Accuracy stability comprehensive evaluation of meta-action unit in CNC machine tools

To address the shortcomings in the evaluation of precision stability of CNC machine tools, this paper takes the element action unit as the object, analyzes four types of fluctuation mechanisms such as wear, establishes four precision fluctuation models, and proposes accuracy fluctuation rate, accuracy variation rate, accuracy variation coefficient, accuracy stability coefficient (ASC), and comprehensive index accuracy stability index (ASI). In the worm gear rotation unit test, when the torque is 1–24 N m, ASC decreases from 7.88 to 3.15, and ASI increases from 0.0357 to 0.181; When the ASI exceeds the threshold of 0.1, abnormal accuracy is determined. This system effectively quantifies accuracy fluctuations and identifies anomalies, providing reference for accuracy stability evaluation.