基于单参数自调节RM-GO-LSVR的船舶操纵灰箱辨识建模

为实现舵角小、试验数据少条件下船舶操纵辨识建模, 提出了一种船舶操纵运动灰箱模型; 搜集水动力系数已知的船舶运动数学模型作为备选参考模型(RM), 计算被辨识船舶与备选RM的相关系数, 并以此筛选合适的RM; 运用相似准则将观测数据映射到RM的输入值域, 建立被辨识船舶与RM的运动关联, 获得了RM的加速度项, 并使用线性支持向量回归(LSVR)机补偿被辨识船舶和RM加速度项间的误差; 分析了机理模型, 设计了合适的LSVR输入项, 使用全局优化(GO)算法自动调节了LSVR的不敏感边界参数; 基于自航模试验数据训练了灰箱模型, 并与约束模试验(CMT)结果和计算流体力学结果比较, 验证了灰箱模型的泛化能力和预报精度。研究结果表明: 在20°船艏向、20°舵角Z形试验预报中, 灰箱模型所得第一超越角精度至少比CMT、虚拟约束模试验(VCMT)和RM方法所得结果高1°, 灰箱模型所得第二超越角精度至少比CMT和VCMT所得结果高0.4°; 在35°舵角旋回试验预报中, 灰箱模型所得进距精度至少比CMT、VCMT、数值循环水槽试验(NCWCT)和RM方法所得结果高1%, 灰箱模型所得战术直径精度比CMT所得结果低4%, 比NCWCT所得结果高10%;RM方法有助于灰箱辨识建模, GO算法能够优化LSVR的不敏感边界参数, 建立的单参数自调节灰箱辩识建模方法能够实现小舵角、少数试验条件下的船舶操纵辨识建模。      

Investigation on maneuverability of a twin-screw ship driven by one screw

It is possible for a twin-screw ship that one screw failure occurs during navigation, and the maneuverability in this case should be noticed by ship designers and operators. It is of great significance to evaluate the related risk. Firstly, a mathematical model for the twin-screw ship maneuvering motion with one failed screw is developed based on the maneuvering model group (MMG) equations, and verified by the model test results. Secondly, the maneuvering motions of a twin-screw liquefied natural gas (LNG) ship with one free rotating failure screw or with one locked failure screw are simulated and compared by using the mathematical model. It is shown that the numerical modeling results are in agreement with the model test results. Compared with those of normal navigation, the port turning ability of the ship with one failed port screw is better, but the starboard turning ability and yaw checking ability become worse. The maneuverability of the ship with locked failure screw is better than that with free failure screw, although the ship speed drops obviously.     

双体船平移操纵水动力性能试验研究

介绍了用船模拖曳试验来确定某喷水推进双体船平移运动水动力特性的方法,并对试验结果进行了分析.通过船模试验发现,船体平移时的水动力大小随航速增加而快速增加,在同一航速但不同尾斜角下水动力大小也各不相同;水动力的方向和水动力作用点的位置随航速的改变而改变,但变化幅度不大,受尾斜角影响较大.准确掌握船体平移运动水动力特性,可为合理制定喷水推进器的控制策略,充分发挥喷水推进船优异的机动性、操纵性提供理论依据.     

斜拉桥拉索风-雨致振动(Ⅱ):参数研究

为探讨斜拉桥拉索风-雨致振动的影响因素,基于修正驰振模型,利用空间模型测试的气动力系数,对斜拉桥拉索风-雨致振动的气动力参数、运动参数和结构参数进行了研究.气动力参数包括水路形状、风向角和索径等,运动参数有索的初始状态、水路运动等,结构参数为索的频率、阻尼和质量.研究表明,气动力参数和运动参数将影响拉索风-雨致振动的最大振幅响应,改变发生风-雨致振动的风速范围.     

Experimental Study on Ship-Bank Interaction of Very Large Crude Carrier in Shallow Water

In order to assess the influence of ship-bank interaction on ship manoeuvring motion, planar motion mechanism (PMM) tests on a scale model of the KRISO very large crude carrier (KVLCC2) are conducted in different water depths in circulating water channel (CWC). The asymmetric hydrodynamic derivatives are defined to characterize the bank effect, and they are measured through the straight towing test with varying lateral displacements. The linear and nonlinear hydrodynamic derivatives are determined from the test data of the Fourier integral and mathematical regression model. The rudder and heading angles required at equilibrium conditions in different ship-bank distances are calculated by the manoeuvring model. The directional stability with varying ship-bank distances is studied in terms of eigenvalue analysis. Analysis based on the test results shows that the KVLCC2 model ship appears inherently unstable for keeping course in deep and shallow water conditions. When the ship-bank distance decreases, the increasing ship-bank interaction can dramatically affect some parameters of the criteria for course keeping.     

带有UKBF的船舶动力定位预测控制器设计

为了精准设计水面船舶动力定位控制系统,将无迹卡尔曼布西滤波与非切换解析模型预测控制方法相结合提出一种预测控制器的设计方法.采用无迹卡尔曼布西滤波算法解决非线性连续系统的滤波问题,获取船舶运动状态的估计值;结合相对阶概念,根据船舶运动非线性模型,应用非切换解析模型预测控制方法设计动力定位非线性控制器,使船舶保持在指定位置.研究结果表明:设计控制器的输出较为平滑,有利于减少推进器磨损;设计控制器使船舶北向位置调节时间小于40 s,超调量小于5%,东向位置调节时间小于60 s,超调量小于5%,艏向角度的最大偏移量小于1.5°,令船舶快速到达了指定位置.      

Regularization method and immune genetic algorithm for inverse problems of ship maneuvering

Ship maneuverability, in the field of ship engineering, is often predicted by maneuvering motion group MMG) mathematical model. Then it is necessary to determine hydrodynamic coefficients and interaction force coefficients of the model. Based on the data of free running model test, the problem for obtaining these coefficients is called inverse one. For the inverse problem, ill-oposedness is inherent, nonlinearity and great computation happen,and the computation is also insensitive, unstable and time-consuming. In the paper, a regnlarization method is introduced to solve ill-posed problem and genetic algorithm is used for nonlinear motion of ship maneuvering. In addition, the immunity is applied to solve the prematurity, to promote the global searching ability and to increase the converging speed. The combination of regnlarization method and immune genetic algorithm(RIGA) applied in MMG mathematical model, showed rapid converging speed and good stability.     

水工模型中变态船模的相似性

为将变态船模应用在变态水工模型试验中,从理论上对变态船模的运动特性等进行分析。变态船模在水中运动应满足几何相似、运动相似、动力相似、操纵性相似等相似条件。从水工模型相似律入手,讨论变态船模在水工模型中的相似规律。     

���н�ͨӵ��̬�Ƽ�ص�ʱ�շֲ���̬ʶ��ģ��

为了及时发现和预警城市交通高峰时期的偶发事件,研究了态势监控的城市交通拥堵动态跟踪问题.对交通拥堵的相关属性、变化规律、空间分布以及判别方式等进行综合研究的基础上,分析了道路交通流的非线性动力学特征,建立了基于时空分布的路网交通拥堵态势监控的动态预警模型,提出了解决城市路网交通拥堵的方法,达到了充分利用交通资源、疏导交通、缓解交通拥堵的目的.该模型在对占有率、速度、流量三个基本交通流参数进行处理获得新的交通拥挤判别指标基础上,通过形态识别模型对拥堵状态进行判定.实例分析表明,该模型为缓解城市交通拥堵问题、提高城市交通管理水平、改善道路交通安全形势等具有重要的理论意义和应用价值.     

大型船舶操纵性能综合评价

选取 6种典型的大型船舶操纵性能试验数据 ,分析其影响因素 ,并运用 IMO有关船舶操纵性的衡准 ,确定综合评价指标 ,运用层次分析法对其操纵性能进行排序 ,然后对大型油船、散货船和集装箱船的操纵性能进行比较 ,总结出大型船舶的操纵特点 ,并得出对实际船舶操纵具有指导意义的结论     

Research on Motion Estimation Algorithm of Star Point Based on Nonlinear Gaussian Fitting

The energy distribution model of motion blurred star point is analyzed. The distribution of the star point approximates to a two-dimensional (2D) Gaussian distribution under degeneration. Two multi-parameter nonlinear Gaussian fitting methods (GFMs) are proposed, and the relationship between fitting parameters and motion blur parameters is analyzed. Estimation of the parameters of motion blur by fitting parameters is calculated to realize the error compensation of the motion blur. The simulation results show the effectiveness and accuracy.     

H∞控制在汽车电子稳定性程序中的应用

汽车电子稳定性控制系统（electronic stability program,ESP）可以改善汽车在极限工况下的操纵性和稳定性。建立两自由度车辆模型,基于H∞控制理论研究车辆稳定控制系统,理论上证明电子稳定性程序控制ESP对汽车稳定性作用明显。数字仿真结果表明,该控制方法可有效改善车辆转向时的侧偏角和横摆率的响应特性。     

Robust adaptive horizontal vibration isolation of towed seismic streamers

The horizontal vibration of towed seismic streamers is a main reason for efficiency reduction of the seismic survey and tail tangling. A vibration suppression scheme of towed seismic streamers is investigated in this paper. The towed seismic streamer is divided into two spans, a controlled span, i.e., the low tension span, and an uncontrolled span, i.e., the high tension span, by a bird. The system model includes a hyperbolic partial differential equation with variable coefficient describing the towed seismic streamers, and an ordinary differential equation describing the dynamic of bird. Robust based-model knowledge and adaptive controllers, based on the Lyapunov method, are designed to isolate the vibration of towed seismic streamers caused by the course deviations of towing vessel, the variations of towing vessel velocity and the variations of towed seismic streamer density. The robust based-model knowledge and adaptive controllers exponentially and asymptotically drive the span-towed seismic streamer displacement to zero, respectively. A finite difference scheme is used to validate the efficiency of the control law. The proposed controller can isolate effectively the disturbance originated from the towed vessel, and can provide the improved damping but not sacrifice the isolation performance. The adaptive scheme can tolerate the lack of knowledge of some uncertain parameters and can directly execute the online adjustment of the parameters. Meanwhile, the proposed control law is robust and can resist the model uncertainty due to parameter incertitude, model error and unknown disturbance and so on. The control law only includes velocity and slope, while it does not need the displacement which is difficult to measure in the practical operations. Thus it is easy to implement.     

Numerical study on water depth effects on hydrodynamic forces acting on berthing ships

Due to the restrictions of ports, maneuverability of berthing ships will be affected significantly by water depth. In the present study, numerical simulation of the berthing maneuver of a ship with prescribed translational motion is performed by solving the Reynolds-averaged Navier-Stokes (RANS) equations based on overset grid, and the effects of the quaywall and freesurface are taken into consideration. To validate the present numerical method, comparison is performed between our results and the other results or measurements. It is found that the agreement is significantly better than that resulting from previous CFD-based approach. Subsequently, the effects of various water depths are investigated to evaluate their influences on hydrodynamic forces. The present results can provide helpful guidance on safe maneuvering for vessels’ berthing and fender system design in quays.     

重庆市短途区间客船的安全隐患与对策

针对重庆市短途区间客船的安全隐患及其相关需求,为保障沿河两岸群众的安全出行、巩固水上交通安全形势;讨论了重庆市短途区间客船的现状,含区域分布特征、航区特征、船龄特征等;分析了短途区间客船的安全隐患及其对策,涉及稳性、结构强度、操纵性及GPS系统;提出了短途区间客船安全性技术改造的目标、原则、措施、范围与计划;并对短途区间客船的安全性改造提出了建议。     

坡形和加筋措施对地震响应影响的振动台模型实验研究

实施边坡工程地震性态控制设计方法的关键是揭示边坡土性、坡形对基岩地震动参数传递影响的规律。利用大型振动台分别进行了层状土与边坡模型的振动台对比实验、素土与铺设加筋材料的振动台对比实验。实验发现,与层状土对比,具有临空面的边坡对地震加速度峰值放大系数可增加约30%;素土与铺设加筋材料的层状土实验相比,后者对加速度峰值放大系数则可减小约20%;此外,还对地震作用下模型的动力特性进行了探讨,发现同一模型在重复实验后,土体损伤导致模型自振频率降低,此时土体对地震波表现出更强的放大效应。     

����ģ�ͱ궨������Ӧ���о�

介绍了重力模型的各种不同形式的标定和检验方法，标定方法有最小二乘法、试算法及其该进方法，检验方法包括t检验法和相对差的检验。通过具体的算例，比较分析了它们不同的计算过程和结果，从而得出各类重力模型的标定和检验方法的特点。据此得出在我国的现有情况下的适用性。     

Singular perturbation composite control of a free-floating flexible dual-arm space robot

The Free-floating Flexible Dual-arm Space Robot is a highly nonlinear and coupled dynamics system. In this paper, the dynamic model is derived of a Free-floating Flexible Dual-arm Space Robot holding a rigid payload. Furthermore, according to the singular perturbation method, the system is separated into a slow subsystem representing rigid body motion of the robot and a fast subsystem representing the flexible link dynamics. For the slow subsystem, based on the second method of Lyapunov, using simple quantitative bounds on the model uncertainties, a robust tracking controller design is used during the trajectory tracking phase. The optimal control method is designed in the fast subsystem to guarantee the exponential stability. With the combination of the two above, the system can track the expected trajectory accurately, even though with uncertainty in model parameters, and its flexible vibration gets suppressed, too. Finally, some simulation tests have been conducted to verify the effectiveness of the proposed methods.     

Adaptive robust control for an active heave compensation system

Active heave compensation systems are usually employed in offshore and deep-sea operations to reduce the adverse impact of unexpected vessel’s vertical motion on the response of underwater instruments.This paper presents a control strategy for an active heave compensation system consisting of an electro-hydraulic system driven by a double rod actuator,which is subjected to parametric uncertainties and unmeasured environmental disturbances.Adaptive observer and discontinuous projection type updating law with bounded adaption rate are presented firstly to estimate the uncertain system parameters.Then a similar estimation algorithm is designed by using a multiple delayed version of the system to enhance the performance of parameter observation.A reduced order observer is also introduced to estimate unknown wave disturbances.Using the obtained uncertainty information,the resulting control development and stability analysis are implemented based on the Lyapunov’s direct method and back-stepping technique.The proposed controller guarantees the heave compensation error convergent to a bounded neighborhood around the origin.Simulations illustrate the effectiveness of the proposed control system.     

沥青老化性能评价方法

为了分析旋转薄膜烘箱试验(RTFOT)评价沥青结合料整体老化性能的合理性,以及长期老化与短期老化试验结果之间的关系,采用组分试验、常规指标以及Superpave指标对沥青经短期老化试验(RTFOT)和长期老化试验(PAV)的样品进行了试验研究。结果表明长期老化后沥青样品的组分变化规律与短期老化不一致,物理指标增减幅度不同,但如按指标评价沥青的抗老化特性,两种不同老化方式的沥青优劣排序基本一致,这说明虽然短期老化不能全面反映沥青的抗老化特性,但在目前情况下作为沥青的优选方法是可行的。