Development Of A High-speed Train Bearing Damage Acceleration Sensor Based On Fiber Grating

The running state of bearings has to be the top priority for safety monitoring of high-speed trains,because the damage of bearings would be a severe threat to trains'safety during operation.To come true the early diagnosis of damaged bearings,this project has researched a kind of FBG acceleration sensor based on principle of sonic resonance.Firstly,the thesis has detailedly analyzed merits and demerits of train bearing detection methods,including the method of axial temperature detection,vibration,and generalized resonance.It has also researched train bearing structure,basic characters of damaged bearings and fundamental theory of FBG.In addition,there is a industrial demand survey in the thesis.Secondly,the temperature and resonance combined acceleration sensor whose 3D model is designed by UG is used to detect train bearings.The project has calculated the vibration frequency range caused by damaged bearings which is based on running characters of high-speed trains.Through the software ANSYS,it theoretically has simulated parameters and has explored the optimal materials and sizes of acceleration sensor resonance units.The project has designed fixation and protection structures of sensor,has encapsulated and solidified FBG,and completed mechanical processed and assembled of the sensor.Finally,to test sensing performance of bearing monitoring sensor,the project has designed simulation platform to train bearing damage,including detection simulator,power and transmission structure,and motor drive variable frequency control structure,has constructed and debugged simulation platform.Furthermore,impulse response signal of acceleration sensor has been observed by impacting the bearing seat instantaneously when the generator is continuously running.To sum up,the thesis has designed structure and parameter of acceleration sensor's resonance system by numerical simulation,has designed,processed and encapsulated the sensor,and has established bearing damage simulation platform.These work laid a solid foundation for the follow-up research on continuous impact frequency sensors and verification of the amplitude-frequency response characteristics of the sensors.