링레이저 자이로 3축 단일 디더 형상에 따른 고유 주파수 특성 분석

Abstract

The ring laser gyro, a representative optical gyro, has an area where small angular velocity inputs are not measured due to backscattering of the reflector. This area, referred to as a lock-in, is typically removed by applying a very large sinusoidal vibration to the gyro body. A mechanical device that applies sinusoidal vibration to the gyro body is called a dither. Dithers have various shapes depending on the gyro size, and when the gyro optical path is relatively large, a single-axis dither is applied. In the case of a single-axis dither, it is located at the center of the gyro body, but if the optical path of the gyro is small, a cluster dither that simultaneously applies sinusoidal vibration to the 3-axis gyro should be used. In the cluster dither, unlike the single-axis dither, a gyro body tilted at a certain angle is mounted on the spoke of the dither, and the gyro mounting part for mounting the gyro is attached at the end of the spoke. In addition, the dither fixing hole is located in the center of the gyro body in the case of single-axis dither, whereas is located on the outside of the dither in the case of the cluster dither. Therefore, unlike the single-axis dither, the rotation center of the cluster dither does not coincide with the center of the gyro body, but rather is located at the center of the cluster dither. Depending on the shape of the cluster dither, the dither natural frequency varies and a different dither frequency analysis method must be applied. In this paper, we analyze natural frequency characteristics according to the shape of a cluster dither and present the results. We also verify the results through modeling and simulation.