Gotowa bibliografia na temat „Robust layout”

In today’s dynamic environment, where product demands are highly volatile and unstable, the ability to design and operate manufacturing facilities that are robust with respect to uncertainty and variability is becoming increasingly important to the success of any manufacturing firm in order to operate effectively in such an environment. Hence manufacturing facilities must be able to exhibit high levels of robustness and stability in order to deal with changing market demands. In general, Facility Layout Problem (FLP) is concerned with the allocation of the departments or machines in a facility with an objective to minimize the total material handling cost (MHC) of moving the required materials between pairs of departments. Most FLP approaches assume the flow between departments is deterministic, certain and constant over the entire time planning horizon. Changes in product demand and product mix in a dynamic environment invalidate these assumptions. Therefore there is a need for stochastic FLP approaches that aim to assess the impact of uncertainty and accommodate any possible changes in future product demands.This research focuses on stochastic FLP with an objective to present a methodology in the form of a framework that allows the layout designer to incorporate uncertainty in product demands into the design of a facility. In order to accomplish this objective, a measure of impact of this uncertainty is required. Two solution methods for single and multi period stochastic FLPs are presented to quantify the impact of product demand uncertainty to facility layout designs in terms of robustness (MHC) and variability (standard deviation). In the first method, a hybrid (simulation) approach which considers the development of a simulation model and integration of this model with the VIPPLANOPT 2006 algorithm is presented. In the second method, mathematical formulations of analytic robust and stable indices are developed along with the use of VIPPLANOPT for solution procedure. Several case studies are developed along with numerical examples and case studies from the literature are used to demonstrate the proposed methodology and the application of the two methods to address different aspects of stochastic FLP both analytically and via the simulation method. Through experimentation, the proposed framework with solution approaches has proven to be effective in evaluating the robustness and stability of facility layout designs with practical assumptions such as deletion and expansion of departments in a stochastic environment and in applying the analysis results of the analytic and simulation indices to reduce the impact of errors and make better decisions

The object of this research is to develop robust wire-line systems which demonstrate high performance while simultaneously consuming low power. The main focus of this work is the Clock and Data Recovery (CDR) system, which is the primary circuit of any modern wire-line transceiver. Different techniques starting from circuit-level to system-level have been investigated in this work to improve the performance of multi-gigabit CDRs. A 62 GHz bandwidth amplifier has been presented to address the need for a scalable amplifier for CDR needs. A new technique has been proposed to improve the radiation immunity of latches, to reduce the BER in CDRs occurring due to package radiations. An injection-lock based clock recovery method was investigated as an alternative to PLL based CDRs as they can be used for burst-mode wire-line communication. The investigation yielded the vulnerability of the method to jitter (false-locking and high jitter transfer), the attenuation of which is critical to commercial CDRs. A novel false-lock detector system has been proposed and demonstrated for the first time as a robust solution to the issue of false-locking of CDRs due to repetitive patterns. The implementation of the final CDR system required the use of an L-C tank VCO, the components of which are generic for all commercial CDRs. A new systematic layout technique for the VCO has been proposed and demonstrated in this work to substantially improve the layout area and the associated parasitics, approximately by 70 %. This new layout addresses a critical yet often neglected part of VCO design. Furthermore, a new concept has been proposed to optimize static dividers with respect to their power consumption and number of devices.

Industrin står inför utmaningar på grund av förkortade produktlivscykler och ökad produktvariation. Nuvarande system har svårt att hantera ökade krav. Kollaborativa robotar (cobots) har utvecklats för att övervinna dessa svårigheter och skapa flexibla och anpassningsbara automatiseringsprocesser. Parker Hannifin i Skövde monterar idag hydraulik‐ och pneumatikkopplingar. All montering är manuell, vilket kan resultera i påfrestande ergonomi för arbetarna. Produktiviteten och kvalitetsutfallet lider i nuläget inte av några större problem, men företaget ser ändå anledningar till att automatisera delar av produktionen. Dels vikten av att ständigt försöka förbättra sig både inom ergonomi och produktion, samt att en förnyelse av företaget sker. Projektets syfte är att hitta en arbetsstation lämpad för kollaborativ automatisering. Stationen och dess moment ska därefter studeras för att kartlägga vad som krävs för att göra en förbättring genom en automatiserad layout. Målet med arbetet är att det ska kunna användas som underlag i framtiden för beslut om investering. Olika arbetsstationer och moment kommer studeras för att kunna välja en lämplig process för automatisering. För att kartlägga vad som krävs av ett layoutförslag behöver information om komponentkandidater samlas in. Jämförelser kommer sedan göras baserat på konceptets parametrar. Årskostnad mellan kollaborativ och manuell station kommer jämföras utifrån uppskattad livslängd på investeringen. Produkttyp 1 är en spillfri produkt och har goda förutsättningar att öka i volym i framtiden. I dagsläget har stationerna för tillverkning av produkttyp 1 och 2 hög beläggning. Stationen X ansågs därför vara en lämplig kandidat och valdes till projektet. När sammanställningarna av parametrarna och jämförelserna var gjorda, valdes UR5 från Universal Robots som robotmodell med gripper från Robotiq och vision system från Sick. Ett layoutförslag skapades där roboten utför monteringens sista moment, 11–15. Med en beräknad livslängd på sju år, visade det sig att en investering med föreslagen layout inte skulle vara ekonomiskt lönsamt jämfört med manuellt arbete. På grund av att en mycket högre produktionsvolym krävs i station X, bör implementationen istället undersökas på annan station så att roboten får högre beläggning. Arbetet har även undersökt lösningar till olika moment som inte tagits med i förslaget. Trots att layouten inte är mer lönsam än dagens manuella montering, ses projektet som lyckat och arbetet som ett värdefullt underlag för framtiden. Det är inte bara ekonomin som är viktig att reflektera över, utan kvalité och ergonomi är aspekter som kan dra stor nytta av kollaborativa robotar.<br>The industry today stands before challenges because of products shortened lifecycle and increased variation. Present systems are having a difficult time handling these demands. Collaborative robots (cobots) have been developed to overcome these problems and creating flexible and adjustable automation processes. Parker Hannifin in Skövde is a manufacturer of hydraulic and pneumatic couplings. All assembly is done manually at present, which can cause issues ergonomically for the workers. The productivity and quality are not suffering from any major problem now, still the company sees reasons to automate parts of the production. Partly because the importance of always trying to improve the production and ergonomic, but also the renewal of the company that follows is a reason. The purpose of the project is to find a workstation suitable for collaborative automation. The station and the processes are then to be studied to define what is needed for improvement through an automated layout. The goal is that the project will work as support for future decision concerning an investment. Different stations and moments will be studied for choosing an appropriate process to automate. Information regarding components needs to be collected, for mapping the needs of the layout. Comparisons will then be made from the concept’s parameters. Yearly cost between collaborative and manual station will be compared based on an approximately life time of the investment. Product type 1 is a new type of spill free product and its volume have good conditions to increase inthe future. Today the stations for manufacturing product type 1 and 2 have a high occupation. Station X was considered an appropriate candidate and was chosen for the project. After a compilation of the comparisons been made, the robot model UR5 from Universal Robots with a gripper from Robotiq and vision system from Sick, was chosen. A proposed layout was made where the robot is performing the last moments, 11‐15, of the assembly. The results showed that with an approximate life time of seven years, the investment would not be financially profitable compared to manual labour. The implementation should instead be investigated in a different station, concerning the high production volume that is needed in station X. The work has resulted in several solution for moments not included in the proposition. The project is still viewed as successful and the work as useful support for the future, despite results showing that the layout is not more profitable than today’s manual assembly. It is just not the economical aspect that is important to reflect over, but quality and ergonomic are fields that can benefit from collaborative robots.

The diploma thesis deals with the design of a robotic workplace layout for finishing operations on the stator of an electric motor. Three variants of the workplace layout were created, these variants were evaluated, and then the most suitable variant was selected. Suitable subcomponents have been created for this variant, such as the end effector, deburring spindles, rotary stand and milling table. A risk analysis was also created for her to ensure the safety and protection of the operator. The most suitable variant was transferred to the Process Simulate software, where its functionality was verified and the real cell cycle was determined.

Nowadays, assembly robots are increasingly used in the manufacturing industry to replace or collaborate with human labors. This is the goal of the dual arm assembly robot developed by ABB. With the rapid upgrading in consumer electronics products, the lifetime of an assembly line could be only a few months. However, even for experienced programmers, to manually construct a good enough assembly sequence is time consuming, and the quality of the generated assembly sequence is not guaranteed. Moreover, a good robot assembly sequence is important to the throughput of an assembly line. For dual arm robots, it is also important to obtain a balance between the two arms, as well as handling scheduling conflicts and avoiding collisions in a crowded environment. In this master thesis, a program is produced to automatically generate the optimal assembly sequence for a class of real-world assembly cases. The solution also takes the layout of the assembly cell into account, thus constructing the best combination of cell layout, workload balancing, task sequence and task scheduling. The program is implemented using Google OR-Tools – an open-source support library for combinatorial optimization. A customized search strategy is proposed and a comparison between this strategy and the built-in search strategy of Google OR-Tools is done. The result shows that the used approach is effective for the problem study case. It takes about 4 minutes to find the optimal solution and 32 minutes to prove its optimality. In addition, the result also shows that the customized search strategy works consistently with good performance for different problem cases. Moreover, the customized strategy is more efficient than built-in search strategy in many cases.<br>Numera används monteringsrobotar alltmer inom tillverkningsindustrin för att ersätta eller samarbeta med människor. Detta är måluppgiften för den tvåarmiga monteringsroboten, YuMi, som utvecklats av ABB. Med den korta produktlivslängden för hemelektronikprodukter kan livslängden för en monteringslinje vara ett fåtal månader. Även för erfarna robotprogrammerare är det svårt och tidsödande att manuellt konstruera en tillräckligt bra monteringsordning, och dessutom kan resultatets kvalitet inte garanteras. En bra monteringsordning är nödvändig för genomströmningen i en monteringslinje. För tvåarmiga robotar, är det också viktigt att få en balans mellan de två armarna, samt hantering av schemakrockar och undvika kollisioner i en trång miljö. I detta examensarbete har ett program skrivits, som automatiskt genererar optimala lösningar för en klass av verkliga monteringsfall. Lösningen tar hänsyn till utformningen av monteringscellen och arrangerar cellen på bästa sätt, balanserar arbetsbelastningen, ordnar och tidsbestämmer uppgifter. Programmet använder sig av Google OR-Tools – ett öppet kodbibliotek för kombinatorisk optimering. Dessutom föreslås en skräddarsydd sökstrategi, som jämförs med Google OR-Tools inbyggda sökstrategi. Resultatet visar att den använda metoden är effektiv för problemtypen. Det tar ungefär 4 minuter att hitta den optimala lösningen och 32 minuter för att bevisa optimalitet. Dessutom visar resultatet att den anpassade sökstrategin konsekvent har en bra prestanda för olika problemfall. Dessutom är den anpassade strategin effektivare än den inbyggda sökstrategin i många fall.

Este trabalho visa explorar técnicas de projeto de células que possibilitem a minimização dos efeitos da variabilidade de processo sobre o comportamento elétrico dos circuitos integrados. Para este trabalho foram abordados aspectos de regularidade, principalmente na camada de polisilício. A técnica de folding foi explorada em conjunto com a regularidade como possível metodologia de projeto voltada para a minimização dos efeitos da variabilidade de processo. Leiautes de portas lógicas complexas e básicas foram criadas utilizando tecnologia em 65nm. Os netlists dos leiautes extraídos foram simulados utilizando modelos que refletiam os efeitos da variabilidade sobre os parâmetros tecnológicos mais afetados pela variabilidade de processo. Os parâmetros selecionados para este experimento foram a largura (W) e comprimento (L) do canal do transistor, espessura do óxido de porta (Tox) e a mobilidade (μ0) das cargas. Os dados referentes ao pior caso envolvendo atraso e potência consumida de cada porta foram utilizados como métricas de comparação. Os resultados encontrados demonstram que a utilização da técnica de folding juntamente com aspectos de regularidade tornaram os experimentos menos sensíveis às variações do processos de manufatura de circuitos integrados. Essas reduções de sensibilidade chegaram em algumas situações à 33.22% para as portas básicas e de 28.96% para as portas complexas. A adição de folding e regularidade da camada de polisilício, trazem desvantagens significativas em área e potência consumida de cada porta. Pelos experimentos realizados é possível verificar aumento superior a 100% em área de algumas portas e de até 20.54% de aumento em potência. A união destas duas técnicas pode ser utilizada para tornar, por exemplo, o caminho crítico de um circuito integrado mais robusto quanto as variações de temporização e de potência.<br>This paper aims to explore for design techniques that allow the minimization of the effects of process variability on the electrical behavior of integrated circuits. To this work were discussed aspects of regularity, especially in poly-silicon layer. The technique of it folding was explored in conjunction with the regularity as possible design methodology aimed to minimizing the effects of process variability. Complex and basic layouts logic gates were built using 65nm technology. The it netlists extracted from layouts of the gates were simulated using models that reflected the effects of variability on the main technological parameters such as W, L, Tx, mu0 of the charges. The worst delay of each port and power consumption parameters were used for comparison in this work. The results show that using the it folding with regularity aspects of the experiments turns the layout gates less sensitive to process variations. These sensitivity reductions reached in some situations to 33.22 % for the basic gates and 28.96 % for the complex gates created. This techniques brings significant disadvantages in size and power consumption. For the experiments you can check increase of over 100% in area and up than 20,54% increase in power. These techniques should be used with discretion, especially on projects where there are area or consumption restrictions.

The topic of this diploma thesis was chosen by Valeo Compressor Europe Company. The aim is to propose an automation of the production line for grinding of a compressor part. The part is internally termed “Cylinder,” and it is an integral part of a new type of a rotational compressor for air-conditioning units of automobiles. The diploma thesis includes a complete proposal for the automation of workplace. The current state, the proposal of the concept, technical specification of the project, and the choice of a suitable supplier and economical assessment are included. The data were provided by Valeo Compressor Europe Company.

Nel presente elaborato è stato valutato l’inserimento di robot commerciali per il caricamento di materiali da processare da macchine automatiche del tè. Sono state affrontate sia valutazioni di tipo progettuale che di tipo economico al fine di poter ottenere e confrontare soluzioni che fossero concretamente realizzabili, in linea con le normative vigenti ed economicamente vantaggiose rispetto alle convenzionali soluzioni senza robot. L’elevato numero di aspetti da considerare ha richiesto lo studio e l’integrazione di campi tematici differenti.

Prepreg is a fibre reinforced polymer composite material often used by the aeronautical industry. The material supplier has pre-impregnated the fibre often with an epoxy resin and cured it to a semi-viscous B-stage where the material is tacky (adhesive). Manual layup of prepreg components is still common because there are only a few automated layup techniques which has limited geometric capability and high investment cost. Swerea SICOMP is a research institute which have in collaboration with partners developed a manufacturing demonstrator for automated layup of carbon fibre prepreg components based on robotic handling. The manufacturing demonstrator is able to; feed out prepreg from a spool onto a cutting table, cut the prepreg into plies, pick the plies from the cutting table and place them on a layup table, consolidate the prepreg plies on the layup table and remove the backing paper that covers one side of the prepreg. Three robustness problems has been identified and these forms the bulk of this master’s thesis. The first problem is that the robot is unable to place the plies on the cutting table with sufficient accuracy due to fluctuating position of the prepreg on the cutting table. The second problem is that the end effector used for the pick and place operation sometimes fails to pick the adhesive plies from the cutting table. The problem originates in limited holding force by the end effectors suction cups and limited capability to perform a peeling motion when picking due to the design of the end effector. The third problem is that process variables like temperature is believed to effect the robustness of the demonstrator but has not been further studied. The first problem was solved by implementing a probing routine which measures the position of the prepreg on the cutting table with an array sensor mounted to the robot. The measurement values are used to reprogram subsequent operations. The second problem seems to be solved by designing and implementing a new pick and place end effector. The new end effector has higher holding force and better capability to perform a peeling motion while picking and placing the tacky prepreg plies. Tests with the new end effector has been promising, the pick and placeoperation performs robustly, but all ply geometries was not tested and some minor adjustment is needed to further improve the placing accuracy. The third problem has not been solved but studied. A literature study reviled that temperature, relative humidity and prepreg out of freezer age is likely to effect the prepreg adhesive properties which in turn is known to effect the robustness. A test procedure has been devised to test how these variables effect the robustnessof the demonstrator. The tests should be conducted when all process steps in the demonstrator is up and running.

Global competition is growing for companies everywhere and the demand for new and improved products are rising for each day that passes. The globalization brings new opportunities as well as new challenges since companies need to stay up to date and implement new technologies to stay competitive. Not only do customers want up to date products, they also want high quality, low price and individualized products, customized for their needs. This puts high demand on manufacturing companies to adapt their businesses, increase product diversity and to being able to introduce new variations and new products quickly.  Since the drastic evolution of technology has increased the competitiveness of industrial companies, and the mass customization demands have increased, the necessity to investigate potential system alternatives towards improving production processes, with the help from the new technology, is required. One way of doing this is to revaluate one's assembly layouts since the layout design decision is highly connected to the product portfolio and the production volumes. The specific objective of this thesis is to broaden the case company’s, ABB, knowledge on ways their assembly of large robots can be improved with the focus on potential future assembly solutions. The overall aim of this thesis work is to identify state-of-the-art possible layout design alternatives, evaluate their performances and finding a method of choosing the final layout approach. This is answered by research questions connected to plant layout selection methodology, plant layout options and finally recommendations for the case company. The methodology chosen for deciding the recommended layout is the fuzzy Analytical Hierarchy Process which is a multi-criteria decision-making tool suitable for decision problems with a hierarchical structure, having main attributes and sub attributes connected to each main attribute. Twenty-four attributes were created and ten layouts based on company observations and a literature study. The layout with the highest score was a layout based on a modernized version of the common fixed position layout. The overall recommendation for the case company was to focus on having a layout in the future with focus on a high technology level as well as high flexibility, for also receiving high performance.