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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.

In order to meet production requirements of small quantity and large variety for versatile market demands, industrial robots with dexterous end-effectors are usually applied to the flexible manufacturing systems. However, owing to constraints of robot¡¦s accuracy, repeatability, and resolution, assembled parts may experience collision during the insertion process. Both positional and angular errors, 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 device. Most traditional remote center compliance (RCC) devices aim to solve insertion difficulty for round peg insertion. This dissertation is devoted to analyze the insertion behavior and develop a new remote center compliance device for square pegs, which lack of the axial symmetry property of round pegs. The presented Passive Multiple Remote Center Compliance Device (MRCC) introduces a new azimuthal compliance over traditional passive compliance mechanisms that can effectively compensate the peg¡¦s orientation deviation for polygonal assembly. Besides, a special feature of the adjustable compliance provides capability to overcome the gravity effect. Non-vertical insertions therefore become possible. A spring-supported object in space is also adopted for stability analysis of the compliant device. Actual experimental assembly processes demonstrate promising results on polygonal insertions in both traditional top-down and horizontal directions. The assembly process of a square peg consists of approach, one-point contact, two-point contact, three-point contact, four-point contact, rotation, departure from chamfer crossing, and insertion. Full analysis of the square peg mating process, using a quasi-static approach will be presented. Constraints that can avoid the jamming and wedging phenomenon for successful assembly will also be established. Furthermore, a novel geometric insertion map, which is able to predict regions of failure and success before actual insertion takes place, is developed to improve efficiency of successful assembly for square pegs.

ABSTRACT FLEXIBLE ASSEMBLY LINE DESIGN PROBLEM WITH FIXED NUMBER OF WORKSTATIONS Barut&ccedil / uoglu, Sirin M.S. Department of Industrial Engineering Supervisor: Prof. Dr. Meral Azizoglu July 2009, 70 pages In this thesis, we study a Flexible Assembly Line Design problem. We assume the task times and equipment costs are correlated in the sense that for all tasks the cheaper equipment gives no smaller task time. Given the cycle time and number of workstations we aim to find the assignment of tasks and equipments to the workstations that minimizes the total equipment cost. We study a special case of the problem with identical task times. For the general case, we develop a branch and bound algorithm that uses powerful lower bounds and reduction mechanisms. We test the performance of our branch and bound algorithm on randomly generated test problems. The results of our experiments have revealed that we are able to solve large-sized problem instances in reasonable times.

Volvo trucks can be ordered with many options to meet customers' demands. This challenges the efficiency of the manufacturing process, especially at the final assembly line where bare chassis are customised with parts and accessories. In the future, assembly lines may be more flexible to allow for assembly of different parts at higher efficiency. This thesis presents problem areas in traditional assembly lines and proposes a proof-of-concept for future flexible assembly line sequencing, as well as a computer simulation tool with the capability to evaluate variances in production capacity when trucks of different size and parts are assembled in consecutive order. Virtual models of flexible assembly lines are constructed as part of a software solution and used to simulate production sequences of varying truck configurations. Data collected from all simulations show a correlation between production capacity and the order in which vehicles are produced. The assembly line configuration itself has also shown to greatly impact efficiency and might lead to an improvement of at least 39%, as well as limitations of tools and workers with specific capabilities. However, the presented performance numbers do not represent all possible simulation outcomes, which beyond the assembly line configuration also depend on things like product complexity and the assembly sequence of individual products.

L’émergence des matériaux composites dans le domaine aéronautique a permis d’alléger considérablement les structures. Cependant l’adaptation du processus d’assemblage aux contraintes imposées par la présence de ces matériaux n’est pas encore complète. De nombreuses opérations considérées comme non-productives sont nécessaires pour garantir le respect des nouvelles exigences. Dans le cadre du projet européen LOCOMACHS, l’utilisation d’un outil de simulation d’assemblage est envisagée afin de limiter le recours à ces opérations. Ces travaux s’inscrivent dans le cadre de la validation, par la mesure, des modèles utilisés pour la simulation d’assemblage flexible. Une méthode d’évaluation de la géométrie d’un composant souple est mise en œuvre afin de compenser par simulation numérique les effets de l’environnement sur le composant lors de sa mesure. Une analyse de sensibilité de la méthode aux variations des différents paramètres de mesure et de simulation est réalisée afin de définir un cadre pour la mise en œuvre. Une analyse modale des écarts à une géométrie de référence contribue à la correction de certains paramètres du modèle utilisé pour réaliser la compensation par simulation. Cette géométrie de référence est obtenue par une méthode de retournement appliquée dans un contexte flexible, afin d'annuler certains effets de l'environnement sur la géométrie mesurée du composant. Le jeu entre les composants assemblés est la caractéristique géométrique prépondérante dans un assemblage de structure aéronautique composite. La simulation d’assemblage, à partir des mesures réalisées sur les composants souples, permet d’évaluer le jeu entre les composants avant leur assemblage. Des méthodes de mesure de jeu dans un assemblage de composants souples sont proposées, et leur mise en œuvre expérimentale est réalisée. La confrontation des jeux mesurés et simulés permet de souligner d’une part les performances de l’outil de simulation, et d’autre part les difficultés liées à la modélisation des environnements de mesure et d’assemblage réels. / The emergence of composite materials in aeronautics leads to lighter structures. However, these new materials induce new constraints to the assembly process. The adaptation is not yet complete. Indeed many operations are necessary to respect the new requirements, but are considered as non-productive. In the context of the European project LOCOMACHS, an assembly simulation tool is developed to limit the use of these operations. This thesis relates to the validation, from the measure, of the models used for flexible assembly simulation. A method to evaluate the geometry of a flexible component is implemented. The method compensates, by simulation, the effects of the environment on the component during its measurement. A sensitivity analysis of the method against changes in various measurement parameters and simulation parameters is performed in order to define a framework for implementation. Parameters of the model used to perform the compensation by simulation are not representative of the actual behavior. A modal analysis of deviations to a chosen reference geometry contributes to the adjustment of these parameters. This reference geometry is obtained by a reversal method applied in a flexible context to cancel some of the effects of the environment on the measured geometry of the component. The gap between the assembled components is the geometric key characteristic in an assembly of aeronautical composite structure. The assembly simulation, from measuring data of flexible components, enables to evaluate the gap between the components prior to assembly. Gap measurement methods in an assembly of flexible components are proposed, and they have been experimentally performed. The comparison of measured and simulated gaps highlights the performance of the simulation tool, and the difficulties in modeling actual measurement environment and actual assembly environment.

Until recently, few technologies have been applicable to increase flexibility in the manufacturers’ assembly applications, but the introduction of industrial robots in collaborative assembly applications provides such opportunities. Specifically, these collaborative assembly applications present an opportunity to, in a fenceless environment, combine the flexibility of the human with the accuracy, repeatability, and strengths of the robot while utilizing less floor space and allowing portable applications. However, despite the benefits of industrial robots in collaborative assembly applications, there are significant gaps in the literature preventing their implementation. Based on this background, the objective of this work is to support the implementation of industrial robots in collaborative assembly applications. To fulfill this objective, this work included two empirical studies; first, an interview study mapped the attributes of industrial robots in collaborative assembly applications. Second, a multiple-case study mapped the critical challenges and enabling activities when implementing these collaborative assembly applications. The studies were also combined with literature reviews aiming to fill the theoretical gaps.  The work provides an implementation process with enabling activities that can mitigate critical challenges when implementing industrial robots in collaborative assembly applications. The implementation process shows enabling activities in the three first phases: pre-study, collaborative assembly application design, and assembly installation. These enabling activities are mapped to the 7M dimensions as a way to clearly show how they can support the implementation of industrial robots in collaborative assembly applications. The implementation process contributes to filling the identified gaps in the literature and provides practitioners with activities that managers could consider when implementing collaborative robots in collaborative assembly applications. Finally, this work suggests that future research could aim to validate the implementation process in a case study or investigate further the last two phases of the process. / Hittills har få tekniker kunnat öka flexibiliteten i tillverkarnas monteringsapplikationer, men introduktion av industrirobotar i samarbetande monteringsapplikationer öppnar upp för sådana möjligheter. Specifikt så presenterar dessa samarbetande monteringsapplikationer en möjlighet att, i en staketlös miljö, kombinera människans flexibilitet med industrirobotens precision, repeterbarhet och styrka men samtidigt nyttja litet golvutrymme och tillåta bärbarhet. Emellertid, trots fördelarna med industrirobotar i samarbetande monteringsapplikationer, finns det signifikanta gap i litteraturen som förhindrar dess implementering.  Baserat på denna bakgrund är syftet med detta arbete att stödja implementeringen av industrirobotar i samarbetande monteringsapplikationer.  För att fullfölja detta syfte inkluderade detta arbete två empiriska studier. Först, en intervjustudie som kartlagde attributen för industrirobotar i samarbetande monteringsapplikationer. För det andra, en flerfallstudie som kartlagde de kritiska utmaningarna och möjliggörande aktiviteterna för implementeringen av dessa samarbetande monteringsapplikationer. Studierna kombinerades också med litteraturstudier med målet att fylla de teoretiska gapen.  Detta arbete ger en implementeringsprocess med möjliggörande aktiviteter som kan mildra de kritiska utmaningarna under implementeringen av industrirobotar i samarbetande monteringsapplikationer. Implementeringsprocessen visar möjliggörande aktiviteter i de tre första faserna; förstudie, design av samarbetande monteringsapplikationer och monteringsinstallation.  Dessa möjliggörande aktiviteter är kartlagda mot 7M dimensionerna som ett sätt att tydligt visa hur dessa kan stödja implementeringen av industrirobotar i samarbetande monteringsapplikationer. Implementeringsprocessen bidrar till att fylla de identifierade gapen i litteraturen och ger till praktiker aktiviteter som ledare kan beakta vid implementeringen av industrirobotar i samarbetande monteringsapplikationer. Slutligen, detta arbete föreslår att framtida forskning syftar att validera implementeringsprocessen genom en fallstudie eller vidare undersöka de två sista faserna av denna process.

In this master thesis is structural design modular roller conveyor which is part of the flexible assembly line automotive seats. The work includes design and functional solution for driven roller track. Present structural design of roller conveyors is summarized in the first part work.

This master thesis deals with a structural design of the modular roller conveyor which is part of the flexible assembly line of automotive seats. The work includes design and functional solution for a driven roller track. Present structural design of roller conveyors is summarized in the first part of the work.