Computer-Aided Design and Manufacturing : Methods and Tools

Manufacturing contributes to over 60 % of the gross national product of the highly industrialized nations of Europe. The advances in mechanization and automation in manufacturing of international competitors are seriously challenging the market position of the European countries in different areas. Thus it becomes necessary to increase significantly the productivity of European industry. This has prompted many governments to support the development of new automation resources. Good engineers are also needed to develop the required automation tools and to apply these to manufacturing. It is the purpose ofthis book to discuss new research results in manufacturing with engineers who face the challenge of building tomor­ row's factories. Early automation efforts were centered around mechanical gear-and-cam technology and hardwired electrical control circuits. Because of the decreasing life cycle of most new products and the enormous model diversification, factories cannot be automated efficiently any more by these conventional technologies. With the digital computer, its fast calculation speed and large memory capacity, a new tool was created which can substantially improve the productivity of manufactur­ ing processes. The computer can directly control production and quality assurance functions and adapt itself quickly to changing customer orders and new products.

1 CAD Systems and Their Interface with CAM.- 1.1 Introduction.- 1.2 Philosophy of the Application of CAD Systems.- 1.3 Software Structure of CAD Systems.- 1.4 Computer Internal Model.- 1.4.1 Different Geometric Models for CAD.- 1.4.2 Importance of Technology-Oriented Model for CAD/CAM.- 1.5 Interfaces of CAD Systems.- 1.5.1 Database Manipulation Language (DML).- 1.5.2 Initial Graphics Exchange Specification (IGES).- 1.5.3 Graphical Kernel System (GKS).- 1.6 Integration of the Manufacture Planning Process.- 1.6.1 Planning Process Based on CAD Models.- 1.6.2 NC-Machine Tool Programming Based on CAD Models.- 1.7 Economic Aspects.- 1.8 Conclusion.- 1.9 References.- 1.10 Additional Literature.- 2 Design for Assembly.- 2.1 Introduction.- 2.2 Design for Assembly Philosophy.- 2.3 Determination of the Most Appropriate Process.- 2.4 Re-design for Manual Assembly.- 2.4.1 Classification and Coding for Handling and Insertion.- 2.4.2 Sequence of Design Analysis.- 2.4.3 Determination of the Sequence of Assembly.- 2.4.4 Compilation of the Worksheet.- 2.4.5 Determination of Assembly Efficiency.- 2.4.6 Elimination of Potentially Redundant Parts.- 2.4.7 Re-design of High-Cost Handling or Insertion Parts.- 2.5 Re-design for Automatic Assembly.- 2.5.1 Classification and Coding for Automatic Handling.- 2.5.2 Classification and Coding for Automatic Insertion.- 2.6 Robots in Manufacturing.- 2.7 Characteristics of Assembly Robots.- 2.8 Requirements for Robotic Assembly.- 2.8.1 Faster Robots.- 2.8.2 Limited Capability, Cheap Robots.- 2.8.3 Versatile, Inexpensive Grippers.- 2.8.4 Identification of Assembly Families.- 2.8.5 Improved Assembly Efficiency.- 2.8.6 Low Cost Feeding.- 2.9 Classification and Coding for Automatic Parts Handling for Flexible Assembly.- 2.10 Classification and Coding for Automatic Insertion for Flexible Assembly.- 2.11 Conclusions.- 3 Technological Planning for Manufacture ― Methodology of Process Planning.- 3.1 Methodology of Process Planning.- 3.1.1 Introduction.- 3.1.2 Tasks of Process Planning.- 3.1.3 Generation of the Process Plan.- 3.1.4 Principles of Process Planning.- 3.2 Development of APT and EXAPT.- 3.2.1 APT System.- 3.2.2 EXAPT System.- 3.2.2.1 Programming of N/C Turning Operations.- 3.2.2.2 Programming of Drilling and Milling Operations.- 3.2.2.3 Programming of Punching, Nibbling and Flame-Cutting Operations.- 3.2.2.4 Programming of Wire-Eroding Operations.- 3.2.2.5 Files for Working Data.- 3.3 Techniques of Computer Aided Process Planning.- 3.3.1 Dialog Aided Planning.- 3.3.2 Algorithms.- 3.3.3 Decision Tables.- 3.3.4 Data Files.- 3.4 Graphical Simulation of Manufacturing Processes in Process Planning.- 3.5 Systems for Computer Aided Process Planning Including Quality Control.- 3.5.1 AUTAP System.- 3.5.2 ARPL System.- 3.5.3 CAPEX System.- 3.5.4 CAPP System.- 3.5.5 DISAP System.- 3.5.6 DREKAL System.- 3.5.7 PREPLA System.- 3.5.8 CAPSY System (Inspection Planning).- 3.6 The CAPSY Process Planning System.- 3.7 Planning of Assembly Sequences.- 3.8 N/C Technology.- 3.9 N/C Programming on the Shop Floor Using Graphical Simulation Techniques.- 3.10 Programming of Robots Using Graphical Techniques.- 3.11 Integrated Aspects of Technological Planning.- 3.12 References.- 4 Evolutionary Trends in Generative Process Planning.- 4.1 Introduction.- 4.2 The Principal CAPP Methodologies.- 4.3 Generative Process Planning.- 4.3.1 Extended Part Programming Systems.- 4.3.2 GPP Using Decision Tables and Tree Structures.- 4.3.3 Iterative Algorithms.- 4.3.3.1 Recursive Process Planning.- 4.3.4 The Concept of Unit-Machined Surfaces.- 4.3.4.1 COFORM.- 4.3.4.2 APPAS.- 4.3.4.3 AUTAP and AUTAP-NC.- 4.3.4.4 More Sophisticated GPP Systems.- 4.4 Adequacy of the Existing GPP’s in the Wake of New Developments.- 4.4.1 Recent Trends in the Design of CMS Control Systems.- 4.5 Dynamic GPP Using Pattern Recognition Techniques: A New Concept.- 4.5.1 Proposed Representation Schemes.- 4.5.1.1 Object Representation.- 4.5.1.2 Machine Tool Representation.- 4.5.2 Process Planning Steps (Briefly).- 4.5.2.1 Flexible Planning Logic.- 4.5.2.2 Identification of Surface Precedences.- 4.5.2.3 Selection of Machines, Tool Bits and Clamping Positions.- 4.6 References.- 5 Design Methodology of Computer Integrated Manufacturing and Control of Manufacturing Units.- 5.1 Introduction.- 5.2 The Need for a Methodology and a Conceptual Model of a CIM System.- 5.2.1 The Use of a Design Methodology.- 5.2.2 The Complexity of Computer Integrated Manufacturing.- 5.3 Conceptual Model of a CIM System.- 5.3.1 The Notion of the System.- 5.3.2 Conceptual Models.- 5.3.3 ICAM Model and Architecture.- 5.3.4 GRAI Conceptual Model.- 5.4 Methods of Designing Production Control Systems.- 5.4.1 The Structured System Analysis and Design Method (SSAD).- 5.4.2 ICAM Definition Language (IDEF).- 5.4.3 GRAI Method of Process Analysis.- 5.5 Design of Flexible Manufacturing Systems Using Modelling Techniques and Simulation.- 5.5.1 What is a Flexible Manufacturing System?.- 5.5.2 Design of Flexible Manufacturing Systems.- 5.5.3 GRAI Methodology.- 5.6 The Control of the Manufacturing Unit.- 5.6.1 Scheduling.- 5.6.2 Classification of Scheduling Problems.- 5.6.3 Scheduling Method.- 5.7 GRAI’s Approach to Manufacturing Control.- 5.7.1 Introduction.- 5.7.2 GRAI’s Approach to Modelling.- 6 Computing Aids to Plan and Control Manufacturing.- 6.1 Hierarchical Computer Control Equipment for Manufacturing Systems.- 6.1.1 Introduction.- 6.1.2 Definition of Hierarchical Control Systems.- 6.1.3 Control Tasks at Each Level in the Hierarchy.- 6.1.4 The Communication Network.- 6.1.5 Influence of VLSI Technology on Hierarchical Control Systems.- 6.1.5.1 Minicomputers for Higher Control Levels.- 6.1.5.2 Microcomputers for Operational Control Levels.- 6.1.5.3 VLSI Interface Modules.- 6.1.5.4 Memory.- 6.1.5.5 VLSI Data Peripherals.- 6.1.5.6 Data Peripherals.- 6.1.6 Software and System Development Aids.- 6.2 Hierarchical Control Architecture for Manufacturing Cells.- 6.2.1 Introduction.- 6.2.2 Robot Architecture.- 6.2.3 Internal Robot Data Representation.- 6.2.4 Task Decomposition and Execution.- 6.2.5 Data Flow and Computational Concept.- 6.2.6 Conclusion.- 6.3 Graphical Simulation Techniques for Planning and Programming of Robot Based Manufacturing Cells.- 6.3.1 Introduction.- 6.3.2 System Structure for Interactive Planning with a Graphic Simulator.- 6.3.3 Conclusion.- 6.4 Advanced Computer Architectures (5th Generation).- 6.4.1 Introduction.- 6.4.2 Components of 5th Generation Computers.- 6.4.3 Applications of 5th Generation Computers.- 6.4.4 The Basic Software System and Programming Languages.- 6.4.5 Computer Architecture of the 5th Generation Computer Systems.- 6.4.6 Conclusion.- 6.5 References.- 7 Programming of Robot Systems.- 7.1 Robot Languages in the Eighties.- 7.1.1 Introduction.- 7.1.2 Robot Programming.- 7.1.3 Languages and Software Environments.- 7.1.4 Functional Language and Logic Programming.- 7.1.5 European Robot Languages.- 7.1.6 Conclusions.- 7.2 Programming Languages for Manipulation and Vision in Industrial Robots.- 7.2.1 Introduction.- 7.2.2 How to Classify Robot Programming Languages.- 7.2.3 Joint-Level Languages: The Example of MAL.- 7.2.4 Manipulator-Level Languages: Mathematical Foundations.- 7.2.5 Object Representation in Robot Programming Languages.- 7.2.6 At the Object Level: AL and Vision.- 7.2.7 Object and Task Levels: Problems.- 7.2.8 Conclusions.- 7.3 Programming a Vision System.- 7.3.1 Introduction.- 7.3.2 A Vision System for Industrial Applications.- 7.3.3 Logical Organization of GYPSY.- 7.3.4 LIVIA: The User Programming Language.- 7.3.5 Examples of LIVIA Programs.- 7.3.6 Additional Position-Independent Features for Blobs and Models.- 7.4 Towards Automatic Error Recovery in Robot Programs.- 7.4.1 Introduction.- 7.4.2 A Method for Automatic Error Recovery.- 7.4.2.1 Dynamic Model.- 7.4.2.2 Semantics.- 7.4.2.3 Knowledge Base.- 7.4.2.4 Recovery Procedure.- 7.4.3 Concluding Remarks.- 7.5 References.- 8 Present State and Future Trends in the Development of Programming Languages for Manufacturing.- 8.1 Introduction.- 8.2 Programming of Machine Tools.- 8.2.1 The APT Language.- 8.2.2 The EXAPT Programming System.- 8.2.3 Interactive Symbolic Programming.- 8.2.4 Special Purpose Languages.- 8.2.5 Generative Programming by the Machine Tool Control.- 8.3 Programming Languages for Robots.- 8.3.1 General Requirements for Programming Languages for Robots.- 8.3.2 Programming Methods for Robots.- 8.3.2.1 Manual Programming.- 8.3.2.2 Programming with the Help of the Robot’s Brake System.- 8.3.2.3 Sequential Optical or Tactile Programming.- 8.3.2.4 Master-Slave Programming.- 8.3.2.5 Teach-In-Method.- 8.3.2.6 Textual Programming.- 8.3.2.7 Acoustic Programming.- 8.3.2.8 Design Considerations for a High Order Language.- 8.3.3 A Survey of Existing Programming Languages.- 8.3.4 Concepts for New Programming Languages.- 8.3.5 Programming with a Natural Language.- 8.3.6 Implicit Programming Languages.- 8.3.7 Programming Aids.- 8.4 Process Control.- 8.4.1 Extensions of Existing Programming Languages.- 8.4.2 PEARL ― A Process and Experiment Automatic Realtime Language.- 8.4.3 ADA.- 8.4.4 Tools for the Development of Process Control Systems.- 8.5 Commercial Data Processing.- 8.6 Future Trends.- 8.7 References.- 9 Quality Assurance and Machine Vision for Inspection.- 9.1 Introduction.- 9.2 Quality Assurance: Functions, Problems and Realizations.- 9.2.1 Quality Assurance Functions.- 9.2.2 Design of a Computer Integrated QA System.- 9.2.3 Hierarchical Computer Systems for Quality Assurance.- 9.2.4 Architecture of a Data Acquisition System.- 9.2.5 Quality Assurance Methods.- 9.2.6 Measuring Methods for Quality Assurance.- 9.2.6.1 Contact Measurement.- 9.2.6.2 Non-Contact Measurements.- 9.2.6.3 Manual Input.- 9.2.7 Computer Languages for Test Applications.- 9.2.8 Implementation of a QA Computer System.- 9.3 Machine Vision: Inspection Techniques, Mensuration and Robotics.- 9.3.1 Visual Inspection Tasks.- 9.3.2 Machine Vision Techniques for Inspection.- 9.3.2.1 Template Matching.- 9.3.2.2 Decision-Theoretic Approach.- 9.3.2.3 Syntactical Approach.- 9.3.3 Automated Microscopic Material Testing.- 9.3.4 Laser Based Measurements and Inspection.- 9.3.4.1 Quantitative Mensuration.- 9.3.4.2 Semi-Quantitative Mensuration (Scanner).- 9.3.5 Synthetic Images for Defect Classification.- 9.3.6 Robot Vision for Recognition and Sorting.- 9.3.6.1 Interfacing of a Vision System with an Assembly Robot.- 9.3.6.2 Sorting of Castings.- 9.4 References.- 10 Production Control and Information Systems.- 10.1 Strategies for the Selection of Software Packages in Production.- 10.2 Data Management Requirements for Production Control.- 10.2.1 Development of a Data Base Scheme for Primary Data.- 10.2.1.1 Bill of Materials.- 10.2.1.2 Work Descriptions.- 10.2.1.3 Manufacturing Equipment.- 10.2.2 Special Cases of Variant Production.- 10.2.3 Data Management with Software Packages.- 10.2.3.1 Conventional File Management.- 10.2.3.2 Specialized Data Base Systems.- 10.2.3.3 General Data Base Systems.- 10.2.3.4 System-Independent Data Bases.- 10.2.4 Future Developments in Data Management.- 10.3 Planning Strategies for the Implementation of Production Control Systems.- 10.3.1 Planning Stages.- 10.3.1.1 Master Production Scheduling.- 10.3.1.2 Material Requirement Planning.- 10.3.1.3 Capacity Planning.- 10.3.1.4 Job Shop Control.- 10.3.1.5 Data Collection.- 10.3.2 Implementation Strategies.- 10.4 The Interface Between CAD and Production Control.- 10.5 The Interface Between Production Control and Marketing.- 10.5.1 Master Production Scheduling.- 10.5.2 Order Handling.- 10.6 Factors Influencing the Acceptance of Production Control Software.- 11 Economic Analysis of Computer Integrated Manufacturing Systems.- 11.1 Introduction.- 11.2 Process Planning.- 11.3 Capacity Analysis Using CAN-Q.- 11.4 Capital and Labour Requirements.- 11.5 Payback, Capital Cost, and Taxes.- 11.6 Cost Comparisons.- 11.7 System Efficiency.- 11.8 Justification and Automation Equipment.- 11.9 Summary.- 11.10 References.- 11.11 Appendix.- Contributors.