Research on reliability comprehensive evaluation method of five-axis CNC machine tools based on AHP and extension theory

摘要

Currently, some five-axis CNC machine tools have almost achieved the same advanced level of the western countries in terms of functionality and performance. However, the reliability of system is much lower than similar foreign products. The reliability has become one of bottlenecks to restrict the development of domestic CNC machine tools. At present, domestic reliability research of CNC machine tools developed rapidly, but the evaluation research is limited to a single indicator, lacking overall evaluation about it. To fully evaluate the reliability of five-axis CNC machine tools, the matter-element model of reliability evaluation is established with the application of matter-element in extension theory, and the reliability evaluation indices system is established comprehensively. The correlation functions are introduced to calculate the correlation degree, and the weights of each evaluation indices are determined by using AHP. The actual example and result on two types of domestic CNC machine tools show that the proposed method is effective, reasonable, and accurate in the process of reliability evaluation. The proposed methodology provides a detailed instruction for comprehensive reliability evaluation of CNC machine tools.