Reliability Assessment for CNC Equipment Based on Multi-Parameter Degradation Data

Abstract

The modern high-end CNC equipment with high reliability and long life expectancy makes traditional methods of equipment reliability assessment difficult due to the multiple performance parameters as well as less failures and degradation data. This paper proposes a performance reliability assessment based on multiple parameter degradation data, which deals with reliability evaluation with small numbers of samples. With the analysis of performance degradation processes and rules, the framework of the performance reliability assessment for multiple parameters is proposed. Using the degradation data of multiple performance parameters of CNC equipment, a covariance matrix is built to determine the correlation between the performance parameters. The degradation trajectories of the performance parameter(s) are curve fitted by Support vector machines (SVM). The reliability when the degradation curve reaches its specified threshold is calculated. According to both the reliabilities of non-relevant performance parameters and relevant performance parameters, the joint reliability of the system is calculated. Finally, using a specific type of CNC machine tool as an example, the performance reliability assessment method is verified.