Study And Application Of Fault Diagnosis System For Appliances

In recent years, the fault diagnosis has become more sophisticated and the household appliances have been widely used. This paper synthetically applies a variety of intelligent diagnostic methods such as expert system, fault tree analysis, and fuzzy reasoning technology, takes household appliances as research object, and designs a fault diagnosis system to achieve the intelligent fault diagnosis of household appliances.According to the development demand of fault diagnosis system in allusion to home appliance. The fault diagnosis system is divided into two aspects, off-line fault diagnosis and online fault diagnosis. In the off-line fault diagnosis system, intelligent fault diagnosis is based on the expert system platform, establishes the relationship between fault symptoms and fault reasons through the fault tree analysis, then combines with prior knowledge of experts so as to improve the knowledge base of experts fault, consequently, we can realize the experts reasoning machine by the method of fuzzy reasoning. The fuzzy membership information of fault symptom is achieved by human input from web page interface, accordingly accomplishes the process of fuzzy reasoning, and obtains the conclusions of off-line fault diagnosis. In the same time, solution and maintaining method can be proposed with the expert system explain mechanism. The difficult point of online diagnosis is to establish the dynamic diagnostic model for the appliances, analyses the operating characteristics of appliance through real-time collecting the status information, dynamically establishes the online fault diagnosis model by the least square method, according to experts and the actual test results, selects the membership function of faults for failure fuzzy reasoning, gets the results of fault diagnosis. When the appliances go wrong, the system presents the faults reason and the optimal solution. This paper takes rice cooker as a research object, analyses the temperature curve characteristics of rice cooker. The dynamic diagnostic model on top and bottom of the rice cooker can be obtained by the least square method. Various kinds of dynamic models for other rice cooker can be easily set up through proper test with different rice quantity. This modeling method has a very good adaptability.Experiments demonstrate that the accuracy of off-line fault diagnosis is up to 80%. Online diagnosis model of rice cooker can meet the requirements of fault diagnosis. And the temperature curve on the top of the rice cooker is more stable, the model has a high precision with the actual measurement error less than 0.05%. While the temperature sensor which is relatively close to the heating element on the bottom of the rice cooker changes more, yet the measurement error is less than 0.2%. We can also consider the diagnosis has a higher accuracy...