This paper proposes a method which is to achieve an optimal production scheduling and parts selection and to manage parts variety under mass customization for multi-period. The target is running shoes product. The proposed method uses a combinatorial auction imitating a negotiatiou process between manufacturer and customers. A customer memorizes a history of negotiation by using pheromone statistic data to make a bid with cooperation between bidders. This paper attempts to use the pheromone statistic data for part development.

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The main goal of this research is to make a production schedule considering to add rapid orders in mass customization. For minimizing total due date, combinatorial auction is applied into the planning phase to develop an optimal plan. In operational phase, a technique for insefling additional orders at an idle time is proposed using single auction. To evaluate effectiveness of the proposed approaches. eomnuter experiments are conducted.

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This study deals with a cyber-physical manufacturing simulator capable of measuring the energy efficiency and productivity based on real- time measurement of material flow and power consumption of the real system. We here attempt to implement a scheduler function onto the simulator to make it possible to observe effects of scheduling results on the energy efficiency (amounts of product per consumed energy) of the manufacturing process. Some simple simulations using a miniature flexible transfer line demonstrate the total energy efficiency may vary drastically according to a job sequence.

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[in Japanese]

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[in Japanese]

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[in Japanese]

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[in Japanese]

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[in Japanese]

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[in Japanese]

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[in Japanese]

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[in Japanese]

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[in Japanese]

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ln cellular manufacturing systems, workers carry out the whole production activities, and the performance of workers' activities changes during production processes. We are engaged in development of dynamic production management system. The previous study shows that the decrease of processing time depends on the learning level for work procedure. The purpose of this study is to predict processing times of workers in consideration of ability difference. This study proposes a method for analyzing workers' heart rate variability to estimate the learning level in real time. The method determines the amount of change in processing times in response to activation level of parasympathetic nerve. Experimental results show that the proposed method is effective for prediction of processing times with consideration of personal differences.

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[in Japanese]

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We propose a computer-aided assembly process planning to facilitate and shorten process-planning operations that are becoming cumbersome due to the diversification of manufacturing. The system has two features, modular design of the assembly process and automated line balancing. In the modular design of the assembly process, various assembly tasks are built with elemental tasks, the minimum unit of assembly process, that have abstract representation to be applicable for any products. Automated line balancing generates a good task assignment for users' requirements by solving constraint satisfaction problem. The experimental result in the assembly process design of a laptop computer shows facilitation of a process definition operation by reuse of modules, and reduced hours in a line balancing operation.

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In sheet metal processing, nesting and scheduling are important factors for the efficient manufacturing. Nesting and scheduling often become a trade-off. In our previous studies, therefore, we have proposed an integrated method of nesting and scheduling. In the previous study, the operational sequence of punching process is modified by using genetic algorithm. We were able to reduce total tardiness about 7 % on average by this method. However, in the previous study, scheduling problem was solved under the condition that punching process has only single machine. In the actual manufacturing site, there are some equipment in punching process. In this study, therefore, we propose a scheduling method by using the genetic algorithm and dispatching rule. In this method, we decide the operational sequence of punching process by using the genetic algorithm for the case when the equipment are the special purpose machine, by using simple rule for the case when the equipment are the general-purpose machine. Finally, we verify the effectiveness of the proposed method through some computational experiments.

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[in Japanese]

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[in Japanese]

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In the case of recent large-scale earthquakes, some factories which is affected by them have to stop production, and it influenced the entire supply chain in chains. As one of risk measures, there is a decentralization of supplier’s production bases, but it needs large costs of transporting and purchasing machines and duplications of metal molds, jigs and tools. Therefore, after considering cost effectiveness, it is necessary to decentralize supplier’s production bases. In this research, we propose a method of evaluating plans to decentralize supplier’s production bases for virtual scenarios. We consider the risk at the time of earthquake as the expectation which is sales opportunity loss and restoration costs multiplied by an earthquake probability, and then simulate costs in virtual supply chain and evaluate the effectiveness of these plans.

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In recent years, the global supply chain contains many uncertain elements. It is necessary to flexibly respond to the change to make an optimal decision-making. For supply chain decision-making, the game theoretical approaches are widely used and have addressed leader-follower relationship. However, most of conventional works assume that the leader-follower relationship for multiple companies are treated as constant in all time periods. In this paper, a multi-period supply chain planning model that can change the relation of supply chain over time periods under uncertainty is developed. The effects on the change of leader-follower relationship are investigated from computational experiments.

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[in Japanese]

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We propose a method to generate robot-motions for product assembly in 3-D virtual workspace. In our method, an assembly operation is built as a combination of elemental tasks including robot-motion sequences. These elemental tasks are abstracted to be applicable for any products, and their motion information does not include any concrete positions in 3-D space. Then, teaching points to perform each of elemental tasks are numerically calculated by the motion-sequence, and 3-D models of products and facilities. These teaching points are merged and ordered in a sequence of elemental tasks. Finally, robot-motions for an assembly operation are generated from these points by inverse kinematics. An experimental result of assembly operations for a commercial laptop computer shows that our system reduced the teaching-time to 25 percent compared to manual operation using a teaching pendant.

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[in Japanese]

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Recently, layered modeling has been widely used as one of manufacturing methods for directly shaping complicated part shapes. Among them, fused deposition modeling is very widespread because of low cost. In this method, there is a problem that distortion occurs due to thermal contraction of the molding material depending on the asymmetry of the molding shape and the stacking order, and the shape accuracy at the time of completion is deteriorated. In this paper, we propose a method that focus on the temperature distribution of the modeled object, detect the insufficiently cooled portion from the temperature distribution of the object being shaped using thermography, selective suppress the occurrence of distortion.

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The cell structure is expected as a new internal structure of parts to realize light weight and high strength. However, there are some problems in fabrication with additive manufacturing (AM). In this study, the effect of cell size on strength of cell structure fabricated by AM is evaluated. The body-centered cubic cell (bcc) structure fabricated with ABS resin is chosen as a target cell structure. First, the displacement in tensile tests is simulated with Finite Element Method (FEM). Then, using universal testing machine, tensile tests are conducted on several sizes and different deposition directions of the cell structure fabricated by AM. The results of tensile experiments are compared with that of simulation, and the effects of cell size and deposition direction on strength are discussed.

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[in Japanese]

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A general-purpose three-dimensional thermohydraulics numerical simulation code SPLICE was developed at Japan Atomic Energy Agency and designed to deal with gas-liquid-solid consolidated incompressible viscous flows with a phase change process in various laser applications, such as welding, coating, cutting, etc. The result obtained from metal powder laser additive manufacturing simulations is very encouraging in the sense that the SPLICE code would be used as one of efficient tools to provide the laser irradiation conditions.

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In this report, educational cases utilizing additional manufacturing technology at Institute of technogists are introduced. Thirty-one compact AM (additional manufacturing) devices were introduced, and in undergraduate courses they were set up for 3DCAD, modeling, analysis, etc.It is used for verification of total, manufacturing, analysis and so on. In the future, I will report on additional points such as points that I noticed in order to further promote additional manufacturing Institute of technologists, companies and others.In connection with this, we are planning to introduce cases developed from case studies used in creative-type lessons and engineering collaborative projects.

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Transportation as the connector of two consecutive processes is necessary to ensure continuity of production even though they are considered as lean waste. On the other hand, Overall Equipment Effectiveness (OEE) which measures single process with respect to time, speed and quality losses for monitoring purpose, is not able to quantify any losses exits between processes such as excessive or ineffective transportation. Different scenario of transportation is simulated in this paper to study and quantify its impact on the production system. In last, OEE is compared to highlight the limitation in term of deviation between performance of production system and OEE measures.

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Multi-cluster tools are widely used for semiconductor manufacturing. Multi-cluster tools can cause a deadlock due to resource conflicts. The deadlock may cause a serious decrease of throughput and a deterioration of quality of product. Therefore, the deadlock prevention method is necessary. In this paper, the optimal supervisor of multi-cluster tools is derived by reachability analysis of Petri nets for deadlock prevention. The effects of the optimal deadlock-free model is evaluated from the viewpoint of the scheduling performance.

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In recent years, planning method of maintenance process for workshop has become an important issue. In the planning process, it is necessary to determine transfer route and posture for the transportation process of removed and installed equipment. Hence, geometric simulation based on a plant CAD model is used to detect interference between plant structure and the transferred equipment. In conventional simulation, relationship between equipment posture and detected interference is displayed by computer graphics on 2D display and it is difficult directly to recognize the distance between the equipment and structure. Therefore, the determination of the posture is accomplished by trial and error in the work of the site. In this study with 3-dimensional measurement of the path on the structure of the plant, it does not cause interference during loading based on the sense of distance that is obtained by displaying the structure on the carrying object and path virtual reality (VR) for the purpose of development of the technology to support the plan of carrying equipment posture.

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[in Japanese]

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We consider a two-echelon supply chain planning problem with investment decision for market impact to demand for a single manufacturer and a single retailer under demand uncertainty. In the mathematical model. we assume that the average demand increases if the investment is increased. The supply chain planning problem is formulated as a bilevel programming problem. An efficient solution procedure based on Lagrangian relaxation is developed. The effectiveness of the proposed method is confirmed from computational experiments in several case studies.

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A combinatorial optimization problem of food packing in actual equipments, so-called automatic combination weighers, is treated. The primary objective of the food packing problem aims at the total weight of chosen items for a package as close to a specified target weight as possible. The food packing problem is NP-hard, while for a given real ε > 0, an O(n² /ε) time algorithm delivers the heuristic total weight at most (1 + ε) times the optimal total weight. Numerical issues of the O(n² /ε) time heuristic algorithm are discussed.

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A variant of 0-1 knapsack problem in graph structure is considered. Given a directed bipartite structure with a set of items and a set of players, the problem asks to find an arc reversing strategy of the players which collects items in their cooperation with a budget constraint so that the total profit of the collected items is maximized. The problem is also viewed as a generalization of an integrated circuit design problem. Two greedy heuristic algorithms are designed for the problem, and numerical experiments are conducted to demonstrate the performance.

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[in Japanese]

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[in Japanese]

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[in Japanese]

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Recently, “Industrial Internet” and “Industry 4.0”, which refer to the integration of physical industrial machinery with software, internet, along with network sensors, actuators, and other industrial components, are discussed intensively. These technologies provide decantation of manufacturing with cloud-based manufacturing system (CBMS). Since the CBMS enables distributed manufacturing between connected companies, utilization of manufacturing facilities in these companies. As a result, these companies can reduce production cost. We investigate economical effectiveness of the distributed manufacturing with simulation study for machining shop. We also summarized system requirement and issues in industrialization.

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[in Japanese]

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[in Japanese]

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ln high-value-added machining of complicated shapes, it is essential to appropriately utilize machining know-hows regarding workpiece clamping and fixing, selection of cutting tools and decision of cutting conditions. However, the process planning has been determined by skillful experts to achieve complex-part machining. In order to realize high efficient machining. it is necessary to obtain these tacit knowledges and to formulate the implicit machining know-how owned by skillful experts. This study focuses on rough machining process of complicated shapes as the first step and proposes a method to logically decide workpiece shapes during machining to ensure the stiffness by using computational results based on topology optimization that is known as one of the structure optimization methods.

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Manufacturing industry tends to high-mix low-volume production in recent years. Therefore, it is strongly required to develop a computer aided process planning (CAPP) system to shorten the preparation time and to generate NC program. Feature recognition has been treated as a key technology to develop a CAPP system. In authors’ previous study, novel machining features for multi-tasking machine tools have been proposed. The machining features can correspond to several alternative machining methods. However, complex target shapes of practical mechanical parts have not been considered. In order to solve this problem, special shapes such as chamfer part and freeform surface are firstly approximated and machining features such as cylinder or cuboid are recognized from the converted simple shapes in this study. From the results of conducted case study, it is found that the proposed feature recognition method has a potential to deal with complex target shapes of practical mechanical parts.

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In recent years, multi - axis control cutting machines have become widespread and it has become possible to process complicated shape parts by bringing the tool closer from any direction. Meanwhile, avoiding unintended interference between the tool and the workpiece is an important issue. On the other hand, interference detection using simulation on a computer is used, but in utilization it is necessary to match the computer model with the state in the processing machine in real space. At present, this work is realized by visual observation, and it is difficult to avoid human error. Therefore, in this research, we developed a system that obtains the state of obstacles in a multi-axis processing machine in a non-contact and high-speed manner and performs interference judgment with the tool.

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[in Japanese]

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[in Japanese]

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This paper analyzes lot planning of players through a production planning game. The proposed game simulates a labor-intensive production site like a kitchen. In the game, a player does paper work and creates triangular pyramids and dices using scissors and tape. The player is given an arbitrary number of orders at a certain time. The player selects the lot size in consideration of productivity and quality for the given order. By lot production, cutting the paper collectively and making creases make the processing time shorter. However, there is a possibility that quality may be affected. The players’ lot plan for the amount of orders and the order arrival frequency through the results of the game are examined.

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[in Japanese]

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To desire a sustainable society, circular economy for End-of-Life (EOL) assembled products has been required. To recycle or to reuse the parts of the EOL. assembled products, manual disassembly is required which has higher cost due to labor one. To establish environmental but economic recycling factories in practice, disassembly or crushing is selected for each part considering recycling rate and cost. Igarashi et al. (2014) proposed a disassembly parts selection considering the recycling rate and cost. However, part reuse is not considered. This study proposes the disassembly parts selection with minimization of cost and maximization of recovery rate including recycling and reuse considering life expectancy of parts.

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