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Articolo in rivista, 2023, ENG, 10.1016/j.ifacol.2023.10.635

Digital Event-Based Stabilization of Nonlinear Time-Delay Systems

M. Di Ferdinando and S. Di Gennaro and A. Borri and P. Pepe

Department of Information Engineering, Computer Science, and Mathematics, Center of Excellence DEWS, University of L'Aquila, Italy; Institute of Systems Analysis and Computer Science, National Research Council, Rome, Italy

In this paper, the stabilization problem of nonlinear time-delay systems via quantized sampled-data event-based controllers is investigated. Fully nonlinear (i.e., possibly non-affine in the control) systems affected by state delays are studied. Sufficient conditions are provided for the existence of a suitably fast sampling and of an accurate quantization of the input/output channels such that the digital implementation of the continuous-time controller at hand, updated through a proposed event-triggered mechanism, ensures the semi-global practical stability property, with arbitrarily small final target ball of the origin, of the related closed-loop system. A spline approximation methodology is used in order to cope with the problem of the possible non-availability in the buffer of suitable past values of the system variables needed for the digital implementation of the controller. The stabilization in the sample-and-hold sense theory is used as a tool to prove the results. In the theory here developed, the case of non-uniform quantization of the input/output channels and the case of aperiodic sampling are both included. The proposed theoretical results are validated through an application concerning the plasma glucose regulation problem in type-2 diabetic patients.

IFAC-PapersOnLine 56 (2), pp. 5969–5974