Application of a Zero-speed Fin Stabilizer for Roll Reduction of a Marine Robot near the Surface

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.

Lift fin stabilizers based on data fusion with wavelet denoising technology

Fin stabilizers with fin-lift feedback control can shield the mapping error of calculation between the fin angle and fin lift force,which is in the fin stabilizer with fin-angle feedback control.In practice,there are some technical difficulties in lift fin stabilizers,such as lift force detection and lift force sensor installation,so it cannot achieve the good antirolling performance.Therefore,a fin stabilizer system with fin-lift/fin-angle integrated control is brought forward.Data fusion based on wavelet denoising technology is employed in the system,which combines lift with fin angle local information from two sensors with different frequency ranges in order to eliminate redundant and contradictory information,and using complementary information to obtain the relative integrity of the lift force signal.The system model is established in this paper,and the fusion signal and the antirolling performance of this model are simulated respectively.The result shows that the control system can meet the antirolling need in different sea situations.

Fuzzy-PID controlled lift feedback fin stabilizer

Conventional PID controllers are widely used in fin stabilizer control systems, but they have time-variations, nonlinearity, and uncertainty influencing their control effects. A lift feedback fuzzy-PID control method was developed to better deal with these problems, and this lift feedback fin stabilizer system was simulated under different sea condition. Test results showed the system has better anti-rolling performance than traditional fin-angle PID control systems.

Research on the influence of action between fin and anti-rolling tank on the integrated stabilization effect

Through analyzing the roll model of the integrated system of fin and anti-rolling tank, this paper uses binomial equation to simplify the module and check how the approximate parameters simulate the original function. Based on the simplified module, the influence of fin and anti-rolling tank on the coefficient items of the roll module is discussed, and the influencing factors between fin and anti-rolling tank are analysed. And through simulation, the influence of action between fin and anti-rolling tank on the static characteristics, and the integrated stabilization effect, are analyzed.

Energy Optimization of the Fin/Rudder Roll Stabilization System Based on the Multi-objective Genetic Algorithm （MOGA）

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.

Stability Analysis for Projectile with Wrap-Around Fins

Based on the stability theory, numerical simulations and theoretical calculations are performed for a projectile with wrap-around fins. Its stability is analyzed and the flow field is simulated with computational fluid dynamics method. Consequently, the pitching moment coefficient of the projectile is further investigated under the conditions of Mach number ranging from 0.3 to 0.8, attack angle from 0 to 8° and yaw angle from 0 to 4°. A trajectory equation is established and its trajectory characteristics are also explored. All the results of theoretical analysis, numerical simulation and trajectory equation agree well with each other, which indicates the projectile is flying steadily at the given conditions. These results provide an effective way for judging the stability of the projectile with wrap-around fins.

Design of Fin-propeller Test Set-up and Analysis of Roll Stabilization Ability

Presents the fin-propeller test set-up to solve the problem of roll stabilization with ships in full speed range, withwhich, tests were run in water rank for acquisition of data, and concludes from data acquired that the fin-propeller test set-up produces more lift than simple fin, and provides lateral thrust as well, and it is therefore an effective roll stabilization devicefor ships in full speed range.

Robust Control Based on Feedback Linearization for Roll Stabilizing of Autonomous Underwater Vehicle Under Wave Disturbances

In the case of Autonomous Underwater Vehicle （AUV） navigating with low speed near water surface, a new method for design of roll motion controller is proposed in order to restrain wave disturbance effectively and improve roll stabilizing performance. Robust control is applied, which is based on uncertain nonlinear horizontal motion model of AUV and the principle of zero speed fin stabilizer. Feedback linearization approach is used to transform the complex nonlinear system into a comparatively simple linear system. For parameter uncertainty of motion model, the controller is designed with mixed-sensitivity method based on H-infinity robust control theory. Simulation results show better robustness improved by this control method for roll stabilizing of AUV navigating near water surface.

Prediction of Stabilization of Ship in Random Wave

In this paper we show thc method of energy in part with which we can get the model of random wave,and predict theroll motion of unstabilized ship and stabilized ship using the wave model.The control parameters of fin stabilizer are determinedaccording to the performance index. The simulation of the system is also made in this paper. The comparison of the simulationwith real ship indicates that the method can be used in the prediction of roll motion of a stabilized ship in random wave.

基于S7-1500 PLC和Profinet的减摇鳍电控系统

文章主要针对减摇鳍设备控制系统的特点及控制要求,提出了一套以西门子S7-1500控制器和Profinet总线技术为核心的控制系统。该系统设有主站及智能从站,主站与从站之间采用Profinet总线进行通信。介绍了控制系统的整体架构、硬件选型、软件设计及其网络配置等。着重说明了电液伺服控制系统实现过程、模拟正弦信号产生过程、PID控制器及减摇鳍装置启动流程的设计。研究证明,该控制系统各环节运行稳定,具有较高的可靠性且易于操作。

尾翼控制小型超空泡航行体运动稳定性分析

为探究可偏转尾翼对小型超空泡航行体运动状态的影响,建立了具备尾翼控制功能的小型超空泡航行体非线性动力学模型,对航行体动力学系统进行仿真计算,根据Lyapunov指数谱和相轨图对系统稳定性进行判定,运用非线性动力学方法,对不同尾翼反馈增益下的稳定系统、周期振荡系统以及混沌系统进行分析,得到了速度衰减情况下无动力小型超空泡航行体保持稳定运动的反馈增益参数区间,结果表明,无动力小型超空泡航行体可以通过调整尾翼的反馈增益参数进行姿态控制并实现稳定运动。

基于液压控制技术的船舶自动应急抗倾覆装置设计

船舶在航行过程中受到波浪影响容易发生倾覆事故,对人员安全造成极大威胁。本文在研究Conolly船舶横摇模型的基础上,提出一种基于液压控制技术的船舶自动应急抗倾覆装置的设计方案,使用减摇鳍来降低船舶的横摇幅度,并通过DSP控制器+Conolly船舶横摇模型的闭环控制方案实现船舶自动应急抗倾覆的目的。通过升力传感器、行程反馈和角度反馈的信号,然后计算出最优的控制信号发送给液压缸并驱动减摇鳍,产生与船舶横摇方向相反的力矩,系统能够动态响应海况变化和船舶运动,对自动应急抗倾覆装置进行仿真,结果表明,系统具有较好的适应性和实时性。

17m超高坐地式玻璃肋幕墙系统结构性能和试验研究

文章以泰康大厦工程为背景,针对超高坐地式玻璃肋幕墙系统进行了大风压作用下的结构性能和位移能力试验研究,通过有限元、试验、理论三者进行对比分析。研究表明,该幕墙系统不仅满足1.75kPa风压作用下的结构性能要求和2.63kPa大风压下结构的安全性能要求,而且满足三个方向位移能力的要求。充分说明17m超高坐地式玻璃肋幕墙系统的设计方案安全可行,设计方案和试验结果可为今后超高坐地式玻璃肋幕墙系统的设计提供支持。

收放式减摇鳍安装工艺

以某船的大型收放式减摇鳍为例,介绍收放式减摇鳍的基本组成、技术参数、运行原理和安装工艺流程。重点介绍模块化的安装方案,通过该方案有效解决供货周期无法匹配建造周期的问题。实践表明,该工艺满足船舶减摇鳍的安装质量使用要求,可供同类型减摇鳍的安装参考。

减摇鳍在智能船舶的应用

基于某在建智能科研船舶,小型智能船舶的智能船体、智能能效监测功能的要求,配备了减摇鳍装置。详细剖析减摇鳍作用原理、减摇鳍装置的组成结构、各结构的功能作用以及对减摇鳍装置的定位及安装要求。为配置减摇鳍装置的船舶提供了理论设计依据及安装应用指导。从而更好的实现船舶的安全稳性,满足智能船舶在风浪中的航速和能效要求,节约燃料的同时也能确保船舶设备的使用寿命。

某型减摇鳍电控系统原理与故障分析

文章简述了某型减摇鳍电控系统的工作原理,在此基础上着重探讨了5种常见故障以及针对故障进行原因分析,并介绍了实际工作中总结出的排故方法,为该型减摇鳍电控系统的修理工作提供了依据。

光纤环网通信技术在减摇鳍控制系统中的应用

主要介绍了光纤环网通信技术在减摇鳍控制系统中的应用,提出一套基于光纤环网连接,多控制器冗余设计为核心的减摇鳍控制系统,介绍控制系统组成、交换机参数设置等,着重介绍Modbus TCP I/O主从站参数设置、软件设计方法以及通过S7通信设计实现中央处理器(CPU)之间数据交换等,为提高减摇鳍控制系统的可靠性提供一条新途径。

某型减摇鳍电控系统工作原理分析及故障排查

文章以某型减摇鳍电控系统为例,阐述了其组成、基本工作原理以及常见故障排除思路,对修理过程中遇到的减摇鳍电液随动系统不工作、锁鳍缓慢等减摇鳍电控系统常见故障的原因进行了分析并提出了解决方法,可为同类型故障的排除提供参考。

带尾翼爆炸成型弹丸的新技术

应用在药型罩表面贴附惰性隔板的方法可以研制出尾翼稳定的爆炸成型弹丸(EFP)。回收试验表明,尾翼的数量与隔板的数量相对应,隔板越厚,隔板处药型罩压垮变形与无隔板处变形差异就越大,形成的尾翼较为明显,可以根据尾翼形状和数量要求来设计隔板。

基于Weis-Fogh机构的零航速减摇鳍升力模型的研究

随着减摇技术的发展,出现了一种可以使用减摇鳍在零航速下进行减摇的新方法,这种方法使减摇鳍既可以在零航速下进行减摇也可以在中高航速下满足减摇的需要。文章结合国外的相关文献,对零航速下减摇鳍的工作方式和产生的升力进行了相关的研究。并根据Weis-Fogh机构流体动力学知识对升力进行了分析,建立了零航速下减摇鳍的升力模型,根据模型进行了升力仿真研究。