基于模糊综合评判与FMEA的数控机床故障分析

Fault Analysis of CNC Machine Tool Based on Fuzzy Comprehensive Evaluation and FMEA Methods

针对数控机床加工质量、系统工作性能下降引起的机械类故障,提出了基于模糊综合评判与FMEA的数控机床故障分析方法。采用故障模式及影响分析法(FMEA)对数控机床的各类故障进行深入分析,并按照FMEA硬件法对故障进行分类,得到关键部件故障模式;采用专家调查表的方式确定了各个故障的严重度(S)、频度(O)、探测度(D);引入模糊综合评判理论对FMEA定性分析方法的风险顺序数进行等级隶属度划分,建立二级模糊评判模型,并对主轴系统和进给系统的机械类故障进行了定量分析。结果表明:反模糊化后的综合评价值为85.08,验证了模糊综合评判和FMEA对数控机床机械类故障综合分析的有效性。分析结果为数控机床测试点的选择提供了完备有效的保障。

Aimed at the mechanical fault of CNC machine tool leading to the decline in the quality of machining and the degrada- tion of system performance, the fault analysis method of CNC machine tool based on fuzzy comprehensive evaluation and failure modes and effects analysis （FMEA） was proposed. The thorough analysis was carried on using the FMEA for various types of fault of the ma- chine, which were classified according to the hardware method of FMEA to obtain failure mode of key parts. The way of expert survey table was used to determine the severity of each fault （S）, frequency （O）, and detectability （D）. The theory of fuzzy comprehensive evaluation was introduced to classify hierarchies membership degree of risk priority number of qualitative FEMA, and the secondary fuzzy evaluation model was established. The mechanical fault of the main shaft system and feed system were carried on the quantitative analysis. The results show that the comprehensive evaluation value after the blur is 85.08, analysis of which verifies the validity of fuzzy comprehensive evaluation and FMEA on comprehensive analysis of the mechanical fault of CNC machine tool, which provide the com- plete effective safeguard for the selection of test points of CNC machine tool.