Frederic dot Jouffroy at astrium dot eads dot net
James dot Etchells at esa dot int
The correlation of Thermal Mathematical Models (TMMs) with test data is a particularly challenging activity because it happens just before the final flight predictions when the project is on the critical path. Current methods for correlation of TMMs typically rely on a heuristic approach which requires a great deal of manual work. This often yields results which are barely satisfactory, in terms of accuracy, but extremely costly, in terms of engineering time.
Although current methods for TMM correlation are predominantly manual, there are, in principle, a variety of different optimisation algorithms that could be used to automate or semi-automate the process. Among these stochastic techniques, Genetic Algorithms (GA) seem well suited to the problem in question and, furthermore, they have already been used by Astrium (and others) for post-test mechanical model correlation.
In 2005-2006 a joint CNES-Astrium R&D activity was initiated with the objective of verifying the feasibility of correlating thermal models to test results using GA. The conclusions of this study were that, although promising results were obtained, more work was required to obtain a well established and generic methodology suitable for use on space projects.
Using the 2005-2006 CNES activity as a starting point, two further activities were intiated in 2006-2007, the current activity (ESA/ESTEC contract No. 19840/06/NL/PA) sought to:
Additionally, a second CNES-Astrium R&D activity was started to invesigate further the localisation of errors in TMMs
In order to draw on more experience in the field of optimisation, a cooperation was established between Astrium and the Laboratoire d'Optimisation Globale (DSNA/SDER/LOG), located at the École Nationale de l'Aviation Civile (ENAC) in Toulouse.
The following material is available for download on this website:
|File Name||Document Title|
|thcor-asf-005-rpt.pdf||Bibliography study of optimisation methods with focus on genetic algorithm techniques w.r.t. post-test thermal model correlation problem|
|thcor-asf-006-tn.pdf||Test plan & test models for verification of post-test thermal model correlation by using a stochastic global optimisation method|
|thcor-asf-013-tn-1.pdf||Verification of feasibility of post-test thermal model correlation by using genetic algorithms: analysis of test plan results|
|GeneticAlgorithms.pdf||Presentation given at the 2007 European Workshop on Thermal and ECLS Software|
Material produced from the CNES R&D studies, mentioned above, may also become available on this web-page in the future.
The downloads below require a valid username and password. To obtain a username and password, please send an e-mail to email@example.com stating your name, occupation and organisation. You will receive your username and password within 1 to 7 days usually.
Any feedback, comments or suggestions for future work relating to this study are much appreciated. Correspondence can be sent to the contact addresses at the top of this page and we will try to reply to you swiftly.
The subject material was produced under contract from the European Space Agency. Therefore it is freely available to organisations and individuals located in one of the Agency's member or cooperating states according to the criteria set out in Article II (3) of Annex V of the European Space Agency Convention (see http://www.esa.int -> "About ESA ..."). The subject material shall not be redistributed or published in any form outside the recipient's organisation. By downloading the material from this website you consent to these Terms and Conditions.
A. No warranty: The subject material is provided without any warranty of any kind, either expressed, implied, or statutory, including, but not limited to, any, warranty that the subject material will conform to specifications, any implied warranties of merchantability, fitness for a particular purpose, or freedom from infringement, any warranty that the subject material will be error free. This agreement does not, in any manner, constitute an endorsement by the European Space Agency of any results, resulting designs, hardware, software products or any other applications resulting from use of the subject material.
B. Waiver and Indemnity: Recipient agrees to waive any and all claims against the European Space Agency, its contractors and subcontractors. If recipient's use of the subject material results in any liabilities, demands, damages, expenses or losses arising from such use, including any damages from products based on, or resulting from, recipient's use of the subject material, recipient shall indemnify and hold harmless the European Space Agency, its contractors and subcontractors, to the extent permitted by law. Recipient's sole remedy for any such matter shall be the immediate, unilateral termination of use of subject material.