基于CKF的非线性船体变形惯性测量方法

CKF-based inertial measurement methods to determine nonlinear hull deformation

船体变形的精确测量对于优化大型船体结构设计、不同部位的刚度设计以及提高舰船传递对准精度都有很现实的意义,而基于惯性传感器的角速率匹配法是测量船体变形的研究热点。针对大型船体中惯性测量单元存在大安装误差角的情况,建立非线性的船体变形模型以及光纤陀螺的漂移模型,采用CKF滤波方法进行估计;理论推导了UKF与CKF两种非线性滤波的估计精度,并进行了理论比较分析与仿真验证。结果表明随着航向安装误差角从30°增加到50°,静态误差角和动态误差角的估计精度始终保持在20″以内。与UKF相比,随着系统非线性程度的增强,CKF的性能优势更加明显。

Accurate measurement of the deformation of a hull structure is of real significance in efforts to optimize large hull designs,maximize the stiffness of different parts,and improve the alignment and transfer precision of ships. Methods that measure hull deformation based on inertial angular rate sensor matching are a current research hot- spot. In the case of large misalignment angles for large hull inertial measurement units,a non-linear hull deformation model and a drift model of FOG were established using the C K F filtering method for estimation. The estimation accuracies of two nonlinear filtering methods, i. e.,UKF and CKF,were then theoretically derived, compared,and simulated. R e-sults showed that as the heading misalignment angle is increased from 30° to 50°,the estimation accuracies of the static and dynamic error angles remain within 20M. Compared with that of U K F ,the performance advantage of CKF becomes more apparent following enhancement of the degree of non-linearity of the system.