船舶纵向运动控制模型的建立及仿真

针对船舶在海上运动的情况,提出了一种水动力模型的建立方法.依据切片理论建立了不同浪向下船舶纵向运动的水动力模型.基于船模水池实验,在分析442 t水面舰艇典型海况下水动力系数的基础上,通过仿真研究,推导出一种实时在线的船舶纵向运动控制模型;给出了计算实例并进行了误差均值和误差方差的可信度检验,置信度95%.该模型可实时在线地计算出船舶在任何航向、航速及海情下与频率无关的船舶纵向运动水动力系数,从而得到实时在线船舶纵向运动控制模型.所建立的水动力模型拟合均方差的相对值在0.4%～13.9%,平均拟合均方差的相对值为6.6%.通过MATLAB仿真计算证明:该模型完全能控、完全能观和渐进稳定.

Modeling and simulation on control of ship longitudinal motion

With the aid of slice theory, the hydrodynamic models for ship longitudinal motions were built up in terms of various wave directions. Based on the water pool experiments and the analysis of hydrodynamic coefficients of the 442T surface ship in particular sea situation, an on-line real-time control model for ship longitudinal motions was derived through computer simulations. The computational examples were given. The confidence test was made for mean error and mean square error, reaching up to 95 percent. This model can on-line compute the hydrodynam- ic coefficients of ship longitudinal motions independent of frequencies in any direction and sea situation, at any speed, so that an on-line control model of ship longitudinal motion was obtained. The fitted mean variance of hydrodynamic model proposed in this paper lies between 0.4% and 13.9% , while the average fitted mean variance is 6. 6%. The results of simulation with MATLAB indicate that this model is completely controllable, visible and asymptotically steady.