Sujets de travaux de fin d études (liste provisoire)

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1 Sujets de travaux de fin d études (liste provisoire) Accélération dans les automates temporisés Les automates temporisés constituent un formalisme simple et expressif permettant de modéliser des systèmes informatiques qui combinent des mécanismes discrets et continus. Ces structures prennent la forme d automates finis étendus par un certain nombre d horloges, représentées par des variables réelles dont la valeur évolue continûment avec le temps. Il est possible de vérifier un grand nombre de propriétés de systèmes modélisés par des automates temporisés en analysant les propriétés d accessibilité de ceuxci. L approche classique pour effectuer cette analyse consiste à explorer l espace des configurations accessibles d un automate temporisé en décomposant cet espace en régions qui peuvent être considérées individuellement. Récemment, des procédés d accélération ont été développés afin d améliorer les performances et les résultats de cette technique d exploration, en exploitant des opérateurs capables de synthétiser rapidement de grands ensembles de configurations accessibles. L objectif du travail consiste à implémenter ces procédés au sein d un outil de vérification, et d en comparer expérimentalement les performances avec celles d outils existants. Contact : B. Boigelot. 1

2 Développement d un outil de validation de conjectures basé sur les automates De nombreuses connexions ont été établies entre des théories arithmétiques comme l arithmétique de Presburger, l arithmétique additive des entiers et des réels ou encore la théorie monadique du second ordre, et les automates finis. Ces connexions ont permis d obtenir des procédures de décision efficaces et élégantes pour de telles théories : une formule peut être décidée en construisant explicitement un automate correspondant, et en déterminant ensuite si le langage accepté par cet automate est vide ou non. L objectif de ce travail consiste à suivre cette approche afin de développer un outil permettant à des mathématiciens de valider ou d infirmer automatiquement des conjectures. La première étape consistera à définir un langage d expression de ces conjectures qui est adapté aux besoins des chercheurs et se prête à une traduction automatique vers des automates. La seconde étape visera à développer un outil capable d effectuer efficacement cette traduction. Contact : B. Boigelot. 2

3 Simulation physique d actuateurs robotiques complexes Ce travail s inscrit dans le cadre du de veloppement d une plate-forme de robot humanoı de compatible avec les exigences du concours RoboCup. L objectif du travail consiste a concevoir un outil base sur un moteur de simulation physique, capable de simuler dynamiquement le comportement d un robot construit par assemblage d un ensemble de servomoteurs nume riques, et permettant d analyser les interactions d un tel robot avec son environnement. Remarque : D autres sujets de travaux de fin d e tudes sont envisageables dans le cadre de RoboCup, en fonction des pre fe rences des e tudiants. Contact : B. Boigelot. 3

4 Robotique et agriculture Plusieurs sujets de travaux de fin d études ouverts aux ingénieurs électroniciens et informaticiens, ainsi qu aux étudiants de master en sciences informatique, sont proposés par la Faculté Agro-Bio Tech de Gembloux. Les informations détaillées peuvent être consultées sur la page la-liste-de-propositions-de-tfe-du-departement-biose/?encadrant=moorthy Contacts : Sruthi Moorthy (Gembloux / Montefiore). Benoît Mercatoris, Gembloux Agro-Bio Tech. 4

5 Mesure en traitement en temps réel des paramètres de vol d une grenade Implantée à Herstal (Liège), FN Herstal, numéro un mondial dans son secteur d activités, possède une longue expérience en développement, fabrication et commercialisation de gammes complètes d armes et d accessoires destinés à la défense et aux forces de l ordre. FN Herstal fait partie du Groupe Herstal, actif également dans les domaines de la chasse, du tir et de l Outdoor sous le nom de Browning. En pleine croissance, elle occupe aujourd hui quelque personnes. Dans le cadre de nos études amont, nous souhaitons mesurer les paramètres de vol d une grenade 40 mm. Un premier prototype de la plateforme de mesure a été réalisé l année dernière dans le cadre d un TFE. Celui-ci permet de mesurer les accélérations subie par le projectile au moment du tir et pendant le vol. Nous souhaitons poursuivre ces études cette année en rapprochant l analyse et la collecte des données. Dans ce but, nous proposons un sujet de TFE axé sur la mesure et le traitement en temps réel des données dans la plateforme électronique existante. Contact : M. Hugues Libotte, Hugues.Libotte@fnherstal.com 5

6 MASTER THESIS / INTERNSHIP ECLIPSE BASED SATELLITE ON BOARD CONTROL PROCEDURE DEVELOPMENT ENVIRONMENT Context The On Board Software (OBSW) is the software running on board the satellites, the probes or the launchers to manage, control and command, autonomously or in cooperation with the ground, the system and the various subsystems of the platform or of the payloads to ensure the mission. It is an embedded, real time, critical software that executes remotely and that has to cope with the constraints of the Space environment. It is most of the time written in C (or sometimes in Ada) and it is compiled and linked in a software image that is loaded in ROM in the On Board Computer (OBC) and that can hardly be modified afterwards. On Board Control Procedures (OBCPs) are then intended to introduce some flexibility. These are flight procedures written in a high level user language, typically a scripting language, and that can be uploaded, interpreted and executed on board, on demand, at any time, and that may interact, to some extent, with the rest of the on board data handling system. OBCPs provide a flexible way to operate the spacecraft, to extend the on board software functionality or to modify the behaviour of on board applications, even after launch. Depending on the intended usage the functionality that must be offered can drastically differ. It is possible to build an OBCP chain that provides access to all the on board functions or one may want to confine it to a closed and secured playground with no access to hazardous functions. On board control procedures may indeed serve different goals: A first goal can be to allow the on board execution of ground procedures. This can be for nominal operation or for fault recovery. This makes the whole system more autonomous, reduces the reaction time and facilitates the work of the operators. In this case, the on board procedure only requires access to the telemetry and to the telecommands, atop of a minimum set of control statements and logical operations. Another goal can be the ability to implement simple on board applications, either for test and integration purpose, for rapid prototyping or even for the actual management of payloads. This kind of on board procedure relies on an access to the underlying hardware, e.g. through a dedicated driver interface in addition to the TM/TC interface. Timing and performance issues are also important. SPACEBEL S.A. (Registered Office) Rue des Chasseurs Ardennais 6 Liège Science Park, B-4031 ANGLEUR Tel. : +32 (0) Tel. : +32 (0) RPM Liège VAT : BE info@spacebel.be sales@spacebel.com SPACEBEL N.V. Ildefons Vandammestraat 7 Hoeilaart Office Center, B-1560 HOEILAART Tel. : +32 (0) Tel. : +32 (0) RPR Brussel

7 PPS/pps/L-15- Page : 2 Finally, on board procedures can be defined to debug, modify or even correct the behaviour of the on board software. In this case, an on board procedure is an alternative to a real on board software patch. For such procedures, intrusive access to the rest of the on board software is required. The code that is uploaded on board must already be compiled on ground. Embarking a parser and a compiler on board is indeed a priori rejected since this would infringe technical and safety constraints of the on board software. The high level Language is first compiled and linked on ground to yield an intermediate code that can efficiently be uploaded and interpreted on board. The entire OBCP Chain therefore extends on ground and on board. The Ground Development Environment is used on ground to prepare the OBCP. It is ideally integrated with the Ground Software Development Environment on an appropriate workstation. It typically consists of an OBCP source code editor, an OBCP compiler and a ground-based OBCP execution and debugging environment (e.g. based on stubs/simulators or on the real flight software). It takes as input the OBCP written in the high level user language and produces the intermediate target byte code. The On Board Execution Environment executes on board the Spacecraft. It is a Virtual Machine that is integrated with the On Board Software that interprets the instructions of the target byte code and that interacts with the rest of the On Board Software while also providing some kind of isolation for fault containment. This virtual machine can for instance be a virtual stack machine or a virtual register machine or it could even be an emulation of an existing and simple processor. Spacebel has an OBCP solution. The Ground Development Environment is based on Lex and Bison compilation techniques. The On Board Execution Environment is based on a Virtual Stack Machine extended with specific instruction that access the underlying on board software services. This solution is being used to operate satellites. The feedback from the users is that while the On Board Execution Environment performs satisfactorily, the Ground Development Environment suffers from some limitations. Also, any modification to the OBCP Chain, e.g. to extend the operation set or support new data types, show rather painful

8 PPS/pps/L-15- Page : 3 Objective The main objective of the proposed subject is therefore to revisit the Ground Development Environment of the existing OBCP Solution while keeping the On Board Execution Environment essentially unchanged. The Ground Development Environment shall be redeveloped and it shall be integrated in the Eclipse Integrated Development Environment (IDE). To this end, it should rely as much as possible on the Eclipse Modelling Framework (EMF) and of the related technologies. In particular, it is expected that Xtext provides for part of the compilation chain and that the compilation chain connects to the Satellite Reference Data Base (SRDB) for mnemonic resolution. The possibility to generate OBCP or OBCP skeletons from UML models expressed in Papyrus should also be considered in option. The On Board Execution Environment and in particular the Virtual Machine shall be kept essentially unchanged or should only be submitted to minor modifications. This also means that the Target Language shall also remain essentially unchanged but for some possible extensions. In particular, easiest ways to extend the operation set, e.g. to access underlying OBSW services, shall be investigated. Based on existing mission and existing validation facility, a demonstrator will be deployed to exercise the new environment. The demonstrator is intended to exercise existing OBCP and on the whole to validate the above objectives.

9 PPS/pps/L-15- Page : 4 Scope The first task consists in redeveloping the compilation chain. As explained above, it is expected that Xtext provides for part of the solution. Xtext ( is a framework for the development of external textual Domain Specific Languages (DSLs) that integrates with technology from Eclipse Modeling such as EMF, GMF, M2T and parts of EMFT. The OBCP high level user language can be considered as such a DSL. It should ideally be preserved as much as possible. It shall first be define in the grammar language supported by Xtext. From the grammar definition, Xtext can then generates the parser, builds the Abstract Syntax Tree (AST) meta model (implemented in EMF) and yields a sophisticated Eclipse Text Editor. This is the automatic part of the process and the main benefit of Xtext. Xtext and EMF come up with a validation framework that shall be investigated to statically verifiy validity of the OBCP against the syntax, the references to the SRDB or arbitrary rules, while editing and before compiling. The back end that generates the target code from the AST however still needs to be developed. This is an major part of the work. As part of this back end, the connection to the Satellite Reference Data Base (SRDB) shall allow to replace textual reference to parameter and variable by their numerical identifier or memory location. A second task consists in investigating the ability to extend the operation set, by defining call backs that can be invoked by the on board interpreter. This potentially implies extensions of the on board interpreter.

10 PPS/pps/L-15- Page : 5 The Company Spacebel is a software engineering company that has grown in the space market to become a trusted developer of advanced IT solutions and a provider of related IT services. So far, Spacebel have contributed to the success of more than 30 Space missions aimed at better understanding the Earth and the Universe. The company serves space agencies, government departments, major aerospace companies, European institutions as well as the commercial market. Its skills range from the design, development, integration and validation of IT systems for the space industry over the mastering of geospatial information systems to the definition and analysis of earth observation microsatellites missions and systems. Spacebel deliver on board control and data handling software, simulation infrastructure and models, satellites and mission control centres as well as earth observation services provisioning infrastructures. It is active in several domains, mainly earth observation, space flight, and science, not to forget telecoms, navigation, exploration, launchers, balloons and space situational awareness. The company also offers earth observation services for forestry, water, industrial risks, atmosphere, mine exploitation and natural resources management. It contributes to help decision makers world-wide in protecting and improving people s life sphere. Banking on more than 25 years of success in the space market and on the experience gained through its participation to major space missions, Spacebel has developed the ability to take responsibility of complete Earth Observation solutions based upon micro-satellite platforms. Established in 1988 and since then an ever-growing company, Spacebel draws its actual success upon its core business in the space industry. Today, the company is well recognised as a partner of choice in space applications where software solutions have to be produced. The unique combination of advance technology knowledge, dynamism, expertise and innovation allow us to convert today s technical challenges into Spacebel customer s competitive advantages. Spacebel designs, develops and implements "tailor-made" software systems for the space industry, in particular. The company can take large responsibilities in the development of software systems, starting at initial specification phases and extending up to commissioning and final acceptance. Figures Spacebel was established in The company s shareholders equity currently amounts to 6 M, shared by Belgian, public and private, actors only. Its turnover is steadily increasing and was around 11 M in The company employs more than 80 collaborators, all of them being involved in space projects. Spacebel has offices in Belgium, in Liège in the Walloon region and in Hoeilaart in the Flemish region, nearby Brussels, as well as a subsidiary in Toulouse, France.

11 PPS/pps/L-15- Page : 6 Domains Following strategic decisions of diversification combined with the constant expansion of its activities, Spacebel is organised in several business units dedicated to specific application domains. On-Board software for the command and the control of the Platforms and the Payloads of the Spacecrafts as well as for Launchers. Ground infrastructure software for the mission and satellite control and planning as well as for the reception, processing and dissemination of the mission data and the integration of Earth Observation services, catalogues and products. Simulation and Modeling software such as Target Simulators, Software Verification Facilities and Training, Operations and Maintenance Simulators. Environmental resources management and security management solutions exploiting the space and remote sensing data and making use of geographical information systems. Earth observation small satellite mission and systems analysis and definition Quality Project management and quality requirements are the daily concern of everybody working in the company. Spacebel master the ECSS E, Q and M standards. The company is approved ISO 9001:2000 as well as Tick IT and has always qualified itself successfully during external quality audits. Location Internship (if internship is choosen) is to be carried out at Spacebel premises in Liege, Belgium. Liège ( and is a Frenchspeaking, university, lively city located along the river Meuse and close to the Ardennes, 25 km south of Maastricht in the Netherlands and 40 kilometers west of Aachen in Germany. Spacebel is settled within the Spatiopole, in the Liège Science Park, on the wooded heights of the Sart Tilman, near the university. Spacebel site in Liège welcomes twenty engineers in embedded software and geographic information system. Contact Person Paul PARISIS Business Unit Manager Flight Software Paul.Parisis@spacebel.be