Research Of Board Level Circuit Fault Diagnosis System Based On Expert Knowledge

The main work of this thesis is to study fault diagnosis system for electronic equipment,which intents to provide expert knowledge approach for fault diagnosis of circuit board level.In the section of knowledge base, mainly on the knowledge base system SQL Server database design and development. This expert knowledge base consists of the extension rule base and case library. Among them, the rule base contains a lot of extension bar rules, and the extension rule is expressed by the extension of knowledge out. Case base is described under way to build cases, it is the case with all the characteristics of fault indicators described. Part of the design inference, the main use case-based and rule-based extension mechanism for hybrid reasoning. Among them, the diagnosis began, under the sign of the failure to obtain information on whether the search in case there is a match library in the case, so the case-based reasoning; the case if there is a match, then turned to the rules of reasoning based on extension.Finally, the failure of power supply circuit and audio management unit in airborne electronic equipment, for example, case-based reasoning systems were used and extension inference system for fault diagnosis, so as to achieve the board is expected to circuit fault diagnosis effects and purposes, it also underlined the board-level circuit fault diagnosis expert system the practicality and reliability.