Study Of Diesel Engine Fault Diagnosis Based On Fuzzy Diagnosis Technique

Diesel engines are widely used as important power-supply equipments in many fields. And because of its complexity in structure, high power output and poor working environment, intelligent and cost-effective maintenance technology is urgently wanted.In order to fill this blank, a diesel engine fault diagnosis system based on fuzzy diagnosis technique was researched and developed in this thesis. By solving the fuzzy relationships between faults and fault symptoms, it's competent for diesel engine intelligent condition tracking and quick fault diagnosis.Through collecting in-cylinder pressure data, solving the combustion and heat release models, the full working process information of the diesel engine can be further deduced. By mathematical statistics, characteristic functions of fault symptoms were derived, that present the fault symptoms'intensities. Employing the experiences of experts and precise analysis of the data, the dependency of the fault symptoms on the faults was decided, and the fuzzy fault diagnosis matrix was founded. Through precise calibration of the fuzzy fault diagnosis model a quick and correct fault diagnosis was realized.The diagnosis device was designed based on PC104 industry embedded computer data bus, and the whole device met national standard for EMC. Its software was developed by OOP method, which make it easily maintained and extended. The system is easy to use, reliable and steady in operation. The data processing system on ground serves for measured data transfers, graphic analysis of data, fault diagnosis, and engine condition tracking.