Computer-Aided Design and Manufacturing

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.

Contenu

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…