An Error-Based Safety Buffer for Safe Adaptive Control (Extended Version)

TL;DR

This paper introduces a novel adaptive control framework that integrates control barrier functions to ensure safety and stability in feedback linearizable systems with uncertainties, without requiring excitation conditions.

Contribution

It develops a real-time control architecture combining adaptation and barrier functions for safety-critical systems with parametric uncertainties, achieving near-zero conservatism.

Findings

Guarantees stability and safety despite uncertainties

Achieves control objectives with minimal conservatism

Demonstrates effectiveness through simulations

Abstract

We consider the problem of adaptive control of a class of feedback linearizable plants with matched parametric uncertainties whose states are accessible, subject to state constraints, which often arise due to safety considerations. In this paper, we combine adaptation and control barrier functions into a real-time control architecture that guarantees stability, ensures control performance, and remains safe even with the parametric uncertainties. Two problems are considered, differing in the nature of the parametric uncertainties. In both cases, the control barrier function is assumed to have an arbitrary relative degree. In addition to guaranteeing stability, it is proved that both the control objective and safety objective are met with near-zero conservatism. No excitation conditions are imposed on the command signal. Simulation results demonstrate the non-conservatism of all of the theoretical developments.