专业英语作业PPT.ppt

Vibration-based Fault Diagnosis of Gearbox Using Fuzzy Logic Technique Contents 1. Introduction The conventional methods for processing measured data contain the frequency domain technique, time domain technique, and time– frequency domain technique. These methods have been widely employed to detect gear failures. However, in many fault diagnosis process, the equipment failures of various faults and fault symptoms were a number of reasons. A failure symptoms may be caused by several different causes, and different reasons for the failure may produce the same failure symptoms, especially when several simultaneous failure symptoms, use more traditional methods of fault diagnosis appeared to be inadequate. 2. Fuzzy logic technique Fuzzy logic diagnosis is to make use of fuzzy mathematics method，using mathematical formulas to describe the complex relationship between the fault symptoms and the cause of the malfunction. And then according to the mathematical approach to make a comprehensive reasoning, and ultimately get a more concrete results. In order to diagnose the fault indication from the cause of the malfunction，it must pre-determine the degree of membership between fault symptoms and the cause of the malfunction Then to establish the fuzzy relationship matrix, and finally by calculating a conclusion. 3. The calculate approach fault symptoms collection: cause of the malfunction collection: fuzzy logic matrix (according to membership function): The relationship between them is as follows: 4. The step of  Fuzzy logic technique 5. Examples of the diagnosis process Next, we will have a brief introduction of the calculate descriptive statistics of apply fuzzy logic techniques for fault diagnosis. 5.1 The specific content of the descriptive statistics 5.2 Calculate approach of Several important descriptive statistics Standard err