Event driven intelligent PID controllers with applications to motion control

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Control of Drilling Vibrations: A Time-Delay System-Based Approach

International audienceThe main purpose of this study is the control of both axial and torsional vibrations occurring along a rotary oilwell drilling system. This work completes a previous author's paper [Boussaada I., Mounier H., Niculescu S-I., Cela A. 2012] which presents the description of the qualitative dynamical response of a rotary drilling system with a drag bit, using a model that takes into consideration the axial and the torsional vibration modes of the bit. The studied model, based on the interface bit-rock, contains a couple of wave equations with boundary conditions consisting of the angular speed and the axial speed at the top additionally to the angular and axial acceleration at the bit whose contain a realistic frictional torque. Our analysis is based on the center manifold theorem and normal forms theory whose allow us to simplify the model. By this way we design two control laws allowing to suppress the undesired vibrations guaranteeing a regular drilling process. The obtained results are numerically illustrated

Analysis and control of quadrotor via a Normal Form approach

International audienceThis paper focuses on the analysis and control of some mathematical models representing the dynamics of a quadrotor. By using a normal form approach, the highly coupled parts in the quadrotor system are eliminated, while all possible properties of the original system are not changed. The bifurcations of the system are then analyzed. A two dimensional system is deduced at the origin which can determine the stability and possible local bifurcations of the system. Based on the normal form and indirect method of Lyapunov, we propose a state feedback control method with computational simplicity as well as practical implementation facility. Comparing to a standard PID control, the proposed method has faster response time and less tracking errors especially with wind disturbance

Etude de synthèse / une articulation entre enseignement et projet

International audienceLe déroulement des études à l?ESIEE, école d?ingénieurs en 5 ans, est articulé selon une progression de projets et de stages devant permettre à l?élève d?acquérir des compétences techniques, humaines et de gestion de projet. Nous décrivons ici l?étude de synthèse de quatrième année, menée selon un schéma légèrement différent permettant aux élèves d?aborder globalement un système technique complexe. Il nous a paru important d'inclure cette étude de synthèse, permettant aux élèves de valider leurs acquis dans le cadre d'une démarche projet et d'en dégager la cohérence, en introduction de leurs stages professionnels en entreprise

Analysis of drilling vibrations: A time-delay system approach

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Trading Quantization Precision for Sampling Rates in Systems with Limited Communication in the Uplink Channel

There are many situations where distributed control applications have to exchange information through limited bandwidth communication channels. Examples may be found in areas ranging from the underwater robotics to the control of satellites clusters. Bandwidth limitations affect the behavior of these systems. For that reason, there is a strong need for developing methods that maximize the relevancy of the exchanged control information. In general, increasing control inputs update frequency improves the disturbance rejection abilities whereas increasing their quantization precision improves the steady state performance (set point tracking precision for example). However, when the bandwidth is limited, increasing the update frequency necessitates the reduction of the quantization precision and vice versa. Motivated by these observations, and focusing on the uplink bandwidth limitations, an approach for the dynamical on-line state-feedback assignment of control inputs quantization precision and update rate is proposed. This approach, which is based on the model predictive control (MPC) technique, enables to choose the update rate and the quantization levels of control signals from a predefined set, in order to optimize the control performance. A heuristic approach allowing an efficient choice of the elements of this set is proposed. Practical stability properties of the approach are then studied. Finally, the effectiveness of the proposed method is illustrated on a simulation example

Counting Characteristic Roots of Linear Delay-Differential Equations. Part I: Frequency-Sweeping Stability Tests and Applications

International audienceThis chapter addresses the stability analysis of linear dynamical systems represented by delay differential equations with a focus on the effects induced by the delay, seen as a parameter, on the dynamical behavior. More precisely, we propose a frequencysweeping framework for treating the problem, and the stability problem is reformulated in terms of properties of frequency-sweeping curves. The presentation is teaching-oriented and focuses more on discussing the main ideas of the method and their illustration through appropriate examples and less on explicit proofs of the results. Some applications from Life Sciences complete the presentation

Complete stability for neutral time-delay systems: A unified frequency-sweeping approach

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