Reproduction de : Mémoire d'ingénieur : informatique : Grenoble, CNAM : 1986. / Titre provenant de l'écran-titre. Bibliogr. p. 86.

Reproduction de : Thèse de docteur-ingénieur : automatique : Grenoble, INPG : 1981. / Titre provenant de l'écran-titre. Bibliogr.

Cette thèse part du concept hégélien de négativité et construit, à partir de l’œuvre de Freud, un concept de négativité psychique. Nous nous intéressons à la façon dont le travail du négatif – dialectique et psychique – a été reçu et critiqué. La reconstitution de cet horizon critique nous permet de dégager que les pensées hégélienne et freudienne sont contestées car ce sont des pensées du sens plein. La charge et la cible critiques peuvent se résumer par un mot, celui de sens. On leur reproche alors d’être incapable de concevoir le non-sens ou les intermittences du sens. Celles-ci resteraient impensées et seraient même impensables dans le cadre de ces deux théories. Nous distinguons trois figures du non-sens que nous nommons : dysfonction, dis-fonction ou différence et automatisme. Le travail du négatif constituerait alors un déni de ce qui ne fonctionne pas, de ce qui dis-fonctionne et de ce qui fonctionne tout seul. Nous nous proposons de relire le concept de négativité de façon à le ressaisir au contraire comme une pensée des intermittences du sens. Le travail du négatif serait ainsi ouvert sur la dysfonction, la différence et l’automatisme. / This PhD thesis starts with the Hegelian concept of negativity and it constructs a concept of psychic negativity based on the work of Freud. We put the focus on how the Work of the Negative – dialectic or psychic work – has been interpreted and criticized. The reconstitution of this critical horizon leads to the identification that Hegelian and Freudian thoughts are challenged, because they are thoughts of sense understood as a total sense. Then, they are accused of being unable to conceive the nonsense or the intermissions of sense. We can distinguish three forms of these intermissions that we call dysfunction, difference (dis-function) and automatism. The work of negative wouldn’t understand what does not work, what works different ways and what works alone. We intend to reread the concept of negativity in order to define it on the contrary as a way of thinking the intermittent sense. The work of the negative is open to the dysfunction, the difference and the automatism.

No description available.

This dissertation introduces the Explicit Reference Governor: a simple and systematic add-on control unit that provides constraint handling capabilities to any pre-stabilized nonlinear system by suitably manipulating its applied reference. The main innovation of the proposed framework is that constraint satisfaction is ensured without having to solve implicit equations. As a result, the Explicit Reference Governor is particularly well suited for applications with limited computational capabilities. The basic idea behind the scheme consists in manipulating the derivative of the applied reference so that, at any given time instant, the currently applied reference will not cause a violation of constraints anytime in the future. The theory behind the proposed framework is presented in general terms and is then detailed to provide specific design strategies. Possible extensions to ensure robustness are also proposed. In addition to introducing the general theory of the Explicit Reference Governor, the dissertation illustrates its step-by-step implementation on Unmanned Aerial Vehicles. / Doctorat en Sciences de l'ingénieur et technologie / info:eu-repo/semantics/nonPublished

Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.

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In this work, we investigate the active vibration isolation and damping of sensitive equipment. Several single-axis isolation techniques are analyzed and tested. A comparison between the sky-hook damper, integral force feedback, inertial velocity feedback and LagLead control techniques is conducted using several practical examples. The study of single-axis systems has been developed and used to build a six-axis isolator. A six degrees of freedom active isolator based on Stewart platform has been designed manufactured and tested for the purpose of active vibration isolation of sensitive payloads in space applications. This six-axis hexapod is designed according to the cubic configuration; it consists of two triangular parallel plates connected to each other by six active legs orthogonal to each other; each leg consists of a voice coil actuator, a force sensor and two flexible joints. Two different control techniques have been tested to control this isolator : integral force feedback and Lag-Lead compensator, the two techniques are based on force feedback and are applied in a decentralized manner. A micro-gravity parabolic flight test has been clone to test the isolator in micro-gravity environment. ln the context of this research, another hexapod has been produced ; a generic active damping and precision painting interface based on Stewart platform. This hexapod consists of two parallel plates connected to each other by six active legs configured according to the cubic architecture. Each leg consists of an amplified piezoelectric actuator, a force sensor and two flexible joints. This Stewart platform is addressed to space applications where it aims at controlling the vibrations of space structures while connecting them rigidly. The control technique used here is the decentralized integral force feedback.

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