基于LQR限宽水域中KVLCC2操纵运动控制研究

在航道宽度受限制的水域中,船舶会受到岸壁效应的影响,横向力与首摇力矩将发生变化,这会对船舶的航行安全产生不利的影响。鉴于此问题,本文应用现代控制理论最优控制LQR方法,对在限制水域中航行的超大型油轮KVLCC2的操纵运动进行控制研究。为便于LQR控制器的设计,采用线性状态空间形式的操纵运动方程,基于数值模拟获取的相应线性水动力系数,计算出使目标函数值最小的增益矩阵K,从而得到满足最优控制规律的时域舵角变化,实现对不同宽度水域中船舶运动的最优控制,并与极点配置控制法作比较,验证LQR控制器的优越性。结果表明,当船岸距离d/L≥1.2时,船舶基本不受岸壁效应的影响,控制幅度极小;当岸壁距离d/L=0.25时,摆舵角度将超过6°,同时船舶前进速度也将下降,下降幅度将超过前进速度的10%,岸壁效应明显。     

大型重载船舶在受限水域操纵中若干问题探讨

大型重载船舶航行在受限水域,不仅缩小了可航水道的宽度,并且富余水深小,浅水效应与岸壁效应明显,增大了操纵难度.此文结合水深、航道宽度等影响因素,阐述了大型重载船舶港内受限水域操纵中,对于船位控制、过弯操纵以及拖轮应急制动等方面的特殊要求,并结合船舶操纵实际,提出在受限水域中的安全操纵要领及注意事项.     

重载船舶安全驶出黄骅港航道应注意的几个问题

黄骅港航道水域属于受限水域,船舶在此种水域中航行时,会发生浅水效应及岸壁效应,重载船舶这种效应更甚。文章根据黄骅港水域的特点,提出了航行于黄骅港航道时应注意的问题及应采取的安全操纵方法。     

自然环境对船舶操纵的影响与控制

船舶操作是控制船舶在水中运动的技术,其要求操作者掌握熟练的操作技术,以协调船舶在水域上的运行状态.一般情况下,船舶操纵由专业技术人员完成,主要工作内容是按照船舶的操纵性能和车、舵效应,结合风、流和水域等客观条件,运用船舶推进器、舵、锚、缆、拖船等,以保持或改变船舶运动状态.文章分析了自然环境对船舶操纵的影响与控制.     

船舶受限水域航行安全研究

船舶大型化发展导致其无法避免航行于受限水域,受限水域对船舶安全航行的威胁不容忽视,为提高船舶在受限水域的航行安全,本文将岸壁效应和浅水效应对船舶航行的影响进行了阐述,并提出了相应的应对措施,以期对船舶在受限水域的安全航行有所裨益。     

浅狭航道中船舶操纵性能的预报仿真

利用深水平面MMG船舶操纵运动数学模型,通过浅水修正和岸壁效应近似建立了船舶在浅狭航道中操纵运动数学模型,针对M ariner船开展了浅狭航道中的操纵运动预报,探讨了直航状态下浅水及岸壁效应对船舶运动轨迹和航向的影响,仿真结果能够为船舶在浅狭航道中的操纵与控制提供参考。     

广州港航道船舶“侧壁效应”现象的危害及预防

<正>0引言多次经人工疏浚的广州港航道,宽度为100~250 m,航道边缘及外侧的水深相差很大,时有变化。对于大型船舶,可航水域宽度受到限制,当船舶因避让或因操纵人员的疏忽而使船位偏离航道中线、过于靠近航道一侧岸壁航行时,往往发生船尾被吸向岸壁、偏离主航道,同时船首向航道中心线快速偏转且操满舵无法克服的"侧壁效应"现象。这种现象会引发船尾触碰航道岸壁,损及车舵,若发生在两船会遇时容易造成两     

基于CFD的内河船深浅水中操纵性预报

由于岸壁效应和浅水效应,内河船舶在限制水域作操纵运动时通常受到比在开阔水域中更大的水动力.这些水动力对船舶操纵性具有不利影响,有可能导致船舶碰撞或触底等海上事故.因此,为了在船舶设计阶段预报其操纵性能,考虑浅水效应和岸壁效应以准确计算内河船舶操纵运动水动力非常重要.本文基于CFD方法,通过对粘性绕流进行数值模拟,对长江中营运的三艘内河船舶的操纵运动水动力进行计算.首先,为了验证数值方法的可靠性,对标模KVLCC2纯横荡和纯首摇试验的水动力进行计算,并将计算结果与现有的试验数据进行对比.然后,对三艘内河船舶在不同水深下的静舵试验、纯横荡和纯首摇试验进行数值模拟,计算得到水动力及相应的线性水动力导数.最后,基于计算得到的水动力导数,获得Nomoto模型中的操纵性参数,对比分析三艘内河船舶在深浅水中的操纵性能.结果表明,本文方法可以揭示不同水深下三艘内河船舶的操纵性变化趋势.该方法可为船舶设计阶段内河船舶深浅水中的操纵性预报提供一种实用的工具.     

基于变结构控制理论的船舶非线性控制仿真研究

为了提高船舶的航行安全性以及航行中的舒适性,设计了舵鳍联合减摇控制器.分析了船舶运动的非线性模型,根据实际情况进行假设,得到了船舶舵鳍联合减摇控制系统的状态方程,把非线性船舶鳍联合控制模型转化为可控正则型;将船舶运动模型看作是由横摇、艏摇、横荡3个子系统构成的大系统,进行了舵鳍联合控制,设计了分散变结构控制器,最后针对这类控制器进行了MATLAB仿真研究.仿真结果表明舵鳍联合控制器能够很好的抑制船舶的横摇和艏摇,并能尽可能大的减小横荡.     

大型船舶在浅窄水域航行的风险控制

大型船舶的增加使得许多水域相对变浅变窄已成为一种较为普遍的现象. 当船舶从深水开阔水域驶入浅窄水域时,周围水流的分布、水阻力、船速、吃水和操纵性等会发生一系列的变化,如船体下沉、纵倾变化、操纵性能变差、螺旋桨转速下降、舵效降低、回转性能变差等等,大型船舶浅窄水域航行的风险增加.因此船舶进入浅水区域,增强风险意识,熟悉大型船舶的操纵性能及浅窄水域对其的影响,对于安全航行和操纵的风险控制非常重要.     

Circular motion tests and uncertainty analysis for ship maneuverability

Circular motion test data and uncertainty analysis results of investigations of the hydrodynamic characteristics of ship maneuvering are presented. The model ships used were a container ship and two tankers, and the measured items were the surge and sway forces, yaw moment, propeller thrust, rudder normal and tangential forces, pitch and roll angles, and heave. The test parameters were the oblique angle and yaw rate for the conditions of a hull with a rudder and propeller in which the rudder angle was set to zero and the propeller speed was set to the model self-propulsion conditions. Carriage data showing the accuracy of the towing conditions in the circular motion test are also presented. It was confirmed that the uncertainties in the hydrodynamic forces such as the surge and sway forces, yaw moment, rudder tangential and normal forces, and propeller thrust were fairly small. The reported uncertainty analysis results of the circular motion test data may be beneficial in validating data quality and in discussing reliability for simulation of ship maneuvering performance.     

船舶操纵模拟器操纵仿真数学模型

系统地论述了船舶操纵仿真数学模型。包括船舶操纵基本模型、水动力、螺旋桨推力及扭距、主机扭距、舵力及其力矩、风、浪、流、锚、缆、拖轮的作用力、浅水影响及侧壁效应,最后给出了主要仿真结果和主要结论     

操纵运动船舶的水动力计算研究

以船舶操纵水动力预报为研究背景,通过对商用计算流体力学软件FLUENT的二次开发,采用其动网格技术以及后处理系统,对大型船舶操纵水动力导数进行了数值计算.船体按照斜航、不同舵角、纯横荡和纯首摇等状态做运动,得出随船坐标系下作用于其上的水动力及力矩.通过进行基于最小二乘法的曲线拟合,最终求得船舶操纵水动力导数.计算结果与势流理论计算结果一致,表明了所提出的计算方法适用于复杂船舶运动的水动力导数计算.     

Study on the maneuverability of a large vessel installed with a mariner type Super VecTwin rudder

The suitability of the Mariner type Super VecTwin rudder (hereinafter, the MSV rudder) for a large vessel is assessed in this article. Several experiments in a maneuvering pond were carried out and their results analyzed and summarized. Free-running tests such as turning, zigzag, and stopping tests were carried out with a 4-m free-running model of a very large crude carrier (VLCC) ship with the MSV rudder and the Mariner rudder. The results were compared to validate the maneuverability of a VLCC-sized a ship installed with the MSV rudder. A mathematical model of an MSV rudder is proposed for maneuvering simulation of a large vessel. To develop a maneuvering simulation for the model ship that was used in the free-running tests, hydrodynamic coefficients were estimated based on Kijima's regression formula. The coefficients of interaction between the hull and rudder (t_R, a_H, x_H) were obtained from a self-propulsion test in a towing tank. The complicated flow around the rudders is simplified to model the flow speed around the rudders. This simplified flow speed is utilized to compare the time histories of the free-running tests with the simulations. The mathematical model of the MSV rudder was further improved using the results of this comparison.     

船舶操纵回转特性的多目标优化设计应用

定常回转直径作为衡量船舶操纵性的一个指标受到人们的普遍重视。为提高船舶的回转性能,基于船舶四自由度的操纵性方程,分析船舶回转直径和回转横倾,讨论影响回转性能的舵型因素,并将其作为优化设计变量,利用Isight优化设计平台,采用遗传算法进行舵型参数的优化设计。通过选取某高速船作为优化对象,利用该方法进行舵型优化后,回转直径及回转横倾都减小。表明借助Isight的优化功能可以实现船舶操纵性能的优化。     

基于神经网络的船舶操纵运动建模研究（英文）

In this paper, Neural Networks(NNs) are used in the modeling of ship maneuvering motion. A nonlinear response model and a linear hydrodynamic model of ship maneuvering motion are also investigated. The maneuverability indices and linear non-dimensional hydrodynamic derivatives in the models are identified by using two-layer feed forward NNs. The stability of parametric estimation is confirmed. Then, the ship maneuvering motion is predicted based on the obtained models. A comparison between the predicted results and the model test results demonstrates the validity of the proposed modeling method.     

Modeling of ship maneuvering motion using neural networks

In this paper, Neural Networks (NNs) are used in the modeling of ship maneuvering motion. A nonlinear response model and a linear hydrodynamic model of ship maneuvering motion are also investigated. The maneuverability indices and linear non-dimensional hydrodynamic derivatives in the models are identified by using two-layer feed forward NNs. The stability of parametric estimation is confirmed. Then, the ship maneuvering motion is predicted based on the obtained models. A comparison between the predicted results and the model test results demonstrates the validity of the proposed modeling method.     

动态执行机构的船舶逆最优变速循迹控制（英文）

A controller which is locally optimal near the origin and globally inverse optimal for the nonlinear system is proposed for path following of over actuated marine crafts with actuator dynamics. The motivation is the existence of undesired signals sent to the actuators, which can result in bad behavior in path following. To attenuate the oscillation of the control signal and obtain smooth thrust outputs, the actuator dynamics are added into the ship maneuvering model. Instead of modifying the Line-of-Sight(LOS) guidance law, this proposed controller can easily adjust the vessel speed to minimize the large cross-track error caused by the high vessel speed when it is turning. Numerical simulations demonstrate the validity of this proposed controller.     

X型尾舵潜艇操控与运动关系研究

在分析潜艇X型舵水动力特性的基础上,建立X型舵与十字型舵操纵力的等效关系,用于指导潜艇X型舵的初步设计;分析X型潜艇的操控与潜艇运动的关系,用于潜艇X型舵的自动控制装置设计,部分解决了X型舵自动控制装置相关理论问题。