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DISCO - 2015
Overall Objectives
New Results
Bilateral Contracts and Grants with Industry
Bibliography
Overall Objectives
New Results
Bilateral Contracts and Grants with Industry
Bibliography


Section: New Results

Continuous-discrete observers

Participants : Frederic Mazenc [Disco] , Emilia Fridman [Tel-Aviv University] , Michael Malisoff [LSU] , Vincent Andrieu [LAGEP] .

We solved several problems of observer design pertaining to the fundamental and difficult case where the measurements are available at discrete instants only.

1) We considered the problem of stabilizing a linear continuous-time system with discrete-time measurements and a sampled input with a pointwise constant delay [20] . In a first part, we designed a continuous-discrete observer which converges when the maximum time interval between two consecutive measurements is sufficiently small. In a second part, we constructed a dynamic output feedback by using a technique which is strongly reminiscent of the reduction model approach. It stabilizes the system when the maximal time between two consecutive sampling instants is sufficiently small. No limitation on the size of the delay is imposed and an ISS property with respect to additive disturbances is established.

2) The problem of designing continuous-discrete observers for a large class of continuous time nonlinear time-varying systems with discrete time measurements has been addressed in several contributions: [12] , [17] and [53] . Some technical obstacle encountered in [12] were overcome in [17] by using the notion of cooperative systems, which led to results consisting in explicit expressions of the largest sampling interval under which the observers converge to the solutions of the original system