Optimization of product assignment to assembly lines

Dissertação de mestrado em Industrial engineering and ManagementThe work presented in this dissertation was developed in an industrial context integrated in the production control and management department of the Bosch Car Multimedia Portugal S.A – Braga automatic insertion. The problem addressed in this dissertation was finding the best distribution of product families to assign in different lines according to the physical and technical constraints of the assembly lines. In the approach of the problem, it was used tools and techniques of the Operational Research discipline through mathematical modeling, in order to analyze complex situation and obtain more efficient solutions to help in the decision-making process. Based on production data, production needs forecasts and assembly line physical availability, models with different sets of constraints and objective functions were created to present solutions that best fit the question and the specific problem of the present production context. Through specific software that suited the problem, the previously created models were solved, and the solutions were analyzed and evaluated to suit the company’s current needs and for possible and feasible implementation of the solutions.O trabalho apresentado nesta dissertação foi desenvolvido em contexto industrial integrado no departamento de planeamento e controlo de produção da área de inserção automática da Bosch Car Multimédia Portugal S.A - Braga. O problema abordado nesta dissertação foi encontrar a melhor distribuição de famílias de produtos a alocar nas diferentes linhas de produção de acordo com as suas restrições físicas e técnicas. Na abordagem do problema recorreu-se a técnicas de Investigação Operacional através de modelação matemática, para analisar situações complexas e obter soluções mais eficientes. Tendo como base dados da produção, previsões de necessidades e disponibilidade física da produção, foram criados modelos com diferentes conjuntos de restrições e funções objetivo por forma a apresentar soluções que melhor se adequassem à pergunta e ao problema específico do contexto produtivo presente. Através da utilização de software, foram resolvidos os modelos criados anteriormente, sendo que as soluções foram analisadas e avaliadas para a adequação às necessidades atuais da empresa e para a sua possível e viável implementação

Algorithmic Solutions for Combinatorial Problems in Resource Management of Manufacturing Environments

This thesis studies the use of heuristic algorithms in a number of combinatorial problems that occur in various resource constrained environments. Such problems occur, for example, in manufacturing, where a restricted number of resources (tools, machines, feeder slots) are needed to perform some operations. Many of these problems turn out to be computationally intractable, and heuristic algorithms are used to provide efficient, yet sub-optimal solutions. The main goal of the present study is to build upon existing methods to create new heuristics that provide improved solutions for some of these problems. All of these problems occur in practice, and one of the motivations of our study was the request for improvements from industrial sources. We approach three different resource constrained problems. The first is the tool switching and loading problem, and occurs especially in the assembly of printed circuit boards. This problem has to be solved when an efficient, yet small primary storage is used to access resources (tools) from a less efficient (but unlimited) secondary storage area. We study various forms of the problem and provide improved heuristics for its solution. Second, the nozzle assignment problem is concerned with selecting a suitable set of vacuum nozzles for the arms of a robotic assembly machine. It turns out that this is a specialized formulation of the MINMAX resource allocation formulation of the apportionment problem and it can be solved efficiently and optimally. We construct an exact algorithm specialized for the nozzle selection and provide a proof of its optimality. Third, the problem of feeder assignment and component tape construction occurs when electronic components are inserted and certain component types cause tape movement delays that can significantly impact the efficiency of printed circuit board assembly. Here, careful selection of component slots in the feeder improves the tape movement speed. We provide a formal proof that this problem is of the same complexity as the turnpike problem (a well studied geometric optimization problem), and provide a heuristic algorithm for this problem.Siirretty Doriast

Automatic assembly design project 1968/69: report of the control and motivation committee

Methods of control for automatic assembly machines are surveyed. The control requirements of the versatile automatic assembly machine are analysed, and the most practical system is specified and designed in detail

Large-Scale Additive Manufacturing Machine

This master thesis contains an overview of the additive manufacturing technology and building process of the large-scale Fused Deposition Modelling (FDM) additive manufacturing machine from the old Wafer Handling Diffusion machine. The thesis study is mainly focused on practical work and describes the techniques used during the project execution. The built machine can print large 3D prototypes from PLA plastic of three different colors. The final product of this thesis is a fully working large-scale AM machine made with the relatively small budget of 10.000 NOK which the university can use for educational purposes

Optimization of robotic assembly of printed circuit board by using evolutionary algorithm

This research work describes the development and evaluation of a custom application exploring the use of Artificial Immune System algorithms (AIS) to solve a component placement sequencing problem for printed circuit board (PCB) assembly. In the assembly of PCB’s, the component placement process is often the bottleneck and the equipment to complete component placement is often the largest capital investment

Innovation in composite additive manufacturing

This master thesis contains an overview of existing additive manufacturing methods and considers possible new methods. The purpose being to develop a method for additive manufacturing that can create 3D objects with composite material and/or out of metal. Further this method should work on a low cost additive manufacturing machine. A development process is used in order to select an appropriate method. The method is then divided into parts that are individually analysed in order to produce a proof of concept model. Initially an overview of existing patents regarding additive manufacturing was conducted in order to see if the devised problem was addressed and how. A patent search regarding both additive manufacturing of composites and of metallic objects was performed. The next phase was conducting a market overview of existing low cost 3D printers and selecting one model that was appropriate for purchase. The purchased 3D printer was then assembled and tested to build up a general experience of properties and limitations of low cost printers. These properties regard both control parameters, mechanical properties (such as eigen frequencies, resolution) and print limitations (typical errors, materials etc.). Concept generation took place by brainstorming a wide range of possible ideas to address the project goal. Existing manufacturing methods and processes that inspired the concepts are described in the theory. The final concept was selected by a process of first concept screening followed by concept scoring and selection. After screening the bulk of four concepts remained. One mainly addressed the goal of manufacturing metallic parts and the others composites. Further literary study of material properties and manufacturing processes relevant to these methods was conducted for the scoring step. Also appropriate retailers of materials and parts and machines were contacted for relevant cost information. The selected concept uses photopolymers cured by UV radiation. In order to finalise the proof of concept a print head was constructed and several tests were conducted in order to observe possible fill rates and required radiation levels in order to achieve a required flow rate and curing times respectively. Finally suggestions for further development and studies is summarised.This project aimed to look at low cost 3D manufacturing technologies and develop a method to expand existing material options. Existing manufacturing methods for sets of materials were conducted in order to map out possible manufacturing steps. A review of existing models of 3D-printers was done and one was purchased and assembled. Design concepts were developed inspired by existing manufacturing methods and one method was selected using a pre-mixed compound and UV curing matrix material extruded through a nozzle and solidified with directed UV-LEDs in order to allow for manufacturing of composites. The method was verified to work and suggestions for further improvements and studies were made

NASA Tech Briefs, August 2000

Topics include: Simulation/Virtual Reality; Test and Measurement; Computer-Aided Design and Engineering; Electronic Components and Circuits; Electronic Systems; Physical Sciences; Materials; Computer Programs; Mechanics; Machinery/Automation; Manufacturing/Fabrication; Mathematics and Information Sciences; Medical Design