安装误差对于电场式圆时栅传感器测量精度的影响规律及抑制方法

Influence of installation error on the measurement accuracy of electric field type circular time-grating and the suppression method

在纳米时栅传感器安装过程中,转子相对于定子的偏心或偏摆,是角位移传感器整周测量误差的主要来源。运用面积积分法进行数学建模,分析在安装不满足正对平行条件时的整周误差及其谐波频次,揭示采用多个电极进行信号拾取会具有一种匀化效应,能够减小由安装带来的谐波误差。采用印制电路板(PCB)工艺制造直径为305 mm的传感器样机,在不同测头数量的条件下进行精度对比实验。实验结果表明:多测头结构能够对整周误差产生抑制与匀化作用,使传感器整周测量精度达到1.5″,接近平行正对安装时的测量精度,验证了多测头结构对安装误差的抑制作用。

The eccentricity of the rotor relative to the stator during the installation of the nano time grating sensor is the main source of the full circumference measurement error of the angular displacement sensor.In this paper,mathematical modeling using the area integration method is applied to analyze the full-perimeter error and its harmonic frequency brought by the installation not satisfying the orthogonal parallelism condition.It reveals that using multiple electrodes for signal pickup has a homogenization effect and reduces the harmonic error brought about by the installation.A prototype sensor with a diameter of 305 mm is fabricated by using a printed circuit board(PCB)process,and accuracy comparison experiments are conducted under different probe numbers.Our experiments show after the error elimination and homogenization caused by multiple probe structures,the sensor achieves a full circumferential measurement accuracy of 1.5″,close to the measurement accuracy of parallel square mounting,demonstrating the suppression of mounting errors by multiple probe structures.