【作者】 施平安；

【导师】 叶家玮；

【作者基本信息】 华南理工大学 ， 船舶与海洋结构物设计制造， 2013， 博士

【摘要】 舰船在海上实施并靠补给等作业时，由于受到风浪的影响及两船间的水动力干扰，会产生比单船时更剧烈的摇荡运动，过大的横摇运动甚至会导致两船的上层建筑发生触碰。为了避免上述碰撞危险，提高海上并靠的可作业海况，论文提出了基于磁流变技术的舰船并靠变阻尼波浪补偿方法，对舰船并靠的横摇和横荡运动姿态进行约束。论文采用理论研究、计算机软件仿真和船模水池试验相结合的研究方法，对舰船并靠变阻尼波浪补偿进行了较为系统的研究。论文解决的关键问题包括：波浪中舰船并靠相对运动特性研究、相对运动极短时间预报、变阻尼波浪补偿及控制、模型试验信号采集与处理、加速度信号处理，以及舰船并靠相对运动和变阻尼波浪补偿模型试验。论文在研究过程中主要开展了以下几方面的工作：（1）基于三维势流理论，对规则波和不规则波中舰船并靠相对运动特性进行研究，并提出一种基于AQWA和谱分析法的不规则波中舰船并靠相对运动特性研究方法。（2）对舰船并靠相对运动预报进行研究。对较低海况下的相对运动采用AR模型进行极短时间预报；对较高海况下的相对运动采用混沌Elman神经网络进行极短时间预报。混沌Elman神经网络适应波浪中舰船并靠相对运动的非线性、非平稳性和混沌特性，它以混沌系统相空间重构得到的最佳嵌入维数作为网络的输入节点数，并在网络权值调整的反向传播算法中加入混沌噪音以实现混沌反传，能够充分获取当时环境和情况下舰船并靠相对运动特性；仿真研究表明，该方法能够有效预报并靠两船的相对运动。（3）对基于磁流变技术的舰船并靠变阻尼波浪补偿及控制进行研究，这是波浪补偿研究的一个新思路。针对波浪中舰船并靠相对运动特性，设计制造了基于磁流变技术的变阻尼波浪补偿器，并在分析其性能的基础上建立了力学模型；充分利用其输出阻尼力可控的特性，建立舰船并靠变阻尼波浪补偿时域运动状态空间方程，设计并实现基于最优控制理论的clipped optimal control控制策略对舰船并靠的横摇运动姿态施加约束；以两艘在波浪中并靠的船舶模型为例，对舰船并靠波浪补偿的有效性进行数值仿真和船模试验验证，结果表明：采用变阻尼波浪补偿能够有效地减小并靠两船的横摇运动响应。（4）对模型试验信号采集与处理方法进行研究，特别是有关加速度信号处理的研究。加速度信号处理是船舶并靠模型试验研究的关键，为了提高加速度信号积分成位移后的相位和幅值的精度，提出了基于EMD（经验模态分解）自适应滤波和频域积分的加速度信号处理方法。该方法先对加速度信号进行EMD分解得到n个本征模态函数IMF，然后基于相关规则确定属于高频的IMF个数（h），并对这h个高频IMF进行自适应滤波去噪，最后通过FFT变换在频域进行积分得到位移信号。仿真研究表明这种加速度信号处理方法比纯粹的频域积分法效果好，舰船并靠相对运动模型试验数据处理结果也证明了这种方法的有效性。（5）确定了模型试验的相似准则，建立舰船并靠波浪补偿模型试验，对舰船并靠相对运动和变阻尼波浪补偿分别进行模型试验，进一步验证了舰船并靠变阻尼波浪补偿能够有效地减小并靠两船的横摇运动响应。更多还原

【Abstract】 When two vessels float parallel alongside at sea to do the operation of replenishment, thesix-degree-of-freedom motions of them are much larger than themselves alone, due to theimpact of wave and hydrodynamic interaction. In certain cases, the relative motions are toolarge, even leading to the collision of their superstructure. In order to avoid the abovementioned danger and to improve the sea state of side-by-side ship operation, a variabledamping wave compensation method is presented, which restrict the roll and sway of the twoside-by-side ships.The research for the variable damping wave compensation was carried out by theoryanalysis, computer simulation and model test in this dissertation. The key problems whichwill be solved in this paper are as follows: the characteristics of relative motion of twoside-by-side ships, the short time prediction of relative motion, the variable damping wavecompensation and its control strategy, the signal acquiring and processing for model test, theacceleration signal processing, and model test for relative motion and variable damping wavecompensation. The main contents of this paper are:1. Based on the three dimensional potential flow theory, the characteristics of relativemotion between two side-by-side ships are studied in the regular and irregular waves. Anda new method for analyzing relative motion characteristics of two side-by-side ships inirregular waves was presented which based on AQWA and spectrum analysis.2. The prediction of relative motion between two side-by-side ships are studied. The relativemotion of low seas is predicted by AR model. The relative motion of high seas ispredicted by chaotic Elman neural network. Chaotic Elman neural network fits for thenonlinearity, nonstationarity and chaotic characteristics of two side-by-side ships in waves.The optimal embedding dimension acquired by phase space reconstruction is used for thenumber of input nodes, and a chaotic back-propagation algorithm was applied, in whichchaotic noise is added into weight update process. It can obtain the the characteristics ofthe relative motion between two side-by-side ships under the prevailing conditions andenvironments. The simulation result shows that the proposed method can predict therelative motion of two side-by-side ships effectively.3. The variable damping wave compensation based on magneto-rheological technology andits control strategy are studied, which presents a new idea for the research of wavecompensation. By consideration of the relative motion characteristics, variable damping wave compensator is designed and manufactured, which is based on themagnetorheological technology. Its mechanical model was established by the analysis ofits performance. By taking full advantage of its controllable damping force characteristics,temporal state-space equations of variable damping wave compensation of twoside-by-side ships is built. The clipped optimal control strategy is designed and realized torestrict the roll motion. By taking the two side-by-side ship models in waves as example,numerical simulation and model test are executed to prove the efficiency of variabledamping wave compensation. The results shows that variable damping wave conpensationcan reduce the roll motion responses of two side-by-side ships.4. Signal acquiring and processing for model test is studied, especially about the processingof acceleration signal. Acceleration signal processing is key to the side-by-side shipsmodel test. In order to improve the accuracy of the phase and amplitude of the results ofacceleration integration, a method based upon EMD adaptive filtering and frequencydomain integration is presented. The acceleration signal is decomposed by EMD into nIMF, and then based upon appropriate rules, the number of IMF pertaining highfrequency(h) is determined, and they are adaptively filtered to cancel noise. Finally, FFTtransformation is applied, frequency domain integration is done, and then IFFT is used toacquire displacements. Simulation results show that this acceleration signal processingmethod is better than the pure frequency domain ingegral. The data processing result ofside-by-side ship model test also show the validity of this method.5. Model test similarity principle is determined, and model test for side-by-side ship wavecompensation is established. Model test is performed for relative motion of twoside-by-side ships and variable damping wave compensation, which further validate theeffective reduction of roll motion responses by variable damping wave compensation.更多还原