Dipl.-Ing. Peter Binde

Case Based, Self Learning Assistant for FEM Analysis in the Design Process

Industry and Research Project

CADFEM Usermeeting 2002

Peter Binde

Dipl.-Ing. Peter Binde

Content

- Dr. Wallner Group

- Motivation for a new Assistant System

- Concepts for Knowledge Reuse

- Analysis of Cases from Industrial Applications

- Concept for the Assistant System

- Integration with an CAD/FEM/PDM-System

- State of the Project and open Issues

Dipl.-Ing. Peter Binde

Dr. Wallner Group

Consulting and Servicearound CAD, CAE, PDM

Competences:

- Process-analyses and -syntheses- Trainings and workshops- User-support and hotline- FEA / MKS analysis and

design- Integration-solutions and

software-development

Dipl.-Ing. Peter Binde

Dr. Wallner Group

30 Persons, 10 Years ExperienceFocus on Unigraphics, iMAN

Locations: Bremen

Wiesbaden

Stuttgart

München

Dipl.-Ing. Peter Binde

Motivation for a new Assistant System

Present Situation:- More and more FEA becomes

the designers daily work

Solution:- Store and reuse knowledge from

existing FEM analysis cases

Deficits:- Often special-knowledge is necessary- Use of different methods for same problems- Knowledge stays in the heads of specialists and key users- Examples and summarised methods are only static- Databases organize data, but do not know about the content

Dipl.-Ing. Peter Binde

Concepts for Knowledge Reuse

Classification of Systems:a) Product configuration systems:

intelligent assembly structuresIntelligent partsIntelligent FEM-models

b) Process modellers and wizards: Guide through a special process

c) Systems providing the actual knowledge in context to the actual stage of design

Automatically documenting of included knowledge

Dipl.-Ing. Peter Binde

Concepts for Knowledge Reuse

Knowledge Management using Semantics and Features

Features model design characteristics

Example Feature Weld point:included information:

- Group of involved elements- Connectivity to geometry- Strength requirements- Tolerances- Costs- Manufacturing processes ...

Advantage: Weld point can be processed as a „weld point“.

Dipl.-Ing. Peter Binde

Concepts for Knowledge Reuse

Knowledge Management using Semantics and Features

We try to build up models only by use of featuresThis method automatically captures knowledge

CAD Features

(1) Sketch(2) Revolved(3) Pocket(4) Pocket(5) Hole(6) Threads

FEM Features

Fixed FaceCentrifugal LoadConcentrated Mass

Stress ToolFatigue Tool

Dipl.-Ing. Peter Binde

Concepts for Knowledge Reuse

Rule based versus case based approaches

Rule based Case based

Content: Rules CasesSolving: Applying / Finding, interpreting

combining rules and adapting most similar case

Learning: Applying new rules Applying new cases

Novice:Applies rules

Expert:Applies experience from past cases

Dipl.-Ing. Peter Binde

Concepts for Knowledge Reuse

Case based Method: Case Based Reasoning (CBR)

Retrieval of relevant cases

Selectionof most appropriate cases

Creationof a solution by adapting knowledge

Validationof the new solution, by questioning the user

Storinga solution in the case base

Focus today

Case Base

Dipl.-Ing. Peter Binde

Analysis of Cases from Industrial Applications

About 100 cases are analysed for their characteristics

Goal: - Find a way to classify FEA cases- Find a way to store case knowledge- Find a similarity measure- Prove transferability of case knowledge

Results: - Classification by design characteristics- Features describe design characteristics Hierarchy of design characteristics- Similarity can be found by comparison of features- Case knowledge can be transferred

- Result depends strongly on the use of semantics and features

Dipl.-Ing. Peter Binde

Concept for the Assistant System

Concept for the Information-model

FEA Application Case:IncludesKnowledge Elements

Task 1

Solution 1

Solution 6 Solution 7 ...Solution 5

Solution 2 Solution 3 Solution 4

Task 2 …

Assembled Task 1

Admin-Data

Knowl. Pattern: References stored in a Database

Admin-Data

Assemb.-Task

Task

Task

Task

Dipl.-Ing. Peter Binde

Integration with an CAD/FEM/PDM-System

Storing an analysis case in the case base:

Dipl.-Ing. Peter Binde

Integration with an CAD/FEM/PDM-System

Retrieving similar cases from the case base:

Example Problem Characteristic: Convection on a exhaust pipe1) User defines the problem as far as he can by use of CAD /

FEM features, 2) He selects the interesting

characteristics, 3) He asks for similar

cases.

Dipl.-Ing. Peter Binde

Integration with an CAD/FEM/PDM-System

Retrieving similar cases:

4) The system searches for similar characteristics in the case base

5) It shows the datasets of the found cases in a folder

Dipl.-Ing. Peter Binde

State of the Project and open Issues

At present: - State of initial Implementation- Users are limited to consultants of Dr. Wallner Group- Client server model, based on an iMAN-Web Portal- Users are allowed to retrieve cases as well as

providing new cases via the www.

Future:- Use for FEM-trainings- Opened for customers

Case Base

iMAN Web Server

Oracle DatabaseKnowledge

Patterns

iMANVol

Location Bremen

iMANVol

Customer

Location Wiesbaden

Location Stuttgart

Location München

AssistantSystem

Dipl.-Ing. Peter Binde

VIELEN DANK!