Data integration in preliminary Airplane Design

88 Pages·2009·2.67 MB·English

Data integration in preliminary
Airplane Design
diploma thesis
cand. aer. Daniel Böhnke
istributed ystems and omponent oftware epartment
D S C S D
nstitution for imulation and oftware echnology
I S S T
at the erman erospace enter
G A C (DLR)
imilarity echanics roup
S M G
nstitute for tatics and ynamics of erospace tructures
I S D A S
at tuttgart niversity
S U
2009
Cologne, July
Eidesstattliche Erklärung
Hiermit erkläre ich, dass ich die vorliegende Arbeit selbständig und ohne fremde
Hilfe bzw. unerlaubte Hilfsmittel angefertigt, andere als die angegebenen Quellen
und Hilfsmittel nicht benutzt und die den benutzten Quellen wörtlich oder inhaltlich
entnommenen Stellen als solche kenntlich gemacht habe.
31 2009
Köln, .Juli
Task
At the German Aerospace Center (DLR) development is carried out concerning in-
terfaces, program libraries and tools for the integration of numerical applications in
the areas of preliminary airplane design and air transport missions (e.g. for the do-
mains of aeronautics, structure, propulsion, combustion chamber, atmosphere, cosmic
radiation, and mission analysis).
pacs
DesignedforthistaskanewDLRdataformat(C )wasspecifiedforthecombined
ml
storage of data from all involved tools in X . Other formats known in preliminary
so 10303 ml
airplane design are I , wide spread in industry, and the U , originating from
software development. The goal of this work is to analyze the named models. Addi-
pacs so 10303
tionally, the possibilities to store C information in I are to be elaborated.
pacs
For C a software interface for tools exists that allows the export and import of
data. As an additional (optional) part of the diploma thesis the interface is to be
so 10303
extended tointerface relatingI data. Thiscan beaccomplished bedeveloping
so 10303
import/export filters or by the direct integration of I data interfaces. The
development of the interface needs to carried out either in Java or Python.
Abstract
A multidisciplinary approach to preliminary airplane design is seen as one of the
major improvements for future design tasks. Several approaches can be found in the
literature. The key to a multidisciplinary approach is a central model that contains
all data and is accessible for all domains. The goal of this work is to analyze three
differentmodelsinrespecttotheirbenefitsfordataintegrationinpreliminaryairplane
pacs lr tep so
design. The models are C , developed at the D , S , published by the I , and
ml mg
the U , released by the O . For this purpose a lexical overview of the important
terms is given. Additionally several methods for the classification of information are
introduced and requirements for information models are set up. The main part of the
workiscontributedtotheanalysisofthedifferentmodels. Aconclusionisdrawnthat
ml
suggests a solution for a future information model using a combination of the U /
ml pacs
SysML and X . Subsequently a prototype for a converter tool, that processes C
tep ttas fw 614
data to S is developed. The converted geometry data of the A V is used
for validation and shows the quality of the tool.
Contents
1 1
. Introduction
11 1
. . Research Motivation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
12 2
. . Introduction to Information Models . . . . . . . . . . . . . . . . . . . . .
13 4
. . Research Outline . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2 5
. Information in Airplane Design
21 5
. . Information Classification . . . . . . . . . . . . . . . . . . . . . . . . . . .
22 6
. . Information Objects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3 11
. Requirements for Information Models
31 11
. . Important Aspects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
32 16
. . Abstraction Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4 20
. Information Models
41 10303 21
. . ISO . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
42 36
. . CPACS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
43 48
. . UML . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
44 52
. . Analysis/Comparison . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5 55
. Converter for Information Models
51 56
. . Development Tools . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
52 60
. . Converter Structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
53 62
. . Validation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6 63
. Summary
61 63
. . Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
62 64
. . Discussion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
63 65
. . Outlook . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
66
Biblography
614 71
A. Section Volumes ATTAS VFW
73
B. Setup for Development Framework
74
C. Java Code for Point Entities
Nomenclature
API Application Programming Interface
CAD Computer Aided Design
CAM Computer Aided Manufacturing
CPACS Common Parametric Aircraft Configuration Scheme
DLR German Aerospace Center
EDM Engineering Data Management
EXPRESS Modeling Language
IGES Initial Graphics Exchange Specification
ISO International Organization for Standardization
KBE Knowledge Based Engineering
OMG Object Management Group
PDE Product Data Exchange
PDM Product Data Management
PLM Product Lifecycle Management
RMS Root Mean Square
SET Standard D’Echange et de Transfert
STEP Standard for the Exchange of Product Data
SysML Systems Modeling Language
TIGL TIVA Geometric Library
TIXI TIVA XML Interface
UML Unified Modeling Language
VDA Verband Deutscher Automobilindustrie
XMI XML Metadata Interchange
XML Extensible Metadata Language
XSD XML Schema Definition
List of Figures
21 50 6
. . Kinds of Knowledge, from [ ] . . . . . . . . . . . . . . . . . . . . . . . .
31 17
. . Class and Object. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
32 18
. . Generalization Example . . . . . . . . . . . . . . . . . . . . . . . . . . . .
33 19
. . Association Example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
41 tep 24
. . Structure of S items . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
42 xpress 26
. . Parameter and type in E . . . . . . . . . . . . . . . . . . . . . . . .
43 27
. . Point Entity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
44 xpress 28
. . Generalization in E . . . . . . . . . . . . . . . . . . . . . . . . . . .
45 29
. . Complex Entity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
46 28 32
. . Example for an Part file . . . . . . . . . . . . . . . . . . . . . . . . . . .
47 pacs 37 38
. . C Structure, from [ ] . . . . . . . . . . . . . . . . . . . . . . . . . . .
48 pacs 45
. . Header for a C example . . . . . . . . . . . . . . . . . . . . . . . . .
49 igl 37 47
. . T -GUI, from [ ] . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
410 9 50
. . Point Class, from [ ] . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
411 9 51
. . Airplane Design Language Class Diagram, from [ ] . . . . . . . . . . . .
51 57
. . Express Project in Eclipse Navigator . . . . . . . . . . . . . . . . . . . . .
52 61
. . Converter Structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1 72
A. . Delta per Section . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2 72
A. . Volume Measuring in Catia . . . . . . . . . . . . . . . . . . . . . . . . . .
1 73
B. . Eclipse for Java . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2 73
B. . Libraries in Converter Project . . . . . . . . . . . . . . . . . . . . . . . . .
1. Introduction
11
Theintroductionissplitintothreeparts. Atthebeginningsection . givesanoutlook
about the motivation for the work carried out. A short lexical overview is listed in
12
section . . This section outlines some of the major terms for information models.
13
Finally, section . introduces the concept and structure of this work.
1.1. Research Motivation
In preliminary airplane design various engineering domains have to be combined.
Aerodynamics and structure, flight control and systems as well as cabin design are
just some of the domains to be named. Different calculation methods like numerical
simulationsbasedongeometricaldata,oranalyticsbasedonsymbolicequationscome
along with these disciplines. Supplementary, shorter product design cycles have to be
7 17
established even though product complexity increases [ , ].
The data from all domains has to be available instantly to allow shorter iteration cy-
cles and multidisciplinary design. Product Lifecycle Management and Product Data
Management systems have been developed to handle product data. These Systems
howeverdonothandledatainawaythatitisaccessibleasknowledge. Differentengi-
55
neering domains still can not interact, as there is no common language available [ ].
A holistic model accessible for all domains is the key to realize these tasks. Several
information models in preliminary airplane design are known.
At the German Aerospace Center (DLR) efforts are put in combining data for pre-
liminary airplane design in a single information model. The Common Parametric Air-
craft Configuration Scheme (Cpacs) enables project partners to adjoin and share data
32 37
from one single source [ , ].
Along with Cpacs there are other information models such as the STandard for the
Exchange of Product model data (Step) published by the International Organization for
tep
Standardization (ISO). S is widely spread in today’s industry, especially for the
tep
exchange of geometric data. Usage of S is made in aerospace, automobile and ship
18
engineering [ ].
TheUnifiedModelingLanguage(UML),havingitsoriginsinsoftwareengineering,being
distributed by the Object Management Group (OMG), and its successor the Systems
Engineering Language (SysML) have also been used to model airplane data [9, 38, 59].
1.2 Introduction to Information Models 2
Thegoalofthisworkistoanalyzeandcomparetheseinformationmodels. Wewantto
find out, in which ways these different information models can help to increase speed
and quality of future aircraft design projects.
pacs
Along with the analysis a converter is written allowing the output of C data to
tep
S . The converter allows the transfer of one information model to another and
enables even more people to work on the same project. This can help to increase the
pacs
acceptance of C inside and outside the DLR.
1.2. Introduction to Information Models
hen use a word umpty umpty said in a
“W I ,” H D
rather scornful tone it means just what
, “ I
choose it to mean neither more nor less
- ”
Alice in Wonderland
Lewis Carroll
In this section a short lexical overview for information models is given. The major
termsininformationmodelingaredefined. Subsequently,characteristicsandstructure
of information models are described.
At first, the term information should be defined. Several formulations can be found
1
in the literature describing the term. The Oxford English Dictionary [ ] defines in-
formation as “knowledge communicated concerning some particular fact, subject, or
event” whereas knowledge is specified as “the fact, state, or condition of understand-
11
ing”. The german encyclopedia Brockhaus [ ] defines information as “knowledge
aligned in format”. Additionally, a philosophical interpretation of the term informa-
49
tion is given in [ ] stating that information is “knowledge that can be communicated
xpress
concerning its content and matter”. The major E book Information Model-
xpress 52
ing the E Way [ ] characterizes information as “data placed in context”. The
definitionofdatacanagainbefoundintheOxforddictionaryas“facts,esp. numerical
facts, collected together for reference or information”.
Asitcanbeseenfromthevariousquotes,thereisnodistinctdefinitionofinformation.
Inthisworkwewillsticktothecommoneconomichierarchyofdata,informationand
55
knowledge, where knowledge is on the top of this hierarchy. As mentioned in [ ]
manyofthePDMandPLMsystemsneitherofferaholisticrepresentationnordothey
handle knowledge. Integrating data into a preliminary airplane design process will
therefore target the modeling of information, as we put data in context. Of course,
the engineers view of a future product will include raw numerical data. The goal of
modeling however should be to allow an understanding and reconstruction of these
data.
1.2 Introduction to Information Models 3
42
An information model is defined in [ ] as “a collection of symbol structure types [..]
and a collection of general integrity rules”. Symbol structure types describe entities
that can be produced inside the information model. General integrity rules check for
theconsistencyoftheproducedentitiesinsidethemodel. Atypicalinformationmodel
15
isdescribedbytherelationaldatabasemodelfrom[ ]. Themodelisestablishedfrom
the three different symbol structures: table, tuple and domain. The integrity rule for
the relational database is defined as: No two tuples within a table can have the same
key.
36
Another more extensive definition for an information model is given in [ ], “an in-
formation model is a representation of concepts, relationships, constraints, rules, and
operations to specify data semantics for a chosen domain of discourse”. One of the
first attempts to create modern information models was established by the creation of
13
the Entity Relationship Model described in [ ].
The creation of an information model is described in the literature as well. During the
developmentprocessofaninformationmodel,fourdifferentworldsaredistinguished
29
by [ ]:
⇀ subject world
subject matter of the information system
⇀ system world
information system itself
⇀ usage world
organizational environment
⇀ development world
describes the creation of the information system
58
This definition goes along well with the three schemes architecture in [ ] that arro-
gates an external (usage world) and an internal (system world) schema as well as a
conceptual schema (subject world). The development world is not regarded in this
paper.
In modern industry the usage and subject world are more complex as a product ori-
ented view and a resource oriented view exist. The parallel existence of ERP and
22
PDM-Systems shows this conflict [ ].
For the creation of every information model an information modeling language is
36
needed. The definition of an information modeling language is given in [ ] as “an
information modeling language is a formal syntax that allows users to capture data
semanticsandconstraints”. Severalinformationmodelinglanguageshavebeendevel-
def1x xpress
oped over the past decades. I , E and UML are just some of the languages
to be named.