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Applications of GMDH-type modeling in manufacturing
JournalofManqf~__ ringSystems Volun~ 12/No. 1
Cumulative Abstract Index
manufacturing system is given by the entropy of the language produced by the productions of its grammar. Shortcomings of such a measure are discussed along with proposals for future work. Ktgword~: Flexible Manufacturing Systems, Flexibility, Manufacturing Models, Grammars, Routing
1988~ Voi. 7/No. 3 Justification of FM$ with the Analytic Hierarchy Process, R. Wabalickls, pp. 175-82 Developing a justification methodology for an FMS requires the use of traditional engineering economy tools end innovative r a ~ o oProcedures to fully evaluate nn the benefits of the gy. This paper gives an overview of the potential benefits derived from an FMS implementation and a method to quantify these benefits for use in engineering economy studies. The analytic hierarchy process is recommended for this application. An example of its use is given to determine the best manufectur~8eywoSY stem" rda: Plex/ble Menufacturin~ - Systems, Analytic Hierarchy Process, Capital Equipment Justification, Machine Tool Justification, Justification of Computer Integrated Manufacturing
Tolerance Verification Through Manufactured Part Modeling, F. Etesami, pp. 223-32 The geometry of manufactured parts is always sii~7,htiydifferent from the theoretically prefect design dascripuon models. Certain inspection tests determine whether such variations are within acceptable range. There is, however, no theory for compiling the results of such tests and measurements in building a geometric model for the part. A menufacmred part model can be used for tolerance verification, robot guidance in tight assembly tasks, and for quality and process control applications. In this paper a modelinl~scheme is proposed to integrate different forms of observations m constructing a part model. Imperfect features are modeled by constructor solids which have perfect forms. The boundaries of these solids tightly enclose the functional features and represent the extent of their geometric variations. The part model is then used to interpret the meaning of some pracuced tolerance specification statements. Keywords: Tolerancing, Computer Aided Manufactorm8, Geometric Modeling, Geometric Feature
Early Cost Estimating in Product Design, P. Dewhurst, G. Boothroyd, pp. 183-91 This paper describes product costing procedures which are intended to form the basis for a design analysis method for product design for efficient manufacture (Dl~r). This DI~/I method, presently being developed by the writers, will form a logical extension of their design for assembly procedures. Design for efficient manufacture will consist of two steps. The first step is the identification of the appropriate materials and manufacturing processes for the component parts of a new product design. The second step is the detailed design of the individual components consistent with the capabilities and limitations of the material-process combinations. A prerequisite for making sound judgments in the choice of materials and processes is the availability of manufacturing cost information at the early product concept design stage. Tiffs implies the need to estimate menutacturing costs before component part designs are fully detailed and without full knowledge of the manufacturing processing plans. Keywords: Product, Design, Manufacture, Cost
Vision Assisted NC Milling Path Generation, S. Anand, S. Raman, R. Wysk, pp. 233-40 CAD/CAM software are an interrelated mesh of computer rngramming systems that serve to monitor, process and control flow of manufacturing data. Modern day techniques rely extensively on the intel~rafiun of standards like the initial graphics exchange specification (IGES) with automated path planmng modules. The intent of such an integration is to maintain the system as generic as possible. Integration of the various aspects of manufacturing systems provides total automation of the system. A machine vimon system was used to generate the NC code to face mill any planar polygnnal part. The vision system helps to capture the image of the face of a polygonal object. This image is decoded into edges and vertices by pefform.ing computations in software, based on simple image prooessmg rules. Then the software passes the control to a path planning module. This module selects the most efficient tool path and generates the part program to face mill the part. This paper presents a detailed description of the algorithm developed along with its application environment. Keywords: Machine Vision, Path Planning, NC Milling
A Framework for a Rule-Based Expert Fixturing System for Face
Milling Planar Surfaces on a CAD System Using Flexible F~t~res: B. Nnaji, S: Alladin, P. Lyu, pp..193-207 . • objective oz this resenrcn paper is to present a Irameworx for an expert system which will aid in the automatic layout of fixture models on a CAD/CAM system for given applications through an interactive process. The designs will be graphically represented as solid models on the screen of a computer aided design system, thereby simulating the actual ~hysical) fixture assembly, hence causing substantial savings wlth respect to the economics associated with a trad/tional fixturing operation. Face milling is used to demonstrate the concept. ords: Modular/Flex/ble Flxtoring, Expert Systems, CAD/ , Fixturi~ Rules, 3:2:1 Concept.
Applications of GMDH.Type Modeling in Manufacturing, P. Chan, P. Ferrei~ C. Lin" pp. 241-53 This paper introduces the group method of data handling (GMDH) algorithm which addresses the problem of modeling complex systems. It is a heuristic self-organizing modeling approach for modeling different processes/phenomena on a metalworking shop floor. These models which can be used in monitoring/prediction of the processes also present information in a concise and accurate form to the planning functions, such as Fl~nooess planning and scheduling. This helps in making these ctious more dynamic and the decisions more realistic. Most shop floor processes are difficult to model b~cause of the large number o f influencing factors and the complex interactions between them. The GMDH is p~icularly well suited for the modeling end control of manufacturing processes and shop floor phenomena. In this paper the GMDH algorithm is described and
A Grammatical Approach to Rouging Flexibility in Large Manufacturing Systems, D. Upton, M. Barash, pp. 209-21 This paper considers the nature of routing flexibility in menufacturing systems and prop.oses methods for its quantification. Firstly, a measure of flexibility appropriate to Markovien routing is presented. It is shown that various other measures of the flexibility of systems so modelled presented in the literature are unrepresentative of the degree of routing flexibility. The information-theoretic approach to the Merkovien model is then extended to a more realistic grammatical model, along with an example. It is shown that an adequate measure of the flexibility of the
67
• l ofrManyfacturing n a t Systems L l ln ~ 1 ~.J.IMO. J.
Cumulative Abstract Index
its application in three problems, i.e., Modeling of positioning error of a machine under varying thermal conditions, modeling tool wear and tool wear rate, and modeling of cutting forces is presented. Keyworda: Modeling, Adaptive Control, Positioning Errors, Tool Life, Metal Cutting, FMS, CIM
1988~ Vol. 7/No. 4 A Simulation Model for Use in Designing Robotic Assembly Cells, C. Cash, W. Wilhelm, pp. 279-91 This paper describes an approach for modeling the operations of robotic assembly cells as well as a simulation model whichhnplements the approach. Use of the model as a decision aid for the cell design~ is demonstrated using a hypothetical example. A variety of typical "what if' studies are made and used to support recommendations for improved cell design. The antithetic variate variance reduction method is applied to analyze the trade-off between precision achieved and run time required by the simulation model.
This paper describes a new control architecture and a set of underlying design principles for developing and implementing faulttolerant m*nofacturing systems consisting of processing machines, robots, control computers and human operators. Significant innovations in the approach include the concept of "intelligent manufactured parts", the use of a "flat" beterarchicel architecture as opposed to the widely used hierarchical architecture, unification of simulation and control in system development and operation, integration of humans as "colleagues" of other entities rather than "masters", end achievement of implicit modifiability and fanlt-tolerance. An experimental heterarchically controlled manufacturing system has been developed in which robotic cells manipulate and manufacture parts. The system is comprised of ~ n d e n t robot,.part processing, mJnefactured part. and bum!n entities that cooperatively control the system through messages exchanged on a communication network. Successful design and implementation of the expe~nental system has shown that the approach presented in this paper has attractive properties that should be considered in future system designs, addressing a need for new system architectures and design philosophies that result in reduced complexity, higher fault tolerance, shorter development times, and lower development costs. Keywords:Distributed Control, Hetm'archic~ Systems, Fault Tolerance, Hi~chicel Systems, Dlstn'buted Intelligence, System
Integration
Method
Robotic Deburring of Two.DimensionalParts with Unknown Geometry, H. Kaxereoni, pp. 329-38 The work presented here is an approach in robotic deburring of twodimensional parts with unknown geometry. Two problems have been addressed in this paper: tracking the part contour, and control of the metal removal process. The tracking mechanism is a roller bearin~ mounted on a force sensor at the robot endpeint. The tracking control loys the force measured by this force sensor to find the normal to_ • part surface, while the deburring algorithm uses another set Ot
Task Level Off.LineProgramming Systemfor RoboticArc Welding.An Overview,J.Rubinovitz,R. Wysk, pp. 293-306 A structure for a CAD based, task level off-line prngramming system for robotic arc welding is presented. The welding task is specified using a solid modeling CAD system. A model of the robot motion capabilities, as well as several algorithms, are used to plan the thof motion between weld seams for the robotic welding process. • output of the system, in the form of a robot level program, is transferred to a specific robot controller using an interface module, which was also created for this research. An example welded part is used to show that the system can enhance the productivity and efficiency of robotic arc welding, for both low batch and high batell production. Keywords:Robotics, Off.L/me P r o ~ , Arc Welding, CAD, CAM, Productivity
~
effectiveness of the approach. Keywords: Robotics, Control, Deburring
A Review of Recent Developments in Robot Metrology, B. Jiang, J. Black, R. Duralsamy, pp. 339-57 This•aper provides a review of various measurement techniques, and testing methods, conditions and specifications (TMCS) for determining performance of. a robot. First, the principles of operation, accuracy and rapeatabdlty of measurement systems, and any special features are summarized. Then, the TMCS pronged by the Robotic industries Association, the International Organization for Standardization, a Japanese standard testing proposal, and several individuals are reviewed, and future research needs ere identified. Keywords:Robotics, Melrolo~, Performance Measurements, 3-D Measurements
A KinematicApproachfor Coordinated Motion of a Robot and a Positioning Table, M. Jouaneh, D. Dornfeld, pp. 307-14 Tracking a path for such applications as welding using a coordinated motion scheme between a five axis robot and a two-dimensional table offers several advantages over the use of a single manipulator. Faster execution speed, ability to handle large workpieces, and improvements in tracking accuracy at sharp corners in the path can be achieved through such a scheme. This paper discusses a method for coordinating the motion of two such manipulators where the two s~?Alators are simultaneously moved to track a path at constant method for resolving the motion among the two manipulators based on kinematics is presented. Implementation of the scheme on an industrial manipulator and a positioning table is discussed. Actual results of tracking a path under different control scenarios are presented. Keywords: Coordinated Motion, Two Manipulators, Path Planning, Kinematic Approach
1989~ Vol. 8/No. 1 Automating Process Planning: Using Feature Interactions to Guide Search, C.-Hayes, P. Wright, pp. 1-16 Machinist is an expert system that automatically makes procuss plans for fabricating metal parts on a CNC machine tool. It is part of an overall effort to automate the job shop. The type ot parts that it handles are prismatic, with features cut into one or
Fault-Tolerant Heterarchieal Control of Heterogeneous Manufacturing System Entitles, N. Duffle, R. Chitturi, J. Mou, pp. 315-27
68
Cumulative Abstract Index
manufacturing system is given by the entropy of the language produced by the productions of its grammar. Shortcomings of such a measure are discussed along with proposals for future work. Ktgword~: Flexible Manufacturing Systems, Flexibility, Manufacturing Models, Grammars, Routing
1988~ Voi. 7/No. 3 Justification of FM$ with the Analytic Hierarchy Process, R. Wabalickls, pp. 175-82 Developing a justification methodology for an FMS requires the use of traditional engineering economy tools end innovative r a ~ o oProcedures to fully evaluate nn the benefits of the gy. This paper gives an overview of the potential benefits derived from an FMS implementation and a method to quantify these benefits for use in engineering economy studies. The analytic hierarchy process is recommended for this application. An example of its use is given to determine the best manufectur~8eywoSY stem" rda: Plex/ble Menufacturin~ - Systems, Analytic Hierarchy Process, Capital Equipment Justification, Machine Tool Justification, Justification of Computer Integrated Manufacturing
Tolerance Verification Through Manufactured Part Modeling, F. Etesami, pp. 223-32 The geometry of manufactured parts is always sii~7,htiydifferent from the theoretically prefect design dascripuon models. Certain inspection tests determine whether such variations are within acceptable range. There is, however, no theory for compiling the results of such tests and measurements in building a geometric model for the part. A menufacmred part model can be used for tolerance verification, robot guidance in tight assembly tasks, and for quality and process control applications. In this paper a modelinl~scheme is proposed to integrate different forms of observations m constructing a part model. Imperfect features are modeled by constructor solids which have perfect forms. The boundaries of these solids tightly enclose the functional features and represent the extent of their geometric variations. The part model is then used to interpret the meaning of some pracuced tolerance specification statements. Keywords: Tolerancing, Computer Aided Manufactorm8, Geometric Modeling, Geometric Feature
Early Cost Estimating in Product Design, P. Dewhurst, G. Boothroyd, pp. 183-91 This paper describes product costing procedures which are intended to form the basis for a design analysis method for product design for efficient manufacture (Dl~r). This DI~/I method, presently being developed by the writers, will form a logical extension of their design for assembly procedures. Design for efficient manufacture will consist of two steps. The first step is the identification of the appropriate materials and manufacturing processes for the component parts of a new product design. The second step is the detailed design of the individual components consistent with the capabilities and limitations of the material-process combinations. A prerequisite for making sound judgments in the choice of materials and processes is the availability of manufacturing cost information at the early product concept design stage. Tiffs implies the need to estimate menutacturing costs before component part designs are fully detailed and without full knowledge of the manufacturing processing plans. Keywords: Product, Design, Manufacture, Cost
Vision Assisted NC Milling Path Generation, S. Anand, S. Raman, R. Wysk, pp. 233-40 CAD/CAM software are an interrelated mesh of computer rngramming systems that serve to monitor, process and control flow of manufacturing data. Modern day techniques rely extensively on the intel~rafiun of standards like the initial graphics exchange specification (IGES) with automated path planmng modules. The intent of such an integration is to maintain the system as generic as possible. Integration of the various aspects of manufacturing systems provides total automation of the system. A machine vimon system was used to generate the NC code to face mill any planar polygnnal part. The vision system helps to capture the image of the face of a polygonal object. This image is decoded into edges and vertices by pefform.ing computations in software, based on simple image prooessmg rules. Then the software passes the control to a path planning module. This module selects the most efficient tool path and generates the part program to face mill the part. This paper presents a detailed description of the algorithm developed along with its application environment. Keywords: Machine Vision, Path Planning, NC Milling
A Framework for a Rule-Based Expert Fixturing System for Face
Milling Planar Surfaces on a CAD System Using Flexible F~t~res: B. Nnaji, S: Alladin, P. Lyu, pp..193-207 . • objective oz this resenrcn paper is to present a Irameworx for an expert system which will aid in the automatic layout of fixture models on a CAD/CAM system for given applications through an interactive process. The designs will be graphically represented as solid models on the screen of a computer aided design system, thereby simulating the actual ~hysical) fixture assembly, hence causing substantial savings wlth respect to the economics associated with a trad/tional fixturing operation. Face milling is used to demonstrate the concept. ords: Modular/Flex/ble Flxtoring, Expert Systems, CAD/ , Fixturi~ Rules, 3:2:1 Concept.
Applications of GMDH.Type Modeling in Manufacturing, P. Chan, P. Ferrei~ C. Lin" pp. 241-53 This paper introduces the group method of data handling (GMDH) algorithm which addresses the problem of modeling complex systems. It is a heuristic self-organizing modeling approach for modeling different processes/phenomena on a metalworking shop floor. These models which can be used in monitoring/prediction of the processes also present information in a concise and accurate form to the planning functions, such as Fl~nooess planning and scheduling. This helps in making these ctious more dynamic and the decisions more realistic. Most shop floor processes are difficult to model b~cause of the large number o f influencing factors and the complex interactions between them. The GMDH is p~icularly well suited for the modeling end control of manufacturing processes and shop floor phenomena. In this paper the GMDH algorithm is described and
A Grammatical Approach to Rouging Flexibility in Large Manufacturing Systems, D. Upton, M. Barash, pp. 209-21 This paper considers the nature of routing flexibility in menufacturing systems and prop.oses methods for its quantification. Firstly, a measure of flexibility appropriate to Markovien routing is presented. It is shown that various other measures of the flexibility of systems so modelled presented in the literature are unrepresentative of the degree of routing flexibility. The information-theoretic approach to the Merkovien model is then extended to a more realistic grammatical model, along with an example. It is shown that an adequate measure of the flexibility of the
67
• l ofrManyfacturing n a t Systems L l ln ~ 1 ~.J.IMO. J.
Cumulative Abstract Index
its application in three problems, i.e., Modeling of positioning error of a machine under varying thermal conditions, modeling tool wear and tool wear rate, and modeling of cutting forces is presented. Keyworda: Modeling, Adaptive Control, Positioning Errors, Tool Life, Metal Cutting, FMS, CIM
1988~ Vol. 7/No. 4 A Simulation Model for Use in Designing Robotic Assembly Cells, C. Cash, W. Wilhelm, pp. 279-91 This paper describes an approach for modeling the operations of robotic assembly cells as well as a simulation model whichhnplements the approach. Use of the model as a decision aid for the cell design~ is demonstrated using a hypothetical example. A variety of typical "what if' studies are made and used to support recommendations for improved cell design. The antithetic variate variance reduction method is applied to analyze the trade-off between precision achieved and run time required by the simulation model.
This paper describes a new control architecture and a set of underlying design principles for developing and implementing faulttolerant m*nofacturing systems consisting of processing machines, robots, control computers and human operators. Significant innovations in the approach include the concept of "intelligent manufactured parts", the use of a "flat" beterarchicel architecture as opposed to the widely used hierarchical architecture, unification of simulation and control in system development and operation, integration of humans as "colleagues" of other entities rather than "masters", end achievement of implicit modifiability and fanlt-tolerance. An experimental heterarchically controlled manufacturing system has been developed in which robotic cells manipulate and manufacture parts. The system is comprised of ~ n d e n t robot,.part processing, mJnefactured part. and bum!n entities that cooperatively control the system through messages exchanged on a communication network. Successful design and implementation of the expe~nental system has shown that the approach presented in this paper has attractive properties that should be considered in future system designs, addressing a need for new system architectures and design philosophies that result in reduced complexity, higher fault tolerance, shorter development times, and lower development costs. Keywords:Distributed Control, Hetm'archic~ Systems, Fault Tolerance, Hi~chicel Systems, Dlstn'buted Intelligence, System
Integration
Method
Robotic Deburring of Two.DimensionalParts with Unknown Geometry, H. Kaxereoni, pp. 329-38 The work presented here is an approach in robotic deburring of twodimensional parts with unknown geometry. Two problems have been addressed in this paper: tracking the part contour, and control of the metal removal process. The tracking mechanism is a roller bearin~ mounted on a force sensor at the robot endpeint. The tracking control loys the force measured by this force sensor to find the normal to_ • part surface, while the deburring algorithm uses another set Ot
Task Level Off.LineProgramming Systemfor RoboticArc Welding.An Overview,J.Rubinovitz,R. Wysk, pp. 293-306 A structure for a CAD based, task level off-line prngramming system for robotic arc welding is presented. The welding task is specified using a solid modeling CAD system. A model of the robot motion capabilities, as well as several algorithms, are used to plan the thof motion between weld seams for the robotic welding process. • output of the system, in the form of a robot level program, is transferred to a specific robot controller using an interface module, which was also created for this research. An example welded part is used to show that the system can enhance the productivity and efficiency of robotic arc welding, for both low batch and high batell production. Keywords:Robotics, Off.L/me P r o ~ , Arc Welding, CAD, CAM, Productivity
~
effectiveness of the approach. Keywords: Robotics, Control, Deburring
A Review of Recent Developments in Robot Metrology, B. Jiang, J. Black, R. Duralsamy, pp. 339-57 This•aper provides a review of various measurement techniques, and testing methods, conditions and specifications (TMCS) for determining performance of. a robot. First, the principles of operation, accuracy and rapeatabdlty of measurement systems, and any special features are summarized. Then, the TMCS pronged by the Robotic industries Association, the International Organization for Standardization, a Japanese standard testing proposal, and several individuals are reviewed, and future research needs ere identified. Keywords:Robotics, Melrolo~, Performance Measurements, 3-D Measurements
A KinematicApproachfor Coordinated Motion of a Robot and a Positioning Table, M. Jouaneh, D. Dornfeld, pp. 307-14 Tracking a path for such applications as welding using a coordinated motion scheme between a five axis robot and a two-dimensional table offers several advantages over the use of a single manipulator. Faster execution speed, ability to handle large workpieces, and improvements in tracking accuracy at sharp corners in the path can be achieved through such a scheme. This paper discusses a method for coordinating the motion of two such manipulators where the two s~?Alators are simultaneously moved to track a path at constant method for resolving the motion among the two manipulators based on kinematics is presented. Implementation of the scheme on an industrial manipulator and a positioning table is discussed. Actual results of tracking a path under different control scenarios are presented. Keywords: Coordinated Motion, Two Manipulators, Path Planning, Kinematic Approach
1989~ Vol. 8/No. 1 Automating Process Planning: Using Feature Interactions to Guide Search, C.-Hayes, P. Wright, pp. 1-16 Machinist is an expert system that automatically makes procuss plans for fabricating metal parts on a CNC machine tool. It is part of an overall effort to automate the job shop. The type ot parts that it handles are prismatic, with features cut into one or
Fault-Tolerant Heterarchieal Control of Heterogeneous Manufacturing System Entitles, N. Duffle, R. Chitturi, J. Mou, pp. 315-27
68