两极平行充磁转子全位置传感器的研究

Research of Rotor Whole-position Sensor Based on Two-pole Parallel-magnetizing of Permanent Magnet

为了满足在低速高精度伺服控制系统中对转子位置高分辨率的要求,提出了一种利用线性霍尔元件作为位置信号传感器元件,对永磁体随转子旋转而产生旋转变化的磁场进行检测,对输出信号进行相关的处理从而获得转子连续位置的新方案。文章对两极平行充磁转子全位置传感器的关键部件永磁体及测量算法进行了研究:利用等效磁荷模型推导出圆柱形永磁体的磁感应强度的空间分布的近似解析表达式,并且利用三维有限元分析软件对推导的近似解析公式进行了验证,根据其轴向分量在某平面圆上的正弦分布规律,并针对两点测量在永磁体偏心时存在测量误差大的问题,提出了四点测量的算法,仿真及试验结果表明,采用此算法检测转子的位置具有很高的分辨率,完全可以满足低速高精度伺服控制系统对转子位置的要求。

In order to meet the requirement of high-resolution for rotor position in the low-speed and high-precision＇s servo control system, a new method that by means of detecting the rotating magnetic field produced when the permanent magnet follows rotor rotation with linear Hall ICs, obtained the rotor continuous position by further analog and proposed digital process to the output signal. The permanent magnet which is the key component of rotor whole-position sensor and measurement algorithm were researched. An approximate calculation formula for the air-gap magnetic flux density excited by the 2-pole parallel-magnetized cylinder was derived according to equivalent magnetic-charge model and verified by the three-dimensional finite element analysis software, according to the sine distribution of axial component on circle of certain plane, proposed a four-point measurement algorithm to solve the issue that there is big error of measurement when permanent magnet eccentricity by the two-point measurement. The resuits confirm that there is high-resolution for rotor position by the proposed algorithm and can completely meet the low -speed and high-precision＇s servo control system.