Bus Air-conditioning Control Cabinet Fault Diagnosis System Design

Due to the safety requirement of the railway, this paper takes example for KLC4OC[2]-1T1 air-condition controller to study the train air-condition controller fault diagnosis system. Based on the analysis of the working principles and the circuit features of the air-condition controller, the circuit is described by the logic signal, and according to the fault features of the components and some rules the number of sample is decided. Base on the applicability analysis about some main fault diagnosis methods to the air-condition controller, the expert system based on fault tree is used. It makes automatic knowledge acquisition come true and ensure the consistency and maturity of the knowledge. The photocoupler and SCM are used to sample signal from air-condition controller and transmit data to PC. By using Visual Basic6.0 under Windows2000 the man-machine interface, knowledge database and its management, obverse reasoning, explainer and diagnosis result output are programmed. The AutoCAD is developed using Visual Basic6.0 and ObjectARX in order to drive the AutoCAD drawing. As a result, the drawing can dynamically display the work states of the air-condition controller and locate the component on the center of picture-window. The result obtained from the air-condition simulator proved that the project of the train air-condition controller fault diagnosis system is feasible.