线性测微电感的精化

为提高测微电感传感器的测量精度,提出了基于赫姆霍兹线圈理论设计螺线管线圈的方法,改善了螺线管线圈内轴向上磁场的分布均匀性。首先,分析了螺线管线圈模型,建立了螺线管线圈参数与轴向磁场强度分布相互关系的广义函数模型。然后,通过线圈与磁芯的尺寸确定了系统轴向磁场强度分布函数模型,结合磁芯移动区间范围设置磁场均匀度最小误差目标函数,通过对目标函数寻优得到各螺线管线圈的各项参数。最后,搭建了测微电感传感器的测试系统,测试了传感器性能。实验结果表明:与传统线圈相比,改进型螺线管线圈在100μm测量范围内的线性度由0.46%提高到0.30%。实验显示通过对不同规格的螺线管线圈进行组合,可使得螺线管内轴向上磁场强度分布均匀,从而提高了测量精度。

Improvement of precision for linear inductance micrometer

To improve the performance of a micrometer inductive sensor, a design method of solenoid coils was put forward based on the theory of Helmholtz coils to improve the uniformity of the axial magnetic field of a solenoid coil. Firstly, the model of the solenoid coil was analyzed and the generalized function model between the parameter of solenoid coil and the axial magnetic field intensity distribution was established. Then, the system function model for axial magnetic field intensity distribution was determined based on the parameters of the core and coil sizes, the minimum error objective function of the uniformity for the magnetic field was set from the core moving range, and the best parameters of solenoid coil by objective function optimization were obtained. Finally, a test system for the micrometer inductive sensor was established to get its detection performance. The test results show that modified solenoid coil improves the linearity from 0.42% to 0.25% in 100 μm measurement range as compared with the original solenoid coil. It concludes that the modified solenoid coil uniforms the intensity distribution of the axial magnetic field and enhances the measurement accuracy.