Research On The Principle And Structure Of A Resonant Magnetic Sensor Based On A Magnetostrictive/tuning Fork Resonator

As one of the three major technologies in the information industry,sensor technology is an important part in the informationization of weapon equipment industry,and is widely used in the defense industry.Magnetic sensor technology is one of the sensor technologies and one of its important branches.In this paper,a magnetostrictive material is combined with a tuning fork resonator to design a magnetostrictive/fork resonator resonator-type composite magnetic sensor.The magnetostrictive force acts on the tuning fork resonator to cause the frequency deviation of the tuning fork resonator.The resonant magnetic sensor designed by this principle can be characterized by high Q,low power consumption and digital frequency output.Through theoretical analysis,COMSOL finite element software simulation,and experimental verification,the principle of the composite resonant sensor of magnetostrictive/fork resonator resonator was analyzed,and its structure design and optimization were carried out.The main research work of this paper is as follows:1)The mechanism of magnetostrictive effect,the properties of magnetostrictive material and the finite element simulation method are introduced.2)The natural frequency variation characteristics of the tuning fork resonator under axial force are analyzed by using the dynamic differential equation.The COMSOL finite element analysis software was used to analyze the modal of the three-beam tuning fork resonator,and the natural frequency of the optimized mode was simulated and compared with the change of external force.3)The magnetostrictive force transfer characteristics and magnetostrictive force-frequency conversion characteristics of the magnetostrictive/fork-resonator composite magnetic sensor structure were analyzed by COMSOL finite element analysis software.The results show that:for single-layer structure,bending moment is generated due to asymmetric structure,and the effect of magnetostrictive force on the longitudinal force of the magnetostrictive force to the tuning fork resonator is low(9.47%),resulting in the resonant frequency of the tuning fork is lower with the change of the magnetic field(1.76%);Due to the symmetrical structure of the double-layer structure,the force transmission efficiency(28.1%)and the rate of change of the resonant frequency(11.82%)are significantly enhanced.4)Two kinds of magnetostrictive/fork resonator composite magnetic sensor samples were maded and compared.The results shows that:for a single magnetostrictive layer composed of asymmetric sensing structure combined with magnetostrictive/fork resonator,0-10630e DC magnetic field changes,the total frequency change is 161Hz(about 2.18%),the sensitivity is 0.152Hz/Oe;adopt double magnetostrictive layer consisting of magnetostrictive/tuning fork resonator/magnetostrictive symmetry sensor structre,under the dc magnetic field changes of 0?1063 Oe,the total capacity of 1089 Hz frequency change(about 14.6%),the sensitivity of 1.023 Hz/Oe.The experimental results are in good agreement with the results of finite element analysis,verifying the feasibility of the sensor principle and optimizing the structural design..