Research

I work in the field of control theory and its applications. I mainly focus on the problems of dynamic output feedback stabilization, observability singularities in control systems, and observer design for nonlinear or infinite dimensional dynamical systems. I am currently working on the problem of control and observation of neural fields.

Keywords: Stabilization, Output feedback, Observability, Dissipative systems, Luenberger observers, Infinite-dimensional systems, Back and Forth Nudging, Crystallization processes, Neural fields

Research collaborators

• Vincent Andrieu

• Daniele Astolfi

• Jean Auriol

• Pauline Bernard

• Antoine Chaillet

• Jean-Paul Gauthier

• Swann Marx

• Andrii Mironchenko

• Lassi Paunonen

• Ludovic Sacchelli

• Ulysse Serres

• Cyprien Tamekue

• Nicolas Vanspranghe

• Fabian Wirth

Publications

Journal articles

• L. Brivadis, A. Chaillet, A. Mironchenko, F. Wirth. Forward completeness implies bounded reachable sets for time-delay systems on the state space of essentially bounded measurable functions, Submitted to L-CSS and CDC 2024 (Milan). [Hal]

• A. Chaillet, F. Wirth, A. Mironchenko, L. Brivadis, For time-invariant delay systems, global asymptotic stability does not imply uniform global attractivity, Submitted to L-CSS and CDC 2024 (Milan). [Article] [Hal] [Git]

• L. Sacchelli, L. Brivadis, U. Serres, I. Ben Yaacov, Output feedback stabilisation of bilinear systems via control templates, Submitted to L-CSS and CDC 2024 (Milan). [Hal]

• V. Andrieu, L. Brivadis, J.-P. Gauthier, L. Sacchelli, U. Serres, Exponential stabilizability and observability at the target imply semiglobal exponential stabilizability by templated output feedback, Submitted to Systems & Control Letters, 2024. [Hal]

• L. Brivadis, A. Chaillet, J. Auriol, Adaptive observer and control of spatiotemporal delayed neural fields, Systems & Control Letters, Vol. 186, 105777, April 2024. [Hal] [Article] [Git]

• N. Vanspranghe, L. Brivadis, Output regulation of infinite-dimensional nonlinear systems: a forwarding approach for contraction semigroups, SIAM Journal on Control and Optimization, Vol. 61, Pages 2571-2594, 2023. [Hal] [Article]

• L. Brivadis, C. Tamekue, A. Chaillet, J. Auriol, Existence of an equilibrium for neural fields under output proportional feedback,  Automatica (technical communique), Vol. 151, 110909, May 2023. [Hal] [Article]

• L. Brivadis, V. Andrieu, P. Bernard, U. Serres, Further remarks on KKL observers, Systems & Control Letters, Vol. 172, 105429, February 2023. [Hal] [Article]

• L. Brivadis, Jean-Paul Gauthier, Ludovic Sacchelli, Output feedback stabilization of non-uniformly observable systems, Proceedings of the Steklov Institute of Mathematics, Vol. 321, Pages 69–83, 2023. [Hal] [Article]

• L. Brivadis, L. Sacchelli, New inversion methods for the single/multi-shape CLD-to-PSD problem with spheroid particles, Journal of Process Control, Vol. 109, Pages 1-21, 2021. [Hal] [Article] [Git]

• L. Brivadis, J.-P. Gauthier, L. Sacchelli, U. Serres, New perspectives on output feedback stabilization at an unobservable target, ESAIM Control, Optimisation and Calculus of Variations, Vol. 27, 102, 2021. [Hal] [Article]

• S. Marx, L. Brivadis, D. Astolfi, Forwarding techniques for the global stabilization of dissipative infinite-dimensional systems coupled with an ODE, Mathematics of Control, Signals, and Systems, Vol. 33(4), Pages 755-774, 2021. [Hal] [Article]

• L. Brivadis, J.-P. Gauthier, L. Sacchelli, U. Serres, Avoiding observability singularities in output feedback bilinear systems, SIAM Journal on Control and Optimization, Vol. 59(3), Pages 1759–1780, 2021. [Hal] [Article]

• L. Brivadis, V. Andrieu, U. Serres, J.-P. Gauthier, Luenberger observers for infinite-dimensional systems, Back and Forth Nudging and application to a crystallization process, SIAM Journal on Control and Optimization, Vol. 59(2), Pages 857–886, 2021. [Hal] [Article]

• L. Brivadis, L. Sacchelli, V. Andrieu, J.-P. Gauthier, U. Serres, From local to global asymptotic stabilizability for weakly contractive control systems, Automatica (technical communique), Vol. 124, 109308, February 2021. [Hal] [Article]

• L. Brivadis, V. Andrieu, E. Chabanon, E. Gagnière, N. Lebaz, U. Serres, New dynamical observer for a batch crystallization process based on solute concentration, Journal of Process Control, Vol. 87, Pages 17-26, March 2020. [Hal] [Article]

Conference papers

• V. Pachy, V. Andrieu, P. Bernard, L. Brivadis, L. Praly, On the existence of KKL observers with nonlinear contracting dynamics, Submitted to MICNON 2024 (Lyon). [Hal]

• N. Vanspranghe, L. Brivadis, L. Paunonen, On forwarding techniques for stabilization and set-point output regulation of semilinear infinite-dimensional systems, To appear in IEEE CDC, 2023 (Singapore). [Hal]

• L. Brivadis, L. Sacchelli, Output feedback stabilization of non-uniformly observable systems by means of a switched Kalman-like observer, IFAC World Congress, Pages 9517-9522, Volume 56(2), 2023 (Yokohama). [Hal] [Git] [Article]

• L. Brivadis, A. Chaillet, J. Auriol, Online estimation of Hilbert-Schmidt operators and application to kernel reconstruction of neural fields, IEEE CDC, Pages 597-602, 2022 (Cancún). [Hal] [Git] [Article]

• L. Brivadis, L. Sacchelli, A switching technique for output feedback stabilization at an unobservable target, IEEE CDC, Pages 3942-3947, 2021 (Austin). [Hal] [Article]

• L. Brivadis, L. Sacchelli, Approximate observability and back and forth observer of a PDE model of crystallization process, IEEE CDC, Pages 4436-4441, 2021 (Austin). [Hal] [Article]

• S. Marx, L. Brivadis, D. Astolfi, Forwarding design for stabilization of a coupled transport equation/ODE with a cone-bounded input nonlinearity, IEEE CDC, Pages 640-645, 2020 (Jeju Island). [Hal] [Article]

• L. Sacchelli, L. Brivadis, V. Andrieu, U. Serres, J.-P. Gauthier, Dynamic output feedback stabilization of non-uniformly observable dissipative systems, IFAC World Congress, Vol. 53(2), Pages 4923-4928, 2020 (Berlin). [Hal] [Article]

• L. Brivadis, V. Andrieu, U. Serres, Luenberger observers for discrete-time nonlinear systems, IEEE CDC, Pages 3435-3440, 2019 (Nice). [Hal] [Article] [Slides]

Thesis

• L. Brivadis, Stabilization of non-uniformly observable control systems and infinite-dimensional observers, Ph.D. thesis, May 2021. [Hal] [Report of the PhD commitee and reviews of the reviewers Christophe Prieur and Fabian Wirth]

• L. Brivadis, Algorithme d’estimation pour une EDP hyperbolique décrivant un procédé de cristallisation, Master's thesis, October 2018. [Hal] [Manuscript]

Communications