Cette thèse CIFRE est réalisée dans le cadre d’un partenariat entre le laboratoire IMS de l’Université Bordeaux I et Airbus Operations S.A.S à Toulouse. Le thème abordé concerne la détection robuste et précoce de deux types particuliers de pannes dans le système de commandes de vol, à savoir l’embarquement et le grippage des gouvernes de profondeur. Afin de contribuer à l’optimisation du design structural des futurs avions, l’objectif est de proposer des méthodes capables d’améliorer les performances en détection des techniques actuellement en place, tout en garantissant un haut niveau de robustesse. Trois stratégies de surveillance à base de modèle sont présentées. La première solution est basée sur un filtre de Kalman dédié, associé à une procédure d’optimisation de ses paramètres. La seconde technique est basée sur un test de décision appliqué dans l’espace paramétrique, à une direction sensible identifiée. Finalement, une troisième approche consiste à utiliser un différentiateur à modes glissants pour estimer les dérivées du signal d’entrée et de sortie de la boucle d’asservissement. Les méthodes développées ont été implémentées dans le calculateur de commandes de vol et validées sur les bancs de tests Airbus et même en vol. Les résultats expérimentaux ont clairement mis en évidence l’apport des techniques présentées dans cette thèse par rapport à l’état de l’art industriel. / The research work done in this PhD has been carried out under an industrial convention (CIFRE) between the IMS laboratory (Bordeaux University, France) and Airbus Operations S.A.S. (Toulouse, France). The thesis deals with two important Electrical Flight Control System failure cases: runaway (a.k.a. hard over) and jamming (or lock-in-place failure) of aircraft control surfaces. Early and robust detection of such failures is an important issue for achieving sustainability goals and for early system reconfiguration. The thesis focuses on the elevator runaway and jamming. Three model-based monitoring strategies are presented. The first approach is based on a dedicated Kalman filtering with optimised tuning parameters. The second method is based on a decision test applied to an identified sensitive direction in the parametric space. Finally, the third solution is based on a sliding mode differentiator. The techniques have been implemented in the flight control computer and validated on Airbus test facilities and during real flight tests. The experimental results confirmed that good level of performance and robustness can be obtained.

The first aim of this diploma thesis is to clarify problems with circuit elements described by the fractional-order dynamics, show their basic properties and possible applications in circuits with lumped parameters. The second topic is covering the synthesis of two-terminal devices which have different fractional-orders for requested phase shifts. For this kind of devices, the thesis also describes their optimization and approximation in the frequency domain and subsequent implementation in the form of passive ladder structures. The final part of diploma work will be focused on practical realization of universal fractional PID controller and the verification of proper function of this multi-port in various configurations to prove its correct function via real measurement of frequency and time responses.

SMEs have been developing rapidly in Sweden since the last decade; many of them have developed a strong brand and went global. Brands can be utilized as a tool for people involved in the ecosystem to consistently communicate with the stakeholders. On the customers’ side, decisions on purchasing certain products are often made by symbolic attributes. According to studies, brand management can benefit an organization’s performance. Brand management is critical for the substantiality of SMEs. Many studies have been done on brand management in larger organizations. Only some research has been done on SMEs brand management, from which it was concluded that SMEs placed very little or no priority on brand management. In this thesis, the author studies brand management in SMEs in Sweden, by using Wong and Merrilees’s model (2005) on three archetypes of brand orientation. The aim of this study is to get insights on what brand-related activities can help with the goal of heightening brand awareness for customers. This research is done by a qualitative study based on three in-depth interviews undertaken with small-sized organizations and a supplementary desktop research with data from authority.