振动对光纤陀螺线形测量系统影响分析

Analysis of Influence from Vibration on FOG Based Measurement System

摘要:

在使用光纤陀螺测量系统对桥梁线形进行测量的过程中,由于线形测量结果是通过积分算法得到的,所以来自汽车发动机和路面不平的振动影响会给测量结果带来巨大的误差,并且这类误差会随着测量时间和距离的增加变得越来越大,呈现出发散的特性;为了减小这些振动给测量结果带来的误差,可以使用时频分析的手段,通过时间信息和运动速度得到位置和路况信息,进而得到不同路况下的频域特点;选择路面完好的路段进行实验,点状减速带代表路面不平,使用Morlet小波对光纤陀螺采集到的信号进行时频分析,发现了不同工况下带来的振动噪声信号的频域特点,并且确定了27 Hz以上均为振动带来的噪声信号;在实际对某跨江大桥的线形测量中,使用切比雪夫滤波器去除光纤陀螺所采集到27 Hz以上的噪声信号,相比没有使用低通滤波处理的线形,测量精度提高了50%。

Abstract:

In process of measuring the line-shape of bridge structure by FOG based measurement system,as the line-shape is calculated by the integral algorithm, the vibration and shock from vehicle and rode surface can result in large measurement error. And the error will be accumulated with the increase of measurement time and distance, showing the characteristics of divergence. In order to reduce the influence from vibration and shock, obtaining location and traffic information through the data of time and speed with the means of time-frequency analysis, and then getting the frequency characteristics of different road conditions. Choosing a flat road with a dotted speed bump to complete the experiment, then finding different road conditions will bring in different frequency domain characteristics, also finding the signal above 27 Hz is noise by time-frequency analysis with Morlet Wavelet Transform. At last, taking a River Bridge as an example, processing FOG signal with Chebyshev low-pass filter to remove the noise signal higher than 27 Hz, and results show that the measurement precision have been improved by 50%.