Utility of Radio Transmission Probes for Identifying Non-stationary Thermal Errors of Spindle Units

Abstract Thermal errors caused by internal and external heat sources constitute a significant part of the geometric errors in machine tools (MTs). With machining accuracy and MT utilisation rates continuously rising, the thermal behaviour of MT structures research is crucial for advancing manufacturing efficiency. To mitigate costly structural redesigns, thermal errors can be reduced through two primary strategies: direct methods (real-time measurement of the tool-workpiece contact point) or indirect approaches (predictive models). These methods avoid the need for active thermal control mechanisms, which are often costly to implement and operate, especially when using climate chambers. As MT sensory equipment continues to improve, predictive models adaptable to areas of higher nonlinearity and inhomogeneity in thermo-mechanical systems are becoming more prevalent, leveraging real-time feedback from intermittent probing of manufactured parts. This study investigates the utility of radio transmission part probe (RMP) measurements for non-stationary thermal error identification on MTs. Experimental validation involves exposing the target MT to controlled conditions in a climate chamber, including different spindle speeds and ambient temperature settings.