English

Converse Barrier Functions via Lyapunov Functions

Optimization and Control 2026-04-22 v2 Systems and Control Systems and Control

Abstract

We prove a robust converse barrier function theorem via the converse Lyapunov theory. While the use of a Lyapunov function as a barrier function is straightforward, the existence of a converse Lyapunov function as a barrier function for a given safety set is not. We establish this link by a robustness argument. We show that the closure of the forward reachable set of a robustly safe set must be robustly asymptotically stable under mild technical assumptions. As a result, all robustly safe dynamical systems must admit a robust barrier function in the form of a Lyapunov function for set stability. We present the results in both continuous-time and discrete-time settings and remark on connections with various barrier function conditions.

Keywords

Cite

@article{arxiv.2007.11086,
  title  = {Converse Barrier Functions via Lyapunov Functions},
  author = {Jun Liu},
  journal= {arXiv preprint arXiv:2007.11086},
  year   = {2026}
}

Comments

Preprint submitted for publication; v2 corrected the non-strict inequality in condition (3) of Definition 5 with a strict inequality (thanks to a comment by Stefan Ratschan)

R2 v1 2026-06-23T17:17:55.945Z