旋转加速度计重力梯度仪加速度计标度因数实时反馈调整方法  

Real-time feedback adjusting methods for accelerometer scale factor in gravity gradiometer of rotating accelerometer

作　　者：钱学武[1] 蔡体菁[1] 

机构地区：[1]东南大学仪器科学与工程学院,南京210096

出　　处：《中国惯性技术学报》2016年第2期148-153,共6页Journal of Chinese Inertial Technology

基　　金：国家高技术研究发展计划(863计划)项目(2011AA060501)

摘　　要：旋转加速度计重力梯度仪在实际工作过程中,由于平台稳定性、旋转机构控制精度、敏感器安装误差、加速度计标度因数匹配性以及其他噪声源的存在,对高精度重力梯度测量构成严峻挑战。在诸多影响因素中,加速度计标度因数的不一致性对测量精度影响最大。本文提出一种旋转加速度计重力梯度仪加速度计标度因数实时反馈调整方法,旨在提高获取重力梯度信号的能力。该方法首先对相对两只加速度计的和输出信号以及重力梯度仪总输出信号分别进行带通滤波,然后对滤波器输出信号中含有加速度计标度因数不平衡信息信号进行幅值解调,对三组解调结果分别进行平滑处理,采用模糊PID控制算法实时反馈调整加速度计内部的电磁线圈力矩,达到调整加速度计标度因数的目的。实验测试分析表明,采用模糊PID反馈调整算法可以快速实现四只加速度计标度因数一致,相对两只加速度计标度因数调整量级可以达到10?7,两对加速度计标度因数的调整量级可以达到10?5,提高了获取重力梯度信息的能力。High-precision measurement in gravity gradiometer of rotating accelerometer encounters severe challenge when exists such factors as the instability of the platform, the limited accuracy of the rotating mechanism, the accelerometer＇s misalignment, the inconsistency of accelerometer＇s scale factors and other noises. Among these factors, the accelerometer scale-factor mismatching plays a decisive role. This paper proposes an algorithm to solve this problem. Firstly, the band-passing filters are used to filter the output signals of the two opposing accelerometers and the total output signal of the GGI, respectively. Secondly, the output signals of filters are demodulated, and then, three demodulation results are smoothed. At last, the scale factor with the Fuzzy-PID feedback algorithm is adjusted. Experiment results by the proposed method prove that the inconsistency of the scale factors of four accelerometers on GGI can be dramatically improved, the adjustment level of the scale factor unbalances between the accelerometers pairs can reach 10？7, and the adjustment level of the scale factor balance of two pairs of accelerometers can reach 10？5, which show that the precision of gradient signal can be improved.

关 键 词：重力梯度仪 旋转加速度计 标度因数调整 带通滤波器 

分 类 号：U666.1[交通运输工程—船舶及航道工程]