Simplified 5-Axis Ball End Milling performs simultaneous 3-axis controlled ball end milling with intermittent changing of the relative tool orientation to a workpiece. In this study, the objective is to find the effective tool orientation series with Genetic Algorithm (GA) in order to maximize the removal volume and to reduce the number of changing the tool orientation. The geometric simulation system with Voxel model to calculate the removal volume has been developed. Tool orientation series are represented as a gene in GA. The availability of the method is supported by the results of comparative experiments. Additionally the probability of this method is discussed from the view point of the general problem definition in the cutter selection and the determination of tool orientation series.

View full abstract

The objective of this research is to realize a small batch size production like customised gadgets. Agile provision of high-quality parts is an essential technology for small batch size production. Because only few repetition is expected in small batch size parts fabrication, machining operation would be executed by trial and error. An interactive machining system is proposed to support human operators in trial and error situation. The system is based on the distributed problem solving technique. The operator can reconfigure the planning objectives and planning strategies. Prototype system of the operation planning for interactive machining is developed. A example problem for operation planner reconfiguration is also demonstrated in this paper.

View full abstract

In recent years, an attempt of intelligent machine tool using open CNC unit and network communication has been discussing. The development of sharing the machine tool and product information is progressing. We are aiming at the development of the machining agent system that has the database of machining condition, process design and so on, and can treat various information through the network. The machining agent system can perform self-machining by inputting only 3D-CAD data. This paper describes the outline of the system including the development of module software for generating NC data based on the 3D-CAD data transmitted through the network.

View full abstract

To find and use skillfully manufacturing software components which are provided by various venders, this paper proposes the standardized methodology for showing the precise capability of their software components and for searching for good and proper manufacturing software components. The capability profile is used for improvement of this kind of interoperability. The capability profile is created by filling an adequate template. The templates are prepared corresponding to capability classes of manufacturing activities. For the identification of processes of the manufacturing software components which have the required capabilities, requirements are also described as capability profiles. Adequate software components are selected by matching among their profiles in the database and required profiles.

View full abstract

Designing a production line involves section-wide people such as production engineers, machine tool designers, and on-site associates. They participate in the cooperative design review (DR) to construct a better production line. However, in the current DR, there is a limited method to communicate with each other, so it takes time and cost to integrate their ideas. Also, they have different standpoints for evaluating the system, which cause difficulty in decision-making. In this study, we clarify the logical DR method by considering "Think", "Communicate", and "Determine", and develop and verify the production line examination support system by applying it to an actual test case.

View full abstract

To survive in recent severe competitions, manufacturers are facing a lot of problems, such as shortening lead time, cutting indirect cost and so on. Variety of study on scheduling method has been proposed to solve these problems. In most of the studies, time and quantity based criteria, such as lead time, number of tardiness, inventory level and so on, are applied for evaluating their performance. Product cost is important criterion form economical aspect, however, it is rarely applied in the studies. In this study, we propose a cost oriented scheduling method and its characteristics are investigated through experiments with a distributed virtual factory.

View full abstract

This paper proposes an approach to production planning in a supply chain that uses not only new parts but also reusable parts to make products. Such a supply chain is faced with an issue that the timings and quantities of returned products and reusable parts included in them are unknown. Our approach resolves the issue by sharing information among companies included in the supply chain. In this approach, a product manufacturer first obtains the data on the quantity of sold products from retails. Next, by using the data and reliability models of the products, the product manufacturer predicts the quantities of returned products and reusable parts at each time period. Using the result of the prediction, the product manufacturer performs production planning and informs suppliers of planned orders of new and reusable parts. The suppliers do their production planning based on the planned orders. A supplier of reusable parts sends the product manufacturer the data on returned products and reusable parts that the supplier obtained actually. The data are used to adjust the reliability models and consequently to make production plans adequate.

View full abstract

When part reuse strategy is adopted in the closed loop manufacturing, parts are supplied from disassembly plants as well as new part manufacturing plants. This paper deals with ordering policies of new parts so as to make the most use of reused parts in the production process. We propose to consult the information in the disassembly plant in determining the order quantity of new parts in order to avoid excess and shortage of part stock, when supply lead time of new parts and reused parts are different. Effectiveness of the proposed method is evaluated by the life cycle simulation.

View full abstract

This paper concerns with a sequencing problem to raise the efficiency of line handling in a mixed-model assembly line where products are assembled in the same cycle time. The goal of the sequencing is to attain two objectives simultaneously, i.e., smoothing of work-load and smoothing of part usage. On real mixed-assembly lines, there exist large variations in the assembly times among different product-models. This causes inefficiency such as line stop or increase in idle time. In this paper, we propose a sequencing method to achieve the above two objectives with the help of Relief Man in such situation. For this purpose, the sequencing problem of minimizing both line stop times and idle times is formulated. Since this problem refers to combinational optimization problems, we develop a hierarchical method that applies meta-heuristics like SA(Simulated Annealing) together with TA(Tabu Search). Finally, we examine effectivness of the proposed method through computer simulations.

View full abstract

A scheduling problem is formulated in order to consistently manage every production equipment such as machine tool, assembly robot, AGV, storehouse, material shelf, and so on. The production equipments are classified into three devices, which are producer, location, and mover. This paper especially focuses on a role of buffer, and analyzes the differences among these devices. A unified scheduling formulation is derived from the results of the analysis based on the role of the devices. A scheduling procedure is proposed based on dispatching rules. Computational simulations are executed about job shop type manufacturing. The influence of bottle necked production devices and finite capacity buffers on the productivity is discussed.

View full abstract

We have proposed a decision making model for online scheduling based on task delays which can be a measure to determine a suitable timing of rescheduling. This paper deals with efficiency of such task delays in rolling schedules strategy. In the strategy, a multi-period scheduling problem is solved by using rules automatically obtained from training cases and only the first period's schedule is applied, then the multi-period model is updated one after another. We investigate the effectiveness of our delay-based approach by applying it to job shop scheduling with random machine breakdowns.

View full abstract

Tool sharing among machining centers in flexible manufacturing system is effective to improve system performance. Since job buffer is important to decrease the impact of job transfer delay which results in idling time of machining center, the proper job buffer capacity must be considered in the tool sharing policy. In this paper, an adjustment method for loading balance among machining centers is proposed to cope with the loading unbalance caused by dynamical job releases. With different transfer speeds and job buffer capacities, the proposed method is investigated by simulations. Simulation results show that adequate buffer capacity is important to satisfy the effectiveness of the proposed method.

View full abstract

Quality in ultra-precision cutting is not only accuracy of form, but also surface integrity. Therefore, in-process monitoring of the surface integrity enables to realize stable and high quality ultra-precision cutting. However, measurement of surface integrity of ultra-precision cut surface is very difficult because of its fineness. Consequently, purpose of this study is to estimate surface integrity of ultra-precision cut surface by using indirect methods. In previous studies, it was revealed that tool flank wear and vibrations of cutting tool system strongly affect on surface integrity. Furthermore, static cutting forces could be closely related with progress of tool flank wear. Taking account of these results, surface integrity of ultra-precision cut surface of aluminum alloy were investigated if it could be related with static cutting forces and vibrations of cutting tool system. As a result, it was demonstrated that the surface integrity could be monitored with static cutting forces and vibrations of cutting tool system.

View full abstract

A model-based information exchange infrastructure using XML technologies for FA systems is discussed by FA Open Systems Promotion Forum (FAOP). Then a concept of the information exchange infrastructure among schedulers, MESs, and production equipments using XML description is developed. The model of the information exchange infrastructure consists of a production equipment model and engineering information model. This paper describes overview of the production equipment model, the engineering information model, and developing activities of these models by FAOP.

View full abstract

Manufacturing-support Data Center Services using Internet, called RFM (Remote Factory Management is presented. The concept deploys not only maintenance services but also consulting services with inter-enterprise collaboration by engineering companies and machine tool vendors for multi-vendor s manufacturing systems. Major key issues are 1) FDC; introduction of Factory Data Center Services providing reliable network infrastructure and related platform functions 2)FDML; a versatile XML like language effective in describing field operating devices as well as machine status, 3)ASP; user oriented application service concept utilizing broadband network. Results obtained in the RFM trial using FDC, FDML and the related technologies has been performed.

View full abstract

In order to introduce network-based production system into manufacturing industries, we propose FDML(Field Data Markup Language) as a data format for circulating manufacture information, and develop FDC(Factory Data Center) which is consist of Information Sharing Platform Server and FDAU(Field Data Acquisition Unit). In this report, we explain basic functions of the Information Sharing Platform with experimental manufacturing environment.

View full abstract

This paper discusses a manufacturing support system, which contains not only maintenance services but also consulting services with inter-enterprise collaboration by engineering companies and machine tool vendors for multi-vendor's manufacturing systems. The support system is called ASSIST (After Sales Support Inter-enterprise collaboration System using information Technologies). On the other hand, standardization technologies such as FDML (Field Data Markup Language) and FDC (Factory Data Center) for remote factory management services are discussed by standardization activities. Therefore, a prototype system of FDML application to make ASSIST comply with the standard specifications has been developed. This paper describes a concept of the ASSIST, the FDML application and a development of a prototype system of the ASSIST using the FDML application.

View full abstract

In order to design and develop production design systems including intellectual operations to fit for different production culture, this paper proposes the method to design the production design systems adapted to each area/society A or B belonging to different production culture where each operator works with turn-key decision or with eager morale, respectively. Profiled unskillness factor from background of production culture is related to technical factors by though model, 2-dimensional model and Quality Function Deployment in this study. First-level operators and beginner-level operators who are representative for A and B respectively performed their operations in the production design systems adapted to A and B based on the method. As a result, the design task time and process cycle time consider the method to have a possibility of adaptation to two type of production culture.

View full abstract

Recently, we have been facing with the environmental problems. So the social system must be changed to a sustainable cycle-oriented social system immediately. However, in many cases, those studies focused the control of the closed circulation loop by the side of a producer, and decision making at the time of product disposal of a consumer was seldom considered. In this paper, we suggest a hypothesis that we can form the sustainable cycle-oriented social system by the consumer's value creation. So we suggest that consumers are influenced by the information support, and in that case, we inspect social circumstances and our belief by means of a computer simulation.

View full abstract

We consider that a MAS has to be designed to have the ability of specialization like social insects. Social insects elicit many types of phenotype from a same genotype. They adapt to their environment by activating an appropriate part of genotype to construct a society as a result. In this research, we adopt a Cooperative Co-evolutionary Genetic Algorithm(CCGA) approach to yielding the ability of specialization in a MAS.

View full abstract

Reinforcement learning is one of effective mechanisms which enable an agent to acquire its behavior. But when an environmental change occurs, the agent has to learn again from scratch. In this paper, the agent system is constructed by using the probabilistic network in order to cope with this problem. In concrete terms, an agent acquires its action through reinforcement learning, and its result is replaced to a probabilistic network which is a more flexible expression. Through the navigation problem, the availability of the proposal technique is shown.

View full abstract

Remanufacturing is an industrial process in which used products are completely disassembled and then removed parts are cleaned, often refurbished, and assembled, if necessary, with new parts. This paper deals with process planning and scheduling in such remanufacturing. If we make a process plan and a schedule in advance of remanufacturing execution, we can not perform remanufacturing according to the process plan and schedule since there are a lot of uncertainties in remanufacturing. To resolve this issue, we propose on-the-spot process planning and scheduling for remanufacturing. This approach makes a process plan or decision every time it is to be made during the remanufacturing execution. Simulations are carried out to show the effectiveness of the approach.

View full abstract

This paper deals with a real-time scheduling system of HMS (Holonic Manufacturing System). A decision making process based on the effectiveness values have been proposed and applied to the real-time scheduling problems of the HMS in the previous report. New systematic methods for the individual holons are proposed, in the paper, to determine the effectiveness values based on the estimation of the future HMS status, aiming at improving the previous methods. The effectiveness of the proposed methods are verified through the case studies.

View full abstract

One of the major research motivations in social science is the maximisation of the total public welfare in the society. Interactions amongst decision makers in the society are quite complex, and the interactions result in the social equilibrium with robustness. In this paper we try to take a metaphor of the social science aiming at the methodology to develop intelligent artificial systems with adaptive behaviour. The realisation of effective B2B commerce systems or sophisticated SCM is expected with this research.

View full abstract

Market Oriented Programming is known as a method for solving resource allocation problem. In this method, we obtained an equilibrium solution by building a perfectly competitive market on computer virtually, and deriving a Pareto optimum solution. However the market where the assumption of the perfectly competitive market is applicable seldom exists. In our research, we focused on oligopoly market as imperfectly competitive market in which the number of producers is a finite number. And then, we clarified the characteristics of the aquired solution and compared them with the perfectly competitive market. Finally we show clearly that an equilibrium solution exists also in an imperfectly competitive market.

View full abstract

Unscheduled disruptions often occur in the actual manufacturing systems, and an initial production schedule may not satisfy the constraints due to the disruptions. A reactive scheduling method based on Genetic Algorithm (GA) was, therefore, proposed to improve the disturbed production schedule in the previous research. This research deals with improvement of the reactive scheduling method for tardiness minimization problems. A new crossover method is proposed to generate more suitable individuals in the reactive scheduling process than the previous crossover method. A prototype of reactive scheduling system was developed to evaluate the effectiveness of the proposed method.

View full abstract

The disassembly sequence of used products which is the opposite of the assembly sequence can not be suitable for preferential disassembly of parts for reuse. By cutting or breaking parts for recycle, more efficient disassembly sequences may be generated. Therefore, a method to generate possible operation sequences for efficient disassembly including cut or break of parts is proposed. First, two kinds of precedence constraints for disassembly are represented as a directed graph. One is related to the geometry and the other is related to the fixing feature. Next, necessary conditions for preferential disassembly of a target part by cutting another part are shown. It is possible to determine from the directed graph whether those conditions are satisfied or not. Moreover, possible cutting position can be also determined by introducing faces for the fixing feature. Finally, it is demonstrated that our developed system can generate efficient disassembly/cutting sequences from a product data.

View full abstract

This paper deals with a work support system to support novice workers in production, maintenance and disassembling work. In order to realize effective and corporative support, the work monitoring function that recognizes the performed work and shares work information is needed. As a prototype system, a work process recognition system using RFID sensing has been developed. ID tags are attached on each part, and the ID number is read by a reader with an antenna mounted on worker's hand. Since the RFID readable area is limited, every tag is not always read in normal operation. In this paper, a method that confirms the work process with interactive actions between the worker and the support system is considered.

View full abstract

Under the keen competition between industries worldwide, the products' improvement cycle and the model-change cycle become shorter and shorter. In such circumstances, the facility life cycle also becomes shorter in automated production lines. In consequence, the facility life cycle cost increases. To cope with that, we have developed so called the 'Protean Production System (PPS)', which can have longer life and lower facility life cycle cost than existing production systems. The PPS is attributed by several unique features such as 'Lot Circulation Flow System', 'Function Divided Modules' and 'Plug and Play techniques', and has been applied to our plant since 1998.

View full abstract

Press forming simulation has been developed as a tool to evaluate the formability of auto body parts. The prediction accuracy of the simulation about forming defect, such as split and wrinkle is sufficient to design the forming process or die geometry. However, the prediction accuracy of springback behavior is insufficient to evaluate the dimensional accuracy. In order to improve the accuracy of simulation, new material model was taken into forming simulation. The material model is characterized by the accurate description of transient Bauschinger effect (Yoshida-Uemori model). Simulation results with new material model are compared with experimental ones. It is confirmed that the prediction accuracy is improved.

View full abstract

During the progress of changes in the surroundings of the automobile industry and a wide variety of consumer preferences, it is very difficult for us to estimate future consumption trends in production volume or specifications. To timely provide low-priced and high-quality competitive products even in these surroundings, we should create a production system that can promptly accommodates the changeable production volume or specifications while maintaining highly efficient conventional production. We found one potential solution to the issues surrounding the development of the independent production system capable of promptly responding, without losses, to line balancing of manual processes most susceptible to changes in yield cycle time caused by the changes in production volume or specifications or time differences in assembly between models on a mixed production line. This paper introduces one of applicable examples of the independent production system for a wide-variety/low-volume assembly line used for obsolete-model engines, which was adopted as the 1st step activity.

View full abstract