High-accuracy Modeling of Ship Deformation Based on Inertial Measuring Method

Abstract

High-accuracy modeling is the key problem of ship deformation measurement based on inertial measuring method. This paper is to find a high-accuracy modeling method based on the ship deformation data measured by optical devices. According to different modeling methods, mathematical models are designed by the analysis of the initial measurement data. Wavelet analysis method is introduced in the process of modeling. Attitude matching method is selected as the simulation algorithm and Kalman filter equations are set up based on the algorithm. Simulation results show that the ship deformation can be represented accurately by mathematical models. The Precision Estimation result is better than 0.4''.

A model-free hull deformation measurement method with time delay compensation

“…where T is the sampling time, q i, k is the kth sampling value of q i , and q i, kÀ1 is the (k -1)th sampling value, i = 1, 2, 3, 4. By inserting equation (12) into equation ( 7), we get…”

“…[1][2][3][4][5][6][7][8] If the inertial sensors used are accelerometers and gyroscopes, velocity and angular velocity matching function can be established based on the sensor information. 9,10 In addition, in order to improve the signal-to-noise ratio of the deformation measurement results, the attitude matching function has been established by choosing attitude as observation, compared with the other two methods; it can obtain higher precision deformation estimation results, 11,12 for this reason we use it as the basis of inertia matching method in this article. In terms of hull deformation model, IMMM commonly divides the hull deformation into static deformation and dynamic deformation and models them, respectively.…”

“…The second-order Gauss-Markov process is the most commonly adopted to depict the dynamic deformation according to its time characteristics. [1][2][3][6][7][8][9][10][11][12][13][14][15][16][17] To improve the dynamic deformation model according to the specific working condition and environment, an integrated Gauss-Markov processes model has been proposed 5 instead of the traditional second-order Gauss-Markov process model. Although IMMM with this model can give acceptable results in many applications, it has been recognized that these dynamic deformation model does not consider correlation between three dimensions.…”

“…Hull deformation estimation is of great significance for inertia matching method to acquire high accurate result. Kalman filtering is the most widely used state estimation method for hull deformation estimation; [1][2][3][4][5][10][11][12][13][14][15][16][17][18][19][20] it can solve linear problem with good convergence and the ability to remove high-frequency noises. However, when the inertia matching function is nonlinear, KF is not suitable.…”