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This paper addresses the challenge of the robotized insertion of ring-shaped elastic objects into parts' outer grooves, which is a key operation in several industrial processes. We propose a novel flexible strategy to insert ring-shaped elastic objects of different sizes and stiffnesses, exploiting a generic robot and a simple - yet effective - fixture. Despite the overall complexity of the procedure is entirely poured on the mentioned fixture, its simplicity of realization and implementation allows to equip the robot with a generic gripper, without the use of any additional sensor. The effectiveness of the proposed strategy is assessed via experimental tests.

This paper contributes to a novel approach for analysing and quantifying the benefits for reconfigurable cellular manufacturing and assembly systems (RCMS/RCAS), also known as Matrix production, based on modelling and dynamic simulation. International market trends concerning consumer behaviour and demand result in increasing flexibility requirements, which conventional production lines struggle to meet, thus creating the need for flexible production and assembly systems such as Matrix production. The flexibility results in additional variables and thus a more complex system behaviour. To utilize its benefits, the design and setup of a matrix production is crucial and for potential real-world applications. However, methods to quantitatively assess beneficial features of a matrix production are only beginning to appear in the literature, making decision-making for a production system transformation challenging. This paper contributes a simulation-based approach to analyse the performance benefits of matrix production using modelling and dynamic simulation. The method is demonstrated with a simplified automotive assembly use case for a dynamic multi-variant production. The results confirm the feasibility of the method and quantify the potential for increased assembly system performance gained from specific flexibility features in a matrix production.

The transformation toward electromobility presents a significant challenge to the battery cell production processes. It is, therefore, necessary to establish efficient and robust operations and machines to meet the forecasted demand for manufactured cell capacity. Currently, the development and ramp-up phases of production machines, especially for cell stack assembly, are characterized by high material scrap rates and large personnel expenses. Aspects such as the web tension of electrodes or separator materials during separation and stack assembly have a significant influence on the subsequent intermediate product properties, and therefore present a key challenge. Herein, the optimal methodology for the web tension control of electrode materials is determined via a model-based approach by the means of a digital twin. The focus is hereby set on a production machine for the flexible cell stack assembly. Appropriate control methods are implemented and validated on the real system, thus reducing material scrap rates and overall costs. The control of the web tension by means of an unwinder and material storage was found to be optimal on the basis of the model and confirmed experimentally.

The first-priority directions for modern engineering, especially for multiproduct manufacturing, include the intensification of manufacturing processes, increasing the efficiency of technological equipment, and reducing the time required to implement technological solutions. Fixture design is a complicated and time-consuming process that requires considering many parameters of the closed-loop technological system “machine tool — fixture — cutting tool — workpiece”. One machined part can have several fixture layouts corresponding to all specified parameters; however, their effectiveness differs depending on production conditions. Search for an optimal fixture for specified production conditions is an essential stage of production planning. It has been proved that the efficiency of a manufacturing process should be assessed using single economic indicator — the cost of machining, which considers the costs of time, the total costs for process realisation, and a batch of parts. The paper aims to substantiate the efficiency of manufacturing processes in machining complex parts using flexible fixtures by developing a mathematical model that considers the cost of time, the cost of implementing the manufacturing process, and the batch value of parts production. This approach estimates the efficiency of manufacturing processes for machining complex parts and choosing the flexible fixture layout that corresponds to specific production conditions. It was proved that flexible fixtures could be effectively used for machining small batches of parts with frequent readjustments to new workpieces and short-term machining. A tendency has been established that the higher number of nomenclature of parts contributes to expanding the scope of the effective use of flexible fixtures.

Today robotics offers robust and sophisticated hardware solutions that are leading the market to mass production. However, the high demand for small batches of highly customized products requires flexible processes, and the considerable cost of programming robotic systems induces many companies to still rely on manual labor even for low value-added tasks. In this context, Learning from Demonstration (LfD) has established as a promising method for transferring capabilities from humans to robots. This paper proposes a programming framework that allows non-expert users to intuitively program a robotic system for a product testing task. Finally, we validated our approach in both a simulated environment and real-world use cases.

This study proposes a supply chain management model with a flexible production rate and a price discount offer for the backorder situation, where the ordering cost is lead time dependent. This lead time demand may follow a known distribution, or it may not have any specified distribution with the aim of minimization of supply chain cost under the simultaneous optimization of the production rate, lot size in each shipment, number of shipments, lead time, probability of movement of uncontrolled state to controlled state, safety factor, and price discount backorder. Three-types of inspections are considered to maintain the quality of products. Three different algorithms are designed to solve the model numerically. Three numerical experiments have been considered to validate the stability of this study. The average total cost for the triangular distribution reveals the minimum total cost of the supply chain management. The comparison with the existing literature demonstrates the major benefit of flexible production rate. It provides the reduction of movement of uncontrolled state probability during flexibility of the production rate, which indicates the reduction of defective products. The effectiveness of the key parameters has been tested through a sensitivity analysis. The results show that the material cost parameter is most sensitive parameters among all cost parameters. Quality improvement cost is another sensitive parameter which is obtained from the sensitivity analysis. Finally, this model converges over the existing literature through several aspects like movement of uncontrolled probability, the reduction of defective product and total supply chain cost.

espanolEl proposito de este articulo es analizar tres politicas de mantenimiento en una celula de fabricacion flexible de una empresa de fabricacion mecanica. Las politicas fueron el mantenimiento oportunista, en el que todas las maquinas se reparan cada vez que se detiene la celula, el mantenimiento correctivo, en el que solo se reparan las maquinas que fallan cuando se detiene la celula, y el mantenimiento correctivo parcial, en el que solo se repara el subsistema fallido cuando se detiene la celula. El metodo de investigacion es el modelado cuantitativo y la simulacion por computadora. La celula forma parte de un sistema de fabricacion flexible (FMS) e incluye dos robots en paralelo y una maquina CNC. El analisis de datos previos proporciono las funciones de confiabilidad, utilizando modelos Weibull y exponenciales. La evaluacion de las politicas se baso en el numero de reparaciones y el MTBF resultante de la celula. La simulacion conto con veinte repeticiones de las tres politicas para fundamentar el analisis. El estudio concluyo que dos politicas son casi igualmente efectivas, el mantenimiento correctivo y el mantenimiento correctivo parcial. La politica de mantenimiento oportunista es menos efectiva que las demas. El articulo tambien calcula la confiabilidad sistemica de la celula. EnglishThe purpose of this article is to analyze three maintenance policies in a flexible manufacturing cell from a mechanical manufacturing company. The policies were opportunistic maintenance, in which all the machines are repaired whenever the cell stops, corrective maintenance, in which only the failed machines are repaired whenever the cell stops, and partial corrective maintenance, in which only the failed subsystem is repaired whenever the cell stops. The research method is quantitative modeling and computer simulation. The cell is part of a flexible manufacturing system (FMS) and includes two robots in parallel and a CNC machine. Previous lifetime data analysis provided reliability functions, using Weibull and exponential models. The evaluation of the policies relied on the number of repairs and the resulting MTBF of the cell. The simulation relied on twenty replications of the three policies to ground the analysis. The study concluded that the two policies, the corrective maintenance, and the partial corrective maintenance are almost equally effective. The opportunistic maintenance policy is less effective than the others. The article also calculated the systemic reliability of the cell.

A growing number of robots collaborating closely with human operators is envisaged to be employed in manufac- turing assembly lines in the next future. It has been demonstrated in many research works that robots increase the productivity and efficiency of the manufacturing process. However, safety is a challenging problem to be considered in human-robot collaborative applications. This work outlines a flexible human- robot collaborative framework, which is the core of a brand new project to be fully developed in the very next future, to provide intuitive and safe human-robot interactions, leveraging mobile robots and manipulators.

This work presents a human-robot collaboration paradigm that goes beyond the pure human-robot coexistence, achieving a flexible and human-aware integration of different operators in a work-cell. A dynamic scheduler able to plan the operations of multiple agents with on-line adaptation to human completion times and flexible management of failures is introduced. Instructions are communicated to the human through visual and haptic cues. In particular, a new tactile communication paradigm based on the association between operations and the portion of workspace in which they are performed is presented. The proposed approach was tested in a realistic human-robot collaboration scenario through an experimental campaign that involved 16 participants.

Depalletizing robotic systems are commonly de- ployed to automatize and speed up parts of logistic processes. De- spite this, the necessity to adapt the preexisting logistic processes to the automatic systems often impairs the application of such robotic solutions to small business realities like supermarkets. Integrating a robotic system into the supermarket depalletizing process demands a high level of autonomy, based on strong perceptive, executive and gripping capabilities. This abstract describes an integrated robotic depalletizing system designed to be easily deployed into supermarket logistic processes. The system is described along with its main components, showing how the proposed framework performs in a real supermarket scenario.

In most cases, the system control is made in a sampled manner, measuring the controlled value at a predefined frequency given by the sampling time. However, not all processes provide relevant information at regular intervals, especially in manufacturing. To reduce the costs and complexity of systems, event-based measuring is necessary. To control this kind of process, an event-based controller is needed. This poses some challenges, especially between the event-triggered measurement, as the process runs in an open loop. In the literature, most event-based controllers are based on the comparison of the error value with a predefined value and activate the controller if this value is crossed. However, in this type of controller, the measured value is measured at a predefine interval and is not suited for most event-based processes. In manufacturing systems, the most usual event-based process is represented by the conveyor transportation system. In this process, the product position is measured only in key locations on the conveyor. For the optimal operation of a flexible manufacturing system, the presence of a product in a key location at predetermined intervals is necessary. For this purpose, this article presents an event-based PID controller implemented on a conveyor transportation system.

The Industry 4.0 paradigm is the focus of modern manufacturing system design. The integration of cutting-edge technologies such as the Internet of things, cyber–physical systems, big data analytics, and cloud computing requires a flexible platform supporting the effective optimization of manufacturing-related processes, e.g., predictive maintenance. Existing predictive maintenance studies generally focus on either a predictive model without considering the maintenance decisions or maintenance optimizations based on the degradation models of the known system. To address this, we propose PMMI 4.0, a Predictive Maintenance Model for Industry 4.0, which utilizes a newly proposed solution PMS4MMC for supporting an optimized maintenance schedule plan for multiple machine components driven by a data-driven LSTM model for RUL (remaining useful life) estimation. The effectiveness of the proposed solution is demonstrated using a real-world industrial case with related data. The results showed the validity and applicability of this work.

This paper presents a complete framework for dynamic task scheduling in the context of flexible human-robot assembly. A Digital Twin tracks the state of the process in realtime by monitoring the activity of humans and robots. Scheduling decisions are taken online based on the current state and the predicted evolution of the system., https://youtu.be/t2jMVi4kDio

Funder: Arm, Robotics competitions stimulate the next generation of cutting edge robotics solutions and innovative technologies. The World Robot Summit (WRS) Industrial Assembly challenge posed a key research challenge: how to develop adaptive industrial assembly robots. The overall goal is to develop robots where minimal hardware or software changes are required to manufacture a new or altered product. This will minimise waste and allow the industry to move towards a far more flexible approach to manufacturing; this will provide exciting new technologies for the manufacturing industry and support many new business models and approaches. In this paper, we present an approach where general-purpose grippers and adaptive control approaches have been developed to move towards this research goal. These approaches enable highly flexible and adaptive assembly of a belt drive system. The abilities of this approach were demonstrated by taking part in the WRS Industrial Assembly Challenge. We achieved second place in the kitting challenge and second place in the adaptive manufacturing challenge and were presented with the Innovation Award.

The ABAQUS finite element simulation software is used to simulate the flexible multi-point three-dimensional stretch bending process of aluminum profiles. The effect of process parameters on the web thickness of rectangular profile in flexible multi-point three-dimensional stretch bending is studied by orthogonal experiment and range analysis. The process parameters used in the experiments include pre-stretching value, post-stretching value, the number of multi-point dies and friction coefficient. The optimal combination of process parameters is obtained by numerical simulation and experimental verification. When the aluminum profile is completed flexible multi-point stretch bending according to the best parameters, the thickness thinning of outer web and inner web is the smallest. The experimental result is closed to the numerical simulated results. The effectiveness of the numerical simulation is verified by the corresponding experimental methods.

Purpose The installation of industrial robots requires security barriers, a costly, time-consuming exercise. Collaborative robots may offer a solution; however, these systems only comply with safety standards if operating at reduced speeds. The purpose of this paper is to describe the development and implementation of a novel security system that allows human–robot coexistence while permitting the robot to execute much of its task at nominal speed. Design/methodology/approach The security system is defined by three modes: a nominal mode, a coexistence mode and a gravity compensation mode. Mode transition is triggered by three lasers, two of which are mechanically linked to the robot. These scanners create a dynamic envelope around the robot and allow the detection of operator presence or environmental changes. To avoid velocity discontinuities between transitions, the authors propose a novel time scaling method. Findings The paper describes the system’s mechanical, software and control architecture. The system is demonstrated experimentally on a collaborative robot and is compared with the performance of a state-of-art security system. Both a qualitative and quantitative analysis of the new system is carried out. Practical implications The mode transition method is easily implemented, requires little computing power and leaves the trajectories unchanged. As velocity discontinuities are avoided, motor wear is reduced. The execution time is substantially less than a commercial alternative. These advantages can lead to economic benefits in high-volume manufacturing environments. Originality/value This paper proposes a novel system that is based on industrial material but can generate dynamic safety zones for a collaborative robot.

Metal spinning is an incremental forming technique commonly employed in the production of hollow axisymmetric components. In recent years, asymmetric spinning processes have been developed to expand the range of component geometries achievable by the technique. However, most of these processes have employed a solid mandrel to set the target shape and provide internal support to the workpiece, thus requiring new tooling to be manufactured for every new part. Moreover, no studies have been performed on the link between the geometry of the target part and the achievable forming height. In this paper, the range of curvature in the target part's planform is used to quantify its degree of asymmetry, and the influence of this parameter on the formability of spun parts is investigated in a series of experimental trials. The hypothesis that the range of planform curvature predicts the likelihood of workpiece failure is tested. Methods to design the multi-pass toolpaths and the blanks required to spin both axisymmetric and asymmetric components without a mandrel are developed. The results show that increasing the degree of asymmetry of the target part only weakly influences the achievable forming height. This finding points to the potential of the technique to produce multiple geometries flexibly and to reduce the costs of prototyping and testing new sheet metal parts considerably., IMR is supported by a Doctoral Training Partnership (DTP) studentship provided by the UK's Engineering and Physical Sciences Research Council (EPSRC). CJC and JMA are supported by EPSRC grant EP/K018108/1. EGL is supported by EPSRC grant EP/S515760/1. EGL also acknowledges support from an Innovate UK project (FELDSPAR) and earlier funding from Nissan Motor Co., Ltd.

Castellano: En este trabajo se va a desarrollar el control de una base móvil Kobuki que monta encima un brazo robótico WidowX para introducirlo en un sistema de fabricación flexible en el que pueda ofrecer operaciones de transporte y manipulación. Como framework robótico que maneja el conjunto, se utiliza ROS (Robot Operating System) y se realiza un análisis de su funcionamiento e implementación en los equipos. Para efectuar el control se deben conocer las características de los equipos y por ello, se describen sus especificidades y las posibilidades que ofrecen. Además, por tratarse de una plataforma robótica móvil, las comunicaciones entre los distintos equipos que participan deben ser inalámbricas, así que se diseñan e implementan módulos de transmisión inalámbrica de datos. Euskara: Lan honetan, gainean WidowX beso robotiko bat daraman Kobuki base mugikorraren kontrola garatuko da.Honen helburua, fabrikazio malgu sistema batean robot hauek sartzea da, garraio eta manipulazio ariketak egin ditzaten. Framework robotikogisa, ROS (Robot Operating System) erabiliko da eta haren inplementazioa eta lan egiteko erakaztertuko dira.Kontrola garatzeko ekipamenduaren ezaugarriak ezagutzea beharrezkoa da, beraz, haren ezaugarriak eta ematen dituzten aukerak deskribatzen dira. Horrez gain, robot mugikor bat denez, elementu guztien arteko komunikazioak haririk gabekoak izatea ezin hobea izango litzake. Hortaz, haririk gabeko datuen transmisioa izateko zenbait modulu sartu eta garatu egiten dira. English: In this work, the control of a Kobuki mobile base which carries a WidowX robotic arm ontop of itsstructure will be developedwith the aim of introducing it in a flexible manufacturing system in order to performmanipulation and delivery actions.This project will use ROS (Robot Operating System) and its implementation as well as its working structurewill be analyzed. A description of the equipments and the possibilities they offer is done so that the control is performedwith as much resources as possible. In addition, the communications between different elements of the work environment must be wireless since this project’s mobile base independence has to be optimal. As a consequence, some wireless data transmission tools are developed in the project.

International Conference on Industrial Engineering and Industrial Management (13th. 2019. Gijón)

En este trabajo fin de grado se desarrolla el control de un brazo robótico manipulador WidowX y su sensorización, todo ello montado sobre una plataforma TurtleBot 2. Este trabajo pretende integrar las funciones propias del brazo con las de una base móvil para ofrecer servicios de transporte y manipulación en un sistema de fabricación flexible. Para entender este conjunto se describen todos los equipos que lo componen. El control de todos estos dispositivos se realiza desde ROS (Robot Operating System) y se desarrolla la interacción de los equipos en este entorno. Throughout this document, the control of a WidowX robotic arm and its sensorization aredeveloped, mountedon top of a TurtleBot 2 structure. The aim of this project is to add the capabilities this robotic arm provides to a mobile base part of a flexible manufacturing system. Every piece of hardware isdescribed in order to grasp how everything interacts. The control of these devices is conducted using ROS (Robot Operating System). ROS’ working structure and how it manages the devices’ control are explained. Gradu amaierako lan honetan WidowX beso robotiko manipulatzailearen kontrolaeta honengainean zenbait sentsoreen kokapena garatzen dira,TurtleBot 2 robot mugikorraren gainean antolatua. Lan honek besoak ahalbidetzen dituen ekintzak ematen dizkio fabrikazio sistema malguko robot bati. Multzo hau osatzen duten gailu guztiak azaltzen dira. Gailu hauek kontrolatzeko ROS (Robot Operating System) erabiltzen da eta ingurune honetan nola komunikatzen direnazaltzen da.

Gradu Amaierako Lan honetan zehar, JADE agenteak eta PLC bat komunikatzeko plataformaren diseinua garatzen da. Java-z programatutako agente bat automatarekin komunikatuko da, C++-z programatutako eta ODK izeneko erdikari bat erabiliz, etorkizunean plataforma hau manufaktura malguko sistema batean integratzeko. Proiektu honetan plataforma garatzeko beharrezkoak diren errekurtsoak eta erabiliko diren hardwarea eta softwarea garatzeko beharrezkoak diren programak azalduko dira. Along this Final Degree Project,the design of a communication platform between a JADE agent and a PLC is developed.A Java programmed agent is communicated with a PLC program using a middlewarecalled ODK,programmed in aC++ application, to, in anearfuture, be able to have this platform integrated in a flexible manufacturing system.In this project the resources needed to createthe platformare explained, as well as the hardware and the programs that are going to be used to develop the software. Gradu Amaierako Lan honetan zehar,JADE agenteak eta PLC bat komunikatzeko plataformaren diseinua garatzen da. Java-z programatutako agente bat automatarekin komunikatuko da, C++-z programatutako eta ODK izeneko erdikari bat erabiliz, etorkizunean plataforma hau manufaktura malguko sistemabatean integratzeko.Proiektu honetan plataforma garatzeko beharrezkoak diren errekurtsoak eta erabiliko diren hardwarea eta softwarea garatzeko beharrezkoakdiren programakazalduko dira.

The ability to physically enlarge one’s own body structures plays an important role in robustness and adaptability of biological systems. It is, however, a significant challenge for robotic systems to autonomously extend their bodies. To address this challenge, this paper presents an approach using hot melt adhesives (HMAs) to assemble and integrate extensions into the robotic body. HMAs are thermoplastics with temperature dependent adhesiveness and bonding strength. We exploit this property of HMAs to connect passive external objects to the robot’s own body structures, and investigate the characteristics of the approach. In a set of elementary configurations, we analyze to which extent a robot can self-reconfigure using the proposed method. We found that the extension limit depends on the mechanical properties of the extension, and the reconfiguration algorithm. A five-axis robot manipulator equipped with specialized HMA handling devices is employed to demonstrate these findings in four experiments. It is shown that the robot can construct and integrate extensions into its own body, which allow it to solve tasks that it could not achieve in its initial configuration., Autonomous Robots, 39 (1), ISSN:0929-5593, ISSN:1573-7527

8th International Conference on Interdisciplinarity in Engineering (Inter-Eng) -- OCT 09-10, 2014 -- Tirgu Mures, ROMANIA In this study, an implementation of the design of an FMS is performed to calculate necessary number, utilization and sequence of workstations and plant layout for given production quantities of different parts, processing sequence and times. Analytical bottleneck model and rank order clustering techniques are used in the calculation and analysis of the system. Manufacturing cells are constituted for similar parts to simplify the analysis of the system and to efficient use of workstations. Results are compared with the conventional manufacturing conditions to determine the effectiveness of the implementation. (C) 2015 The Authors. Published by Elsevier Ltd. WOS:000358732500026

Considering the worldwide evolutionary stage of Industry 4.0, this study wants to fill in a lack of information and decision-making, trying to answer a question about the level of preparation of Romanian Small and Medium-sized Enterprises (SMEs) regarding the implementation of the new technology. The main purpose of this article is to identify the opinions and perceptions of SME managers in Romania on the drivers and barriers of implementing Industry 4.0 technology for business development. The research method used in the study was analyzed by sampling using the questionnaire as a data collection tool. It includes closed questions, measured with a nominal and orderly scale. 176 managers provided complete and useful answers to this research. The collected data were analyzed with the Statistical Package for the Social Sciences (SPSS) package using frequency tables, contingency tables, and main component analysis. Major contributions from research have highlighted the fact that Romania is in a full transition process from industry 2.0 to industry 4.0. There was also a high level of knowledge of the new Industry 4.0 technology, and a desire to implement it in the Romanian SMEs, as well as the low level of resources needed to implement it.

In the architecture and construction sector the increasing wish for individualization is often expressed in complex-shaped freeform buildings. Due to missing universal and mature construction methods, freeform buildings are usually realized using customized solutions often including material-consuming substructures, while the visible skin has neither structural nor functional properties. In this context a new concept is presented for manufacturing self-supporting lightweight freeform structures that integrates load- bearing, functional properties and façade design in one unit, using a double-layered structure. The realized prototype building demonstrates an efficient lightweight freeform structure with a surface specific weight of less than 16kg/m2.

Keeping in view the concern about environmental protection, the study investigates effects of remanufacturing in an integrated production inventory model consisting of forward and reverse supply chain over infinite planning horizon. This article is developed for the deteriorating products with stock dependent demand under shortages. To make the model more realistic, flexibility of production system has been incorporated during forward manufacturing. We derive total cost function and using the results of calculus, optimum production policy is derived, which minimizes the total cost incurred. The results are discussed with a numerical example to illustrate the theory.

The present paper deals with the questions how product quality can be influenced within product manufacturing and how production control can be optimized for increasing product quality. It focuses on discrete manufacturing processes and presents a methodology to gather and analyze relevant influences on product quality and a multi-agent architecture for flexible and quality focused production control. It will be shown how both approaches can be implemented to achieve a flexible, adaptable and quality focused production process control.

This work proposes the application of a recently developed locomotion system to material handling for a flexible manufacturing layout. The “swing-and-dock” (SaD) model for realizing displacements has been invented for and is used by the mobile robotic fixtures developed in the SwarmItFix European project. This form of locomotion can be a valuable capability for material handling agents, enabling simultaneous handling in a non-linear fashion and increasing manufacturing flexibility. The paper focuses on the design of SaD path planning algorithms for the motion of a single agent. Several possible strategies and solutions are presented, elaborated, and tested via simulations. The results suggest that a Nearest Neighbor with a Random Insert Heuristic approach allows the generation of good solution sequences for a single agent with SaD locomotion visiting a varied size of destinations with stationary obstacles in its path.

Distortion considerably influences manufacturing costs, especially if thin-walled parts are machined. To ensure a flexible economical machining, novel processes have to be developed to control distortion within the process chain. Then, reworking by straightening during quenching or by costly hard processing can be kept to a minimum. The fundamental concept of ‘Distortion Engineering’ is based on the inverse application of identified distortion potential to compensate geometric deviations. In the case of thin-walled bearing rings the distortion is related to both, deviation of the wall thickness and the shape. These deviations originate mainly from an inhomogeneous material removal and uneven residual stress state in the workpieces subsurface caused by deformations due to clamping forces during the soft-turning. An adapted non-circular finishing cut can counteract the distortion. Previous work showed that the adaption of depth of cut depending on assessed geometric irregularities reduces deviations by at least two-third compared to non-compensated cutting. Compensation to zero deviation needs a deeper understanding; hence disturbances during the compensation cuts are investigated within this paper. An uneven change of subsurface residual stress state has a retro-active effect on the workpieces’ shape. Experimental results illustrate that the mechanical process loads are alternating with oscillation of the depth of cut. However, only an impact of adapted cutting on residual stresses perpendicular to the cutting direction (axial stresses) was detected. So far, it can be concluded that adapted cutting not leads to an unexpected change of out-of-roundness during subsequent heat treatment. Additionally, the results revealed that the compensation potential is highly affected by a change of workpieces’ deformation due to material removal during one longitudinal cut.

The design and operation of manufacturing systems is evolving to adapt to different challenges. One of the most important is the reconfiguration of the manufacturing process in response to context changes (e.g., faulty equipment or urgent orders, among others). In this sense, the Autonomous Transport Vehicle (ATV) plays a key role in building more flexible and decentralized manufacturing systems. Nowadays, robotic frameworks (RFs) are used for developing robotic systems such as ATVs, but they focus on the control of the robotic system itself. However, social abilities are required for performing intelligent interaction (peer-to-peer negotiation and decision-making) among the different and heterogeneous Cyber Physical Production Systems (such as machines, transport systems and other equipment present in the factory) to achieve manufacturing reconfiguration. This work contributes a generic multi-layer architecture that integrates a RF with a Multi-Agent System (MAS) to provide social abilities to ATVs. This architecture has been implemented on ROS and JADE, the most widespread RF and MAS framework, respectively. We believe this to be the first work that addresses the intelligent interaction of transportation systems for flexible manufacturing environments in a holistic form. This work was financed by MINECO/FEDER, UE (grant number DPI2015-68602-R) and by UPV/EHU (grant number PPG17/56).

In this paper we address flexibility and investigate the relationship between volume and product mix flexibility. One view of flexibility is that of being a capability in itself: another view is that of flexibility as an enabler, providing the manufacturing system with properties on which other competitive capabilities are built. In this research, the latter view of flexibility is used, where flexibility acts as a second order competitive criterion. The aim is to differentiate between two dimensions of flexibility important to the manufacturing value chain, i.e., volume and product mix flexibility, and to investigate how different flexibility configurations are related to Various manufacturing practices. A clustering research approach is used to identify groups of companies based on flexibility configurations. The groups are then analyzed with respect to characteristics and impact on operational performance. For the empirical investigation, we use empirical data from the high performance manufacturing (HPM) study, including three industries and seven countries-a total of 211 plants. We find that flexibility configurations based on high or low levels of volume and mix flexibility combinations show significant differences both in terms of operational performance, and in terms of emphasis put into different flexibility source factors. Original Publication: Mattias Hallgren and Jan Olhager, Flexibility configurations: Empirical analysis of volume and product mix flexibility, 2009, OMEGA-INTERNATIONAL JOURNAL OF MANAGEMENT SCIENCE, (37), 4, 746-756. http://dx.doi.org/10.1016/j.omega.2008.07.004 Copyright: Elsevier Science B.V., Amsterdam. http://www.elsevier.com/

We present a novel genetic algorithm for the Robotic Cell Problem with controllable processing times. This challenging problem arises in an automated production cell that consists of m consecutive machines as well as a material handling robot. The problem requires finding the operations processing times, job assignment, and robot movements. The objective is to minimize the makespan subject to a budget constraint. We describe a free-slack-based genetic algorithm for the linear resource consumption case. We present the results of a computational study and we provide evidence that the proposed algorithm consistently outperforms MIP-based heuristics from the literature. Springer International Publishing Switzerland 2016. Scopus

An algorithm is presented that is based on a representation method for products, which lets us show, intuitively, the hierarchical relationships among components and/or assemblies of the product. This paper presents an algorithm for establishing a partial non-destructive disassembly sequence of a product. The disassembly sequence can be obtained for a component as well as for a sub-assembly (group of different components). The disassembly sequence is obtained autonomously and automatically and can be used in a flexible manufacturing system. This work was funded by the Spanish CICYT project “Sistema Robotizado de Desensamblado Automático basado en Modelos y Visión Artificial” (TAP1999-0436).

Flexibility of manufacturing systems is an essential factor in maintaining the competitiveness of industrial production. Flexibility can be defined in several ways and according to several factors, but in order to obtain adequate results in implementing a flexible manufacturing system able to compete on the market, a high level of autonomy (free of human intervention) of the manufacturing system must be achieved. There are many factors that can disturb the production process and reduce the autonomy of the system, because of the need of human intervention to overcome these disturbances. One of these factors is tool wear. The aim of this paper is to present an experimental study on the possibility to determine the state of tool wear in a flexible manufacturing cell environment, using image acquisition and processing methods.

In this paper, we present the system architecture of a flexible manufacturing planning and control system, named EtoPlan. The concept is based on the holonic control approach of building multiple and temporary hierarchies (holarchies). This paper describes the system architecture for flexible planning and control of activities and (groups of) Resources in a manufacture-to-order environment. The system architecture consists of generic control modules that can be applied on different hierarchical levels and for different kinds of manufacturing activities. The main function of the Resource Controller is the Determine Applicability function.

Spatial Competition and Flexible Manufacturing with Spatially Discriminatory Pricing Abstract This paper develops a two-dimensional spatial framework to explore the firms' optimal locations and optimal attributes of basic products under linear transportation costs, in which firms have the technique of flexible manufacturing and engage in spatially discriminatory pricing. We can observe in the real world that the technique of flexible manufacturing has been widely adopted by most major manufacturing industries. As indicated by Eaton and Schmitt (1994), the key feature of flexible manufacturing is economies of scope, which can be represented by the production of an array of differentiated products extended by a basic product using the same manufacturing process. The production of the basic product incurs a sunk cost of product development, whose feature can be described by a point on Hotelling's attribute line. This basic product can be modified to produce extended variant products by incurring additional costs. The additional cost of producing an extended variant product is denoted by a per-unit modification cost that is proportional to the distance of the attribute line between the attribute addresses of the basic product and the extended variant product. The game in question is a three-stage game. Firms simultaneously select their equilibrium locations in the first stage. Then, they simultaneously choose the optimal attributes of the basic products in the second stage. Finally, firms engage in spatially discriminatory pricing in the third stage. The main findings of the paper are as follows. First of all, we show that the two firms will agglomerate at the center of the location line and the optimal attributes of the two basic products will be located at the first and third quartiles of the attribute line, respectively, when the ratio of the marginal modification rate to the transport rate is high. Secondly, the two firms will locate separately on the location line and the optimal attributes of the two basic products will remain at the first and third quartiles when this ratio is moderate. Moreover, the two firms will locate at the first and third quartiles of the location line, respectively, and the optimal attributes of the basic products will agglomerate at the center of the attribute line when this ratio is low. JEL Classification: R32, L22 Keywords: Spatial Agglomeration; Flexible Manufacturing; Spatially Discriminatory Pricing

Optimal control strategies are computed for a stochastic discrete time flexible manufacturing and assembly system model. An easy to implement feedback control strategy is also proposed with a cost that compares favourably with the optimal cost.

Union membership displayed an inverted-U-shaped pattern over the 20th century, while the distribution of income sketched a U. A model of unions is developed to analyze these phenomena. There is a distribution of firms in economy. Firms hire capital, plus skilled and unskilled labor. Unionization is a costly process. A union decides how many firms to organize and its members' wage rate. Simulation of the developed model establishes that skilled-biased technological change, which affects the productivity of skilled labor relative to unskilled labor, can potentially explain the observed paths for union membership and income inequality. Journal of Monetary Economics, 2016

Union membership in U.S. displayed a n-shaped pattern over the 20th century, while in- come inequality sketched a ?. A model of unions is developed to analyze this phenomenon. There is a distribution of productivity across firms in the economy. Firms hire capital, plus skilled and unskilled labor. Unionization is a costly process. A union chooses how many firms to organize and the union wage. Simulation of the model establishes that skill-biased technological change, which a?ects the productivity of skilled labor relative to unskilled labor, can potentially explain the above facts. Statistical analysis suggests that skill-biased technological change is an important factor in deunionization.

Flexible manufacturing technologies are supporting the routine production of components with freeform surfaces in a wide variety of materials and surface finishes. Such surfaces may be exploited for both aesthetic and performance criteria for a wide range of industries, for example automotive, aircraft, small consumer goods and medial components. In order to ensure conformance between manufactured part and digital design it is necessary to understand, validate and promote best practice of the available measurement technologies. Similar, but currently less quantifiable, measurement requirements also exist in heritage, museum and fine art recording where objects can be individually hand crafted to extremely fine levels of detail. Optical 3D measurement systems designed for close range applications are typified by one or more illumination sources projecting a spot, line or structured light pattern onto a surface or surfaces of interest. Reflections from the projected light are detected in one or more imaging devices and measurements made concerning the location, intensity and optionally colour of the image. Coordinates of locations on the surface may be computed either directly from an understanding of the illumination and imaging geometry or indirectly through analysis of the spatial frequencies of the projected pattern. Regardless of sensing configuration some independent means is necessary to ensure that measurement capability will meet the requirements of a given level of object recording and is consistent for variations in surface properties and structure. As technologies mature, guidelines for best practice are emerging, most prominent at the current time being the German VDI/VDE 2634 and ISO/DIS 10360-8 guidelines. This considers state of the art capabilities for independent validation of optical non-contact measurement systems suited to the close range measurement of table top sized manufactured or crafted objects. © 2011 Copyright Society of Photo-Optical Instrumentation Engineers (SPIE)., Videometrics, Range Imaging, and Applications XI, May 25-26, 2011, Munich, Germany, Series: Proceedings of SPIE; no. 8085

Given the growing change of market conditions and customer requirements production engineering is facing new challenges. Flexibility is required since shifted production as well as increasing outsourcing activities lead to different conditions in terms of operating resources, knowledge and quality. Thus especially product design must answer to these circumstances to support the production planning process – ideally already in very early stages. Needed are product concepts that can easily deal with these conditions – robust products. For their analysis first key factors in design concerning the production process have to be identified. Constraints of parameters at certain decision points in the design process, i.e. the abstraction level, are examined, as well as any interaction between these key factors with each other regarding aspects such as complexity, similarity and conflicts of objectives. The analysis of possible alternatives of both product and production design will support the generic evaluation of product robustness. The final aim is to generate a guideline for a Design for Production in very early phases that will help product developers in future to know about effects certain design decisions will have on the production layout, independent from the designer´s experience and special knowledge about manufacturing and assembly technologies.

Given the growing change of market conditions worldwide production planning is facing new challenges. Different conditions in terms of operating resources, knowledge and quality ask for more flexible processes. As a consequence these new circumstances have to be taken increasingly into account in early phases of product design. To support the adjustment between product and production development the most significant key factors in design concerning production processes must be identified. Therefore criteria are derived that describe the suitability of a product design to the production and the required quality – a measure to be introduced as product robustness. The methodical analysis of technical parameters of various product concepts, depending on their abstraction level and their interaction with each other, will support the generation of a guideline that indicates important effects certain design decisions have on the early production planning. Finally the measure product robustness can provide a basis for comparisons with measures like costs to support companies´ design decisions worldwide.

Although the demand for Flexible Manufacturing Systems (FMS) is still growing, only a few companies are reported to have operational experience with these systems over a long period. Consequently, the supposed benefits of this new technology have yet to be widely proved in practice. The research reported was carried out to evaluate the experiences of a sample of early adopters of FMS in the United Kingdom, the Netherlands and Belgium, by means of longitudinal case studies. The extent to which the companies managed to achieve their FMS implementation goals is described, and the influence of technical problems, market changes and organisational pressures on goal achievement is demonstrated. It is concluded that in order to introduce and operate FMS successfully, adopters should approach FMS implementation management in a more integrated manner.

The problem of part routing and scheduling in flexible manufacturing systems is considered with the goal of increasing the throughput. The flexible system considered is strongly characterized by the inclusion of assembly among the manufacturing operations to be performed on a mix of part batches. In particular, the logic structure of some basic decision problems is indicated through a set of combinatorial models. Two basic assembly problems characterized by batches of large and small size, respectively, are analyzed. >

Tez (Yüksek Lisans) -- İstanbul Teknik Üniversitesi, Fen Bilimleri Enstitüsü, 2004, Thesis (M.Sc.) -- İstanbul Technical University, Institute of Science and Technology, 2004, Bu tez çalışmasında, ilk olarak esnek üretim sistemine geçiş sürecinin yaşanabileceği geleneksel ve hücresel üretim sistemleri anlatılmıştır. Tezin ikinci bölümünde esnek üretim sistemine detaylıca değinildikten sonra, üçüncü bölümde geçiş sürecinin temel adımları olan sistemin tasarımı ve simülasyonu, bilgi sistemlerinin planlanması, eş zamanlı ürün ve üretim prosesinin kavranması, maliyet hesaplarının yapılması, tedarikçi ve müşterilerle ilişkilerin geliştirilmesi ve organizasyonel satın alma davranışının geliştirilmesinden bahsedilmiştir. Ayrıca dördüncü bölümde Uzel Grubu “Tarım Makineleri Ünitesi”’ nde bulunan ve hücresel üretim sistemine uygun olarak çalışan 3 çalışanlı ve 5 CNC’ li bir hücrenin, bir otomatik taşıma aracı ile esnek üretim sistemine dönüştürülmesi sonucu oluşabilecek yeni durum, ARENA simülasyon programı ile simüle edilmiştir. Elde edilen veriler doğrultusunda “Net Şimdiki Değer Metodu” kullanılarak maliyet analizi yapılmış ve sonuçlar irdelenmiştir., In this thesis, first of all traditional manufacturing systems and cellular manufacturing systems are explained. In the second section of the thesis, flexible manufacturing system is clarified. In the third section, the basic steps of passing process to flexible manufacturing systems “ system design and using simulation program, calculating investment, customer and supplier relations, planning information systems, integrated product and process development” are explained. There is a practice in the forth section. In this practice, a cell, which contains three workers and five CNCs in Uzel Company, are simulate without workers and with an automated transporter vehicle. ARENA simulation program is used to prepare this simulation project. In Addition, cost estimations are calculated with using “Net Present Value Method”., Yüksek Lisans, M.Sc.

The classical “repairman problem” (cf. [Feller, An Introduction to Probability Theory and its Applications, Vol. I, 3rd ed., John Wiley, New York, 1967]) is generalized to consider r failure-prone machine types, each type having its own individual failure rate and repair rate. Each failed machine joins its type queue and is repaired by a single server. Several dynamic service priority schemes are considered that approximate first-come first-served, longest-line first, and least-available first situations. A heavy-traffic asymptotic analysis determines approximations to the time-dependent mean and covariance of individual-type queue lengths and shows that the marginal joint distribution of queue lengths is approximately Ornstein–Uhlenbeck. Numerical illustrations of approximation accuracy are provided, as well as suggested applications to computer performance and manufacturing systems analysis.

Production and operations management (POM) is an important activity in all organizations which can make use now of protocols and networking technologies for providing more efficient tools. In this paper, we describe the implementation of a set of primitives suitable for supporting production management (PM) applications. The PM service is based on the Manufacturing Message Specification (MMS) protocol of the Manufacturing Automation Protocol (MAP) architecture. The MMS is modeled according with its companion standard and the solution is oriented for manufacturing., {"references":["Jay Heizer and Larry Render.Production & Operations Management.Prentice Hall, 4 edition edition, February 1996.","Kusiak and S.S. Heragu. Computer Integrated Manufacturing: AStructural Perspective.IEEE Network, 2(3):14–22, May 1988.","L.J. McGuffin, L.O. Reid, and S.R. Sparks.MAP/TOP in CIMDistributed Computing.IEEE Network, 2(3):23–31, May 1988.","G. G Wood. Survey of LANs and Standards.Computer Standards &Interfaces, 6(1):27–36, January 1987.","ISO International Standars Organization. ISO - ISO/IEC 7498-1 - Information technology — Open Systems Interconnection — BasicReference Model: The Basic Model, 1994.","Andrew S. Tanenbaum.Computer Networks. Prentice Hall, 1 editionedition, 1981.","Joberto S. B. Martins. Redes Industriais: O Estado da Arte da Tecnologia. In: Seminário sobre Redes de Comunicação Industrial, pages 1–10, São Paulo, 1990. SOBRACON.[","ISO International Organization for Standardization/ IEC InternationalElectrotechnical Commission 9506. Manufacturing Message Specifica-tion - MMS, 1998.","General Motors. Manufacturing Automation Protocol - MAP, 1982.","A. K. Rae.An MMS Companion Standard for Production Management.Thesis, University of Strathclyde, Glasgow, United Kingdom, 1991.","ISO International Organization for Standardization. ISO/IEC 9506-4 -Industrial Automation Systems - Manufacturing Message Specification- Companion Standard for Numerical Control, 1992.","ISO International Organization for Standardization. ISO/IEC 9506-3 Industrial Automation Systems - Manufacturing Message Specification- Companion Standard for Robotics, 1991.","ISO International Standars Organization. ISO-IEC 9506-5 IndustrialAutomation Systems - Manufacturing Message Specification - Part 5:Companion Standard for Programmable Controller, 1999.","ISA International Standards Association. ISA DS72.02 Process Message Service, 1987.","Mônica V. C. Aguiar, Elizabeth Sphor, Joberto S. B. Martins. Aspectos de Implementação de um Servidor MMS. In: Simpósio Brasileiro de Redes de Computadores, pages 331–342, Florianópolis,1991. Brazilian Computer Society - SBC.","SISCO Systems Integration Specialists Company. Overview and Introduction to the Manufacturing Message Specification (MMS). Techical Report 11/95, 1995.","Elizabeth Sphor, Mônica V. C. Aguiar, Joberto S. B. Martins. Programação de CPs em Redes Industriais com Suporte MMS. In: Anais da IX Congresso Brasileiro de Automática, volume 1, pages 1–2. Sociedade Brasileira de Automação - SBA, June 1992.","Fernando W. Cruz and Joberto S. B. Martins. Uma Abordagem para a Gerência de Produção em Redes Industriais. In: Anais do X Simpósio Brasileiro de Redes de Computadores - SBRC, pages 121–132. Brazilian Computer Society - SBC, May 1992.","Fernando W. Cruz and Joberto S. B. Martins. PAGP - Um Padrão Associado para a Gerência de Produção. In: Anais da Conferência Internacional sobre Aplicação Industrial de Eletricidade - INDUSCON, São Paulo, 1992. IEEE Institute of Electrical and Electronics Engineers.","Sun Microsystems. Network Programming Guide. Manuals. Sun Microsystems, USA, 1990."]}

The paper presents recent trends of production automation in Finland. It evaluates the technological stage reached so far and makes an assessment of future visions. Also some main features of industrial structure in Finland are described to form a better understanding of diffusion of modern automation systems.In connection with the implementation experience, special attention is paid to the analysis of the impact of production automation on smazll and medium scale industry.Design and training problems related to the automation-oriented technologies in flexible manufacturing systems are also discussed and a design strategy assessment is made.