English

A Generalization of the Passivity Theorem and the Small Gain Theorem Based on $\rho $-Stability, with Application to a Parameter Adaptation Algorithm for Recursive Identification

Optimization and Control 2019-02-11 v1

Abstract

The usual passivity theorem considers a closed-loop, the direct chain of which consists of a strictly passive stable operator H1H_{1}, and the feedback chain of which consists of a passive operator H2H_{2}. Then the closed-loop is stable. Let ρ>1\rho >1. We show here that the closed-loop is still stable when the direct chain consists of a strictly ρ1\rho ^{-1}-passive % \rho ^{-1}-stable operator (a weaker condition than above) and the feedback chain consists of a ρ\rho -passive operator (a stronger condition than above). Variations on the theme of the small gain theorem (incremental or not) can be made similarly. This approach explains the results obtained in a paper on identification which was recently published.

Keywords

Cite

@article{arxiv.1902.03015,
  title  = {A Generalization of the Passivity Theorem and the Small Gain Theorem Based on $\rho $-Stability, with Application to a Parameter Adaptation Algorithm for Recursive Identification},
  author = {Henri Bourlès},
  journal= {arXiv preprint arXiv:1902.03015},
  year   = {2019}
}
R2 v1 2026-06-23T07:35:31.065Z