高精度电磁标定力数值模拟及实验研究

Numerical Simulation and Experimental Methods for High Precision Electromagnetic Calibration Force

高精度电磁标定力源是微推力测量系统的重要组成要素之一。为了获得性能优良的电磁标定力,本文综合采用数值模拟及实验测量两种方法分析研究了线圈和永磁铁相对位置变化时,磁铁几何尺寸对电磁力特性的影响:对于直径较大、厚度较小的永磁铁而言,其电磁力随相对位置的变化会存在极值,且极值点附近的电磁力具有较好的稳定性和一致性。根据电磁力变化趋势特性,提出了线圈和永磁铁相对基准中心(极值点)位置的高精度设置方案,且基准中心位置附近的电磁力变异系数可达0.00252。最后,确定了大直径永磁铁+线圈组合型电磁力产生装置,并基于拟合方法建立了一定包络区间内的高精度电磁力控制关系式,其拟合曲线的估计标准误差约为0.0137。

High precision electromagnetic calibration force source is one of the important components of mi⁃cro-thrust measurement system.For obtaining the electromagnetic calibration force with excellent performance,numerical simulation and experimental research methods are used to analyse the influence of geometry sizes of the permanent magnet on the characteristics of electromagnetic force with the relative position of coil and magnet:For the magnet with larger diameter and smaller thickness,the electromagnetic forces have extreme value with the change of relative position,and the electromagnetic forces near the extreme point have high stability and con⁃sistency.In addition,according to the variation trend of electromagnetic force,a high-precision setting scheme of the fiducial position(the location of extreme point)of coil and permanent magnet is proposed.And the varia⁃tion coefficient of electromagnetic force near the fiducial position is about 0.00252.Finally,the large-diameter magnet and coil combined electromagnetic force generation device is determined,and the high-precision electro⁃magnetic force control relationship with a standard error of estimate 0.0137 is established based on the fitting method.