Control Barrier Functions with Audio Risk Awareness for Robot Safe Navigation on Construction Sites

TL;DR

This paper introduces a control barrier function safety filter that uses real-time audio cues, specifically jackhammer detection, to improve obstacle avoidance and safety in autonomous construction robots navigating dynamic, occluded environments.

Contribution

It presents a novel integration of audio-based risk assessment with control barrier functions for enhanced safety in robot navigation on construction sites.

Findings

The CBF safety filter prevents safety violations in simulation.

Elliptical CBF formulation reduces deadlock and improves target reaching.

Audio risk cues effectively modulate safety margins during navigation.

Abstract

Construction automation increasingly requires autonomous mobile robots, yet robust autonomy remains challenging on construction sites. These environments are dynamic and often visually occluded, which complicates perception and navigation. In this context, valuable information from audio sources remains underutilized in most autonomy stacks. This work presents a control barrier function (CBF)-based safety filter that provides safety guarantees for obstacle avoidance while adapting safety margins during navigation using an audio-derived risk cue. The proposed framework augments the CBF with a lightweight, real-time jackhammer detector based on signal envelope and periodicity. Its output serves as an exogenous risk that is directly enforced in the controller by modulating the barrier function. The approach is evaluated in simulation with two CBF formulations (circular and goal-aligned elliptical) with a unicycle robot navigating a cluttered construction environment. Results show that the CBF safety filter eliminates safety violations across all trials while reaching the target in 40.2% (circular) vs. 76.5% (elliptical), as the elliptical formulation better avoids deadlock. This integration of audio perception into a CBF-based controller demonstrates a pathway toward richer multimodal safety reasoning in autonomous robots for safety-critical and dynamic environments.