Knowledge-Based Manufacturing Within the Extended Enterprise

8/6/2019 Knowledge-Based Manufacturing Within the Extended Enterprise

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Knowledge-based manufacturing

within the extended enterprise

B. Denkena, P.-O. Woelk, R. Apitz

I*PROMS Virtual Conference, July 2005

IFW


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IFW, Universitt Hannover

IFW

page 2Knowledge-based manufacturing within the extended enterprise

Hannover University, IFW

Outline

Introduction

Knowledge and knowledge management

Excursus: STEP

Examples of knowledge-based applications

Collaborative product development in customer-supplier chains

NC code optimisation by preventive compensation of tool

deflection

Application of STEP in manufacturing planning

Outlook and summary


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page 3Knowledge-based manufacturing within the extended enterprise

Hannover University, IFW

Outline

Introduction


Excursus: STEP




deflection


Outlook and summary


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page 4Knowledge-based manufacturing within the extended enterprise Hannover University, IFW

From Symbols to Knowledge

+ syntax

+ meaning

+ context,experiences

DataDataManagement

InformationInformationManagement

KnowledgeKnowledgeManagement

Use machine B, checktolerances, expect longerlead times

Symbols 010001111

diameter 50mmIT 6-0.009 mm-0.025 mm

Knowledge is in need of a well-structured basis for data management like STEP.


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Knowledge Management in the Engineering Domain

Efficient information retrieval requires classification of knowledge items.

Knowledge can be tacit or explicit. Knowledge items can be made explicit by ontologies.

Knowledge may be represented by:

Production rule systems

Semantic nets (eg. frames)

Hybrid / nested systems combining both approaches

Engineering knowledgeEngineering knowledge

Tacit knowledge Explicit knowledge

Internal information sources

External information sources

Physical sources

Technical reports,

other text files

CAD files etc.

Data bases

structuredsemi-structured

unstructuredInformation


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Introduction

What is STEP from the userspoint of view ?

In most cases:Interface for exchange ofinformation about the product

(mostly geometrical, CAD files).

For IT professionals:In addition, data model to storeand retrieve product data

(basis for PDM systems).

But: Use the power of STEP as

an enabling technology for thewhole product creation process!

Descriptionmethods

Descriptionmethods

Implementation methodsImplementation methods

Integrated resourcesIntegrated resources

Conforma

ncetests

Conform

ancetests

Application protocolsApplication protocols

21: Physical file

AP203 AP212 AP214

22: SDAI

11:

EXPRESS(-G)

42: Topology 44: Prod. Struct.

47: Tolerances

STEP-NC(ISO 14649)

STEP-NC

(ISO 14649)

plus accompanying

standards


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Application of STEP Beyond Product Design

Advantages of STEP as a basis for Product Data Management (examples):

Provides proven and reliable data models for several application domains(especially AP 2xx series)

Methodology for data modelling in an application domain

(especially series 2x like EXPRESS, Physical File, Data Binding ) Common concepts as building blocks for data models

(especially series 4x and its generic resources)

Idea of anew product Product

ConceptConcept DesignDesignRamp-up/Planning

Ramp-up/Planning Production

Production

Lifecycle-oriented Product Data Management

STEP

-base

d

Well-structured basis for knowledge-intensive task like product creation!


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Outline

Introduction


Excursus: STEP




deflection


Outlook and summary


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Data Exchange in Collaborative Product Development (1)

Supplier

LH

Customer

Whole

system

Component/subsystem

C

S

C C

LHLH

LH

DL

Delineationof wholesystem

Delineationof subsystem

DL

Constraint

Delineation

Offer LH SP

Link Realisation

Copy ofsubsystemdelineation

Subsystemspecification

Software system

CComponent/

subsystem


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Data Exchange in Collaborative Product Development (2)


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Outline

Introduction


Excursus: STEP




deflection


Outlook and summary


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Preventive Compensation of Tool Deflection (1)

Creating productmodel (parts)

3D CAD


3D CAD

Generating NCcode (eg. CLDATA)

CAM


CAM

Machining ofwork piece

(eg. milling)


(eg. milling)

Problem while using tool with

small ratio diameter-to-length

(e.g. machining of dies & moulds):

Tool deflection!

cuttingforces

tooldeflection


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3D CAD


3D CAD


CAM


CAM


(eg. milling)


(eg. milling)

cuttingforces

tooldeflection

min.Compensation Algorithm:

Determine cutting forces Calculate tool deflection

Adjust tool paths NC code output

Compensation Algorithm:

Determine cutting forces Calculate tool deflection Adjust tool paths NC code output


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1.) ConventionalNC code (sequence

of commands)

2.) Structured NC code(set of sub-sequences)

3.) Classification of segments and selection of suitable compensation strategies.

Thus:

Methodology of STEP-NC(ISO 14649) not onlyuseful for creation of next

generation NC code but also for improving

existing CAD/CAM process

chains!

Thus: Methodology of STEP-NC

(ISO 14649) not onlyuseful for creation of nextgeneration NC code

but also for improvingexisting CAD/CAM processchains!


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Outline

Introduction


Excursus: STEP




deflection


Outlook and summary


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Application of STEP in Manufacturing Planning

Technological point of view:

Process planning

Logistical point of view:

Scheduling

Goal: Manufacture a product according to its design data.

Planning tasks to perform to reach this goal:

Current trend in the manufacturing domain:

Perform process planning and scheduling simultaneously.

Decentralise planning and scheduling tasks.

Amount of necessary manufacturing knowledge rises due to increasing

complexity of products and manufacturing processes.

Approach of a current research project:Application of intelligent software agents to improve planning process.


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Decentralisation of Process Planning Activities

OA ( RA)Estimation of overall times

*Generation of NC programs

SA ( OA, RA)Presentation/editing of process plan sheet

RLPPDetermination of product-specific constraints

RAEstimation of processing times and costs

RASelection of operation sequences and machining parameters

OA RASelection of machine tools, resource allocation

RLPPIdentification of possible machining processes

RLPP

Carried out by

Analysis of product design data

Activity

Legend:

depends on enterprise-specific structures*

carried out by A assisted by BA (B)

solved by co-operation of A and BAB

carried out by AA

Service agentSA

Resource agentRA

Order agentOA

Rough-level process planning (centralised)RLPP

Centralised rough-level

process planning:

Problem solving bynegotiation about

manufacturing tasks/featuresbased on common ontology

Internal decision making ofresource agents

(eg. production-rule-based)


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Reference Models for knowledge-based Manufacturing

Classification of manufacturing processesManufacturing knowledgeProduction processes and flow

...

Classification of manufacturing processes

Manufacturing knowledge

Production processes and flow

...

Machines and plants Manufacturable product program Available manufacturing processes Tools, fixtures, dies and moulds

Quality assurance and testing Staff ...

Machines and plants Manufacturable product program Available manufacturing processes Tools, fixtures, dies and moulds

Quality assurance and testing Staff ...

Parts and assemblies

Product structure, variants Geometry and features Workpiece material Tolerances and fits

CAD/CAE data

...

Parts and assemblies

Product structure, variants

Geometry and features

Workpiece material Tolerances and fits CAD/CAE data ...

Production

P

roduct

Reso

urce

Process

Vision/Designof a new product

Product


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Outline

Introduction


Excursus: STEP




deflection


Outlook and summary


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Documents

Knowledge-Based Manufacturing Within the Extended Enterprise