safe software system development framework for mini unmanned aerial systems a thesis submitted ...

156 Pages·2014·8.16 MB·English

SAFESOFTWARESYSTEMDEVELOPMENTFRAMEWORKFORMINI
UNMANNEDAERIALSYSTEMS
ATHESISSUBMITTEDTO
THEGRADUATESCHOOLOFNATURALANDAPPLIEDSCIENCES
OF
MIDDLEEASTTECHNICALUNIVERSITY
BY
ÖNDERALTAN
INPARTIALFULFILLMENTOFTHEREQUIREMENTS
FOR
THEDEGREEOFMASTEROFSCIENCE
IN
AEROSPACEENGINEERING
SEPTEMBER2014

Approvalofthethesis:
SAFESOFTWARESYSTEMDEVELOPMENTFRAMEWORKFORMINI
UNMANNEDAERIALSYSTEMS
submitted by ÖNDER ALTAN in partial fulfillment of the requirements for the de-
gree of Master of Science in Aerospace Engineering Department, Middle East
TechnicalUniversityby,
Prof. Dr. CananÖzgen
Dean,GraduateSchoolofNaturalandAppliedSciences
Prof. Dr. OzanTekinalp
HeadofDepartment,AerospaceEngineering
Prof. Dr. NafizAlemdarog˘lu
Supervisor,AerospaceEngineeringDepartment,METU
ExaminingCommitteeMembers:
Prof. Dr. NihanKesimÇiçekli
ComputerEngineeringDepartment,METU
Prof. Dr. NafizAlemdarog˘lu
AerospaceEngineeringDepartment,METU
Prof. Dr. OzanTekinalp
AerospaceEngineeringDepartment,METU
Assoc. Prof. Dr. ˙IlkayYavrucuk
AerospaceEngineeringDepartment,METU
Assist. Prof. Dr. AliTürkerKutay
AerospaceEngineeringDepartment,METU
Date:
I hereby declare that all information in this document has been obtained and
presented in accordance with academic rules and ethical conduct. I also declare
that,asrequiredbytheserulesandconduct,Ihavefullycitedandreferencedall
materialandresultsthatarenotoriginaltothiswork.
Name,LastName: ÖNDERALTAN
Signature :
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ABSTRACT
SAFESOFTWARESYSTEMDEVELOPMENTFRAMEWORKFORMINI
UNMANNEDAERIALSYSTEMS
Altan,Önder
M.S.,DepartmentofAerospaceEngineering
Supervisor : Prof. Dr. NafizAlemdarog˘lu
September2014,132pages
DuetotherapidgrowthoftheutilizationofMiniUnmannedAerialSystems(MUAS)
in populated areas, system safety concerns regarding these systems are becoming
more important more than ever. Reliability and robustness of the software systems
(SS), which are embedded within MUASs to handle their autonomy, should be as-
sured by applying safe development methodologies. This thesis introduces a unique
and comprehensive software framework for design, implementation and testing of
MUAS software systems, which ensures desired software system safety is achieved
with reasonable effort by prioritizing and applying software safety (software airwor-
thiness)concept.
The proposed software framework increases software reliability as it simplifies and
assures the implementation of fault detection, tolerance and recovery mechanisms,
and focuses on software system robustness by identifying failure conditions of the
software in MUASs. Besides, as the framework focuses on simple development ap-
proach, it tries to reduce efforts undertaken to perform safety analysis and reviews
in the development life cycle. In addition to design and implementation methodolo-
gies provided by the framework; mission based, full autonomous and simple testing
methodology(AssassinProcessMethod,APM)isintroducedintheframeworktoim-
proveentiresoftwaresystemsafety. Moreover,autonomousAPMhelpssmallMUAS
teamsduringdevelopmentphasebyprovidinghumanreadabletestverificationresults
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asatestassessmentreport.
Throughthisthesis,theframeworkaswellasthephilosophybehindwhysuchframe-
work is necessary, important and unique is explained in detail. Finally, all contri-
butions of the idea to safe software development for MUASs are presented through
a prototype in which the verification and tests of the intended software system have
beenperformed. Intheprototype,aMUAS’ssoftwaresystem,whichisdevelopedby
usingthesuggestedframeworkforacreatedcase,isembeddedintoahardwarearchi-
tecture, and using hardware-in-the-loop (HIL) simulation as a real-time integration
environment, system verification process is iterated for safe software system devel-
opmentstepsintroducedintheframework.
Keywords: Software Airworthiness, Software System Safety, Real Time Operating
Systems, Software Reliability, Hardware-in-the-loop Simulation, Safe Software Sys-
temDesign,SoftwareDevelopmentLife-Cycle,Mission-basedTesting,AssassinPro-
cessMethod-APM
vi
ÖZ
M˙IN˙I˙INSANSIZHAVAARAÇLARI˙IÇ˙INGÜVENL˙IYAZILIMGEL˙IS¸T˙IRME
˙ISKELET˙I
Altan,Önder
YüksekLisans,HavacılıkveUzayMühendislig˘iBölümü
TezYöneticisi :Prof.Dr.NafizAlemdarog˘lu
Eylül2014,132sayfa
Mini ˙Insansız Uçan Sistemler’in (M˙IUS), sayılarındaki ve insanlı bölgelerdeki ope-
rasyonelkullanımlarınınbelirginartıs¸ınabag˘lıolarak,busistemleringüvenlig˘ikonu-
sundaki çekinceler, hiç olmadıg˘ı kadar önemli bir tartıs¸ma konusu haline gelmis¸tir.
Buna bag˘lı olarak M˙IUS’lara entegre edilen ve onların otonom kontrol edilmesini
sag˘layan altsistemleri olan yazılımsistemleri de,genel sistem güvenlig˘ini düs¸ünüle-
rek ve teminat altınaalarak gelis¸tirilmelidir. Bu tez çalıs¸masında;hedeflenen yazılım
sistem güvenlig˘ine, makul bir çaba harcayarak eris¸ilmesini, yazılım sistem güvenlig˘i
konseptini öncelikli görüp, uygulayarak garantilemeyi amaçlayan; yazılım tasarım,
kodlamaveentegrasyonsüreçleriiçingelis¸tirilmis¸ benzersizvekapsamlıbirGüvenli
YazılımGelis¸tirme˙Iskeletitanıtılmaktadır.
Önerilen Yazılım ˙Iskeleti, yazılım güvenilirlig˘ini; yapısındaki hata tanıma, hata to-
leransı ve sistem geri kazanım mekanizmalarıyla arttırmakta, bunun yanında da ta-
nımlanmıs¸ hata durumları için M˙IUS yazılım sisteminin dayanıklılıg˘ını gelis¸tirmeye
odaklanmaktadır. Bu tezde, yazılım gelis¸tirme iskeletince sag˘lanan yazılım tasarım
ve kodlama metotlarına ek olarak; tüm M˙IUS sistem güvenlig˘ini arttıran görev bazlı,
tam otonom test yöntemi Suikast ˙Is¸lem Methodu (S˙IM) önerilmis¸tir. Otonom S˙IM,
ufak M˙IUS gelis¸tirme ekiplerine, sistem güvenlig˘i deg˘erlendirme as¸amalarında; ko-
lay okunup anlas¸ılabilir test dog˘rulama sonuçları ve deg˘erlendirme raporları almala-
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rınısag˘layarak,yardımcıolur.
Bu tezde, yazılım iskeletinin M˙IUS’lar için gereklilig˘inin tartıs¸ılmasının yanı sıra,
böyle bir yapının neden önemli ve benzersiz oldug˘u da detaylı bir s¸ekilde anlatılmıs¸-
tır.Sonolarak,tezdetanıtılankonseptin,M˙IUS’lariçinGüvenliYazılımGelis¸tirmeye
olan katkıları; donanım-döngüde simülasyon yöntemiyle kurulan entegrasyon ortamı
ve onun üzerinde gelis¸tirilen yazılım sisteminin olus¸turulup, dog˘rulama çalıs¸maları
ve testlerin gerçeklendig˘i bir örnek durum çalıs¸ması üzerinde uygulanarak gözlem-
lenmis¸,iskeletinfaydalarıveliteratüreolankatkılarıdetaylarıylasunulmus¸tur.
AnahtarKelimeler:YazılımUçus¸aelveris¸lilig˘i,YazılımSistemGüvenlig˘i,GerçekZa-
manlı˙Is¸letimSistemi,YazılımGüvenilirlig˘i,DonanımDöngüdeSimülasyon,Güven-
likDurumÇalıs¸ması,GüvenliYazılımSistemTasarımı,YazılımGelis¸tirmeDöngüsü,
GörevTabanlıTest,Suikastçi˙Is¸lemMetodu-S˙IM
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ToHappiness&Peace
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ACKNOWLEDGMENTS
I would like to express my sincere gratitude to my supervisor Prof. Nafiz Alem-
darog˘luforhisendlesssupportandencourage.
My special thanks to Burcu Yılmaz and Fulya Tuncer Cetin for their being not only
my colleagues but also perfect friends with undeniable trust. Their advices were the
mostpreciousgiftsIhadevertakenduringthethesisprocess.
Beingaluckyperson,IwouldliketoexpressmyspecialthankstoZeynepKireccias
she always encourages me to achieve better. Without her endless support, this thesis
wouldnotbecompleted.
I would like to thank Engin Çag˘lav for sharing his knowledge and experience with
me. Withouthim,thisthesiswouldbeincomplete.
Ireallywanttoexpressmygratitudetomycolleagues,SinanPakkanandKaanDog˘an
fortheirfriendlysupportandtechnicaladvicewhenIfeltmyselfveryhopeless.
I wish to state my thanks to my dear friend and colleague Hüseyin Kaval for answer-
ingmyquestionswithagreatpatience.
I also want to thank to my special friends Sule Akdogan and Serkan Naneci for their
encouragementsandpresenceeveninthejurytosupportme.
Lastbutnotleast,Iwouldliketoexpressmydeepestthankstomymom,whoalways
supports and encourages me, for her trust, understanding and patience. I am very
luckytohavesuchagreatmom.
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