舵阻摇H∞控制器的设计

舵阻摇的效果对船舶水动力参数敏感,Ｈ_∞控制器对模型不确定性具有良好的适应性。本文设计了一种基于并联控制模式的舵阻摇Ｈ_∞控制器。模拟海上航行条件的计算机仿真表明该控制器具有良好的鲁棒特性。     

采用CFD得到的横摇阻尼的船舶横摇分析：数值和实验研究（英文）

This study investigates the roll decay of a fishing vessel by experiments and computational fluid dynamics(CFD)simulations. A fishing vessel roll decay is tested experimentally for different initial roll angles. The roll decay is also simulated numerically by CFD simulations and is validated against the experimental results. It shows that the roll damping could be obtained by CFD with high level of accuracy. The linear and nonlinear damping terms are extracted from the CFD roll decay results and...     

基于FDLQR的喷流舵船舶航向横摇控制研究

本文探讨了目标船在随机海浪干扰下的喷流舵减摇控制问题。首先,介绍喷流舵流体动力特性,并通过内插值获取理想线性控制输入。将水面船舶4自由度非线性耦合模型简化为3自由度直航线性模型,并针对单舵舵减摇控制问题,提出基于线性模型的分频线性二次型最优控制方法,构建了航向/横摇综合控制仿真数学模型。最后,在不同工况进行喷流舵控制对比仿真研究。结果表明,喷流舵在航向/横摇控制性能上可以获取更优的效果。设计的分频线性二次型最优控制器具有较强的性能跟踪能力,并兼顾到控制成本。基于该控制方法的喷流舵控制对实际船舶航向横摇控制,尤其在低航速航行时的控制具有重要的参考价值。     

破损进出水对船舶参数横摇的影响（英文）

船舶破损进水不一定会导致船舶倾覆,在破损流动过程以及破损流动达到稳定之后,破损船舶的运动特性非常值得研究。文章主要基于CFD方法和势流方法研究了破损进水对船舶参数横摇的影响。首先基于非定常RANS方程结合VOF方法,研究了破损舱室的破损流动过程,并且通过已有的模型试验,验证了计算方法的可靠性;然后,基于三维时域混合源法,考虑破损进出/水引起的额外载荷,研究了破损流动对破损船舶参数横摇运动的影响。研究表明,破损流动对横摇幅值的影响类似于被动减摇水舱,并且影响力度与破损舱室所在的纵向位置有关。     

船舶横摇阻尼的CFD数值模拟研究（英文）

船舶横摇阻尼是影响参数横摇和瘫船稳性等大幅横摇运动的关键参数。文中基于非定常RANS方程在静水中对模型2792进行了自由横摇衰减的数值模拟,该模型是船舶第二代完整稳性衡准制定中瘫船稳性研究的国际标准船模,数值模拟中采用了两种网格类型,一种是滑移网格,另一种重叠网格。计算结果表明,数值模拟的自由横摇衰减曲线和模型试验结果吻合良好,另外CFD计算的横摇阻尼与试验值的误差小于Ikeda’s经验公式计算的误差,证明非定常RANS方程可用于预报横摇阻尼。     

基于改进型消灭曲线法的横摇阻尼估算（英文）

自由衰减试验仍是目前最为有效且常用的估算横摇阻尼系数的方法。横摇阻尼系数的估算精度对于船舶横摇运动的预报起着至关重要的作用。通常采用所谓的消灭曲线法来分析自由横摇衰减数据。该方法的一个不足之处在于其推导是基于忽略了非线性恢复力项的自由横摇运动方程。另一方面,考虑更多非线性成分的能量法能够纳入该因素影响但在实施过程中较为复杂。文中提出了一种改进型的消灭曲线法,能够纳入船体非线性恢复力项的影响。所提出的方法形式简单且相比能量法更易于实施。数值试验证明了改进型消灭曲线法的正确性,并展现了其相对传统消灭曲线法所具有的优势。     

基于T-S模糊模型的船舶舵减横摇H∞状态反馈控制

提出了一种新的船舶舵减摇控制器的设计方法。首先建立了船舶横摇和艏摇运动控制的Takagi-Sugeno(T-S)模糊模型,然后利用并行分布补偿(PDC)原理,得到了该系统的H∞状态反馈模糊控制器。应用李雅谱诺夫稳定性理论和线性矩阵不等式方法推导了H∞控制器的设计。仿真结果验证了所设计H∞模糊控制器能够有效地减小横摇。     

用有效的解析和数值方法估算船舶在随机横浪中的横摇运动（英文）

A steady-state roll motion of ships with nonlinear damping and restoring moments for all times is modeled by a second-order nonlinear differential equation. Analytical expressions for the roll angle, velocity, acceleration, and damping and restoring moments are derived using a modified approach of homotopy perturbation method(HPM). Also, the operational matrix of derivatives of ultraspherical wavelets is used to obtain a numerical solution of the governing equation. Illustrative examples are provided to examine the applicability and accuracy of the proposed methods when compared with a highly accurate numerical scheme.     

基于细菌觅食算法的船舶舵减横摇PID控制器设计

为解决传统舵减横摇PID控制器在外界环境变化时,控制参数不能实时调节,导致减摇效率降低的问题,将细菌觅食算法(BFO)与传统的PID控制结合,设计基于细菌觅食算法的船舶舵减横摇PID控制器(BFO-PID控制器),将船舶的实际船体参数引入到船舶横摇运动控制系统中,通过仿真实验对比船舶在加入BFO-PID控制器前后船舶横摇角的变化,分析改进后的控制器对该型船舶舵减横摇的适用性,实验表明,运用改进后的舵减摇控制器,船舶在不同遭遇角下均具有较好的舵减摇效率,证明控制器改进的有效性,细菌觅食算法提高了舵减摇控制器的鲁棒性。     

基于多目标遗传算法舵鳍联合减摇系统能量优化研究（英文）

Energy optimization is one of the key problems for ship roll reduction systems in the last decade. According to the nonlinear characteristics of ship motion, the four degrees of freedom nonlinear model of Fin/Rudder roll stabilization can be established. This paper analyzes energy consumption caused by overcoming the resistance and the yaw, which is added to the fin/rudder roll stabilization system as new performance index. In order to achieve the purpose of the roll reduction, ship course keeping and energy optimization, the self-tuning PID controller based on the multi-objective genetic algorithm(MOGA) method is used to optimize performance index. In addition, random weight coefficient is adopted to build a multi-objective genetic algorithm optimization model. The objective function is improved so that the objective function can be normalized to a constant level. Simulation results showed that the control method based on MOGA, compared with the traditional control method, not only improves the efficiency of roll stabilization and yaw control precision, but also optimizes the energy of the system. The proposed methodology can get a better performance at different sea states.     

非均匀表面上移动的冲翼艇的横摇-垂荡-纵摇运动建模（英文）

Ground-effect vehicles flying close to water or ground often employ ram wings which generate aerodynamic lift primarily on their lower surfaces. The subject of this paper is the 3-DOF modeling of roll, heave, and pitch motions of such a wing in the presence of surface waves and other ground non-uniformities. The potential-flow extreme-ground-effect theory is applied for calculating unsteady pressure distribution under the wing which defines instantaneous lift force and moments. Dynamic simulations of a selected ram wing configuration are carried out in the presence of surface waves of various headings and wavelengths,as well as for transient flights over a ground obstacle. The largest amplitudes of the vehicle motions are observed in beam waves when the periods of the encounter are long. Nonlinear effects are more pronounced for pitch angles than for roll and heave. The present method can be adapted for modeling of air-supported lifting surfaces on fast marine vehicles.     

浅液深和挡板影响下遭受横摇激励的晃荡问题数值研究（英文）

Sloshing is relevant in several applications like ship tanks,space and automotive industry and seiching in harbours.Due to the relationship between ship and sloshing motions and possibility of structural damage,it is important to represent this phenomenon accurately.This paper investigates sloshing at shallow liquid depths in a rectangular container using experiments and RANS simulations.Free and forced sloshing,with and without baffles,are studied at frequencies chosen specifically in proximity to the first mode natural frequency.The numerically calculated free surface elevation is in close agreement with observations from experiments.The upper limit of the resonance zone,sloshing under different filling depths and roll amplitudes and sloshing with one,two and four baffles are also investigated.The results show that the extent of the resonance zone is reduced for higher filling depth and roll amplitude.It is also found that the inclusion of baffles moves the frequency at which the maximum free surface elevation occurs,away from the fundamental frequency.Finally,a submerged baffle is found to dissipate more energy compared to a surface piercing baffle and that the effect of several submerged baffles is similar to that of a single submerged baffle.     

三维船体横摇运动数值模拟及舭龙骨阻尼特性研究（英文）

为研究舭龙骨阻尼特性及尺寸航速等因素的影响,本文基于计算流体动力学方法分别对有、无舭龙骨三维船体的自由横摇衰减运动以及强迫横摇运动进行数值模拟研究,有无舭龙骨的三维船体的横摇阻尼之差即为舭龙骨阻尼。对F_r=0.138、初始横摇角10°带舭龙骨船体的自由横摇衰减数值模拟算例作了验证与确认分析,自由横摇衰减时历曲线与实验结果吻合较好,固有周期和横摇阻尼精度较高。进一步分析研究了不同几何尺寸、初始横摇角、航速以及频率等参数对舭龙骨阻尼的影响。自由横摇衰减模拟研究中舭龙骨阻尼随着舭龙骨宽度、初始横摇角度的增大而增大;当航速为0时,舭龙骨阻尼在总阻尼占比最大,航速对舭龙骨阻尼绝对值影响较小。强迫横摇模拟研究表明:当横摇角一定,舭龙骨阻尼随着频率的增大而非线性增大,在固有频率附近,粘性效应不可忽略。     

规则迎浪中船舶参数横摇的三维时域预报方法研究（英文）

参数横摇是船舶因复原特性改变而引起的典型非线性现象。文章采用三维时域方法预报规则迎浪中船舶的参数横摇运动。该方法引入匹配面将流域分为内域和外域,内域中采用Rankine源来满足物面条件和线性自由面条件,而外域中应用时域格林函数来满足线性自由面条件和远场辐射条件。数值方法中,Froude-Krylov力和恢复力是通过对船舶瞬时湿表面积积分获得,同时考虑了横摇、垂荡和纵摇三自由度之间的耦合作用,以及非线性横摇阻尼的影响。数值结果与试验结果吻合很好,说明该方法可以有效地预报参数横摇。     

大幅船舶横摇运动非线性附加质量惯性矩和阻尼矩特性的非参数识别（英文）

This study aims to investigate the nonlinear added mass moment of inertia and damping moment characteristics of largeamplitude ship roll motion based on transient motion data through the nonparametric system identification method. An inverse problem was formulated to solve the first-kind Volterra-type integral equation using sets of motion signal data. However, this numerical approach leads to solution instability due to noisy data. Regularization is a technique that can overcome the lack of stability; hence, Landweber's regularization method was employed in this study. The L-curve criterion was used to select regularization parameters(number of iterations) that correspond to the accuracy of the inverse solution. The solution of this method is a discrete moment, which is the summation of nonlinear restoring, nonlinear damping, and nonlinear mass moment of inertia. A zero-crossing detection technique is used in the nonparametric system identification method on a pair of measured data of the angular velocity and angular acceleration of a ship, and the detections are matched with the inverse solution at the same discrete times. The procedure was demonstrated through a numerical model of a full nonlinear free-roll motion system in still water to examine and prove its accuracy. Results show that the method effectively and efficiently identified the functional form of the nonlinear added moment of inertia and damping moment.     

参数横摇对集装箱船设计和运营的影响

<正>纯稳性丧失、参数横摇、骑浪(横甩)是船舶在波浪中的3种典型倾覆现象,其中,参数横摇是目前国际海事组织(IMO)正在研究的船舶第二代完整稳性衡准技术中5种失效模式之一。研究人员普遍认为,参数横摇是由船舶在波浪中的复原力周期性变化而导致的非线性现象,其主要特点是:船舶在顶浪状态下产生垂荡、纵摇运动的同时伴随着大幅度横摇运动。大量研究表明,当船舶的横摇固有频率等于其在波浪中遭遇频率的50%时,船舶可能产生显著的横摇运动,即参数横摇。大型集装箱船的艏     

基于固定网格小波神经网络的不规则波中船舶横摇运动在线预报（英文）

船舶横摇运动预报对于船舶安全与作业非常重要。本文应用固定网格小波神经网络在线预报不规则波中的船舶横摇运动。该固定网格小波神经网络由离散的小波激活函数组成,其结构和参数可以基于滑动数据窗在线调整;在每一个滑动数据窗,误差下降比判据被用来从小波函数库中选择重要的小波函数项来构建小波神经网络模型,直到该模型可以较好地表达所研究的非线性系统,获得的模型一般比较简洁。预报结果表明,仅仅几个小波函数项就可以很好地捕捉到不规则波中船舶横摇运动的非线性动力学内在特性,这不仅展示了小波函数很强的非线性表达能力,也证实了所采用的建模方法对于预报船舶在不规则波中的横摇运动的有效性。     

波激和涡激Spar平台在垂荡主共振时垂荡、横摇和纵摇内共振响应（英文）

The objective of this paper is to study the nonlinear coupling internal resonance of the heave, roll, and pitch response performance of a spar platform when their frequencies are in the ratio of 2:1:1 under wave and vortex exciting loads.The three degree-of-freedom(DOF) nonlinear coupled equations are established by considering a time-varying wet surface with a first-order wave force in heave and pitch and a vortex-induced force in roll. The first-order steady-state response is solved using the multi-scale method in heave main resonance. The multiple solutions of the motion equations are discussed using the analytic method and a numerical simulation. A sensitivity analysis is conducted to test the influence of the damping and internal detuning parameter. The regions of multiple solutions are found, and the jump phenomenon exists with the changes of the wave excitation. The regions of multiple solutions depend on the values of damping and detuning parameter.