The Application And Improvement Of Digital Diagnosis Algorithm For Intelligent Fault Diagnosis System

Driven by some emerging applications, digital system integration is on the rise. To satisfy digital system fault detection requirements, a lot of intelligent fault detection and diagnostic methods have been set up. However, in most of fault diagnosis system, it is difficult to classify multi-line short circuit fault from fixed logic fault. To solve the problem, the paper author widely study in Boolean Matrix theories, fault detection and condensing theorem, fault diagnostic soundness theorem and anti-aliasing theorem, And also make some improvement of some of the algorithm, integrate some of different algorithm, successfully apply the method in the real diagnostic system.In addition, the author also research in general detection optimal algorithm used by fault diagnosis system. Researches show that these general detection optimal algorithms have a lot of flaws in test time cost or low fault coverage rate. On the base of these methods the paper make some improvement to the WOA optimal algorithm in the specified application systems and apply the improvement to a real intelligent diagnostic system. The central idea of the improvement is derived from WOA algorithm. It can guarantee the high fault coverage rate in a complex system. It can detect fixed logic fault and short circuit, the most improvement of the situation is it can pick out multi-line short circuit fault. Experiments show that the improvement can achieve 100% fault coverage rate. Until now haven't found wrongdiagnoses.In this intelligent fault diagnosis system, virtual instrument technology is a key point. "Software is instrument" isn't a slogan but a fact. The author designs diagnosis system software with VISUAL C++ 6.0 , the whole system are divided according to functional block. Some of the blocks are written by MCS-51 ASM and C language and VHDL. With the powerful GUI (Graph User Interface), this diagnosis system is ease to use, and can be conveniently transplanted to other applications.In the hardware part of the intelligent fault diagnosis system, a circuit board for interface is design meticulously by author, the interface board connects PC with CUT, all logic functions needed by the interface board is come through in a CPLD (complex programmable logic device), therefore, the interface board is very small and exquisite.The diagnosis system can detect and diagnose MCU (Microcontroller unit)> PLD(programmable logic device, such as CPLD or FPGA)^ memory(SRAMN PR(m E2PROM> FLASH etc.)> Data transport and interface device(LATCHs BUFFER n Bus Driver and Receiver) n I/O port(input or output port, such as print porU display porU keyboard port).It was well-known that those components are mainly parts in digital system, so this diagnosis system has general-purpose for mostly digital system.For the purpose of latter research, the author also studies the remaining problems of the system, and point out the field of the study of the next period of time. Limited by study time, the author only discusses some basic principle, more work will be done in future.