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An Introduction toX-Analysis Integration (XAI)
Part 1: Constrained Object (COB) Primer
Georgia Tech
Engineering Information Systems Lab
eislab.gatech.edu
Contact: Russell S. Peak
Revision: April 22, 2002
Copyright © 1993-2002 by Georgia Tech Research Corporation, Atlanta, Georgia 30332-0415 USA. All Rights Reserved.Developed by eislab.gatech.edu. Permission to use for non-commercial purposes is hereby granted provided this notice is included.
2Engineering Information Systems Lab eislab.gatech.edu© 1993-2001 GTRC
Nomenclature ABB-SMM transformation idealization relation between design and analysis attributes APM-ABB associativity linkage indicating usage of one or more i
ABB analysis building blockAMCOM U. S. Army Aviation and Missile CommandAPM analyzable product modelCAD computer aided designCAE computer aided engineeringCBAM context-based analysis modelCOB constrained objectCOI constrained object instanceCOS constrained object structureCORBA common ORB architectureDAI design-analysis integrationEIS engineering information systemsESB engineering service bureauFEA finite element analysisFTT fixed topology templateGUI graphical user interfaceIIOP Internet inter-ORB protocolMRA multi-representation architectureORB object request brokerOMG Object Management Group, www.omg.comPWA printed wiring assembly (a PWB populated with components)PWB printed wiring boardSBD simulation-based designSBE simulation-based engineeringSME small-to-medium sized enterprise (small business)SMM solution method modelProAM Product Data-Driven Analysis in a Missile Supply Chain (ProAM) project (AMCOM)PSI Product Simulation Integration project (Boeing)STEP Standard for the Exchange of Product Model Data (ISO 10303).VTMB variable topology multi-bodyXAI X-analysis integration (X= design, mfg., etc.)XCP XaiTools ChipPackage™
XFW XaiTools FrameWork™
XPWAB XaiTools PWA-B™
3Engineering Information Systems Lab eislab.gatech.edu© 1993-2001 GTRC
An Introduction to X-Analysis Integration (XAI) Short Course Outline
Part 1: Constrained Objects (COBs) Primer– Nomenclature
Part 2: Multi-Representation Architecture (MRA) Primer – Analysis Integration Challenges – Overview of COB-based XAI– Ubiquitization Methodology
Part 3: Example Applications» Airframe Structural Analysis (Boeing)» Circuit Board Thermomechanical Analysis
(DoD: ProAM; JPL/NASA)» Chip Package Thermal Analysis (Shinko)
– Summary
Part 4: Advanced Topics & Current Research
4Engineering Information Systems Lab eislab.gatech.edu© 1993-2001 GTRC
mYmX ..
gXmXmpgZ ./..
Information Associativity
Associativity = Relations among objects
m mSystem X System Y
mpg System Z
Similar to electrical circuits
trip mileageon car odometer
gasoline amount & trip mileagein record book
trip gas mileagein calculator
g
5Engineering Information Systems Lab eislab.gatech.edu© 1993-2001 GTRC
Procedural vs. Declarative Knowledge Representations
Procedural RepresentationTraditional programming: C, C++, Java, ...
h
b
A = 1/2 bh
function: areaarea (b,h) return 0.5 * b * h;
state 1bb := 2, hh := 3;AA := area(bb,hh);result: AA := 3;
state 2 (value change)hh := 9;result: AA := 3;
state 3 (I/O change)AA := 6;
result: hh := 9;
/* how compute hh given AA, bb ? */
AAbb
hh
AAbb
hh
AAbb
hh
Declarative RepresentationMath solvers: Maple, Mathematica, ...
relation: r1r1(b,h,A): A :=: 0.5 * b * h;
state 1f :=: new r1(bb,hh,AA) instance;bb :=: 2, hh :=: 3, AA :=: ?;solve f;result: AA :=: 3
state 2 (value change)hh :=: 9;solve f;result: AA :=: 9
state 3 (I/O change)hh :=: ?, AA :=: 6;solve f;
result: hh :=: 6
AAbb
hh
AAbb
hh
AAbb
hh
6Engineering Information Systems Lab eislab.gatech.edu© 1993-2001 GTRC
COB Structure: Graphical Forms
Tutorial: Spring Primitive
v a r i a b l e s u b v a r i a b l es u b s y s t e m
e q u a l i t y r e l a t i o n
r e l a t i o n
s
a b
dc
a
b
d
c
e
a . das
r 1r 1 ( a , b , s . c )
e = f
s u b v a r i a b l e s . b
[ 1 . 2 ]
[ 1 . 1 ]o p t i o n 1 . 1
ff = s . d
o p t i o n 1 . 2
f = g
o p t i o n c a t e g o r y 1
gcbe
r 2
h o f c o b t y p e h
wL [ j : 1 , n ]
w j
a g g r e g a t e c . we l e m e n t w j
Basic Constraint Schematic-S Notation
L
L
Fk
u n d e fo rm e d le n g th ,
s p r in g c o n s ta n t, fo rc e ,
to ta l e lo n g a tio n ,
1x
Lle n g th ,0
2x
s ta rt,
e n d ,
oLLL
12 xxL
LkF
r1
r2
r3
c. Constraint Schematic-S
FF
k
L
deformed state
Lo
L
x2x1
a. Shape Schematic-S
LkFr
LLLr
xxLr
:
:
:
3
02
121
b. Relations-S
SpringElementary
LL
Fk
1x L
0
2x
d. Subsystem-S(for reuse by other COBs)
7Engineering Information Systems Lab eislab.gatech.edu© 1993-2001 GTRC
COB Structure: Lexical Form Spring Primitive
L
L
Fk
u n d e fo rm e d le n g th ,
s p r in g c o n s ta n t, fo rc e ,
to ta l e lo n g a tio n ,
1x
Lle n g th ,0
2x
s ta rt,
e n d ,
oLLL
12 xxL
LkF
r1
r2
r3
Constraint Schematic-S
Lexical COB Structure (COS)
COB spring SUBTYPE_OF abb; undeformed_length, L<sub>0</sub> : REAL; spring_constant, k : REAL; start, x<sub>1</sub> : REAL; end, x<sub>2</sub> : REAL; length, L : REAL; total_elongation, ΔL : REAL; force, F : REAL; RELATIONS r1 : "<length> == <end> - <start>"; r2 : "<total_elongation> == <length> - <undeformed_length>"; r3 : "<force> == <spring_constant> * <total_elongation>";END_COB;
8Engineering Information Systems Lab eislab.gatech.edu© 1993-2001 GTRC
200 lbs
30e6 psiResult b = 30e6 psi (output or intermediate variable)
Result c = 200 lbs (result of primary interest)
X
Relation r1 is suspended X r1
100 lbs Input a = 100 lbs
Equality relation is suspended
a
b
c
Example COB InstanceSpring Primitive
Constraint Schematic-I Lexical COB Instance (COI)
state 1.0 (unsolved):
INSTANCE_OF spring; undeformed_length : 20.0; spring_constant : 5.0; total_elongation : ?; force : 10.0;END_INSTANCE;
state 1.1 (solved):
INSTANCE_OF spring; undeformed_length : 20.0; spring_constant : 5.0; start : ?; end : ?; length : 22.0; total_elongation : 2.0; force : 10.0;END_INSTANCE;
Basic Constraint Schematic-I Notation
22 mm
10 N
2 mm
5 N/mm
20 mm
L
L
Fk
undeformed length,
spring constant, force,
total elongation,
1x
Llength,0
2x
start,
end,
oLLL
12 xxL
LkF
r1
r2
r3
example 1, state 1.1
9Engineering Information Systems Lab eislab.gatech.edu© 1993-2001 GTRC
2 mm
40 N20 N/mm
20 mm
10 mm
32 mm
22 mm
L
L
Fk
undeformed length,
spring constant, force,
total elongation,
1x
Llength,0
2x
start,
end,
oLLL
12 xxL
LkF
r1
r2
r3
Multi-Directional I/O (non-causal)Spring Primitive
Constraint Schematic-I Lexical COB Instance (COI)
state 5.0 (unsolved):
INSTANCE_OF spring; undeformed_length : 20.0; spring_constant : ?; start : 10.0; length : 22.0; force : 40.0;END_INSTANCE;
state 5.1 (solved):
INSTANCE_OF spring; undeformed_length : 20.0; spring_constant : 20.0; start : 10.0; end : 32.0; length : 22.0; total_elongation : 2.0; force : 40.0;END_INSTANCE;
Design Verification
Design Synthesis
example 1, state 1.1
example 1, state 5.1
22 mm
10 N
2 mm
5 N/mm
20 mm
L
L
Fk
undeformed length,
spring constant, force,
total elongation,
1x
Llength,0
2x
start,
end,
oLLL
12 xxL
LkF
r1
r2
r3
10Engineering Information Systems Lab eislab.gatech.edu© 1993-2001 GTRC
Traditional Mathematical RepresentationTutorial: Two Spring System
System Figure
P
k1 k2
2u1u
L10
k1
x12
F1
L1
L1
x11
F1
L20
k2
x22
F2
L2
L2
x21
F2
Free Body Diagrams
22223
202222
2122221
11113
101112
1112111
:
:
:
:
:
:
LkFr
LLLr
xxLr
LkFr
LLLr
xxLr
Variables and Relations
Boundary Conditions
Kinematic Relations
Constitutive Relations
1226
115
24
213
21122
111
:
:
:
:
:
0:
uLubc
Lubc
PFbc
FFbc
xxbc
xbc
11Engineering Information Systems Lab eislab.gatech.edu© 1993-2001 GTRC
spring2
spring1
Constraint Graph-STwo Spring System
P
k1 k2
2u1u
22223
202222
2122221
11113
101112
1112111
:
:
:
:
:
:
LkFr
LLLr
xxLr
LkFr
LLLr
xxLr
L10
k1
L1
L1
L20
k2
x21
x22
F2
L2
F1
x11
x12
u1 u2
P
1226
115
24
213
21122
111
:
:
:
:
:
0:
uLubc
Lubc
PFbc
FFbc
xxbc
xbc
L2
bc4
r12
r13
r22
r23
bc5bc6
bc3
r11r21
bc2
bc1
12Engineering Information Systems Lab eislab.gatech.edu© 1993-2001 GTRC
spring2
spring1
L10
k1
L1
L1
L20
k2
x21
x22
F2
L2
F1
x11
x12
u1 u2
P
L2
bc4
r12
r13
r22
r23
bc5bc6
bc3
r11r21
bc2
bc1
COB Representation Extended Constraint Graph-S: Two Spring System
Extended Constraint Graph-S
Constraint Graph-S
• Groups objects & relations into parent objects• Object-oriented vs. flattened
spring 2
L
Lundeformed length,
spring constant, k
Fforce,
total elongation,
1xLlength,
0
2x
start,
end,
oLLL
12 xxL
LkF
r1
r2
r3
spring 1two-spring system
deformation 1, u1
deformation 2, u2
force , P
L
Lundeformed length,
spring constant, k
Fforce,
total elongation,
1xLlength,
0
2x
start,
end,
oLLL
12 xxL
LkF
r1
r2
r3
partial(BC relations not included)
13Engineering Information Systems Lab eislab.gatech.edu© 1993-2001 GTRC
spring2
spring1
L10
k1
L1
L1
L20
k2
x21
x22
F2
L2
F1
x11
x12
u1 u2
P
L2
bc4
r12
r13
r22
r23
bc5bc6
bc3
r11r21
bc2
bc1
b c 1
s p r i n g 1
2u
s p r i n g 2
1u
P
S p r i n gE l e m e n t a r y
LL
Fk
1x L
0
2x
122 uLu
b c 2 b c 3
b c 4
b c 6
S p r i n gE l e m e n t a r y
LL
Fk
1x L
0
2x
b c 5
011 x
COB Representation Constraint Schematic-S: Two Spring System
Constraint Schematic-S
Constraint Graph-S
• Encapsulated form (hides details)
14Engineering Information Systems Lab eislab.gatech.edu© 1993-2001 GTRC
b c 1
s p r i n g 1
2u
s p r i n g 2
1u
P
S p r i n gE l e m e n t a r y
LL
Fk
1x L
0
2x
122 uLu
b c 2 b c 3
b c 4
b c 6
S p r i n gE l e m e n t a r y
LL
Fk
1x L
0
2x
b c 5
011 x
COB Constraint Schematic-STwo Spring System
22223
202222
2122221
11113
101112
1112111
:
:
:
:
:
:
LkFr
LLLr
xxLr
LkFr
LLLr
xxLr
P
k1 k2
u2u1
System-Level Relations(Boundary Conditions)
Analysis Primitiveswith
Encapsulated Relations
1226
115
24
213
21122
111
:
:
:
:
:
0:
uLubc
Lubc
PFbc
FFbc
xxbc
xbc
15Engineering Information Systems Lab eislab.gatech.edu© 1993-2001 GTRC
COBs as Building BlocksTwo Spring System
P
k1 k2
u2u1
Constraint Schematic-S
Lexical COB Structure (COS)
COB spring_system SUBTYPE_OF analysis_system; spring1 : spring; spring2 : spring; deformation1, u<sub>1</sub> : REAL; deformation2, u<sub>2</sub> : REAL; load, P : REAL; RELATIONS bc1 : "<spring1.start> == 0.0"; bc2 : "<spring1.end> == <spring2.start>"; bc3 : "<spring1.force> == <spring2.force>"; bc4 : "<spring2.force> == <load>"; bc5 : "<deformation1> == <spring1.total_elongation>"; bc6 : "<deformation2> == <spring2.total_elongation> + <deformation1>";END_COB;
b c 1
s p r i n g 1
2u
s p r i n g 2
1u
P
S p r i n gE l e m e n t a r y
LL
Fk
1x L
0
2x
122 uLu
b c 2 b c 3
b c 4
b c 6
S p r i n gE l e m e n t a r y
LL
Fk
1x L
0
2x
b c 5
011 x
16Engineering Information Systems Lab eislab.gatech.edu© 1993-2001 GTRC
state 1.0 (unsolved):INSTANCE_OF spring_system; spring1.undeformed_length : 8.0; spring1.spring_constant : 5.5; spring2.undeformed_length : 8.0; spring2.spring_constant : 6.0; load : 10.0; deformation2 : ?;END_INSTANCE;
state 1.1 (solved):INSTANCE_OF spring_system; spring1.undeformed_length : 8.0; spring1.spring_constant : 5.5; spring1.start : 0.0; spring1.end : 9.818; spring1.force : 10.0; spring1.total_elongation : 1.818; spring1.length : 9.818; spring2.undeformed_length : 8.0; spring2.spring_constant : 6.0; spring2.start : 9.818; spring2.force : 10.0; spring2.total_elongation : 1.667; spring2.length : 9.667; spring2.end : 19.48; load : 10.0; deformation1 : 1.818; deformation2 : 3.485;END_INSTANCE;
Analysis System InstanceTwo Spring System
Constraint Schematic-I Lexical COB Instance (COI)
b c 1
s p r i n g 1
2u
s p r i n g 2
1u
P
S p r i n gE l e m e n t a r y
LL
Fk
1x L
0
2x
122 uLu
b c 2 b c 3
b c 4
b c 6
S p r i n gE l e m e n t a r y
LL
Fk
1x L
0
2x
b c 5
011 x
1 . 8 1 8
1 0 . 0 6 . 0
8 . 0
5 . 5
8 . 0
3 . 4 8 5
9 . 8 1 8
1 0 . 0
1 0 . 0
9 . 8 1 8
1 . 6 6 7
9 . 6 6 7
1 9 . 4 8
1 . 8 1 8
9 . 8 1 8
example 2, state 1.1
17Engineering Information Systems Lab eislab.gatech.edu© 1993-2001 GTRC
Spring Examples Implemented in XaiTools X-Analysis Integration
Toolkit
spring system: similar to state 1.1 (solved):
spring: state 1.1 (solved)
spring: state 5.1 (solved)
18Engineering Information Systems Lab eislab.gatech.edu© 1993-2001 GTRC
Using Internet/Intranet-based Analysis SolversThick Client Architecture - Engineering-Oriented ASP
Client PCs
XaiTools
Thick Client
Users
Internet
June’99-Present:EIS Lab - Regular internal use
U-Engineer.com - Demo usage: - US (SMEs, OEMs, Gov. labs) - Japan
Nov.’00-Present:Electronics Co. - Began production usage (dept. Intranet)
Future:Other company Intranets and/or
U-Engineer.com(commercial) - Other solvers
Iona orbixdj
Mathematica
Ansys
Internet/Intranet
XaiTools AnsysSolver Server
XaiTools AnsysSolver Server
XaiTools Math.Solver Server
CORBA Daemon
XaiTools AnsysSolver Server
FEA Solvers
Math Solvers
CORBA Servers
CO
RB
A IIO
P..
.
Engineering Service BureauHost Machines
2002-04 Updates: SOAP protocol; Patran/Abaqus wrappersASP= application service provider
19Engineering Information Systems Lab eislab.gatech.edu© 1993-2001 GTRC
Subsystem-S
Object Relationship Diagram-S
COB StructureDefinition Language
(COS)
I/O Table-S
Constraint Graph-S
Constraint Schematic-S
STEPExpress
Express-G
COB Modeling Languages & Views
COB InstanceDefinition Language
(COI)
Constraint Graph-I
Constraint Schematic-I
STEPPart 21
200 lbs
30e6 psi
100 lbs 20.2 in
R101
R101
100 lbs
30e6 psi 200 lbs
20.2 in
StructureLevel(Template)
InstanceLevel
20Engineering Information Systems Lab eislab.gatech.edu© 1993-2001 GTRC
Basic EXPRESS-G notationA A is an entity (class)
Instance of A are objects
AA is a simple type ( BOOLEAN, LOGICAL, BINARY, NUMBER, INTEGER, REAL, STRING)
a1A Ba2 A has two attribute, a1 and a2, that
are both type B
A Ba1
S[1;?]A has an attribute, a1, that is a Set of 1 or ore entities of type B
A
CB
A is a supertype of B and C. (B and C are subtype of A)
Unofficial extensions:A has two levels, a1 and a2. a1 is type B. a2 is type C.
AB
a2a1
C
21Engineering Information Systems Lab eislab.gatech.edu© 1993-2001 GTRC
COB Object Model View (EXPRESS-G)Spring Systems Schema
Real
Real
Real
spring _system
spring_2
spring_1
load
deformation1
deformation2
Real
Real
Real
Real
Real
Real
Real
spring
undeformed _length
force
total _elongation
length
end0
start
spring _constant
P
k1 k2
u2u1
FF
k
L
deformed state
Lo
L
x2x1
22Engineering Information Systems Lab eislab.gatech.edu© 1993-2001 GTRC
Express Model: two_spring_system.expspring systems tutorial
SCHEMA spring_systems;
ENTITY spring; undeformed_length : REAL; spring_constant : REAL; start : REAL; end0 : REAL; length0 : REAL; total_elongation : REAL; force : REAL;END_ENTITY;
ENTITY two_spring_system; spring1 : spring; spring2 : spring; deformation1 : REAL; deformation2 : REAL; load : REAL;END_ENTITY;
END_SCHEMA;
FF
k
L
deformed state
Lo
L
x2x1
P
k1 k2
2u1u
23Engineering Information Systems Lab eislab.gatech.edu© 1993-2001 GTRC
Instance Model: Part 21 and Example Application
spring systems tutorial
Fragment from an instance model - Part 21 (a.k.a. “STEP File” - ISO 10303-21)#1=TWO_SPRING_SYSTEM(#2,#3,1.81,3.48,10.0);#2=SPRING(8.0,5.5,0.0,9.81,9.81,1.81,10.0);#3=SPRING(8.0,6.0,9.8,19.48,9.66,1.66,10.0);
24Engineering Information Systems Lab eislab.gatech.edu© 1993-2001 GTRC
Declarative Knowledge / Derivable BehaviorTwo Spring System
22223
202222
2122221
11113
101112
1112111
:
:
:
:
:
:
LkFr
LLLr
xxLr
LkFr
LLLr
xxLr
P
k1 k2
u2u1
Derivable Behavior
1226
115
24
213
21122
111
:
:
:
:
:
0:
uLubc
Lubc
PFbc
FFbc
xxbc
xbc
b c 1
s p r i n g 1
2u
s p r i n g 2
1u
P
S p r i n gE l e m e n t a r y
LL
Fk
1x L
0
2x
122 uLu
b c 2 b c 3
b c 4
b c 6
S p r i n gE l e m e n t a r y
LL
Fk
1x L
0
2x
b c 5
011 x
21
2122
111
:
:
kk
kkPudr
k
Pudr
No need to include explicitly (redundant)
25Engineering Information Systems Lab eislab.gatech.edu© 1993-2001 GTRC
Achieving Effective System Properties via Semantically Rich COBs
P
keffective
2u
Derivable SystemLevel Properties
.
:2
111
:
21
21
1
etc
LLLdr
kk
kdr
effective
effective
No need to derive Minimal extra work Semantically richer
P
k1 k2
u2u1
b c 1
s p r in g 1
2u
s p r in g 2
1u
P
S p r in gE le m e n t a r y
LL
Fk
1x L
0
2x
122 uLu
b c 2 b c 3
b c 4
b c 6
S p r in gE le m e n t a r y
LL
Fk
1x L
0
2x
b c 5
011 x
S p r in gE le m e n t a r y
LL
Fk
1x L
0
2x
e f f e c t i v e s p r in g
Note: A relation for effective undeformed length is also needed, as higher level semantic relations (e.g., that it is the value when F=0) are not yet supported.
26Engineering Information Systems Lab eislab.gatech.edu© 1993-2001 GTRC
COB-based Libraries ofAnalysis Building Blocks (ABBs)
Material Model ABB
Continuum ABBs
modularre-usage
E
O n e D L in e a rE la s t i c M o d e l
T
G
e
t
m a t e r i a l m o d e l
p o la r m o m e n t o f i n e r t i a , J
r a d iu s , r
u n d e f o r m e d l e n g t h , L o
t w i s t ,
t h e t a s t a r t , 1
t h e t a e n d , 2
r 1
12
r 3
0L
r
J
rT r
t o r q u e , T r
x
TT
G , r , , ,J
L o
y
m ateria l m odel
tem perature, T
reference tem perature, T o
force, F
area, A
undeform ed length, L o
to ta l e longation,L
length, L
start, x1
end, x2
E
O ne D LinearE lastic M odel
(no shear)
T
e
t
r1
12 xxL
r2
oLLL
r4
A
F
edb.r1
oTTT
r3
L
L
x
FF
E , A ,
LL o
T , ,
yL
Torsional Rod
Extensional Rod
temperature change,T
cte,
youngs modulus, E
stress,
shear modulus, G
poissons ratio,
shear stress, shear strain,
thermal strain, telastic strain, e
strain,
r2
r1)1(2
EG
r3
r4Tt
Ee
r5
G
te
1D Linear Elastic Model
27Engineering Information Systems Lab eislab.gatech.edu© 1993-2001 GTRC
Flap Link ExampleParametric Design Description
ts1
A
Sleeve 1
A ts2
ds2
ds1
Sleeve 2
L
Shaft
b
h
t
b
h
t
sleeve_2
shaft
rib_1
material
flap_link
sleeve_1
rib_2
w
t
r
x
name
R3
R2
t2f
wf
tw
t1f
cross_section
w
t
r
x
R1
COB flap_link SUBTYPE_OF part; part_number : STRING; inter_axis_length, L : REAL; sleeve1 : sleeve; sleeve2 : sleeve; shaft : tapered_beam; rib1 : rib; rib2 : rib;RELATIONS PRODUCT_RELATIONS pr2 : "<inter_axis_length> == <sleeve2.origin.y> -
<sleeve1.origin.y>"; pr3 : "<rib1.height> == (<sleeve1.width> -
<shaft.cross_section.design.web_thickness>)/2"; pr4 : "<rib2.height> == (<sleeve2.width> -
<shaft.cross_section.design.web_thickness>)/2";...
END_COB;
Extended Constraint Graph
COB Structure (COS)
28Engineering Information Systems Lab eislab.gatech.edu© 1993-2001 GTRC
L
ws1
ts1
rs2
ws2
ts2
rs2
wf
tw
tf
E
name
linear_elastic_model
wf
tw
tf
inter_axis_length
sleeve_2
shaft
material
linkage
sleeve_1
w
t
r
E
cross_section:basic
w
t
r
x,max
r1
mode: tension
ux,max
Fcondition reaction
Representing External Tools as COB RelationsParametric FEA Model
ts1
rs1
L
rs2
ts2tf
ws2ws1
wf
tw
F
L L
x
y
L C
Plane Stress Bodies
),,,...,,,,(),( 1111max,max, FErstswsLru xx
FEA Tool
29Engineering Information Systems Lab eislab.gatech.edu© 1993-2001 GTRC
Constrained Object (COB) RepresentationCurrent Technical Capabilities - Generation 2
Capabilities & features:– Various forms: computable lexical forms, graphical forms, etc.
» Enables both computer automation and human comprehension– Sub/supertypes, basic aggregates, multi-fidelity objects– Multi-directionality (I/O changes)– Reuses external programs as white box relations– Advanced associativity added to COTS frameworks & wrappers
Analysis module/template applications (XAI/MRA): – Analysis template languages– Product model idealizations– Explicit associativity relations with design models & other analyses– White box reuse of existing tools (e.g., FEA, in-house codes)– Reusable, adaptable analysis building blocks
– Synthesis (sizing) and verification (analysis)
30Engineering Information Systems Lab eislab.gatech.edu© 1993-2001 GTRC
Constrained Objects (cont.) Representation Characteristics & Advantages - Gen. 2
Overall characteristics– Declarative knowledge representation (non-causal)– Combining object & constraint graph techniques– COBs = (STEP EXPRESS subset) +
(constraint graph concepts & views)
Advantages over traditional analysis representations– Greater solution control– Richer semantics
(e.g., equations wrapped in engineering context)– Unified views of diverse capabilities (tool-independent)– Capture of reusable knowledge – Enhanced development of complex analysis models
Toolkit status (XaiTools v0.4)– Basic framework, single user-oriented, file-based
See Advanced Topics
for Gen.3 Extensions
31Engineering Information Systems Lab eislab.gatech.edu© 1993-2001 GTRC
Convergence of Representations
Database Techniques(data structure, storage …)
Software Development(algorithms …)
Artificial Intelligence& Knowledge-Based Techniques
(structure combined with algorithms/relations/behavior)
EER
STEP Express
ER
UML
Flow Charts
OMT
Objects
Rules
Constraint graphs
Constrained Object - likeRepresentations
COBs, OCL, ...
32Engineering Information Systems Lab eislab.gatech.edu© 1993-2001 GTRC
Dimensions of Associativity
Operand representation: a, b– Type: numeric, logical, string, …, general object– Human-sensible vs. computer-sensible
» Computer-sensible: Flattened vs. object/feature-oriented
Relation representation: r1, r2– Relation type:
» Math formula, geometric constraint, computable algorithm, computer system (e.g., FEA tool), arbitrary human process, ...
Associativity = Relations among objects
a aaYaX ..
r1System X
System Y
b).(. 2 bZraX
r2 System Z
electricalcircuitsanalogy
33Engineering Information Systems Lab eislab.gatech.edu© 1993-2001 GTRC
Dimensions of Associativity (cont.)
Relation representation (continued)– Explict vs. implicit vs. unrecognized vs. unknown – Human-sensible vs. computer-sensible
» Computer-sensible: Dumb string vs. smart string vs. object/feature-oriented
– Level: instance and/or template (schema, structure) Relation directionality
– Uni-directional vs. multi-directional vs. iteratively multi-directional
Relation duration– Continuous (“live”) vs. event-controlled
Relation granularity– coarse vs. fine (macro vs. micro)
a aaYaX ..
r1System X
System Y
b).(. 2 bZraX
r2 System Z
Associativity graph type– Declarative vs. procedural– Cyclic vs. acyclic
34Engineering Information Systems Lab eislab.gatech.edu© 1993-2001 GTRC
e
se
tr
Pf
02
21
e
be
ht
PCf
),,( 13 hbrfK
Missing Today:Fine-Grained Design-Analysis Associativity
Analysis Model (with Idealized Features)
Detailed Design Model
Channel Fitting Analysis
“It is no secret that CAD models are driving more of today’s product development processes ... With the growing number of design tools on the market, however, the interoperability gap with downstream applications, such as finite element analysis, is a very real problem. As a result, CAD models are being re-created at unprecedented levels.” Ansys/ITI press Release, July 6 1999
http://www.ansys.com/webdocs/VisitAnsys/CorpInfo/PR/pr-060799.html
idealizations
No explicit
fine-grained
CAD-CAE
associativity
inconsisten
cy littleautomation
littleknowledge capture
35Engineering Information Systems Lab eislab.gatech.edu© 1993-2001 GTRC
Constrained Object RepresentationBusiness Benefits
COB end user : Designer (uses COB instances & COB-based applications)– Automation Time savings & consistency– More analysis Improved designs
COB creator : Analyst (creates templates with COB definition language)– Modularity & reusability Faster, consistent modeling– Semantic richness Increased understanding– Knowledge capture Enhanced corporate memory
COB application developer: Programmer (uses COB API to create COB-based custom applications)– Modularity & reusability Faster, consistent application
development
36Engineering Information Systems Lab eislab.gatech.edu© 1993-2001 GTRC
An Introduction to X-Analysis Integration (XAI) Short Course Outline
Part 1: Constrained Objects (COBs) Primer– Nomenclature
Part 2: Multi-Representation Architecture (MRA) Primer – Analysis Integration Challenges – Overview of COB-based XAI– Ubiquitization Methodology
Part 3: Example Applications» Airframe Structural Analysis (Boeing)» Circuit Board Thermomechanical Analysis
(DoD: ProAM; JPL/NASA)» Chip Package Thermal Analysis (Shinko)
– Summary
Part 4: Advanced Topics & Current Research
Other Aspectsfrom [Wilson, 2000] thesis, etc.
38Engineering Information Systems Lab eislab.gatech.edu© 1993-2001 GTRC
COB Meta Information Model & Protocol Generic Nature
GenericMetadata
GenericData
cos & coi contentas java objects
SpecificStructureData (cos)
SpecificInstanceData (coi)
COBInstanceDefinitionData
COBStructureDefinitionData
Example:
COICOICOSCOS
L
kx2
F
LL
x1F 10.010.0
20.020.0
5.05.0
22.022.02.02.0
10.010.0 32.032.0
Graphical Definition Languages & Views
Pro
toco
l
Lexical Definition Languages & Views
Meta InformationModel
• Express-G• Constraint schematics• Parameterized figures• ...
• cos and coi• Express and Part 21• ...
39Engineering Information Systems Lab eislab.gatech.edu© 1993-2001 GTRC
Simplified COB Meta-Model (EXPRESS-G)(page 1/2)
COB SchemaCOB Source
Set
COB SourceSet Link
COB Domain
COB DomainInstance
source_setsL[0:?]
source_sets_linksL[0:?]
set_domainsL[0:?]
set_instancesL[0:?]
Late-bound representation style
40Engineering Information Systems Lab eislab.gatech.edu© 1993-2001 GTRC
Simplified COB Meta-Model (page 2/2)
REAL
STRING
COB ComplexInstance
domain_name
attributesL[0:?]
attribute_name
instance_of
value
valuesL[0:?]
COB Domain
COB PrimitiveInstance
COB DomainInstance
domain
STRING
COB Attribute
instance_of
COB ComplexDomain
COB PrimitiveDomain
COB AggregateDomain
elementsL[0:?]
COB AggregateInstance
elementsL[0:?]
COB Relation relationsL[0:?]
41Engineering Information Systems Lab eislab.gatech.edu© 1993-2001 GTRC
COB Constraint Processing Algorithms“solve” algorithm: constraint graphs with only multi-directional relations
Provisional patent filed 6/2000
Set A
A.a1 = A.a2.b1A.a2.b1 = A.a2.x2.y1A.a2.x2.y1 = A.a2.x2.y2
A.a1 = 5.0
InputConstraint Network
ResultConstraint Network
A.a2.b1
A.a2.x2.y2
A.a2.x2.y1
R1
R2
R3
A.a1
5.0
A.a4
A.a3
R4
2.0 A.a4
2.0
A.a3
R4
2.0
5.0
A.a2.x2.y2
A.a2.x2.y1
R1
R2
R3
A.a1
5.0
A.a2.b1 5.0
5.0
Note: All relations are equality relations.
A.a3 = A.a4A.a1 = 2.0
Set B
Simultaneous Equations
constraintsolver
42Engineering Information Systems Lab eislab.gatech.edu© 1993-2001 GTRC
COB Constraint Processing Algorithms“solve” algorithm: constraint graphs with 1 or more one-way relations
A.a1 = A.a2+ A.b1A.b1 = A.c1A.b2 = A.c2A.b3 = A.c3
A.c1 = 1.0A.c2 = 2.0A.c3 = 3.0
A.a1
Simultaneous-Equation Set 1
A.c1
R1 R3
R4
A.b1
A.a2R2
R5
A.b2
A.b3
A.c2
A.c3
R2
1.0
2.0
3.0
A.c1
R1 R3
A.a1
A.b1
A.a2
1.0
R4
R5
A.b2
A.b3
A.c2
A.c3
2.0
3.0
A.c1
R1 R3
A.a1
A.b1
A.a2
1.0
R4
R5
A.b2
A.b3
A.c2
A.c3
2.0
3.0
1.0
2.0
3.0
A.a1
A.c1
R1 R3
R4
A.b1
A.a2R2
R5
A.b2
A.b3
A.c2
A.c3
R2
1.0
2.0
3.0
1.0
2.0
3.0
A.a1
R1
A.b1
A.a2R2
A.b2
A.b3
R2
1.0
2.0
3.0
A.a1 = A.a2+ A.b1A.a2 = Oneway[A.b1,A.b2,A.b3]
A.c1 = 1.0A.c2 = 2.0A.c3 = 3.0
A.a1
R1
A.b1
A.a2R2
A.b2
A.b3
R2
1.0
2.0
3.02.0
3.0
Simultaneous-Equation Set 2
AB
C
DEF
G
H
Provisional patent filed 6/2000