Study On Intelligent Diagnose System For Abnormity States Of Cold Starting Process In Vehicle Diesel Engine And Its Application

Cold starting process of the vehicle diesel engine involves chemical reactions, fluid flow and transmission of both heat and mass. It is characterized by properties such as multi-variables and non-linear, couple changes with inertia and uncertainty. Therefore, abnormalities of cold starting process of the vehicle diesel engine sometimes happen. A nicer abnormalities intelligent diagnosis system can realize the abnormalities diagnosis of cold starting process and give an alarm based on its status messages, which is useful for operation personnel to do corresponding measurements that can enhance the dependability and security of cold starting process of the vehicle diesel engine.In order to realize diagnosis of abnormalities or potential abnormalities about cold starting process of the vehicle diesel engine fleetly and high effectively, in the paper, abnormity intelligent diagnosis system of cold starting process of the vehicle diesel engine is designed based on fuzzy theory and expert system technology, and main works and innovations are expressed as follows:(1) Some capability parameters of cold starting process are analyzed theoretically and simulated, the results reveal that starting moments minish, resistance moments enhance and fuel are fired more difficultly with the reduce of entironment temperature.(2) Abnormalities diagnosis characteristic of cold starting process of the vehicle diesel engine are analyzed, the working state parameters of cold starting process are manipulated due to the fuzzy theory. And the abnormity diagnosis knowledge of cold starting process is expressed by synthetic knowledge method, knowledge base with more bases and more levels was organized, furthermore, a series of measurements about management and maintenance is adopted.(3) Due to assumed abnormity aggregate educed from a new fuzzy diagnosis model, the inference strategy for abnormity diagnosis of cold starting process of the vehicle diesel engine is designed based on the hybrid reasoning mechanism about backward reasoning of the abnormity type diagnosis and forward reasoning of the factors giving rise to abnormity and eliminating its measures. An uncertainty reasoning method and a fuzzy matching strategy are put forward, the inference engine that collectivity goal reasoning and grade goal reasoning are coupled is designed.All programs in the abnormity diagnosis intelligent systems for cold starting process of the vehicle diesel engine are developed by Visual Basic6.0 and can be run in windows2000 environment. The application results reveal that design of knowledge base is basically reasonable, design of the inference engine is fleet and high effective and its forecasting is basically accurate. In a word, it is successful for design of the abnormity diagnosis intelligent systems of cold starting process of the vehicle diesel engine.