The following paper is accepted and will be presented at CDC 2025 – 64th IEEE Conference on Decision and Control, December 10-12, 2025, Rio de Janeiro, Brazil:

D. Efimov, C. Combastel, A. Zolghadri.  Observer Design for Parameter-Varying Persidskii Systems Using Parameter-Independent Lyapunov Functions.

Abstract: This paper addresses the state observer design for parameter-varying Persidskii systems. These systems exhibit dynamics that depend both on time-varying parameters, as in the Linear Parameter Varying (LPV) framework, and sector nonlinearities of the state, as in classical Persidskii systems. A state observer design is proposed, and its stability is analyzed using parameter-independent Lyapunov functions. The conditions for tuning the observer gains are derived within the input-to-output stability framework. They are first expressed as parameterized matrix inequalities, and then further reduced to linear ones under additional mild assumptions. The effectiveness of the proposed design is shown through an academic example.