Research On Key Technology Of Three-dimension Vibtation Sensor Based On Fiber Grating

With the rapid development of optical technology,fiber gratings are more and more widely used for signal detection in the fields of industry,agriculture,manufacturing.Due to their own advantages such as anti-electromagnetic interference,small size,and high sensitivity.Common detection signals including pressure,temperature,vibration,etc.Because vibration signals are ubiquitous,and it may affect the working status and operational reliability of equipment,so there is a wide range of practical engineering requirement for rapidly and accurately detection to vibration signals.On the basis of checking a large number of related literatures,this paper proposes a three-dimensional vibration sensing structure based on fiber Bragg grating,which is used for detecting vibration signals in view of the shortcomings of the existing vibration detection technology,such as low sensitivity,high cost and narrow detection range.The main contents of the paper are as follows:Firstly,the resonance wavelength response characteristics of the fiber grating under temperature and stress are analyzed,and a structural design scheme of a three-dimensional vibration sensing unit is proposed according to the actual working conditions.Secondly,in ANSYS Workbench,the sensor model is statically and dynamically simulated to obtain the response characteristics of the sensor model.Based on the response characteristics,the linear characteristics,anti-transverse interference capability,frequency characteristics and stability of the sensor structure are verified,and analysis its response characteristics under different excitations.Thirdly,the sensor models under different parameter structure conditions are theoretically analyzed,and the response characteristics,natural frequency and sensitivity of the sensitive grating with different parameters when different excitations are applied are obtained,and the three-dimensional coupling characteristics of the sensor unit are theoretically analyzed.Finally,the sensor response characteristics of a typical vibration sensor unit are experimentally verified.Through the pressure test experiment on the sensor unit,the linear characteristics,sensitive characteristics,stability,recovery and repeatability of the vibration sensor unit were verified.Meanwhile,the response characteristics of the forward pressure and the reverse pressure,and response characteristics of fiber grating fixed at different positions of beam were compared.Aiming at the current problems and needs of three-dimensional vibration measurement technology,this paper proposes a new type of three-dimensional vibration sensing model scheme,and studies the vibration response characteristics of different parameter structure sensing models.Provide a reference for designing a three-dimensional fiber grating vibration sensor that meets actual engineering needs.