Stress monitoring method of SPMMRT track carriage beam based on FBG

The suspended permanent magnet maglev rail transit (SPMMRT), as a new type of rail transit has the advantages of green, intelligent and safety. However, when the vehicle is walking in the rail carriage beam, it will produce lateral swing, which will affect the contact mechanical characteristics between the guide wheel and the steel beam, and then affect the safety, stability and comfort of driving. Therefore, it is necessary to monitor the crossing stress of the carriage beam. In this paper, a stress monitoring method based on Fiber Bragg Grating(FBG) for SPMMRT track carriage beam is proposed. It is used to monitor the stress exerted by the guide wheel on the rail carriage beam when the vehicle is running and whether the stress is within the safe range, which will be related to the safety of the vehicle. The demodulation of the central wavelength of FBG adopts edge filtering scheme. The vertical deflection stress of the steel beam is separated by low-pass filtering method in order to calculate the stress of the guide wheel. The actual test results show that the monitoring method can obtain the force of the vehicle guide wheel on the rail carriage beam in real time, and effectively ensure the safety of driving.