Accuracy reliability evaluation of trusted CNC machine tool based on belief reliability

At present, few studies in the existing literature analyze the evaluation methods for the accuracy reliability of trusted computer numerical control (CNC) machine tool. This study aims to create a systematic method to solve the problem of how to conduct a comprehensive and scientific evaluation of trusted CNC machine tool based on belief reliability theory. Firstly, a definition of accuracy reliability is presented and the factors that affect the accuracy reliability of trusted CNC machine tool are analyzed. Then, a full failure mode method is used to perform failure mode and effects analysis (FMEA) on “mechanical failures”. And a traditional failure chain method is used to perform the FMEA on the other failures, with a focus on “security protection failures”. Moreover, a method for determining the corresponding epistemic uncertainty factor based on the application effectiveness evaluation of security risk factor for trusted CNC machine tool accuracy reliability is presented. Similarly, a method for determining the corresponding epistemic uncertainty factor based on the application effectiveness evaluation of FMEA for trusted CNC machine tool accuracy reliability is presented. Finally, the accuracy of spindle and feeding shaft of trusted CNC machine tool is selected as the performance indicator to measure the overall accuracy of machine tool, and the trusted CNC machine tool accuracy reliability is evaluated based on the belief reliability theory. The results of case studies reveal that the existence of epistemic uncertainty can lower people’s expectations of product reliability. In addition, product reliability can be improved by continuously reducing epistemic uncertainty.