关键词: 非线性系统, 高速数控装备, 故障诊断, 证据理论

Abstract: For the actual demand of high-speed Numerical Control(NC)equipment with complicated nonlinear features, a new fault diagnosis method was proposed based on improved evidence theory and nonlinear featurs. The fault features of high-speed NC equipment with multiple sensors were analyzed, and a group of feature vectors which reflected the system's nonlinear dynamic feature was extracted. The multiple fault diagnosis model based on evidence theory was presented and each evidence's mass functions were obtained according to the similarity among different modes. To solve the composition problem of multiple evidence in the situation of evidence conflicting, a dynamic parameter conflicting evidence combination method was proposed based on average trust degree. Experimental result indicated that this method had high recognition rate when the evidences were conflicting, and had practical value for diagnosis algorithm of nonlinear high-speed numerical control equipment.

Key words: nonlinear system, high-speed numerical control equipment, fault diagnosis, evidence theory