Research On Structural Health Monitoring Technology Of Pantograph-Catenary System Based On Strain Response Inversion Method

In recent years,the speed of Urbanization in China has accelerated significantly,and China vigorously supports the development of public transportation.As a window to show the speed of urban development,the operating mileage of subway continues to climb,and subway lines are getting longer and faster,which has become an indicator of urban development.As of March1,2022,China has a total of 81 urban subway systems in operation,the actual operation of about 2.85 million trains,the passenger flow of about 1.8 billion,the station flow of about 1.8billion.At present,the power supply of subway is mainly through the pantograph-catenary coupling system.Therefore,the structural health monitoring(SHM)of coupled system is very important to the safety of subway line.It is necessary to develop accurate and effective monitoring means to monitor the dynamic contact force between catenary and pantograph in real time.Aiming at the shortcomings of the existing pantograph health monitoring technology,this paper uses a low temperature sensitive fiber grating sensor,a micro fiber grating sensor and an acceleration sensor,and applies them to a certain line of Shanghai Rail Transit and a certain line of Xi’an Metro.In the monitoring of the elevating bow and the operation process of the pantograph-catenary system,a good monitoring effect has been achieved,and a stress-strain analysis has been carried out.The structure of this paper is as follows:The first chapter introduces the significance and principle of structural health monitoring and the development of pantograph-catenary health monitoring,expounds the national standard of pantograph-catenary and the necessity of structural health monitoring,and then describes the main means and application status of pantograph monitoring technology and the shortcomings of current pantograph monitoring technology are introduced.Finally,the main research contents of academic papers are clarified one by one.In the second chapter,the pantograph mechanical model is firstly constructed,a pantograph dynamic contact force monitoring method is proposed,and its mechanical principle is described.Bragg grating(FBG)sensor and equipment selection are described.The third chapter is about the combination of the pantograph monitoring project of a line of Shanghai Rail Transit and a line of Xi’an Metro,a low temperature sensitive fiber grating sensor is used and micro fiber grating sensor to monitor the contact force of the pantograph in the actual engineering site,and monitor the pantograph’s raising,lowering and running process,and get the law of its structural strain response.The monitoring field data shows that the sensor has good low temperature sensitivity can solve this problem of the lack of effective temperature compensation mechanism in the past fiber grating strain sensors,and also greatly simplifies the subsequent data analysis and processing.The above-mentioned real-time monitoring method of structural health based on strain response inversion is used to calculate the magnitude and position of the dynamic contact force between the catenary and the pantograph.The monitoring system is put into use,and the pantograph is monitored and analyzed by taking rigid catenary subway and flexible catenary subway as examples,and its performance is explained.The results show that the strain response inversion method has high measurement accuracy,good data consistency and flexible sensor installation.It can accurately calculate the magnitude and position of the contact force exerted on the pantograph,and has broad application prospects in the structural health monitoring of the pantograph.The fourth chapter is the conclusion and prospect.It summarizes the work content of this academic paper,expounds the research results of this topic,and puts forward ideas and ideas for the further development,innovation and improvement of this research field in the future.