Deciphering Micro-Scale, Sub-Hertz Mechanical Vibrations in Industry 4.0: A Battery-Free Sensing Approach

In industrial systems, monitoring micro-scale vibrations is crucial for assessing the operational health of equipment. Existing solutions typically rely on battery-powered sensors or are constrained by LoS requirements. To address these limitations, we propose Vibro-Stethos, a micro-scale,sub-herz vibration sensing system based on battery-free tags. It innovatively utilizes the resistance characteristic of JFET in the ohmic region to convert the voltage generated by PZT vibrations into antenna’s impedance, enabling the modulation of vibration information into the backscatter signal. An integrated RFID chip enhances identifiability and controllability. Additionally, a GCN-based vibration fault recognition model ensures accurate identification of vibration states regardless of tag placement. Experimental results demonstrate that Vibro-Stethos achieves an amplitude error of 2μm and a frequency error of 0.1Hz, with a sensing range of up to 5 meters. It can also recognize seven types of vibration states with 89.3% accuracy and has proven robust and effective in real plant deployments.