Disturbance Observers for Robust Safety-critical Control with Control Barrier Functions

TL;DR

This paper introduces a disturbance observer-based control method that ensures safety in systems with disturbances by estimating disturbance effects and integrating this into control barrier functions, validated through simulations.

Contribution

It proposes a novel disturbance observer-based safety controller that provides formal safety guarantees and robustness against disturbance estimation errors.

Findings

The controller achieves provably safe behavior under disturbances.

The disturbance observer accurately estimates disturbance effects.

Simulations demonstrate effectiveness with real disturbance data.

Abstract

This work provides formal safety guarantees for control systems with disturbance. A disturbance observer-based robust safety-critical controller is proposed, that estimates the effect of the disturbance on safety and utilizes this estimate with control barrier functions to attain provably safe dynamic behavior. The observer error bound - which consists of transient and steady-state parts - is quantified, and the system is endowed with robustness against this error via the proposed controller. An adaptive cruise control problem is used as illustrative example through simulations including real disturbance data.