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Research interests :

Time delay systems :

StabexpEn

My research meanly focusses on the elaboration of stability criteria of time delay systems.
My research concerns the following topics:

Asymptotic, exponential and absolute stability of systems subject to time-varying delay(s);
Reduction of the conservatism;

Constant, time varying, bounded or non small delays;

Linear, non linear systems with parameter uncertainties

Lyapunov Theory;

Lyapunov-Krasovskii Fonctionals;

Linear Matrix Inequality (LMI)

Integral inequalities.

Control :

ContEn

Design of control laws:

Static state or output feedback;

Sliding mode;

Output feedback using artificial delay;

Adaptative control.

For those controllers, the aim is to guarantee:

Convergence and perfomances of the solutions by introducing exponential bounds;
Robustness with respect to delays, parameters uncertainties, saturations,...

Observation :

ObsEn

In the case of unknow delays:

Observers for unknown inputs;

Sliding mode obervers.

In the case of know delays:

Observers-predicter.

Sampled data systems :

echant

An input delay approach to develop:

Stability criteria for systems sublect to aperiodic samplings
Robust controllers with respects to the samplings or to parameters uncertainties
Continuous observation based on sampled outputs.

Networked controlled systems :

TeleopEn

Remote control is a good way to perform tasks in dangerous or hard-to-reach areas, or to broaden the number of users on a localized testbed. The web technology on the internet appears as a natural, cheap way to ensure the communication link in such remote controlled systems. However the Quality of Service provided by the internet is often good enough for that kind of applications.
However, a communication link unavoidably introduces time delays that have to be taken into account in the control/observation loop.

The stakes are:

to guarantee the convergence and the performance of such a system;

to take into account the variation of the communication delays (by a robust approach or by a delay identification);
to include the problem of lost packets which are considered as a lengthening of the sampling interval;

to develop an real application which is coherent with the control design (particularly concerning the temporality of each sub-program.)