关键词: 安装误差, 多测头, 纳米时栅, 测量精度

Abstract: 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.