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A petri net-based simulation tool for the design and analysis of flexible manufacturing systems
1994 abstract index
show that compaction pressure and rod depth have significant effects on bed fixture performance. Fixture rigidity exhibits different trends with load types. Fixture rigidity is reliable and repeatable under static vertical loading; it is also somewhat linear. Under torque loads, rigidity is highly nonlinear. Fixture rigidity is highly nonlinear in the case of dynamic loads as well. Under the loading conditions outlined above, displacement of the workpiece can be maintained within acceptable tolerances even for close tolerance machining operations and tight indexing applications such as surface inspection. Results of rigidity are conservative because the type of workpiece used in the study represents the worst possible geometry for fixturing.
A Study of the Continuous Flow Model of Production Lines with Unreliable Machines and Finite Buffers, R. Alvarez-Vargas, Y. Dallery, and R. David, pp. 22 l-234 Analysis of asynchronous manufacturing flow lines with deterministic processing times, unreliable machines, and finite buffers is almost always achieved through the use of approximate models, such as the synchronous model or the continuous flow model. Here we are concerned with the continuous flow model. The purpose of this paper is ( 1) to provide a detailed discussion of the continuous flow model as an approximation of the asynchronous model and (2) to establish under what conditions this model provides a good approximation of the original asynchronous model. The second issue is addressed by means of an experimental study. We consider a set of 70 manufacturing lines. For each line, we use simulation to compare the production rate of the continuous flow model with that of the asynchronous model. For some lines, we also compare other performance measures. By analyzing simulation results, we give general conclusions about conditions where the continuous flow model is a good approximation of the asynchronous model. Keywords: Manufacturing Flow Lines, Unreliable Machines, Finite Buffers, Modeling, Performance Evaluation, Asynchronous Model, Continuous Flow Model
Keywords: Flexible Particulate Bed Fixtures, Torque, Vertical Loading, Dynamic Behavior, Static Rigidity Sensor-Based Solution to Contiguous and Overlapping Parts in Vibratory Bowl Feeders, Gary P Maul and Nebojsa I. Jaksic, pp. 190-195 This paper discusses a vibratory bowl feeder with a computer-based sensor system that can recognize correctly oriented parts even when some are contiguous or overlapping. Hardware consists of a vibratory bowl feeder, sensor system, control computer, and software development computer. The sensor system is a linear row of film optics in the side wall and track of the bowl. This configuration creates a 3-D silhouette of the part. An algorithm is developed to recognize parts in the orientation specified by the user. Test results show that the control program functions very well. Keywords: Vibratory Sensors, Part Feeders
Volume 13/Number
Bowls, Low-Cost Vision Systems,
Cellular manufacturing systems have gained significant research attention in recent years because of their inherent ability to spur productivity. Classical cellular manufacturing literature has concerned itself with the problem of identifying appropriate machine-part groups. This paper proposes a mixed-integer nonlinear programming formulation model for the machine layout problem in cellular manufacturing. The objective of the formulation is to minimize a surrogate-weighted cost of intercellular material movement under capacity and part requirement constraints. A heuristic solution method is proposed, and a numerical example is presented to illustrate the model and demonstrate the solution improvement. Keywords: Cellular Manufacturing, Group Technology, Formulation, Machine Layout
Cellular Manufacturing: A Taxonomic Review Framework, 0. Felix Offodile, Abraham Mehrez, and John Grznar, pp. 196-220 The purpose of this paper is to employ a taxonomic framework for a comprehensive review of cellular manufacturing systems. Three classes of machine-part grouping techniques have been identified in cellular manufacturing: visual inspection, part coding and classification, and analysis of the production process. For this review, we concentrate on the latter approach and classify it by assumptions, characteristics, and main properties and results. A comprehensive review and discussions of various models are provided. Model assumptions and characteristics are summarized using a tabular framework. Finally, the paper provides directions for future research. Keywords: Cellular Manufacturing,
4
Formulation of the Machine Cell Grouping Problem with Capacity and Material Movement Constraints, John Grznar, Abraham Mehrez, and 0. Felix Offodile, pp. 241-250
A Petri Net-Based Simulation Tool for the Design and Analysis of Flexible Manufacturing Systems, Dong-Soon Yim and Thomas A. Barta, pp. 25 1-261
Group Technology
452
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
show that compaction pressure and rod depth have significant effects on bed fixture performance. Fixture rigidity exhibits different trends with load types. Fixture rigidity is reliable and repeatable under static vertical loading; it is also somewhat linear. Under torque loads, rigidity is highly nonlinear. Fixture rigidity is highly nonlinear in the case of dynamic loads as well. Under the loading conditions outlined above, displacement of the workpiece can be maintained within acceptable tolerances even for close tolerance machining operations and tight indexing applications such as surface inspection. Results of rigidity are conservative because the type of workpiece used in the study represents the worst possible geometry for fixturing.
A Study of the Continuous Flow Model of Production Lines with Unreliable Machines and Finite Buffers, R. Alvarez-Vargas, Y. Dallery, and R. David, pp. 22 l-234 Analysis of asynchronous manufacturing flow lines with deterministic processing times, unreliable machines, and finite buffers is almost always achieved through the use of approximate models, such as the synchronous model or the continuous flow model. Here we are concerned with the continuous flow model. The purpose of this paper is ( 1) to provide a detailed discussion of the continuous flow model as an approximation of the asynchronous model and (2) to establish under what conditions this model provides a good approximation of the original asynchronous model. The second issue is addressed by means of an experimental study. We consider a set of 70 manufacturing lines. For each line, we use simulation to compare the production rate of the continuous flow model with that of the asynchronous model. For some lines, we also compare other performance measures. By analyzing simulation results, we give general conclusions about conditions where the continuous flow model is a good approximation of the asynchronous model. Keywords: Manufacturing Flow Lines, Unreliable Machines, Finite Buffers, Modeling, Performance Evaluation, Asynchronous Model, Continuous Flow Model
Keywords: Flexible Particulate Bed Fixtures, Torque, Vertical Loading, Dynamic Behavior, Static Rigidity Sensor-Based Solution to Contiguous and Overlapping Parts in Vibratory Bowl Feeders, Gary P Maul and Nebojsa I. Jaksic, pp. 190-195 This paper discusses a vibratory bowl feeder with a computer-based sensor system that can recognize correctly oriented parts even when some are contiguous or overlapping. Hardware consists of a vibratory bowl feeder, sensor system, control computer, and software development computer. The sensor system is a linear row of film optics in the side wall and track of the bowl. This configuration creates a 3-D silhouette of the part. An algorithm is developed to recognize parts in the orientation specified by the user. Test results show that the control program functions very well. Keywords: Vibratory Sensors, Part Feeders
Volume 13/Number
Bowls, Low-Cost Vision Systems,
Cellular manufacturing systems have gained significant research attention in recent years because of their inherent ability to spur productivity. Classical cellular manufacturing literature has concerned itself with the problem of identifying appropriate machine-part groups. This paper proposes a mixed-integer nonlinear programming formulation model for the machine layout problem in cellular manufacturing. The objective of the formulation is to minimize a surrogate-weighted cost of intercellular material movement under capacity and part requirement constraints. A heuristic solution method is proposed, and a numerical example is presented to illustrate the model and demonstrate the solution improvement. Keywords: Cellular Manufacturing, Group Technology, Formulation, Machine Layout
Cellular Manufacturing: A Taxonomic Review Framework, 0. Felix Offodile, Abraham Mehrez, and John Grznar, pp. 196-220 The purpose of this paper is to employ a taxonomic framework for a comprehensive review of cellular manufacturing systems. Three classes of machine-part grouping techniques have been identified in cellular manufacturing: visual inspection, part coding and classification, and analysis of the production process. For this review, we concentrate on the latter approach and classify it by assumptions, characteristics, and main properties and results. A comprehensive review and discussions of various models are provided. Model assumptions and characteristics are summarized using a tabular framework. Finally, the paper provides directions for future research. Keywords: Cellular Manufacturing,
4
Formulation of the Machine Cell Grouping Problem with Capacity and Material Movement Constraints, John Grznar, Abraham Mehrez, and 0. Felix Offodile, pp. 241-250
A Petri Net-Based Simulation Tool for the Design and Analysis of Flexible Manufacturing Systems, Dong-Soon Yim and Thomas A. Barta, pp. 25 1-261
Group Technology
452
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