双层反倾线圈结构的直线时栅位移传感器研究

Research on Linear Time-Grid Displacement Sensor with Double Inverting Coil Structure

针对前期研究的双层直线时栅位移传感器测量误差成分中四次谐波较大,影响传感器测量精度的问题。根据双层激励线圈的结构特点,提出了一种双层反向倾斜线圈结构的直线时栅位移传感器设计方案。通过构建双层反倾线圈产生磁场的数学模型,分析了双层反向倾斜线圈的磁场状态,并利用电磁场有限元仿真分析双层反倾线圈直线时栅位移传感器中倾斜大小和动定尺之间的气隙对测量误差与误差谐波成分的影响,确定了最优化的设计参数。采用PCB(Printed Circuit Board)工艺研制了78个节距大小的传感器样机并进行了精度测试。实验结果表明,双层反倾斜线圈结构对原双层直线传感器中误差四次谐波抑制效果显著,在同样设置条件下,将原测量误差成分中四次谐波从40μm抑制到7μm,抑制效果达到82.5%。最终经过误差修正后的传感器对极内精度达到±13μm。

Aiming at the problem that the fourth harmonic in the measurement error component of the double-layer linear time grating displacement sensor is large,which affects the measurement accuracy of the sensor,according to the structure characteristics of double-layer excitation coil,a linear time grating displacement sensor with double-layer reverse-inclined coil structure is proposed.By building a mathematical model of double-layer reverse-indined coil magnetic field,the double reverse tilt coil magnetic field condition is analyzed,and by using electromagnetic field finite element simulation,the influence of the tilt size of the double layer inverting coil linear grating displacement sensor and the air gap between the dynamic scale and the static scale on measurement error and error harmonic components is analyzed,and the optimized design parameters are determined.PCB Board(Printed Circuit)technology is used to develop 78 pitch sensors and their accuracy.The experimental results show that the double-layer antitilting coil structure has a significant suppression effect on the fourth harmonic of the error in the original double-layer linear sensor.Under the same setting conditions,the fourth harmonic of the original measurement error component is suppressed from 40μm to 7μm,and the suppression effect reaches 82.5%.Finally,the accuracy of the sensor is±13μm after error correction.