Birnbaum importance evaluation method for multistate CNC machine tools under uncertainty title

With the improvement of science and technology, the manufacturing technology of CNC machine tools has become one of the irreplaceable important technologies in the manufacturing field. However, the manufacturing process, in actual production, often makes the accuracy of the product unsatisfactory for a variety of reasons. The importance evaluation is an effective means to identify the weak link of reliability, and the analysis results can be used as the basis for design and maintenance. However, the existing methods of importance evaluation assume that the degradation process is accurate and known. Due to the uncertainty of the parameters of the degradation model caused by the lack of failure data and the unclear mechanism of the CNC machine tool in the manufacturing process, a Bimbaum importance evaluation method of the multi-state CNC machine tool under uncertainty is proposed. On the one hand, based on the Markov model, the reliability modeling of multi-state CNC machine tools is carried out. On the other hand, Dempster-Shafer evidence theory is used to quantify the uncertainty of model parameters. This method is applied to the reliability evaluation of the cutter feeding control system of CNC machine tools. And the result reflect the effect of uncertainty on importance evaluation and ranking.