| There are great variety faults in press system, most of which are blooming. The blooming reflects the relationship between fault sign and fault reason that is the same fault sign corresponding with several reasons, vice verse. It is difficult to identify the factual reason. FTA is the fault analysis method that is fit to solve the complicated system. Therefore, this paper combines FTA with Fuzzy theory. Based on fuzzy theory, the mathematical modal of press fault diagnosis is built. The simple and reliable method is applied, and the some modal number press is taken for example to analyze.The main work done in this paper are:1. According to the press operating principle and the kinematical relation of each mechanism induced fault, the relationship between fault sign and reason is analyzed, and studied. The data base is supplied for fault diagnosis system.2. Based on the fault analysis , the fault tree is built, which can indicate the relation of fault sign and reason visually and obviously, and qualitative analysis is done, namely gaining min cut set. This work provides progress direction for the improvement of the structure and performance of press.3. Because of the complexity and fuzziness of press fault system, intersect of fault tree is always appeared. Therefore, this paper applied the fuzzy theory to offset the drawback of conventional FTA. By means of repeat proof, effective membership function is built, and fuzzy matrix is structured. Lastly the max membership grade principle is applied to diagnose.4. Based on Windows XP platform, VB and SQL Sever language is utilized to develop the press fault diagnosis utility system. There is a diagnosis knowledge base in the system. The user can step by step diagnose through the way of man-machine conversation. Lastly the reason is confirmed, and the eliminated method is supplied.
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