Research On Torque Sensing Based On Magnetoelastic Effect

Torque is an important parameter of mechanical design,and it is one of the basic forms of the drive shaft loads.Torque measurement plays a key role in the development research,safety control,quality inspection,and test analysis of all kinds of mechanical products.This paper introduces the torque measurement methods,such as resistance strain,piezoelectric,photoelectric,magnetoelectric,and capacitance thpes.The torque measuring method based on the magneto elastic effect is described in detail.Then a new torque measuring system based on the inductance coil is put forward.The method derives the mathematical relationship between the permeability of soft magnetic materials and the coefficient of self-inductance L,and deploys L to characterize the torque.This opens up a new way to measure the torque.The main research contents of this dissertation are as follows:Firstly,the mathematical model of magneto elastic effect torque sensor is established,via the theoretical and finite element simulation analyses,taking into account the performance of the soft magnetic materials,the sensing mechanism magneto elastic effect,and the principle of the torque measurement.Secondly,an experimental system for studying the magnetic properties of soft magnetic materials is designed,and set up.A large number of experiments are carried out to analyze the magnetic elastic properties of the materials 1J50,and the factors affecting the magnetization curve are analyzed.Thirdly,through studying the relation between permeability and the coefficient of self inductance,the overall scheme of the torque sensing system based on the magneto elastic effect is designed.It takes the nickel iron alloy 1J50 as a sensitive material and the self induction coil as the main sensing body of the whole measuring device.It applies the principle of electromagnetic induction,and employs the corresponding signal conditioning circuit to establish the torque sensing system and achieve the non contact measurement of torque.Finally,a series of experiments were carried out to demonstrate the linearity and repeatability of the proposed sensor.The error analyses were carried out for future research on further improvement and innovation.Experimental results show that the method using self induction coil to measure torque is feasible.It is a new breakthrough and exploration of magnetoelastic torque measurement methodology.