Introductionto Pems Final Version

8/13/2019 Introductionto Pems Final Version

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Computer Aided Manufacturing

Planning for Mass Customization

Team:Dr. X. Han, S. Yao, Y. Yang, Y. Sun

Advisor: Professor Y. Rong

Software Development Specialist : Chen Bai

Sponsor: Delphi Corporation & NSF



Introduction

Manufacturing planning is to determine the sequence of manufacturingoperations and machine tools, fixtures and cutters used in theseoperations in the manufacture of products.

r Cutter

d

Predefined

toolpath

Cycle time

Overall

toolpath

d

r Cast

iron Part of Family

Machine

tool

BOPFeature methodsPart setup plan

Manufacturing planManufacturing

resource

Standard

Document

Manufacturing planning

for mass customization :

Base on part families

Base on best practice

Maintaining near mass

production efficiency.



System

ArchitectureDatabase &

Knowledge Base

Conceptual Fixture Design

Part Information Modeling

Manufacturing Plan Generation

Setup Planning

Product Design

BOP2

Setup plan DB

Part layout on fixture base

Process sequence generation

Cutting parameter determination

&Global tool path generation

Fixture base determination

Machine tool selection

Feature grouping – DMG generation

Setup generation and sequencing

oMachining surfaces

oWorkpiece orientation

oOperation sequence

Manufacturing feature specification

FTG Generation

Feature manufacturing methods

Fixture Planning

oLocating datum

oLocating

surface/points

oClamping

surface/points

Fixture

Configuration

Design

oFixture component

design

oFixture component position and

orientation

Tolerance Analysis

BOP1

Feature DBProcess DB

BOP3

Part layout

on fixture

base

ManufacturingResource DB

Cutter DB

Fixture DBMachine tool DB

Cycle Time Calculation

&Simulation

Standard Document Output

PEMS(Parametric engineering ofmanufacturing system)

Integration with UnigraphicsCAD package

Associativities between

features and processesBest practice (BOP: bill of

processes) from Delphi

Optimized manufacturing planwith minimum cycle time

Best of practice is divided into

3 levels:

Feature level (BOP1)

Part level (BOP2)

Station level (BOP3)



Software Architecture

CADPackage

XMLPackageDatabasePackage

ReportPackageDesignPackageGUIPackage

Design Workstation

Data

DB Server

Design Workstation Design Workstation

System Deployment Architecutre

OS: Windows / Unix

DBMS: Oracle / SQL Server / MS Access

OS: Windows 2000 / Windows XP

CAD: UG

DB Connection.: ODBC

App.: PEMS3.0

Package DesignDatabase& Knowledge base

CAD platform independent

System stability

System UI

System expendability

XML capable



Manufacturing Features and Machining methods

- Best practice BOP1

H1

H

Angle

Z

X

Y

2 Chamfer1

4 Chamfer2

3 Hole

Surface2

1 Surface1

5

D1

D

Features describe the engineering meaning ofgeometry and act as the building blocks of partinformation models.

Combined manufacturing features are used in masscustomization Combination of basic features

Simplified and specified processes in BOP

Combined manufacturing feature informationstructure:

Surfaces and their parameters, Surface topology relationship

Tolerance among surfaces

Surface finish

Z

X Y

D

Z

X Y

Z

X Y

Z

X Y

Z

X Y

Manufacturingfeature

Surface feature

Depressionfeature

Protrusion

feature

Hole

Slot

Pocket

Combined feature

Auxiliary featureChamfer

groove

Thread

Main feature

Hole combinedwith auxiliary

feature

Surface combine

with hole

Round surface

Rectangle surfae

Surface with curved

boundary

Feature classification

Feature variation



Manufacturing Features and Manufacturing Methods

- Best practice BOP1(Continued)

Parametric cutter design Parametric toolpath

D

CH2

CH3

D1

H1

CH1

CH4

CH1=H1+delta_H1

CH2=H-H1*2+delta_H2

CH3=H1+delta_H1CH4=CH4

H

1

2

3

4

Feature

manufacturing

methods

approaching_value = Point1L12 = H1+6mm;…

Toolpath parameters are

Driven by both featureand cutter parameter.



Setup Planning Flowchart- Best practice BOP2

Part information

- Part family type

- FTG(Feature tolerance graph)

Similar setup

plan exist?

Generate new setup plan1.Locating/clampingsurface

2.Feature-process

sequence in each setup

Automated setup planning

No

Yes

Modify setup plan

END

Main tasks of setup planning

Feature grouping based ontolerance analysis

Setup generation based onmanufacturing resource capabilityanalysis

Locating/clamping surface

determinationMachining surface determination

Process sequence



Manufacturing Resource Capability

Manufacturing resource capability is described in three levels andused to support different function modules.

Station

Part level

Feature level

Shape

capability

Dimension &

precision

capability

Position &

orientation

capability

Mapping Generating

Feature form

Feature

precision

Feature

position &

orientation

Manufacturing resource capability Process Part

Machine tool

axis Fixture

Machine tool

Machine tool

motion&accuracy Cutter

Moving

range

Setup

time

Cutting

parameter

AuxiluaryProcess

parameters

Cutting

libraryConceptual fixture

design

Setup planning

Feature manufacturing

method selection

Manufacturing plangeneration



An Example of Setup Planning



Part Layout on Fixture Base

- Best Practice BOP3

Part layout generation

Part family BOP exist?

Select fixture base

BOP3

Part setup layout

determination

Machine tool check?

yes

no

yes

no

Multi-part fixtures are widelyused in mass customization to

maximize the use of manufacturing

resource capability.



Manufacturing Plan Generation

Optimize the process sequence

Optimize cutting parameters

based on best practice.

Optimize the toolpath generation

with interference checking

Cycle time calculation

Cutting_Time

Rapid_Motion_Time

Tool_Change_Time

Spindle_Set_Time

Other_Time

Generate process sequence

Generate global toolpath

Select cutting parameter Part material DB

Cutter DB

Cutting parameter

DB

Interference exist?

Simulation

Cycle time calculation

Standard document

generation



Standard Document Generation

Document isgenerated basedon the specificrequirement

frommanufacturingenterprises.



Summary

A computer-aided manufacturing planning system has been

developed and implemented for mass customization of part

families.

Best practice is divided into 3 levels: Process selection in manufacturing feature level

Setup planning in part level

Conceptual fixture design and part layout in machine tool level.

Setup planning has been studied based on tolerance analysis

and manufacturing resource capability analysis.

Manufacturing planning optimization has been studied

Documents

Introductionto Pems Final Version