The Research Of Fault Diagnosis Method In Railway Door System Based On The Extended Petri Net

In subway system, door system is one important subsystem which connects body inside and outside, with much more sporadic human factors in complex environment, so the possibility of door system failure is high. The failure of the door system will cause a loss of its own security and passengers’safety; at the same time, it will cause a bad social influence. According to the national statistical data, subway operation mileage is the largest in the urban rail transit in domestic. Because of the large number of the door and frequently using, the corresponding fault faults are frequent in the railway door system. As a result, we need to carry out the study on the door of the analysis of the system failure causes and diagnosis, thus to quickly locate the fault source and improve the efficiency of maintenance, finally reduce the failure shutdown time reduction of railway door.Subway door itself is a complex system, whose failure form is varied and the cause of the problem is complex, it is very difficult to accurately locate the fault source using the traditional method of fault analysis and diagnosis, at the same time, the time of analysis is very long, which is not conducive to the actual engineering application. Therefore, it makes important sense to study an approach which can describe the railway door completely from the angle of the system and locate the fault source quickly depending on the concise type of door fault and the phenomenon description.This paper has carried out the following research on the subway door fault diagnosis methods:Firstly, set the subway door system as the research object, put forward the subway door system fault diagnosis methods based on the analysis of the extended Petri net and the abduction reasoning, with the analysis of Observable Degree in Dimensionality of Time (ODDT), decouple the complicated relationships in the model hierarchically, in order to decrease the solving difficulties and clarify the fuzzy causality, and conduct the system state recognition and behavior analysis at a lower cost.Secondly, subway doors system model is established by refining the subway door system’s working principle of control, mechanical and electronic systems, according to the rules of Petri nets. The fault decoupling method of compound diagnosis is applied to the door system fault diagnosis through the analysis of the system structure and the cause of the problem. At the same time, an instance is given which conduct the subway doors’fault diagnosis aimed at the open and close process, the method is proved to be correct.Thirdly, the subway door decoupling composite fault simulation software is designed based on the composite fault decoupling method proposed in this paper, which realize the fast diagnosis of the subway door fault and the rapid positioning of the fault source, help the relevant personnel to get the subway doors’ fault information in a timely manner and to master the fault transfer situation, thus improve the maintenance efficiency.