STEPTAS: Interface for TRASYS and further developments

1
STEP-TAS Interface for TRASYSand further
developments

• Simon Appel (ESA/ESTEC D/TOS-MVC, The
  Netherlands)Francois Brunetti (Simulog, France)
• Alain Fagot (Simulog, France)
• Hans Peter de Koning (ESA/ESTEC D/TOS-MVC, The
  Netherlands)
• 2002 NASA-ESA Workshop onAerospace Product Data
  Exchange
• ESA/ESTEC, Noordwijk (ZH), The NetherlandsApril
  9-12, 2002

2
Topics

• Why do we need a TRASYS interface?
• Why an independent TRASYS/STEP-TAS converter
  from Europe?
• TRASYS/STEP-TAS bi-directional converter
• TRASYS/ESARAD converter
• Further development of STEP-TAS

3
Why do we need a TRASYS interface?

• TRASYS is used as de-facto exchange format for
  thermal-radiative models in US
• TRASYS thermal interface models are made
  contractually binding for e.g.
• ISS international programmes by NASA-JSC
• Coupled payload / STS cargo bay analysis

4
Why an independent TRASYS/STEP-TAS converter
from Europe?

• For long term do not want point-to-point
  interfaces
• Do not want to depend on proprietary COTS or US
  Gov't software
• Because of complexity of TRASYS features
  transparent and thorough validation absolute
  necessity
• TRASYS interfaces in US tools do not support
  transfer of kinematic behaviour - needed in next
  version converter
• To promote industrial use of STEP-TAS standard

5
TRASYS/STEP-TAS bi-directional converter

• Limited stand-alone TRASYS / STEP-TAS CC1
  converter
• Development by Simulog started Jan-2001
• Version 1.0 will be released in April 2002

6
TRASYS / STEP-TAS converter (1)
TRASYS input file
TRASYS Pre-processor

• Development approach
• Native TRASYS pre-processor validates input file
• New parser developed from scratch in C
• Better interface with STEP-TAS data structure
• Full source control
• No infringement of intellectual property rights

OK ?
No
Yes
TRASYS / STEP-TAS converter
STEP-TAS Part 21 file
7
TRASYS / STEP-TAS converter (2)

• Version 1.0 supports
• User option for English/SI unit conversion
• TRASYS shapes with corresponding STEP-TAS shape
• Non-uniform TRASYS meshing
• Correspondence data
• Implementation of full functionality of converter
  is limited by STEP-TAS library and protocol

8
TRASYS / STEP-TAS converter (3)

• Features in STEP-TAS protocol and/or library
  needed to complete a full converter

9
TRASYS / STEP-TAS converter (2)

• Supported platforms
• Windows NT / 2000
• SGI-IRIX
• SUN/SOLARIS

10
TRASYS / ESARAD Converter t2e (1)

• Generates input files for ESARAD modules geometry
  and ESATAN file formatting
• Parallel development of direct converter was
  needed for a project
• First experience with Python programming
  language
• Significant speed up in development of input file
  parser
• For converter applications no noticeable speed
  loss e.g. ISS model (23000 lines) is converted
  within 20 seconds on pentium IV
• Porting to different platforms is not an issue
  any more

11
TRASYS / ESARAD Converter t2e (2)

• Side products used with the development with
  TRASYS / STEP-TAS
• Extensive suite of unit tests (130) (automatic
  regression tests)
• Tests for each surface type Basic surface
  conversion, Surface duplication, Non-uniform
  meshing, Mirror operations, Coordinate
  transformations, Optical property modifications
  (MODPR, MODTR, MODPRS)
• Test for correspondence data, sub-models, BCS
  duplication/mirroring
• Knowledge of (many !) non-documented TRASYS
  features obtained through reverse engineering

12
TRASYS / ESARAD Converter t2e (3)
TRASYS spheroid
 

• All surface types are supported
• Direct conversion of TRASYS surfaces with
  corresponding ESARAD shell type
• TRASYS surfaces with no corresponding ESARAD
  shell type are converted to a approximate
  facetted representation

ESARAD spheroid approximated with conical facets
13
TRASYS / ESARAD Converter t2e (4)

• Further support a.o.
• Surface and BCS duplication
• Surface and BCS imaging image surfaces are
  transformed to real surface (ESARAD does not
  have image surfaces)
• Correspondence data is converted to ESARAD
  MERGE_NODES statements
• Only surface in BCSs referenced in BUILD
  statement are converted
• MODPR, MODPRS and MODTR are processed

14
TRASYS / ESARAD Converter t2e (5) STS 390 Node
Model - Open Doors
TRASYS
ESARAD
15
TRASYS / ESARAD Converter t2e (6) STS 390 Node
Model - Closed Doors
ESARAD
TRASYS
16
TRASYS / ESARAD Converter t2e (7)

• Stand-alone version is available
• requires no Python installation
• Platform Windows NT/2000
• Free for download at www.estec.esa.int/thermal

17
TRASYS / STEP-TAS Converter STS 390 Node Model -
Open Doors
Baghera View 2.0
TRASYS
18
TRASYS / STEP-TAS Converter STS 390 Node Model
- Closed Doors
Baghera View 2.0
TRASYS
19
Assessment STEP-TAS progress 2001 2002-Q1

• Too slow!
• Insufficient manpower on ESAs side due to other
  commitments
• Still important extension of STEP-TAS take-up
• TRASYS/STEP-TAS converters build up of
  extensive test suite
• PATRAN/STEP-TAS interface implemented by MSC in
  release v2002
• Prototyping started by Maya HTT for
  FEMAP/IDEAS/TMG
• Prototyping started by Alcatel Space on CORATHERM
• Remaining problem areas STEP-TAS very well
  established
• Simplified new architecture STEP-TAS SDK defined

20
Outlook on STEP-TAS (1)

• Establish STEP-TAS Home Page (April 2002)
• http//www.estec.esa.int/thermal/step-tas
• Start STEP-TAS Implementors Forum
• ESA have internally experimented with local
  installation of sourceforge.net and
  savannah.gnu.org open source software development
  environment for community source or open
  source works reasonably well
• distribution of documentation and code,
  discussion forum, e-mail support
• SPR / bug tracking, CVS configuration control,
  test suites
• Provide intermediate STEP-TAS library release on
  PC/Windows correcting currently known issues next
  2 months

21
Outlook on STEP-TAS (2)

• Correct identified problems in STEP-TAS AP (SPR
  List)
• Resolve identified gaps in STEP-TAS AP
• mirror copy, ogive/spheroid/torus shapes
• Up for discussion
• Publish STEP-NRF and STEP-TAS APs in new HTML
  format
• Register as ISO TC184 / SC4 Technical
  Specification or PAS

22
Outlook on STEP-TAS (3)

• Simplify/upgrade STEP-TAS SDK (Software
  Development Kit)
• Remove confusing SET-ATS constructs
• Correct all outstanding SPRs (bugs)
• Move to STEP-TAS ARM based exchange datasets
• Improve performance order of magnitude (dynamic
  memory handling)
• Improve instance navigation in high level API
• set_xxx, get_xxx, get_extent_xxx
• Implement complete global and local (EXPRESS)
  rule checking
• Extend API to cover STEP-TAS CC2 to CC6
  (currently only CC1)
• Base on open source low level STEP library
• Add Python binding for efficient development of
  stand-alone converters

23
STEP-TAS Converter Upgrades

• Work with Alstom on ESARAD/STEP-TAS upgrade
• Make it a separate stand-alone executable
• Start with CC2 (kinematics) CC5 (missions
  aspects) implementations
• Work with Astrium SAS on THERMICA/STEP-TAS
  upgrade
• Work with Simulog and CNES for BagheraView
  upgrade
• Work with Simulog on TRASYS/STEP-TAS upgrade
• Coordinate large model exchange validation
• Work with NASA on US tool / converter upgrades

24
Outlook on STEP-NRF
Each gridpoint in the 3D dataspace is a property
value Each can be scalar, vector, tensor Data
model and implementation designed to handle
sparsely populated dataspace efficiently
model_component (model, node, node_relationship)
state
property_class
abscissa_property
25
Main characteristics STEP-NRFProposed NRF/HDF
architecture
STEP-NRF protocol (discipline- independent)
discipline-specific dictionaries
User Application (Reading or Writing Results Data)
NRF Dictionary Structural
NRF Dictionary Thermal
NRF Dictionary Electrical
NRF Dictionary ...
STEP-NRF SDAI programming library
HDF5 Hierachical Data Format v5 - Public domain
from NCSA - Efficient portable binary storage
format - Full C, Fortran, Java libraries on gt10
platforms - Standard for all NASA EOS missions
and some ESA earth observation - Info/downloads
at hdf.ncsa.uiuc.edu - Many COTS / PD tools with
HDF interface
reference to product (-part), shape, location
NRF HDF mapping
reference to FEM / FE
HDF 5 programming library
AP203 STEP file
HDF5 is an efficient alternative for Part21 for
large amounts of similar data
AP209 STEP file (future)
HDF5 binary results file
COTS or PD Data Analysis / Visualisation
Application with HDF i/f (also via WWW)
26
Beta release SINDA-85 / ESATAN converter

• Developed at ESTEC in Python
• Use STS and ISS thermal interface model
  conversion
• Full Eng/SI unit conversion is implemented also
  for arrays
• Translates user logic (MORTRAN) as well as
  possible
• Will be made available free of charge on
  www.estec.esa.int/thermal
• Validated on NASA-JSC STS 390 Node model
• Open and closed cargo bay doors
• Follow up with bi-directional ESATAN/STEP-NRF
  converters

27
Acknowledgements

• STEP-TAS and STEP-NRF were developed under ESA
  contract in co-operation with CNES by
• Simulog (F, prime)
• Fokker Space (NL)
• Association GOSET (F)
• Epsilon Ingénierie (F)
• Alstom Power (UK)
• Special thanks to Georg Siebes (NASA-JPL) and
  Ruth Amundsen (NASA-LaRC) who are and have been
  the driving forces for the development and
  acceptance of STEP-TAS in the US

28
Backup Slides
29
STEP-TAS Conformance Classes
thermal-radiative model with basic geometry
kinematic model
constructive geometry
space mission aspects
CC-1
?
CC-2
?
?
CC-3
?
?
CC-4
?
?
?
CC-5
?
?
?
CC-6
?
?
?
?
30
STEP-TAS Converter Architecture
Native Tool Format
Thermal Analysis Tool (ESARAD, THERMICA, TRASYS,
TSS, RadCad, TMG, ATM, TAS, Patran)
STEP-TAS High Level Libraries C and Fortran
API (Simulog, France)
STEP-TAS EXPRESS data models
STEP-TAS physical file ISO 10303-21 or XML
SDAI C Library (ISO 10303-24) ST-Developer (STEP
Tools Inc., USA) or Open Source STEP/XML (ISO
10303-28)