应用零航速减摇鳍的海洋机器人近水面时的横摇减摇控制(英文)

A zero-speed fin stabilizer system was developed for rolling control of a marine robot.As a robot steering device near the sea surface with low speed,it will have rolling motion due to disturbance from waves.Based on the working principle of a zero-speed fin stabilizer and a marine robot’s dynamic properties,a roll damping controller was designed with a master-slave structure.It was composed of a sliding mode controller and an output tracking controller that calculates the desired righting moment and drives the zero-speed fin stabilizer.The methods of input-output linearization and model reference were used to realize the tracking control.Simulations were presented to demonstrate the validity of the control law proposed.     

舰用减摇鳍加强结构的CAD/CAE一体化设计

针对减摇鳍安装部位复杂的结构形式和载荷引起的结构设计和载荷分析问题,以某舰用不可收放式减摇鳍的加强结构为例,探讨了减摇鳍加强结构三维设计、载荷分析和性能评估方法,将三维设计软件CADDS5优秀的可视化技术和有限元分析软件MSC.Patran/Nastran强大的结构分析能力有效地结合起来,对其进行CAD/CAE一体化设计分析,获得减摇鳍加强结构的力学特性,为结构优化提供依据.     

CFD Analysis of Flow Characteristics of Corrugated Louvered Fins at Low Reynolds

A 2-D laminar flow model was established for CFD analysis of air-flow between louvered fins. Two louvered fins are studied based on commercial software FLUENT. Air-flow pressure drop characteristics are derived on the calculation of Reynolds number from 75.3 to 600.The numerical results are in good agreement with the experimental data when Reynolds is lower.     

机器鳕鱼胸鳍/尾鳍协同推进直线游动动力学建模与实验研究

设计了一种二自由度胸鳍/尾鳍协同推进的仿生机器鳕鱼,其胸鳍推进机构不仅能够单独实现前后拍翼运动、摇翼运动以及两者的复合运动,而且还可与尾鳍实现协同推进,进而分别建立了胸鳍单独推进、胸鳍/尾鳍协同推进时的水动力学模型。数值仿真及实验结果均表明,胸鳍复合运动与尾鳍协同推进时,仿生机器鱼游速最快,可达0.30 m/s,胸鳍摇翼运动推进时游速最低,仅为0.05 m/s,其他推进方式的游速介于二者之间,但均能够实现稳定的游动。与现有结果相比,所设计仿生机器鱼直线游动模态多样,稳定游速可选范围较宽,机动性较好。     

仿胸鳍/尾鳍推进水下航行器方案设计与模型试验

针对小型水下航行器开展了系统方案设计,系统主要包括中央主体模块、胸鳍模块、尾部推进模块及控制模块。选用可编程序控制器(PLC)实施运动控制,完成了模型制作,编写了控制程序,并进行了初步的模型试验,探讨了仿生水下航行器运动的基本性能。     

CFD simulation of propeller and rudder performance when using additional thrust fins

To analyse a possible way to improve the propulsion performance of ships,the unstructured grid and the Reynolds Average Navier-Stokes equations were used to calculate the performance of a propeller and rudder fitted with additional thrust fins in the viscous flow field.The computational fluid dynamics software FLUENT was used to simulate the thrust and torque coefficient as a function of the advance coefficient of propeller and the thrust efficiency of additional thrust fins. The pressure and velocity flow behind the propeller was calculated. The geometrical nodes of the propeller were constituted by FORTRAN program and the NUMBS method was used to create a configuration of the propeller,which was then used by GAMMBIT to generate the calculation model. The thrust efficiency of fins was calculated as a function of the number of additional fins and the attack angles. The results of the calculations agree fairly well with experimental data,which shows that the viscous flow solution we present is useful in simulating the performance of propellers and rudders with additional fins.     

减摇鳍机械装置设计相关分析

介绍了组成减摇鳍机械装置的液压机组、执行机构和鳍组件三大部分,并从这三大部分对减摇鳍机械装置的设计作了一个基础性分析.减摇鳍装置是一个系统工程,它涉及流体、机械、液压、电子和计算机等学科.其机械装置作用、功能的实现取决于液压动力系统设计的合理和可靠.     

鳍对拖式吊舱推进器水动力性能的影响

为研究鳍的影响,建立了吊舱推进器的水动力性能的计算模型.计算了吊舱推进器安装和不安装鳍时的水动力性能,螺旋桨与吊舱及鳍之间的相互影响通过迭代计算加以考虑.采用基于速度势的基本积分微分方程,并采用双曲面元以消除面元间的间隙.采用Newton-Raphson迭代求解压力分布使得桨叶的随边满足压力库塔条件,用柳泽的方法求得物体表面的速度分布以避免数值求导的奇异性.无鳍.单鳍和双鳍的吊舱推进器水动力性能计算结果表明,附加鳍时吊舱推进器的螺旋桨推力增加,由于鳍上产生推力导致吊舱阻力减小.附加双鳍时的吊舱推进器水动力性能最好,附加单鳍时次之,无鳍时最低.     

百叶窗翅片式散热器性能数值模拟与优化

文章以某百叶窗翅片式散热器为研究对象,取传热因子j、摩擦因子f、综合性能因子JF为量化指标,借助Fluent软件模拟散热器在不同工况下的流场、温度场及压力场分布情况,研究散热器的传热及流阻性能,并通过风洞试验验证仿真结果的可靠性.结合试验结果设计了一种新型孔状百叶窗翅片散热器,与传统百叶窗翅片散热器相比,传热因子最大提...     

基于动态反馈线性化的海洋机器人近水面横摇减摇控制

海洋机器人在近水面低速航行时,在海浪干扰下将产生横摇运动,严重影响机器人安全性能,因此利用零航速减摇鳍系统对横摇运动加以有效控制.针对机器人非线性运动模型及零航速减摇鳍升力模型的特点,利用动态反馈线性化方法设计横摇减摇控制规律.该方法通过将原系统扩展为含有伪状态变量的新系统,实现系统线性化,解决由减摇鳍升力模型引起的系统非线性形式控制输入的问题.理论证明及仿真结果表明该横摇控制规律是稳定有效的.