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Planning and scheduling in Japanese semiconductor manufacturing
1994 abstract index
Simulation is an invaluable tool in designing and analyzing manufacturing systems. A Petri net-based simulation tool is presented to aid simulation projects in manufacturing, including flexible manufacturing systems (FMSs). Three models are developed-an object model, Petri net model, and control model. While hardware components of FMSs are modeled by Petri net objects, control functions are separately modeled and integrated with a Petri net model to resolve conflicts occurring in Petri net execution. Facilities of the developed tool are presented, and a modeling procedure with the tool is illustrated via a case study. Keywords: Petri Nets, Simulation,
Modeling,
Flexible manufacturing and assembly systems consist of machines, robots, and automated guided vehicles aimed at meeting dynamically changing market needs. Numerous asynchronous concurrent actions involved in these systems make analysis of them difficult. Breakdowns of system components further complicate investigation of issues related to design, performance optimization, and control. This paper proposes a new class of modeling tools called augmented timed Petri nets (ATPNS) for modeling and analyzing robotic assembly systems with breakdowns. These models aid designers in better understanding the concurrency, synchronization, and sequential relations involved in breakdown handling and in system simulation for performance analysis. A flexible assembly system consisting of three robots with various breakdown rates is used to illustrate modeling, simulation, and analysis with ATPNs. ATPN models for breakdown handling are presented and analyzed for estimating system performance and for designing the optimum number of assembly fixtures. ATPN models can also be used for real-time system control. Finally, possible extensions to this study are discussed. Keywords: Breakdown Handling, Flexible Assembly Systems, Petri Nets, System Modeling, System Design
FMS
Grouping Parts with a Neural Network, Yunkung and Andrew Kusiak, pp. 262-275
Chung
Recognition of objects is used for identification, classification, verification, and inspection tasks in manufacturing. Neural networks are well suited for this application. In this paper, an application of a back-propagation neural network for the grouping of parts is presented. The back-propagation neural network is provided with binary images describing geometric part shapes, and it generates part families. To decrease the chance of reaching a local optimum and to speed up the computation process, three parameters-bias, momentum, and learning rate-are taken into consideration. The contribution of this paper is in design of a neuro-based system to group parts. The network groups all of the training and testing parts into part families with perfect accuracy. Performance of the system has been tested on a benchmark example and then by experimenting with 60 parts. Keywords: Group Technology, Networks, Artificial Intelligence
Manufacturing,
Volume 13/Number 5 Computer-Aided Process Planning for EDM Operations, Bert Lauwers and Jean-Pierre Kruth, pp. 3 13-322 This paper describes a computer-aided process planning system for electrical discharge machining (EDM). Input to the system is a workpiece description based on process planning features. New process planning feature types have been defined because existing standards such as the CAM-I feature catalog only describe features for prismatic parts. Each feature is characterized by a generic process plan. Generic process plans define possible manufacturing operations that can be applied to a feature. The developed process planning system evaluates the generic process plans of all features included in the workpiece description and combines them into an optimal process plan based on minimal cost. A general strategy to estimate EDM machining times is presented.
Neural
Economic Comparison of Wire Harness Assembly Systems, E. Aguirre and B. Raucent, pp. 276-288 This paper describes typical wire harness assembly methods, including manual. semiautomatic, automatic, and robotized assembly systems. For each case, mathematical models are developed to describe economic performance. The various systems are compared to the harness specification. Finally, the future role of the robotized system is discussed. Keywords: Wire Harness, Assembly Systems, Economic Comparison, Automatic Assembly. Robotic Assembly
Keywords: Computer-Aided Process Planning (CAPP), Electrical Discharge Machining (EDM), Process Planning Features, Knowledge-Based Systems
Augmented Timed Petri Nets for Modeling, Simulation, and Analysis of Robotic Systems with Breakdowns, Kurapati Venkatesh, Mehdi Kaighobadi, MengChu Zhou, and Reggie J. Caudill, pp. 289-301
Planning and Scheduling in Japanese Semiconductor Manufacturing, Izak Duenyas, John W. Fowler. and Lee W. Schruben, pp. 323-332
453
Journal ofManufacturing Vol. 13/‘No. 6
qvstems
1994 abstract index
added flexibility to the incorporation of multiple cacy of the approach has Ke_vwords: Hybrid Manufacturing System,
Described are some methods used by Japanese semiconductor manufacturing companies for long-term planning and short-term scheduling and shop floor control. Tools and techniques used for planning and scheduling in wafer fabrication are identified. General findings are discussed and specific efforts at four companies are described in detail. Manufacturing, Keywords: Computer-Integrated Organizational and Business Issues, Production and Operations Management, International Manufacturing
design approach by facilitating the constraints and objectives. The effibeen demonstrated with an example. Neural Network, Cellular Self-Organizing Network
Sinkage Characteristics of Workpieces in Flexible Particulate Bed Fixtures: An Experimental and Numerical Investigation, Jeries Abou-Hanna, Kiyohisa Okamura, and Timothy McGreevy, pp. 359-369 The concept of flexible particulate bed fixtures (FPBFs or PBFs) in low-volume manufacturing environments has been investigated for its potential use in manufacturing environments. This paper reports findings regarding one of several performance issues that have been under investigation in the past five years, namely the displacement (sinkage) of the workpiece during the compaction process of the particulate. A bed fixture prototype was instrumented to detect the sinkage of a slender cylindrical workpiece and of the compacting plate during compaction. In addition, sinkage characteristics of finned rod workpieces as a function of fin size, rod size, and fin location were investigated to determine the effects that workpiece size and shape have on sinkage. A finite element model of the bed was also used to perform numerical tests and to study the effects of submergence depth and angular position of plain slender rod and finned rod workpieces on sinkage. Sinkage is dependent on subdepth and workpiece initial orientation. mergence Furthermore, fin size and location have a significant effect on the sinkage of the rod with respect to the compacting surface. These results provide trends helpful in applying the particulate bed fixture methodology to environments requiring tight indexing tolerances, such as machining or surface inspection. Keywords: Flexible Particulate Bed Fixtures, Sinkage, Compaction, Workpiece Displacement, Indexing
Seamless Design-to-Manufacture of Marine Propulsers: A Case Study for Rapid Response Machining, Y. Hazony and L. Zeidner, pp. 333-345 Seamless design-to-manufacture (SDTM) is described in the context of rapid prototyping of marine propulsers. SDTM systems, customized for complex mechanical parts, have been demonstrated to reduce design-to-manufacture cycle time by an order of magnitude. They employ conventional manufacturing processes and produce prototypes made of the correct materials as designed. Consequently, SDTM prototypes can be subjected to rigorous geometric, physical, and thermal testing. Conceptual part design and process design are brought forward in SDTM systems to form an integrated design front end. Detailed part and process geometries and NC code are automatically generated using a parametrically driven, rule-based geometric modeler. Both part and process design are described. Rapid Prototyping, Rapid Response Keywords: Machining, Design-to-Manufacture, Five-Axis Machining, Propeller Blades Expert Self-Organizing Neural Network for the Design of Cellular Manufacturing Systems, Harish A. Rao and l? Gu, pp. 346-358 A pragmatic approach to the design of cellular manufacturing systems is often driven by multiple constraints and objectives. Use of neural networks has provided an opportunity to perform computationally intensive, multiconstraint tasks more efficiently. This paper presents a multilayered hybrid neural network to incorporate some of these constraints and objectives for practicality in simulating cellular manufacturing system design. The neural network, which is constraint-bound is structured to include practical limitations such as duplicate machine availability and machine capacity during the cell design process. The expert system, which is interactive, takes its input from the neural network and uses alternate process plans to reassign any exceptional parts that may occur as a result of the constraint imposition during the initial cell design. Thus the hybrid neural net-expert system technique gives an
Automatic Vision Inspection and Measurement System for External Screw Threads, Randal J. Hunsicker, John Patten, Alton Ledford, Cathie Ferman, and Michael Allen, pp. 370-384 Production of threaded parts in some manufacturing environments requires high-precision thread measurement and a reliable inspection method. This paper describes considerations and techniques used in the development of a vision system for measurement and inspection of male screw threads. A two-stage process was developed to calibrate the imaging system. This procedure uses a calibration gauge pin to calibrate the vision system’s pixel scale and two pitch standards (max, min) to correct for lighting and image
454
Simulation is an invaluable tool in designing and analyzing manufacturing systems. A Petri net-based simulation tool is presented to aid simulation projects in manufacturing, including flexible manufacturing systems (FMSs). Three models are developed-an object model, Petri net model, and control model. While hardware components of FMSs are modeled by Petri net objects, control functions are separately modeled and integrated with a Petri net model to resolve conflicts occurring in Petri net execution. Facilities of the developed tool are presented, and a modeling procedure with the tool is illustrated via a case study. Keywords: Petri Nets, Simulation,
Modeling,
Flexible manufacturing and assembly systems consist of machines, robots, and automated guided vehicles aimed at meeting dynamically changing market needs. Numerous asynchronous concurrent actions involved in these systems make analysis of them difficult. Breakdowns of system components further complicate investigation of issues related to design, performance optimization, and control. This paper proposes a new class of modeling tools called augmented timed Petri nets (ATPNS) for modeling and analyzing robotic assembly systems with breakdowns. These models aid designers in better understanding the concurrency, synchronization, and sequential relations involved in breakdown handling and in system simulation for performance analysis. A flexible assembly system consisting of three robots with various breakdown rates is used to illustrate modeling, simulation, and analysis with ATPNs. ATPN models for breakdown handling are presented and analyzed for estimating system performance and for designing the optimum number of assembly fixtures. ATPN models can also be used for real-time system control. Finally, possible extensions to this study are discussed. Keywords: Breakdown Handling, Flexible Assembly Systems, Petri Nets, System Modeling, System Design
FMS
Grouping Parts with a Neural Network, Yunkung and Andrew Kusiak, pp. 262-275
Chung
Recognition of objects is used for identification, classification, verification, and inspection tasks in manufacturing. Neural networks are well suited for this application. In this paper, an application of a back-propagation neural network for the grouping of parts is presented. The back-propagation neural network is provided with binary images describing geometric part shapes, and it generates part families. To decrease the chance of reaching a local optimum and to speed up the computation process, three parameters-bias, momentum, and learning rate-are taken into consideration. The contribution of this paper is in design of a neuro-based system to group parts. The network groups all of the training and testing parts into part families with perfect accuracy. Performance of the system has been tested on a benchmark example and then by experimenting with 60 parts. Keywords: Group Technology, Networks, Artificial Intelligence
Manufacturing,
Volume 13/Number 5 Computer-Aided Process Planning for EDM Operations, Bert Lauwers and Jean-Pierre Kruth, pp. 3 13-322 This paper describes a computer-aided process planning system for electrical discharge machining (EDM). Input to the system is a workpiece description based on process planning features. New process planning feature types have been defined because existing standards such as the CAM-I feature catalog only describe features for prismatic parts. Each feature is characterized by a generic process plan. Generic process plans define possible manufacturing operations that can be applied to a feature. The developed process planning system evaluates the generic process plans of all features included in the workpiece description and combines them into an optimal process plan based on minimal cost. A general strategy to estimate EDM machining times is presented.
Neural
Economic Comparison of Wire Harness Assembly Systems, E. Aguirre and B. Raucent, pp. 276-288 This paper describes typical wire harness assembly methods, including manual. semiautomatic, automatic, and robotized assembly systems. For each case, mathematical models are developed to describe economic performance. The various systems are compared to the harness specification. Finally, the future role of the robotized system is discussed. Keywords: Wire Harness, Assembly Systems, Economic Comparison, Automatic Assembly. Robotic Assembly
Keywords: Computer-Aided Process Planning (CAPP), Electrical Discharge Machining (EDM), Process Planning Features, Knowledge-Based Systems
Augmented Timed Petri Nets for Modeling, Simulation, and Analysis of Robotic Systems with Breakdowns, Kurapati Venkatesh, Mehdi Kaighobadi, MengChu Zhou, and Reggie J. Caudill, pp. 289-301
Planning and Scheduling in Japanese Semiconductor Manufacturing, Izak Duenyas, John W. Fowler. and Lee W. Schruben, pp. 323-332
453
Journal ofManufacturing Vol. 13/‘No. 6
qvstems
1994 abstract index
added flexibility to the incorporation of multiple cacy of the approach has Ke_vwords: Hybrid Manufacturing System,
Described are some methods used by Japanese semiconductor manufacturing companies for long-term planning and short-term scheduling and shop floor control. Tools and techniques used for planning and scheduling in wafer fabrication are identified. General findings are discussed and specific efforts at four companies are described in detail. Manufacturing, Keywords: Computer-Integrated Organizational and Business Issues, Production and Operations Management, International Manufacturing
design approach by facilitating the constraints and objectives. The effibeen demonstrated with an example. Neural Network, Cellular Self-Organizing Network
Sinkage Characteristics of Workpieces in Flexible Particulate Bed Fixtures: An Experimental and Numerical Investigation, Jeries Abou-Hanna, Kiyohisa Okamura, and Timothy McGreevy, pp. 359-369 The concept of flexible particulate bed fixtures (FPBFs or PBFs) in low-volume manufacturing environments has been investigated for its potential use in manufacturing environments. This paper reports findings regarding one of several performance issues that have been under investigation in the past five years, namely the displacement (sinkage) of the workpiece during the compaction process of the particulate. A bed fixture prototype was instrumented to detect the sinkage of a slender cylindrical workpiece and of the compacting plate during compaction. In addition, sinkage characteristics of finned rod workpieces as a function of fin size, rod size, and fin location were investigated to determine the effects that workpiece size and shape have on sinkage. A finite element model of the bed was also used to perform numerical tests and to study the effects of submergence depth and angular position of plain slender rod and finned rod workpieces on sinkage. Sinkage is dependent on subdepth and workpiece initial orientation. mergence Furthermore, fin size and location have a significant effect on the sinkage of the rod with respect to the compacting surface. These results provide trends helpful in applying the particulate bed fixture methodology to environments requiring tight indexing tolerances, such as machining or surface inspection. Keywords: Flexible Particulate Bed Fixtures, Sinkage, Compaction, Workpiece Displacement, Indexing
Seamless Design-to-Manufacture of Marine Propulsers: A Case Study for Rapid Response Machining, Y. Hazony and L. Zeidner, pp. 333-345 Seamless design-to-manufacture (SDTM) is described in the context of rapid prototyping of marine propulsers. SDTM systems, customized for complex mechanical parts, have been demonstrated to reduce design-to-manufacture cycle time by an order of magnitude. They employ conventional manufacturing processes and produce prototypes made of the correct materials as designed. Consequently, SDTM prototypes can be subjected to rigorous geometric, physical, and thermal testing. Conceptual part design and process design are brought forward in SDTM systems to form an integrated design front end. Detailed part and process geometries and NC code are automatically generated using a parametrically driven, rule-based geometric modeler. Both part and process design are described. Rapid Prototyping, Rapid Response Keywords: Machining, Design-to-Manufacture, Five-Axis Machining, Propeller Blades Expert Self-Organizing Neural Network for the Design of Cellular Manufacturing Systems, Harish A. Rao and l? Gu, pp. 346-358 A pragmatic approach to the design of cellular manufacturing systems is often driven by multiple constraints and objectives. Use of neural networks has provided an opportunity to perform computationally intensive, multiconstraint tasks more efficiently. This paper presents a multilayered hybrid neural network to incorporate some of these constraints and objectives for practicality in simulating cellular manufacturing system design. The neural network, which is constraint-bound is structured to include practical limitations such as duplicate machine availability and machine capacity during the cell design process. The expert system, which is interactive, takes its input from the neural network and uses alternate process plans to reassign any exceptional parts that may occur as a result of the constraint imposition during the initial cell design. Thus the hybrid neural net-expert system technique gives an
Automatic Vision Inspection and Measurement System for External Screw Threads, Randal J. Hunsicker, John Patten, Alton Ledford, Cathie Ferman, and Michael Allen, pp. 370-384 Production of threaded parts in some manufacturing environments requires high-precision thread measurement and a reliable inspection method. This paper describes considerations and techniques used in the development of a vision system for measurement and inspection of male screw threads. A two-stage process was developed to calibrate the imaging system. This procedure uses a calibration gauge pin to calibrate the vision system’s pixel scale and two pitch standards (max, min) to correct for lighting and image
454