Study On Algorithm Of Analog Circuit Simulation Used In Fault Diagnosis

How to get test & diagnosis knowledge is a bottleneck for circuit test and diagnosis all the time, while the development of modern simulation technology gives strong support to it. This thesis is based on the project of"Developing Environment for Fault Diagnosis Software"sponsored by Beijing Aerospace Measurement & Control Corp. It discusses the Key techniques of system simulation technology applied to build the test & diagnosis knowledge base and diagnose circuit faults. Mainly studies the algorithms used in analog circuit simulators.This paper first introduces the development and actuality of system simulation technology and circuit fault diagnosis, as well as the application of system simulation technology to circuit test and fault diagnosis. And it describes the project requirement. Then discusses the algorithms used in analog circuit simulators in emphasis. Include the method for building circuit equations automatically, and the algorithms for analysis of linear and nonlinear system.This paper analyses the Simple Nodal Approach, sparse table Approach and the Modified Nodal Approach to building circuit equations, discusses their characteristic. And it presents a partitioning algorithm base on direct methods for analysis of linear system to improve circuit simulation accuracy and efficiency. Then it introduces the application of Newton-Raphson method and modified Newton-Raphson method to circuit analysis.The Fault Diagnosis Software based on circuit simulator is designed and realized using VC++. This paper presents the system in two main parts.Finally the entire work is reviewed and some suggestions are given for the research in future.