By Topic

Emerging Technologies and Factory Automation Proceedings, 1997. ETFA '97., 1997 6th International Conference on

Date 9-12 Sept. 1997

Filter Results

Displaying Results 1 - 25 of 103
  • 1997 IEEE 6th International Conference on Emerging Technologies and Factory Automation Proceedings [front matter]

    Publication Year: 1997 , Page(s): i - xxi
    Save to Project icon | Request Permissions | PDF file iconPDF (1270 KB)  
    Freely Available from IEEE
  • 1997 IEEE 6th International Conference on Emerging Technologies and Factory Automation Proceedings, EFTA '97

    Publication Year: 1997
    Save to Project icon | Request Permissions | PDF file iconPDF (468 KB)  
    Freely Available from IEEE
  • Index to Authors

    Publication Year: 1997 , Page(s): 573
    Save to Project icon | Request Permissions | PDF file iconPDF (81 KB)  
    Freely Available from IEEE
  • Batch-mode decision tree learning applied to intelligent reactive robot control

    Publication Year: 1997 , Page(s): 416 - 420
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (812 KB)  

    This paper presents an efficient approach based on a symbolic method, namely the decision tree learning, to navigate intelligently a robot in a cluttered, unknown and dynamically changing environment. The two major behaviours, namely reactivity and goal-seeking behaviours, are learned from positively reinforced robot motions from a starting point with no rules. The learning emphasis is on the automatic generation of knowledge without human intervention, with the robot being trained successively to generate knowledge increments in the form of vector entities. A decision tree network is grown on the batch of knowledge fragments to generate coherent decision rules incorporating the behaviours to navigate the robot. We also demonstrate the feasibility of behavioural decomposition into behaviour-biased decision trees View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • New lower bound for the hybrid flowshop scheduling problem

    Publication Year: 1997 , Page(s): 446 - 451
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (484 KB)  

    This paper deals with the hybrid flowshop scheduling problem (HFSP). We propose a new lower bound for the maximum completion time (makespan) criterion and a branch and bound procedure to solve a k-stage HFSP in which the maximum completion time is the criterion to be optimized. This problem has been already treated but we prove that our bound is better than those derived for the same criterion. To illustrate this dominance property, we propose experimental results in order to show the efficiency of this bound View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • The performance of alternative strategies for dealing with deadlocks in FMS

    Publication Year: 1997 , Page(s): 281 - 286
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (444 KB)  

    Deadlocks in flexible manufacturing systems (FMS) are caused by resources limitation and the diversity of routings. In the literature, we find different strategies for coping with deadlocks. However, the performance comparison between these strategies is not extensively studied. In this paper, we evaluate, using simulation techniques, the performances of two different strategies: the first is a detection/recovery method based on digraph representation and for which the phase detection is cheap; the second is a prevention method based on Petri nets structure theory results and for which the restriction on the resource usage is limited to local sections. Our simulation study confirms the idea that the class of detection/recovery methods are more efficient than prevention or avoidance methods only if the time corresponding to their recovery phase is negligible relative to processing time. Since this condition is implausible in an FMS environment, the deadlock detection/recovery strategies seem to be not appropriate in this context View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Evolutionary synthesis of optimal control policies for manufacturing systems

    Publication Year: 1997 , Page(s): 304 - 309
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (316 KB)  

    In this paper, evolution strategies are used to synthesise optimal control policies for manufacturing systems. The evolutionary procedure is illustrated by synthesising optimal control policies for a manufacturing system previously considered in the context of genetic synthesis. The performance of evolution strategies and that of genetic algorithms are compared in detail for this system, thus indicating that the evolutionary synthesis procedure is faster than the genetic synthesis procedure View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • On an expert system with multicriteria Tabu search for multiobjective project scheduling

    Publication Year: 1997 , Page(s): 287 - 291
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (480 KB)  

    We present a decision support system for multiobjective project scheduling problems under multiple category resource constraints. It handles quite a general class of nonpreemptive scheduling problems with renewable, nonrenewable and doubly-constrained resources, multiple performing modes of activities, precedence constraints in the form of an activity network and multiple project performance criteria of time and cost type. The system uses a multicriteria decision making and an expert system approaches together with a Tabu search (TS) method for solving the above class of problems. We concentrate on the interactions of the TS algorithms and a knowledge base of the expert system, containing knowledge that concerns different aspects of TS technology, resources and schedules View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Coupling point production control system for quick response to orders and minimum inventories

    Publication Year: 1997 , Page(s): 154 - 159
    Cited by:  Papers (7)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (360 KB)  

    In the proposed production control system, inventories are concentrated at the position where supply lead time and demand lead time are equal, and inventory and production planning are made at this position. This position is defined as the “coupling point”. The coupling point is moved as demand lead time and supply lead time change. Inventory and production planning are made at that new coupling point. This makes the forecasted inventories unnecessary on the demand side of the coupling point, and this also makes quick response to orders possible. This new system has been applied to an electronic device manufacturing process successfully View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Towards an intelligent repository of scheduling methods

    Publication Year: 1997 , Page(s): 310 - 314
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (528 KB)  

    Scheduling is still poorly understood and applied in industry, often leading to unsatisfactory results. The provision of an intelligent repository of scheduling methods (SMs), aiding industrial users in selecting appropriate SMs would be most beneficial. It would also help bridge the gap between academic researchers and industry, by providing a common framework for the definition of scheduling needs and indicating to what degree existing SMs reply to them. We present a new expert system, called SMCT (scheduling method choice tool), that performs this function. We concentrate on two of its aspects: 1) concerning communicating with users who are not experienced in scheduling problems and terminology; 2) and concerning a novel way of structuring scheduling knowledge that is adapted to industrial and academic users View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Fabrication of micro mirror array with hidden joint structures

    Publication Year: 1997 , Page(s): 243 - 247
    Cited by:  Patents (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (792 KB)  

    Micro mirror arrays with hidden joint structures (pin and staples) are designed and fabricated. In order to achieve a high fill-factor and to remove the problems caused by elastic spring structures, a joint structure is placed under the mirror plate. All the structural components except the titanium electrode are fabricated with thermally evaporated aluminum. Semi-cured photoresist and thick photoresist are used for sacrificial layers. The static characteristics of the micro mirror are measured by applying a voltage difference between the mirror plate and an address electrode View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • More effective troubleshooting using data collection on etch equipment: case studies

    Publication Year: 1997 , Page(s): 528 - 531
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (268 KB)  

    The complexity of etch equipment and etch processes drives the need for equally complex troubleshooting systems. Advanced data collection software allows the user to collect and store data from every wafer that is processed. The ability to retrieve the data and review either individual wafer information or data trends has become an effective tool for troubleshooting. Situations that are extremely difficult to troubleshoot without the ability to retrieve process data include intermittent equipment malfunctions, problems found during subsequent processing or inspections, and problems detected at probe. Data collection and archiving gives maintenance and engineering the opportunity to analyze the data long after the process is complete. Analysis of the data often leads to solutions that will prevent another occurrence. Case studies will be used to display the effective utilization of data collection for troubleshooting complex etch problems View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Optimal model matching with disturbance rejection for the non-minimum phase plants

    Publication Year: 1997 , Page(s): 71 - 75
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (356 KB)  

    The design problem of optimal (or perfect) model matching control system with minimal weighted sensitivity to disturbance is considered in this paper. A system is said to achieve optimal (or perfect) model matching control if the system is internally stable and the H-norm of the difference between its closed-loop transfer function and that of the reference plant is minimized (or zero). So, the design of an optimal model matching control system leads to an H-optimization problem. A controller achieving optimal model matching control still has free design parameters, which can be utilized to reduce the effect of external disturbances. The disturbance rejection problem is transferred into another weighted optimization problem with constraints which come from the optimal model matching design. A new method is proposed to solve the resulting two coupled H-optimization problems by interpolation method View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • A system planning method based on templates for large scale manufacturing information systems

    Publication Year: 1997 , Page(s): 149 - 153
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (388 KB)  

    In the practical manufacturing field, we need to develop large scale manufacturing information systems especially in the field of the Japanese steel manufacturing industry where CIM is the core management technology. But they require a large amount of time and manpower, and furthermore it is very difficult to manage their projects. Therefore, we propose analyzing and designing procedures based on a two dimensional template and their criteria for the large scale manufacturing information system architecture in order to ease the analysis and design. In the manufacturing system, there are two important elements which correspond to the two dimensions of the template. One is a functional category and the other is a management structure, and we show its effectiveness by applying this method to the system planning of large scale information systems in a steel manufacturing plant View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Petri nets liveness analysis by minimal siphons

    Publication Year: 1997 , Page(s): 315 - 320
    Cited by:  Papers (6)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (396 KB)  

    In this paper, we presents a class of nets, called process nets with resources (PNRs), which model shared-resource automated manufacturing systems based on the concept of separately specifying the operation and resource requirements. A PNR is built from a live net that is an acyclic net after removing so called process idle places, and a set of places called resource idle places for modeling the availability of system resources. It is shown that the liveness and reversibility of a PNR only depends on whether all minimal siphons are marked View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • The development of PC-based highly model-mixed engine dispatching systems

    Publication Year: 1997 , Page(s): 49 - 54
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (732 KB)  

    This paper aims to propose the design and implementation of a real-time model-mixed engine dispatching system. The proposed engine dispatching system (EDS) is applied to the engine plant of Ford Lio-Ho Motor Company. The production system of Ford Lio-Ho Engine Plant (FLHEP) is a highly model-mixed production system. It attempts to achieve the goals of more flexibility, higher efficiency, lower cost and less shop floor space. In order to handle such a model-mixed production system, an efficient real-time dispatcher, EDS, is required. The EDS is a client-server configuration. The EDS server handles the real-time engine dispatching, operator's loading balance, integrating distributed data and security control. Besides, the EDS server provides the performance measure, graphical user interface, user's classification, production information and dispatching information. On the other hand, the EDS server broadcasts the information to all EDS clients. In this manner, the production information can be synchronized and the engines can be assembled in parallel in FLHEP. The objectives of EDS are to eliminate the bottlenecks of the original system, balance operator's loading, improve product's quality, integrate distributed production data and provide efficient dispatching rules. Since the proposed EDS is constructed by using the modular design and object-oriented approach, it is easy to integrate, extend, test and debug View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Neural net approach for speaker sensitive measure analysis

    Publication Year: 1997 , Page(s): 365 - 368
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (376 KB)  

    Speech signals can be described by filters and excitation. This paper presents an analysis of the speaker information from this view point. We use the self organizing map of Kohonen (SOM) to explore the effectiveness of these two parts of a parameter in representing individual features of speakers. LSPs can be viewed as all-pole filters. Then, the excitation sequences of the filters are studied for discriminative characteristics of the speaker. In the experiment, three kinds of parameters-direct MFCC, LSP, and residual MFCC are used to build a feature map. Finally SOM shows that direct MFCC and LSP produce very similar feature maps for the same speaker in their general feature space. A correlation criterion gives further verification. While the SOMs of excitation signals are less discriminative between each other, they are less speaker sensitive View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Hybrid modeling and simulation of manufacturing systems

    Publication Year: 1997 , Page(s): 555 - 560
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (444 KB)  

    In this paper, a new methodology for modeling and simulation of hybrid manufacturing systems is presented. This methodology which is based on an extension of Petri nets can be used to model, simulate and analyze systems with both time and event-driven parts. This new extension is called GPN (global Petri net). Here we show how it is used to model a jobshop at two abstraction levels. At the higher level the jobshop is modeled as a discrete-event system by a conventional PN. When more details about its behavior is required, we have modeled it as a hybrid system by a GPN. The modeling approach is very general and can be used for any type of hybrid systems. A simulation package developed based on the GPN modeling methodology is used for the simulation of the resulting nets. Various hybrid system properties such as boundedness stability, controllability and liveness can be investigated by the analysis methods developed for GPNs View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Gertrude: OO for BPR

    Publication Year: 1997 , Page(s): 33 - 38
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (652 KB)  

    Gertrude is a business process modeling methodology centered on object orientation. The approach is bottom-up. A technique similar to use cases is the starting point of the analysis: we generate scenarios and we identify the people and their roles. OMT is then used to get a picture of the structure of the enterprise. Afterwards, we produce activity based forms to validate our model against a time-evolving reality. If the “online analysis” does not match the “off-line” picture we go back to the beginning and we start modeling again. Eventually, we get a picture of the reality: it is the basis of the re-engineering process View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Virtual factories: an object-oriented simulation-based framework for real-time FMS control

    Publication Year: 1997 , Page(s): 208 - 213
    Cited by:  Papers (3)  |  Patents (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (592 KB)  

    Increasingly, automation and computer-based control play key roles in the operation of manufacturing systems. These two factors are necessary to support trends towards greater product customization and increased emphasis on reduction of lead times. At the same time, though, automation and computer-based control can be enormously expensive to design and implement in a factory. These high costs motivate the need for modeling and analysis. Existing modeling and analysis tools are effective for high level modeling of manufacturing systems. However, they suffer from limitations which are important in detailed analysis of system performance. This research is motivated by the need to develop modeling tools which support rapid development of detailed simulation models to assess system performance. The fundamental idea is to develop such an environment (i.e., a “virtual factory”) which one may use to test different system configurations and control policies. We demonstrate our work thus far by presenting a case study involving deadlock avoidance in a semiconductor cluster tool View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Sensitivity analysis of priority-based scheduling in manufacturing

    Publication Year: 1997 , Page(s): 465 - 466
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (120 KB)  

    We present a perturbation technique for computing sensitivities of schedules with respect to jobs' release times in a manufacturing system. The processing disciplines at the various servers are based on priorities: each job carries its priority code, and when a number of jobs wait in a buffer, the highest-priority one will be served first. Various manufacturing configurations, like generalized flow shops, assembly systems, and job shops are discussed View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Control of vector discrete-event systems in the context of operational safety

    Publication Year: 1997 , Page(s): 263 - 268
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (488 KB)  

    The aim of this paper is to use the vector discrete-event system (VDES) model in the context of operational safety (OpS). The purpose of OpS is to design and synthesise optimally suited reactivity control over critical failures so as to ensure degraded functioning. OpS attempts to integrate several control techniques which permit continuing production under failure, subject to specific accepted risk. Problems involving controllability, stability and optimization may arise and we propose to investigate them in the framework of VDES in which a useful class of control system can be compactly modeled View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • HIGHROBOT: telerobotics in the Internet

    Publication Year: 1997 , Page(s): 115 - 120
    Cited by:  Papers (4)  |  Patents (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (552 KB)  

    HIGHROBOT is an open workstation based robot control which has full access to the Internet and its Web-technologies. Here, the usage of Java-applets offers new applications in telerobotics. Additionally, the HIGHROBOT system offers access to high speed networks. This leads to a vast field of new applications which cannot be found in traditional control systems. In this paper we present a prototype controller implementation for a manipulator controlled via the Internet. The robot arm can be controlled running a Java applet on a remote system. Our object oriented software architecture is based on the design of a general application independent server concept that can be used in distributed object computing View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Flexible assembly line balancing with alternate assembly plans and duplicate task assignments

    Publication Year: 1997 , Page(s): 171 - 176
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (508 KB)  

    The paper presents integer programming formulations and a heuristic solution procedure for a bicriterion loading and assembly plan selection problem in a flexible assembly line. The problem objective is to simultaneously determine an allocation of assembly tasks among the stations and to select assembly sequences and assembly routes for a set of products so as to balance station workloads and minimize total transportation time in a unidirectional flow system. In the approach proposed, first the station workloads are balanced using a linear relaxation-based heuristic and then assembly sequences and routes are selected for all products, based on a network flow model. An illustrative example is provided View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • An inter-organizational information system design for virtual enterprises

    Publication Year: 1997 , Page(s): 139 - 142
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (292 KB)  

    We have used the term “virtual enterprise” in articulating the 21st century global manufacturing enterprise strategy. One of the key requirements is to design an information system (IS) architecture to control the interoperability of the participated organization's distributed, heterogeneous and concurrent systems. This article presents design of an inter-organizational information system (IOIS) which contains a macro-PDMS model for supporting inter-organizational systems (IOS) such as a virtual enterprise. We have focused on the reactivity problem and we propose also a macro-process model for this kind of organizations View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.