Acoustic Feedback for Closed-Loop Force Control in Robotic Grinding
This provides a cost-effective and easily deployable solution for robotic grinding tasks, addressing a domain-specific bottleneck in industrial automation.
The paper tackles the problem of robotic grinding systems relying on expensive force sensors by introducing a low-cost acoustic feedback system that estimates grinding force from audio signals, achieving a 4-fold improvement in consistency and reducing cost by approximately 200-fold compared to conventional methods.
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.