Design of a low-cost system for the high-frequency measurement of the radial displacements of a cylindrical metal target

This study introduces a cost-effective system designed to measure the high-frequency radial displacements of cylindrical metal targets. Traditional methods often use capacitance or inductive sensors; however, this research presents a novel application of inductive sensors exploiting flexible planar coils placed on curved surfaces and combined with low-cost inductance-to-digital converters (LDCs). This solution allows for high sampling rates and submicrometric resolution, making it suitable for applications requiring accurate radial displacement vibration monitoring (e.g., milling operations). The experimental setup, including custom planar coils and a dedicated test bench, was implemented to measure radial displacement in the plane perpendicular to the cylinder's axis and validated the system's accuracy and effectiveness. Future works will optimize the calibration process and explore dual-parameter measurement to enhance accuracy.