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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

Introduction of artificial delays for control and observation

Participants : Frederic Mazenc [Disco] , Silviu Niculescu [Disco] , Michael Malisoff [LSU] , Nikolaos Bekiaris-Liberis [Tech. Univ. of Crete] .

It is well-known that, in some cases, control or observation problems for systems with or without inherent delay can be solved by artificially introducing delays. We obtained in this field of reseach two distinct new results.

1) In [56] and [54] , we have considered a family of linear time-varying systems with an input, an output and delays in the input. We have shown that, under classical stabilizability and detectability assumptions, all the systems of this family can be exponentially stabilized through a time-varying feedback depending on past values of the output and the input and this without the use of observers or dynamic extensions. Hence, the simplicity of the design and the determination of the value of the solutions in finite time are the main features of the new approach.

2) In [54] , we provided a new backstepping result for time-varying systems with input delays. The novelty of the contribution is in the bounds on the controls, and the facts that (i) one does not need to compute any Lie derivatives to apply our controls, (ii) the controls have no distributed terms, and (iii) no differentiability conditions on the available controls for the subsystems are needed. The result is obtained by the introduction of constant pointwise delay in the input. Thus this result is significantly different for backstepping results for systems with delay in the input as presented for instance in [70] .