5 papers
Conformal Dimension of Measures and Quasisymmetric Dimension Reduction
Hua Qiu, Qi Wang
We prove that the conformal dimension of every locally finite Borel measure is either zero or infinite. The main ingredient is a quasisymmetric dimension-reduction theorem: every f…
Data-Based Analysis of Relative Degree and Zero Dynamics in Linear Systems
Janina Schaa, Thomas Berger
Data-driven control offers a powerful alternative to traditional model-based methods, particularly when accurate system models are unavailable or prohibitively complex. While exist…
An improved input-constrained funnel controller for nonlinear systems
Thomas Berger
We present an improvement of a recent funnel controller design for uncertain nonlinear multi-input, multi-output systems modeled by higher order functional differential equations i…
Some Remarks on Positive/Negative Feedback
Thomas Berger, Achim Ilchmann, Eugene P. Ryan
In the context of linear control systems, a commonly-held intuition is that negative and positive feedback cannot both be stability enhancing. The canonical linear prototype is the…
Funnel control -- a survey
Thomas Berger, Achim Ilchmann, Eugene P. Ryan
The methodology of funnel control was introduced in the early 2000s, and it has developed since then in many respects achieving a level of mathematical maturity balanced by practic…