maximum. / The aim of this study is to synthesize diblock and triblock copolymers based on tert-butyldimethylsilyl methacrylate and dimethylsiloxane monomer units. These monomer units have been selected to elaborate polymer films both hydrolysable in the marine environment and with a low surface energy. These copolymers have been fully characterized and have been formulated to develop FRC/SPC hybrid antifouling coatings. The performances of these new coatings have been compared to the two main types of antifouling coatings on the market:- the Self-Polishing coatings (SPC), based on hydrolysable polymer binders with an efficiency relied on the release of biocides in the marine environment and the erosion of the coating. Unfortunately, these coatings toxic for the marine environment;- the Fouling Release Coatings (FRC), based on hydrophobic and non-toxic silicone-based coatings which limit the adhesion strength of fouling organisms. Nevertheless, they are not efficient during idle periods. Block copolymers with controlled architecture, chemical composition and molar masses have been synthesized via the RAFT process from poly(dimethylsiloxane)-based chain transfer agents. These macro-chain transfer agents have been previously prepared from mono- and di-hydroxylated poly(dimethylsiloxane)s with molar masses of 1,000, 5,000 and 10,000 g.mol-1. Three series of copolymer have been synthesized with molar masses ranging from 12,000 to 60,000 g.mol-1 and a mass content of dimethylsiloxane units ranging from 3% to 57%. The water uptake, the erosion properties (SPC type) and the hydrophobicity (FRC-type) have been studied for both the binders and the coatings formulated with and without biocides. The evolution of the hydrophobic properties of the coatings' surface has been investigated during their immersion in artificial seawater. The anti-adhesion properties of one series of copolymers have been investigated toward two marine bacterial strains. Then, the antifouling efficiency of the binders and the coatings formulated with and without biocides has been evaluated during their in-situ immersion in the Mediterranean Sea for 16 months at a maximum.

Le contact Segment-Piston-Chemise (SPC) est essentiel pour la réduction des émissions de CO2 et de polluants dans les moteurs automobile. Pour optimiser ces deux contraintes antagonistes, il est nécessaire d’étudier l’influence de la microgéométrie afin de trouver de nouvelles architectures de ce contact. L’étude expérimentale étant très coûteuse, il est impératif de pouvoir modéliser les performances du contact SPC. Les méthodes multigrilles permettent de réduire considérablement les temps de calcul. Pour le contact SPC, les méthodes multigrilles classiques perdent leur efficacité en présence de texture. Un nouvel algorithme, basé sur des idées développées par Alcouffe et al. a été conçu qui permet l’étude du contact hydrodynamique en présence de texturation importante. Il a été validé par comparaison avec un modèle analytique 1D, ses performances ont été étudiées et une première étude de l’influence des paramètres sur la portance pour une surface striée a été faite. L’algorithme a ensuite été modifié pour imposer la conservation des flux. Un processus de relaxation plus proche de la physique du phénomène est utilisé. Le code obtenu n’atteint pas l’efficacité multigrille optimale. Cependant sa convergence est suffisamment rapide pour étudier l’influence de pores pour le segment plat et montrer l’importance d’une texturation partielle. Pour finir, le terme transitoire de l’équation de Reynolds est pris en compte. Pour un segment parabolique et une chemise striée, l’influence des paramètres des stries (profondeur, largeur, distance et angle des stries) sur la variation moyenne de la hauteur de film par rapport à une surface lisse est analysée. / The piston ring cylinder liner (PRCL) contact is essential in the CO2 and pollutant emission reduction in internal combustion engine. These two constraints being antagonistic, a compromise has to be found and it is necessary to study the microgeometry influence in order to find new PRCL contact architectures. As experimental study can be very expensive, modeling PRCL contact performance becomes crucial. Multigrid methods allow a huge reduction of the computational time. Unfortunately, in presence of texture, classical multigrid efficiency decays significantly and are not usable. A new algorithm based on an approach developed by Alcouffe et al. was designed that allows the study of the hydrodynamic lubrication of this contact even in the case of a highly varying geometry due to the texture. The obtained code was validated by comparison with a 1D analytical model, its performance was evaluated and a first study of an analytic cross hatched geometry parameter influence on the load carrying capacity was completed. The code was modified to include flow conservation. A relaxation process based closer to the physics phenomenon is used. The code efficiency is not the one that is expected from multigrid technics. However it convergence is sufficiently fast to study the dimple influence for the oil control ring and show the importance of partial texturing. Finally the transient term of the Reynolds equation is accounted for. In the case of a parabolic ring and for a cross hatched liner, the influence of the groove parameters ( depth, width, distance and groove angle) on the average minimum film thickness with respect to the smooth case is analyzed.

Mon travail se concentre sur la morphogenèse épithéliale pendant l’élongation embryonnaire de C. elegans. Ce processus s’appuie sur la transmission de signaux mécaniques, jouent un rôle essentiel également au cours de l’homéostasie tissulaire. Le gène pak-1 joue un rôle essentiel au cours des tels processus à la fois chez l’homme et dans l’élongation chez C. elegans. Nous avons montré que α-spectrine (SPC-1) est un nouveau partenaire de la kinase PAK-1. Pendant mon doctorat, j’ai confirmé que la perte simultanée de PAK-1 et de SPC-1 induit des défauts sévères d’élongation, impliquant une rétractation et un collapse général de l’embryon et suggèrent la présence de défauts biomécaniques. Mon travail était destiné à déterminer comment la perte de PAK-1 et SPC-1 influence le comportement mécanique des cellules épidermales. Cette étude permettra de mieux d’établir le rôle de SPC-1 et de PAK-1 dans la morphogenèse épithéliale et de mieux comprendre la régulation des propriétés mécaniques des cellules dans un contexte vivant. / I study epithelial morphogenesis during C. elegans embryonic elongation. This process depends on mechanical cues that also influence tissue homeostasis. The pak-1 gene plays an essential role equally during such processes in human and during C. elegans elongation. Our work identified α-spectrin (SPC-1) as a new interactor of the kinase PAK-1. During my PhD I confirmed that the simultaneous lack of PAK-1 and SPC-1 induces serious elongation defects, including a retraction and general collapse of the embryo and suggests that the mechanical properties of the epidermis are modified. My work aimed to determine how the simultaneous lack of PAK-1 and SPC-1 could influence these processes. Such studies would allow to better establish the role of SPC-1 and PAK-1 during epithelial morphogenesis and to better understand the regulation of cellular mechanical properties in the living organisms.