Study On The Influence Of Structural Parameters And Temperature On The Performance Of Eddy Current Displacement Sensor

Because of the advantages of simple structure,noncontact,nopollution,fast frequency response and high cost performance,the eddy current displacement sensor is widely used in the field of detecting the displacement,thickness and rotary speed.More and more researcher focus their insterests to improve the eddy current displacement sensor's performences to meet the requirement of the changing environment and special applications.However,it has the disadvantages of low detection distance,low detection precision and susceptibility to environmental factors,especially the temperature drift caused by temperature change in the application,which severely hampers the development of double-coil all-metal package eddy current displacement sensor.So it is necessary to optimize the structural parameters and environmental adaptability of double-coil all-metal package eddy current displacement sensors.In this thesis,the influence of excitation signal,structural parameters and anti-temperature drift on the performance of a new double-coil all-metal package eddy current displacement sensor is studied by the finite element simulation.Then,the simulation results are verified by experiments.This thesis focuses on:(1)The parameters of the double-coil all-metal package eddy current sensor probe are analyzed at room temperature.The numerical model of the displacement sensor is simplified based on axisymmetric structure.The factors such as the frequency and amplitude of the excitation current,the structral parameters of the metal package plate and the metal mounting bracket are analyzed and optimized by the single factor variable method and the orthogonal experiment method.At room temperature,the optimal parameters of the double-coil all-metal package eddy current sensor are obtained.(2)The relationship of all-metal package eddy current displacement sensor output signal and the dispalement is studied at different temperatures.The factors of coil resistance,parameters of metal package plate and magnetic shielding structure that impacted the temperature drift of the sensor are analyzedand compensated.The results show that there is a temperature invariant point under certain conditions after compensating the main influencing factors.(3)The experimental platform was established under both normal temperature and variable temperature,then experiments are carried out to verify the simulations.The results show that the optimal probe structure can be obtained by selecting the appropriate frequency and amplitude of the excitation current and the parameters of the probe structure at the room temperature.And the temperature drift can be effectively reduced by analyzing the variation of the temperature invariant point.