Research On Digital Twin System Of Subway Train For Performance Evaluation

As an important means of transportation in modern cities,the subway is essential to ensure its safe operation.The use of operation and maintenance technology to evaluate subway trains,grasp its current performance and use the result for maintenance and decision-making is a commonly used method.With the development of information technology,the subway operation and maintenance transform to digitization and intelligence has become the general trend,and the traditional single evaluation model also needs to be comprehensive,systematic and intelligent.Digital Twin(DT),as the best way to integrate virtual and real,provides new ideas and methods for digital transformation,and has attracted widespread attention from domestic and foreign scholars and enterprises.This paper applies the concept of digital twin to subway operation and maintenance,and builds a digital twin system of subway train for performance evaluation based on its connotation of "fictional reality",making the traditional evaluation systematic and digitized,which can provide new ideas and references for the construction of subway operation and maintenance.The main research contents and contributions of this article are as follows:(1)Analyze the problems and challenges of the current subway train performance evaluation from multiple aspects,combined with the concepts and characteristics of digital twin,propose the overall reference architecture of digital twin system of subway train for performance evaluation.And explain its operation mechanism from the perspective of operation and maintenance.(2)On the basis of the proposed system architecture,analyze the construction method of the system from the perspective of virtual-reality mapping.The method mainly includes three progressive level,namely model mapping,behavior mapping,and state mapping,realizing the functions of modeling,monitoring and evaluation of trains in virtual space in turn,making the system hierarchical,the content of evaluation richer and the expression of train information more adequate.(3)Based on model mapping,XML is used to establish a road network data model,the train and its component models are established layer by layer to form model information management under the road network;Based on behavior mapping,frame animation technology is used to realize the visualization of train operation in virtual space,and it’s supplemented by OSG technology to further realize the monitoring of trains in transit;Based on the state mapping,the performance evaluation mode based on cloud-edge collaboration is proposed,and the construction rules of the performance evaluation model are established.The online analysis and calculation of the system is realized through C++ and Matlab hybrid programming,and design dynamic library compilation,storage and display call rules to form the integration of any version of the evaluation algorithm model towards the entire road network.(4)Based on MFC,OSG,Web Service,etc.,design and develop a prototype digital twin system of subway train for performance evaluation,to verify the proposed theory and method.The formed system has the functions of modeling,monitoring,evaluation and remote service.