The Rotor Position Identification Technology Of Permanent Magnet Spherical Motor Based On The Sensor Array Code

With the rapid development about the industrialization of our country,the disadvantages of multi-degree-of-freedom motion systems composed of multiple single-degree-of-freedom motors are increasingly apparent.The spherical motor has attracted wide attention from researchers at home and abroad because of its simple structure,small size and ability to realize three-degree-of-freedom motion.However,spherical motors still have technical problems in position detection.This is a major obstacle to the study of closed-loop control systems for spherical motors.Therefore,research on the position identification technology of spherical motors is crucial.Firstly,according to the magnetic field distribution characteristics of the rotor,the inner surface of the stator is divided by the longitude and latitude lines on the spherical surface.A total of 12 intervals are divided.Then,the rotor position is determined by combining the coded signal output by the sensor,the magnetic field value of the sensor output,and the interval on the inner surface of the stator.However,because the interval on the inner surface of the stator is too large,the detected rotor position is too rough,which is not suitable for some fields where the accuracy is relatively high.Therefore,the method is improved and optimized in this paper.In order to make the interval small,this paper proposes a new method of interval division.First,the sensor threshold is designed according to some factors such as the magnetic field characteristics of the rotor.The unit interval is then divided on the inner surface of the stator based on the se nsor threshold.In this paper,the arrangement of the unit interval on the inner surface of the stator is such that the unit interval can cover all positions to which the rotor can move.And the unit interval overlap each other to obtain 128 smaller range intervals.Then,a total of 24 sensors are distributed on the inner surface of the stator based on the sensor threshold and the unit interval.This paper designs the 24-bit code of the sensor output and rotor pole polarity code.The 24-bit code of the sensor output consists of the encoded signals output by 24 sensors.Rotor pole polarity code is a new set of codes.It is a secondary encoding of a sensor that encodes the output of the 24 sensors to one.It is used to determine the polarity of the magnetic po le.The 24-bit code of the sensor array output and rotor pole polarity code can be used to detect the position interval in which the spherical motor rotor is located.It achieves position identification of the rotor.This method is more complicated than the original method and the identification accuracy is higher.This paper designs a rotor position identification system.The system includes a three-axis turntable,a sensor bracket,a motor driving device,a control signal generating device and a data read ing device.The three-axis turntable is driven by a control signal generating device and a motor driving device.The data reading device is used to read data.By designing the placement position of the Hall sensor in the Hall element measuring device,it is ensured that the magnetic field measured by the Hall element contains only a radial component.Finally,several locations for the rotor are given in this paper.The validity of the position identification scheme is verified by theoretical analysis and ro tor position identification system.It provides a new idea for the position identification system of permanent magnet spherical motors.