Position Detection Method Of Spherical Motor Based On 3D Hall Sensor

The permanent magnet spherical motor is a small special motor that can realize multi-degree of freedom motion.The miniaturization and multi-dimensional motion characteristics of spherical motors make them more widely used.Research on spherical motors has been going on for many years,but industrial applications are still not possible.The reasons are manifold.From the perspective of control strategy,position detection limits the development of control strategies.More efficient and accurate position detection strategies can make the movement of spherical motors more precisely.This thesis analyzes the development of the position detection strategy of permanent magnet spherical motor,and proposes a method for detecting the position of three-degree-of-freedom of spherical motor shaft based on 3D Hall sensor,and proves its effectiveness through simulation and experiment.The research content of this thesis is as follows:1)The structure and working principle of a spherical motor prototype are analyzed.The molecular current model and DMP model of the cylindrical permanent magnet magnetic field are modeled and simulated,the results of the two model modeling are close and the error is small.The DMP model is chosen as the basis for subsequent analysis.2)The detection method of 3D Hall sensor position of rotor based on three-dimensional magnetic field is studied.Use air gap magnetic field no longer.Using multiple pairs of permanent magnets and Hall sensors,the magnetic induction intensity detected by a three-dimensional Hall sensor at a fixed point in space is used to calculate the position of the rotating shaft in space;and then the three-dimensional Hall sensor bound to the rotating shaft is used to calculate the angle of rotating rotation.The space coordinate system is established and the mathematical conversion relationship is analyzed.Simulation results prove its effectiveness.At the same time,the influence of errors such as electromagnetic coil and rotor permanent magnet is analyzed.3)The experimental platform of position detection system is designed by this method.The MLX90363 three-dimensional Hall sensor is selected for position information acquisition,and communication with the host computer is realized by STM32F103C8T6 singlechip microcomputer.By comparing with the high-speed camera position detection scheme,the initial point spin motion and the shaft tilt motion experiment were carried out to verify the effectiveness of the position detection method.