Torque Sensing Technology Based On Eddy Current Coupling

Torque is an important form of load in industrial production and mechanical transmission.It has important applications in shipbuilding,aerospace,industry and agriculture.This paper mainly introduces the sensing mechanism and research dynamics of magnetoelastic sensor,and USES the polmo alloy thin strip with good magnetostriction to combine with the non-magnetic shaft to realize the torque measurement of non-ferromagnetic shaft.Based on planar flexible eddy current coil coupling scheme of torque measurement,the measurement scheme is different from traditional coil(excitation-induction)voltage characterization method of torque,but the planar coil inductance scale torque,and through the coupling of coil and the eddy current sensor the change of permeability,to provide a new research direction in the field of torque measurement.The main work of this paper is as follows:Firstly,various torque sensing measurement methods are introduced,especially the working principle and research dynamics of magnetoelastic sensor,and the research direction of magnetoelastic sensor is determined.According to the knowledge of material mechanics,the mathematical model of stress and torque in the direction of±45° of elastic axis is established.The magnetoelastic effect is introduced,and the mathematical relationship between permeability and stress is analyzed through the theory of magnetic equivalence.Secondly,the signal detection principle of the torque measurement system is introduced.The coupling relationship between the planar coil and the eddy current is similar to the sensing mechanism of the eddy current sensor.Design planar flexible coil and inductance detection module,select polmo alloy 1J50 as the magnetic-sensing element,simulate the penetration depth of eddy current generated by different frequency signals by finite element method,and determine the size of magnetic-sensing material.The lift experiment and tensile stress experiment system based on planar flexible coil were built and tested.The lift characteristic and stress detection performance parameters of planar coil were obtained to pave the way for later torque measurement.Finally,a torque measurement system based on flexible coil eddy current coupling was built and tested.The experimental data were processed and analyzed to make a fitting curve and obtain the nonlinear error,sensitivity,hysteresis error and other performance parameters of the experimental system,verifying the feasibility of the torque measurement system.It is a promising research direction in the field of torque measurement to characterize torque by planar coil inductance.