Fault Dictionary Method In Analog Circuit Fault Diagnosis

Currently, the fault diagnosis of analog circuits is the popular problem in the field of Circuit and System, and the hotspot in fault diagnosis. This thesis is based on the project of"Developing Environment for Fault Diagnosis Software"sponsored by Beijing Aerospace Measurement & Control Corp. It discusses deeply some ways to the fault diagnosis, and studies fault dictionary methods to different kinds of circuits.First this thesis introduces the development and actuality of the analog circuit fault diagnosis, as well as the general instance which the interrelated techniques are used in this field. The project requirement is also described.To the characteristics of the analog circuit, the principle of the diagnosis to the analog circuit, the fault reason, the class to the fault and the diagnosis method are introduced. On the basis of diagnosis knowledge and project demand, the paper analyses the request which fault diagnosis can reach and detailedly expatiates and compares the principles of every diagnosis method.For the DC circuit, the project establishes the fault dictionary by using the DC fault dictionary method, which chooses the circuit node voltage as test vector; for the AC circuit, it establishes the fault dictionary by using the Seshu-Waxman method, which chooses the frequency as test vector. The BP network fault dictionary method is detailedly introduced, which can be used both in the DC circuit and the AC circuit.Finally the entire work are reviewed and some suggestions are given for the research in future.