Analysis And Simulation Onthe Fault Of EFI Engine Based On LabVIEW

Automotive engine is a very complex system, and there is more than 40% vehicle faults resulted from it. For avoiding the casualty, the work performance and conditions of engine need to be known in time. So it is very important to research the engine fault diagnosis technology theory and system program. However, the universal platform of an engine fault diagnosis system, which is used for the collection of many parameters acquisition, signal processing and diagnosis reasoning methods, is not very perfect and can not be suited to the demand of modern diagnosis system. At the same time, the fault diagnosis reasoning methods in existence can not be applied into fault system without any changes, it need to be improved.So, the technologies of signal acquisition, signal processing, neural network, rough sets theory and virtual instrument were introduced in this paper. Also the principle, peculiarities and application in fault diagnosis of these technologies were discussed in detail. Then a new engine fault diagnosis expert system, which is based on a virtual instrument universal-platform and with an integration of many artificial intelligent technologies, was proposed too.The main contents of this dissertation is:1. On the basis of analyzing the basic principle, reasoning methods and function peculiarities of some popular fault diagnosis technologies, and their applications in fault diagnosis field, the design view is given. We take the artificial neural network reasoning as a main method of system diagnosis method, the expert system method as the basis of fault system, primarily with additional methods.2. The principle of signal acquisition and signal processing methods, and its applications in engine working temperature, oil pressure and other steadily signal is designed. Also an engine fault symptom signal acquisition instrument on the basis of the power spectral analysis is given too. For improving the precision of measurement date, the data-fusion based on parameter estimation is applied into the measuring exhaust emission contents.3. The concept, structure and peculiarities of the virtual instrument, and the Lab VIEW programming technology are discussed deeply. Also, the main parameters of engine of working performance are analyzed too. Then we designed a new universal platform of engine fault diagnosis measurement, which is based on a virtual instrument and an integration of many artificial intelligent technologies.