Speaker Dr. Daniele Astolfi
CNRS, France
Date｜Time Feb 20 (Friday), 2026｜17:00
Zoom https://snu-ac-kr.zoom.us/my/jingyu.lee
Abstract
Integral action is the standard tool in control theory to achieve robust output regulation and rejection of constant disturbances. While the theory is well-established for linear infinite-dimensional systems, the presence of actuator saturation introduces significant nonlinearities that can compromise stability, leading to phenomena such as integrator windup. This seminar provides a comprehensive overview of integral control for abstract systems governed by Partial Differential Equations (PDEs). We start by reviewing classical results on integral action, followed by a discussion on the stabilization challenges imposed by saturated inputs. The core of the presentation focuses on novel results concerning the stabilization of such cascades when the open-loop operator is conservative (e.g., skew-adjoint) and does not generate an exponentially stable semigroup. This scenario is particularly critical as it lacks natural damping to counteract the saturation effects. We present new necessary conditions for global exponential stability and sufficient conditions for the asymptotic stability of the closed-loop system, extending the applicability of integral control to a wider class of energy-preserving physical systems. The saturated control of gantry crane will be shown as illustrative example.
Biography
Daniele Astolfi received the B.S. and M.S. degrees in automation engineering from the University of Bologna, Italy, in 2009 and 2012, respectively. He obtained a joint Ph.D. degree in Control Theory from the University of Bologna, Italy, and from Mines ParisTech, France, in 2016. He received the HDR (Habilitation à Diriger des Recherches), in 2023, from the University of Lyon 1. Since 2018, he is a CNRS Researcher at LAGEPP, Lyon, France. He is a Senior Member of the IEEE. His research interests include observer design, feedback stabilization and output regulation for nonlinear systems, multi-agent systems and hybrid systems. He serves as Associate Editor of the IFAC journal Automatica and European Journal of Control. He was a recipient of the 2016 Best Italian Ph.D. Thesis Award in Automatica given by SIDRA.
