CAD学习课件Chapter1.ppt

1、CAD/CAM,Computer Aided Design Arithmetic calculations; Cutter offset computation; Postprocessor.,1.1 The Basic Ideas,1.1.2 CAPP Approaches Variant Approach also called Retrieval-type Generative Approach Hybrid Approach,Parts classification and coding and group technology as a foundation,The use of t

2、he computer to create an individual process plan from scratch, automatically and without human assistance.,1.1 The Basic Ideas,1.1.3 CAM Computer Aided Manufacturing Broad sense: All Activity From a Workblank to a Product Process Planning Production Process Schedule Material Running and Control Qual

3、ity Control,1.1 The Basic Ideas,1.1.3 CAM Techniques Computer Aided Manufacturing Narrow sense: NC Programming Tooling Path Planning Cutter Location Generation Tooling Path Simulation Post Process NC Code Generation,The CAM has evolved from the technology of Numerical Controlled machines. On-board e

4、lectronic control systems; Programmed by punched paper tape. Automatically generate tool path from 3D models, simulate the cutting action on-screen.,1.1 The Basic Ideas,1.1.4 CAD/CAM Integration Techniques The Data Auto-transfer and Auto-conversion among CAD,CAPP,and CAM CIMS: Computer Integrated Ma

5、nufacturing System Production Management System(PMS) Engineering Design System (EDS) Manufacturing Automation System(MAS) Quality Management System(QMS),Computer,Architecture of Application,Collaboration Work Environment,Database,Network,Engineering Design System,Production Management System,Quality

6、 Management System,(EDS),(PMS),(QMS),Manufacturing Automation System,Computer Aided Design(CAD/DFX) Computer Aided Process Planning(CAPP) Computer Aided Fixture Design(CAFD) Computer Aided Manufacturing(CAM),Project Management Data Management Material Management Planning Management Manufacturing Res

7、ource Management,Quality Information Management(QIM) Quality Analysis System(QAS) Quality Plan System(QPS) Quality Inspection System(QIS),Production Information System(PIS) Production Schedule Simulation(PSS) Production Schedule Control(PSC) Production Detect and Diagnose(PDD),1.2 Hardware and Softw

8、are,1.2.1 Composition of CAD/CAM System,HARDWQRE,SOFTWQRE,CAD/CAM System,COMPUTER,PERIPHERAL,APPLICATION,SUPPORTING,SYSTEM,1.2 Hardware and Software,1.2.2 Hardware of CAD/CAM System Basic Requirement Strong Graphic Aids Large Storage Volume Convenient Interactive Interface Easy Communication and Net

9、work,1.2 Hardware and Software,1.2.2 Hardware of CAD/CAM System,COMPUTER,PTINTER/PLOTTER,BACKGROUND CONTROL,TAPE,DISK,GRAPHIC INPUT TABLET,SCANER,NC DEVICE,NC DEVICE,GRAPHIC DISPLAY,1.2 Hardware and Software,1.2.2 Hardware of CAD/CAM System Host Storage Facility Input Device Output Device,1.2.2 Hard

10、ware,Host: CPU: Central Processing Unit Memory I/O Output Device Host types: Large-Middle Computer Small Computer Workstation Micro-computer,1.2.2 Hardware,Storage Facilities: Tape Disk Compact Disc (CD) Mobile Hard disk Flash Memory,1.2.2 Hardware,Input Device: Keyboard Mouse Digitizing Tablet Penl

11、ight Trackball Scanner Digitizing Camera Touch Input Device,1.2.2 Hardware,Output Device: Graphic Displayer Printer Plotter,1.2 Hardware and Software,1.2.3 Software of CAD/CAM System,System Software,Supporting Software,Application Software,1.2.3 Software,1.2.3.1 System Software Operation System CPU

12、Management Memory Management I/O Management File Management Compiler System Graphic Interface Standard,1.2.3 Software,1.2.3.2 Supporting Software Single Function Graphic Software with Interactive Function CAD System with 3D Function NC Programming System Engineering Analysis Software Multi-Function

13、CAD:Geometric Modeling, Drafting, Assemble CAE:Finite Element Analysis, Kinematic Simulate, Optimization CAM:NC Programming,Post Process, Inspection Developed Tools,1.2.3 Software,1.2.3.3 Application Software The software is developed for special application based on system software and supporting s

14、oftware,1.2.3 Software,1.2.3.3 Software Configuration,DESIGN DATABASE,ENGINEERING DATABASE MANAGEMENT,3D MODELING,DRAFTING,DOCUMENT,NC PROGRAMMING,GEOMETRIC PARAMETER,SIMULATION,PRELIMINARY,Summary,Basic term: CAD CAM CAPP Hardware and Software classification,Next time,1.3 Enabling Technologies,1.3.

15、1 Data Management Technology File Management System Database Management System(DBMS) Engineering Database Product Data Management (PDM),1.3.1 Data Management Technology,1.3.1.1 File Management System Data file is a set of records with same attribute and same structure The data are managed according

16、to data file unit. The method of managing file is provided by operation system, includes constructing data file,querying data file, storing and retrieving data file etc.,1.3.1 Data Management Technology,1.3.1.1 The Imperfections of File Management System Data redundancy, occupying a large amount of

17、memory, data inconsistent Data depend on application program Lack of effective mechanism of keeping data consistency and security.,1.3.1 Data Management Technology,1.3.1.2 Database Management System A database is defined as an organized collection of data stored on storage in the computer.,Database,

18、Database Management System,Application 1,Application 2,Application n,1.3.1 Data Management Technology,1.3.1.2 The Characteristics of Database Management System Data are separated from applications Eliminate redundancy, data are shared by all applications Keeping data consistency and security,1.3.1 D

19、ata Management Technology,1.3.1.2 Three Different Models of Database,Object,S1,S2,C,D,A,B,Hierarchical database,G,D,E,F,1,4,3,4,3,4,3,4,3,4,Data is represented by a tree structure, which describes relation of one-to-many,Surface Level,Edge Level,Vertex Level,1.3.1 Data Management Technology,1.3.1.2

20、Three Different Models of Database,S1,S2,C,D,A,B,Network database,G,E,F,1,2,3,4,3,4,7,8,5,6,Data is represented by a network structure, which permits modeling of many-to-many correspondence more directly than the hierarchical database,Surfaces,Edges,Vertices,1.3.1 Data Management Technology,1.3.1.2

21、Three Different Models of Database,Relation Line/Curve,Relation Surface,Relational database: data is stored in tables, called relations, that are related to each other,1.3.1 Data Management Technology,1.3.1.3 Object-oriented Database Unlike conventional database processing, CAD/CAM applications requ

22、ire object-oriented accessing and manipulation; Units of retrieval and storage are design object and not individual records in files; Object-oriented database models include the entity relationship model, complex object representation, and abstract data model.,1.3.1 Data Management Technology,1.3.1.

23、4 Engineering Database Satisfying the need for engineering data management Managing diverse style of data, including data, drawing, image, video, audio etc. Based on general database,1.3.1 Data Management Technology,1.3.1.4 Function of Engineering Database Multiple engineering applications from conc

24、eptual design to manufacturing operations. Dynamic modification and extension of the database and its associativity. The iterative nature of design: supporting the tentative, iterative, and evolutionary nature of the design process. Design versions: providing a capability for storage and management

25、of multiple design solutions that may exist for a particular design. Concurrent and multiple users Temporary database support Easy access,1.3.1 Data Management Technology,1.3.1.5 Product Data Management (PDM) PDM is defined as a technology for managing all information and phases related a product; T

26、he information related a product includes graphic file, bill of material, product configuration, transaction file, spreadsheet, bill of vendors The phases related a product include process sequences, process guide, workflow, and process management and definition.,1.3.1.5 Functions of PDM Electro-dat

27、a warehouse and document management Product configuration management Workflow management Assorting and indexing Project management Knowledge management,1.3.1 Data Management Technology,Questions:,What are the main output devices in CAD/CAM systems? How to understand vector graphics? Modular design o

28、f the software have any advantages? What are the ways to transform two-dimensional graphics for the three-dimensional graphics? Please outline the main elements of analysis module. How can you make a good use of grids for sketching?,1.3 Enabling Technologies,1.3.2 Computer Network Technology Compute

29、r network is defined as computer groups linked together by lines of communication (LOC) and communication device LAN (Local Area Network) : computers are linked together and formed a network within an office or a building. WAN (Wide Area Network): computers are linked together and formed a network w

30、ithin a zone.,1.3.2 Computer Network Technology,1.3.2.1 Composition of LAN,1.3.2 Computer Network Technology,1.3.2.1 Composition of LAN Network card Twisted-pair, coaxial-cable, fiber Server Workstation Connector: repeaters, bridge, router, gateway Software,1.3.2 Computer Network Technology,1.3.2.2

31、Topology Structure of LAN,1.3.2 Computer Network Technology,1.3.2.3 Network Protocol,Application Layer Presentation Layer Session Layer Transport Layer Net Layer Data Link Layer Physical Layer,Application Layer Presentation Layer Session Layer Transport Layer Net Layer Data Link Layer Physical Layer

32、,Transport Medium,A P S T N DL PH,Message Message Message Message Message Group Frame Bit,1.3 Enabling Technologies,1.3.3 Group Technology Making full use of similarities in parts Classifying parts to form part families Planning a optimization solution for a part family,1.3.3 Group Technology,1.3.3.

33、1 Encording System of GT Describing a part employing numbers and characters Opitz Cording System JLBM-1 Cording System,1.3.3 Group Technology,1.3.3.2 Method to Classifying Parts Encode Method Classifying parts to form part families according to parts code Production Flow Analysis Method Classifying

34、parts to form part families according to parts process flow, material flow, production process.,1.4 History and Application,1.4.1 History Development and application of unit 19601970: era of conceiving interactive computer graphics 19701980: golden era for computer drafting and the beginning of ad hoc instrumental design applications CAD and CAM Integration 19801990: CAD/CAM heady years of research. Integrating or automating the various elements of design and manufacturing. Concurrent