Acoustic Feedback for Closed-Loop Force Control in Robotic Grinding

2026-02-24

AI Summary

This work addresses the limitations of conventional robotic polishing, which relies on expensive and poorly adaptable force sensors while overlooking the potential of low-cost acoustic signals. The study proposes a novel approach that uses low-frequency audio captured by contact microphones as the sole perceptual modality for closed-loop force control during polishing. By integrating real-time acoustic feature extraction with a force estimation model, the method achieves precise force regulation without requiring dedicated force sensors. Evaluated across varying abrasive wheel conditions, the system demonstrates high control consistency, reduces hardware costs by approximately 200-fold, and improves polishing uniformity by a factor of four. These results substantiate the innovation, efficiency, and practical viability of acoustic feedback in robotic polishing tasks.

Technology Category

• Intelligent Robots: Manipulation
• Natural Language Processing: Safety and Robustness
• Computer Vision: Low Level & Physics-based Vision

Application Category

• Responsible Web: Machine-in-the-loop, human agency and autonomy
• Web Mining and Content Analysis: Robustness and generalizability of Web mining methods
• Economics, Online Markets and Human Computation: LLM based quality controls for crowd work

Abstract

Acoustic feedback is a critical indicator for assessing the contact condition between the tool and the workpiece when humans perform grinding tasks with rotary tools. In contrast, robotic grinding systems typically rely on force sensing, with acoustic information largely ignored. This reliance on force sensors is costly and difficult to adapt to different grinding tools, whereas audio sensors (microphones) are low-cost and can be mounted on any medium that conducts grinding sound. This paper introduces a low-cost Acoustic Feedback Robotic Grinding System (AFRG) that captures audio signals with a contact microphone, estimates grinding force from the audio in real time, and enables closed-loop force control of the grinding process. Compared with conventional force-sensing approaches, AFRG achieves a 4-fold improvement in consistency across different grinding disc conditions. AFRG relies solely on a low-cost microphone, which is approximately 200-fold cheaper than conventional force sensors, as the sensing modality, providing an easily deployable, cost-effective robotic grinding solution.

Problem

• acoustic feedback
• robotic grinding
• force control
• cost-effective sensing
• closed-loop control

Innovation

• Acoustic feedback
• Robotic grinding
• Force estimation
• Closed-loop control
• Low-cost sensing