電腦輔助設計電腦輔助設計ComputerComputer--Aided Design Aided Design

( CAD )( CAD )1. Textbook

-- “Mastering CAD/CAM” (2005)by Ibrabim Zeid, McGraw-Hill (滄海書局 – 0427088787)ISBN 007-123933-2

2. Software : AutoCAD, SolidWorks3. Reference

--“Principles of CAD/CAM/CAE Systems”by Kunwoo Lee, Addison Wesley Publishing,ISBN 0-201-38036-6

-- “ CAD/CAM Theory and Practive” (1991)by Ibrabim Zeid, McGraw-HillISBN 007-072857-7

-- http://www.ncu.edu.tw/~htchuang/me6068

Course DescriptionCourse DescriptionIntroduction of CAD/CAM Introduction of CAD/CAM –– Chap.1Chap.13D Modeling And Viewing 3D Modeling And Viewing –– Chap.2Chap.2Transformation Transformation –– Chap.12Chap.12Modeling Aids and Tools Modeling Aids and Tools –– Chap.3Chap.3Curve Representations Curve Representations –– Chap.6Chap.6Surface Representations Surface Representations –– Chap.7Chap.7NURB Representations NURB Representations –– Chap.8Chap.8Solid Representations Solid Representations –– Chap.9Chap.9Feature Representations Feature Representations –– Chap.10Chap.10Assembly Modeling Assembly Modeling –– Chap.16 Chap.16 Product Data Exchange Product Data Exchange –– Chap.18Chap.18

學 期 成 績

平時成績(出席,作業,報告) :30%

期中考 : 30%

期末考 : 40%

Product Life of CycleProduct Life of Cycle

What Is CAD/CAE/CAMWhat Is CAD/CAE/CAM

Design Engineering Manufacturing

Three steps in making a mechanical product:

Computer

AidedAided

Aided

ComputerComputer--Aided Design (CAD)Aided Design (CAD)

ComputerComputer--aide design (CAD)aide design (CAD) is the technology is the technology concerned with the use of computer systems to assist in concerned with the use of computer systems to assist in the creation, modification, analysis, and optimization of the creation, modification, analysis, and optimization of a design.a design.Any computer program that embodies computer Any computer program that embodies computer

graphics and application program facilitating graphics and application program facilitating engineering functions in the design process is classified engineering functions in the design process is classified as CAD software. as CAD software. Computer aided drafting systems and geometric Computer aided drafting systems and geometric modeling systems are the most important component modeling systems are the most important component of CAD of CAD

ComputerComputer--Aided Manufacturing Aided Manufacturing (CAM)(CAM)

ComputerComputer--aide manufacturing (CAM)aide manufacturing (CAM) is the is the technology concerned with the use of computer technology concerned with the use of computer systems to plan, manage, and control manufacturing systems to plan, manage, and control manufacturing operations through either operations through either directdirect or or indirectindirect computer computer interface with the plantinterface with the plant’’s production resources s production resources Direct applicationDirect application –– NC, PLC, Manufacturing Cell, NC, PLC, Manufacturing Cell, FMSFMSIndirect applicationIndirect application –– MRP, Process Planning, MRP, Process Planning, Scheduling, Inventory Control, Shop Floor ControlScheduling, Inventory Control, Shop Floor Control

Scope of CAD/CAMScope of CAD/CAM

CAD/CAM SystemCAD/CAM System

A CAD/CAM system is a complex application A CAD/CAM system is a complex application that requires both hardware and software.that requires both hardware and software.Hardware Hardware –– Computer (PC or Workstation) and Computer (PC or Workstation) and

Peripheral Devices.Peripheral Devices.Software Software -- Written in C or C++Written in C or C++

Client/Server (Client/Server (主從架構主從架構) ) Standalone (Standalone (單機架構單機架構) )

CAD/CAM Software ArchitectureCAD/CAM Software Architecture

GeometricEngine

ACIS PARASOID

.

.

GeometricEngine

ACIS PARASOID

.

.

Model Database

ProgrammingModule

ProgrammingModule

Application Module•Mass Property Calculations•Assembly Analysis•Tolerance Analysis•Sheet Metal Design•Finite Element Analysis•Mechanism Analysis•Animation Techniques•Plastic Injection Analysis•Manufacturing Application

-CAPP, NC, CIM, -Robot, GT

Application Module•Mass Property Calculations•Assembly Analysis•Tolerance Analysis•Sheet Metal Design•Finite Element Analysis•Mechanism Analysis•Animation Techniques•Plastic Injection Analysis•Manufacturing Application

-CAPP, NC, CIM, -Robot, GT

CommunicationsModule

CommunicationsModule

CollaborativeModule

CollaborativeModule

IGESSTEP

WWW

Graphical User Interface (GUI)Graphical User Interface (GUI)

WirefarmeWirefarme ModelModel

Ambiguity of Ambiguity of WireframeWireframe ModelModel

Representation of CurvesRepresentation of Curves

Given two points p1 and p2, and two vectors v1 and v2,

find four vectors a0, a1, a2, and a3, such that the vector

function S(u) = a0 + a1u + a2u2 + a3u3 satisfies:

1. it is a smooth function in (0≤u≤1), and

2. its meets the boundary conditions

S(0) = p1 and dS(u)/du|u=0 = v1

S(1) = p2 and dS(u)/du|u=1 = v2

S(u) = ???p1

p2v1

v2

x

BB--SplineSpline CurveCurve

p0

p1

p2

p3

p4p5

p6∑=

=6

0(u)(u)

iKii N ,pP

Surface ModelSurface Model

Surface ModelSurface Model

Representation of SurfacesRepresentation of Surfaces

CSG ModelCSG Model

CSG PrimitivesCSG Primitives

Boundary Representation ModelBoundary Representation Model

FeatureFeature--Based ModelingBased Modeling

Computer Aided Process Planning Computer Aided Process Planning (CAPP)(CAPP)

Engineering DesignCAD

ManufacturingCAM

CAPP

Process planning bridges design and manufacturing

Computer Aided Process Planning Computer Aided Process Planning (CAPP)(CAPP)

Assembly ModelingAssembly Modeling

Assembly ModelingAssembly Modeling

Assembly Modeling SystemAssembly Modeling System

MateMate

OffsetOffset

Align facesAlign faces

Align AxesAlign Axes

Standards for Graphical Data ExchangeStandards for Graphical Data Exchange

DESIGN

PLANNING

PRODUCTSUPPORT

ANALYSIS

MANUFACTURING

?

Direct Translators Between SystemsDirect Translators Between Systems

N=5, T=20

N=8, T=56N=6, T=30

N = Number of systemsT = Number of translator n(n-1)

= Application system

Neutral Format TranslatorNeutral Format Translator

N = 5, T = 10

NeutralFormat

Reduce translation Reduce translation costs and improve costs and improve quality through the quality through the establishment of a establishment of a common formatcommon format

Neutral File FormatNeutral File Format

2D drawing or 3D 2D drawing or 3D wireframewireframe modelmodel---- DXF, DWG, IGESDXF, DWG, IGES3D surface model3D surface model---- IGESIGES3D CSG / B3D CSG / B--rep solid modelrep solid model---- IGES, STEPIGES, STEPPDM / Product life cycle dataPDM / Product life cycle data---- STEP STEP