Touching the Sound: Audible Features Enable Haptics for Robot Control

Haptic control interfaces can significantly improve the quality of teleoperation in robotic and mechatronic systems. However, the required force feedback introduces new challenges when highly constrained environments and systems hinder the use of conventional force sensors. In this article, we propose a haptic control method that provides feedback to the operator when force data can be extracted from a sound signal. Since sound can be acquired by a microphone deployed outside the workspace, this method enables remote feedback in any process that can be characterized through acoustic emissions (e.g. machining), without the need for sensors embedded in the system and deployed in the work environment. The performance of the method is verified by an example application with a teleoperated robot that executes a machining process (milling and grinding), whose sound is acquired with a microphone and processed to successfully estimate the machining force for haptic feedback.