Design And Realization Of High-Resolution And High-Accuracy Magnetic Encoder Based On TMR

Magnetic encoder is a sensor for measuring angular displacement/linear displacement,which plays an extremely important role in industrial control,robot and new energy vehicles.However,the resolution and accuracy of magnetic encoders still have certain limitations,which largely limits the applications of magnetic encoders in more fields.In order to expand the market demand of magnetic encoders,it is particularly important to further increase the resolution and accuracy of magnetic encoders.In this paper,starting from the structural design and sensing principle of the magnetic encoder,in order to optimize its resolution and accuracy,the design and realization of a high-resolution magnetic encoder based on tunnel magnetoresistance are proposed.First,the system uses a new type of tunnel magnetoresistance device as the sensitive element in this design.According to analyze the simulation of sensitive components and the single-pole magnetic grid from software Maxwell,the relative spatial position of the sensitive element and the magnetic grid is determined,so that the best working magnetic field and the assembly error can be obtained by the finite element simulation,and then we can determine the overall structure.Second,the sensitive component circuit is designed,and the output signal is preliminarily processed by the signal conditioning circuit,and the data is converted by the high-resolution analog-to-digital conversion circuit.Then the Kalman filter algorithm is used to achieve filtering.After obtaining angle data by angle decoding algorithm,the data is logically divided and output in the form of incremental signal.Finally,a high-resolution and high-accuracy magnetic encoder system based on the tunnel magnetoresistance is realized.With the system completing,it is calibrated by the optical-electricity encoder.The result shows that the resolution can reach 14 bits,and the initial accuracy is 0.0235°,and the angle error range is±0.1°,and the maximum speed can reach 6000 r/min.Compared with similar research,its accuracy is improved by about 60%.