Path Following Control of A Deep-Sea Manned Submersible Based upon NTSM

In this paper, a robust path following control law is proposed for a deep-sea manned submersible maneuvering along a predeterminated path. Developed in China, the submersible is underactuated in the horizontal plane in that it is actuated by two perpendicular thrusts in this plane. The advanced non-singular terminal sliding mode （NTSM） is implemented for the design of the path following controller, which can ensure the convergence of the motion system in finite time and improve its robustness against parametric uncertainties and environmental disturbances. In the process of controller design, the close-loop stability is considered and proved by Lyapunov＇ s stability theory. With the experimental data, numerical simulations are provided to verify the control law for path following of the deep-sea manned submersible.

Design and research on a variable ballast system for deep-sea manned submersibles

Variable ballast systems are necessary for manned submersibles to adjust their buoyancy.In this paper,the design of a variable ballast system for a manned submersible is described.The variable ballast system uses a super high pressure hydraulic seawater system.A super high pressure seawater pump and a deep-sea brushless DC motor are used to pump seawater into or from the variable ballast tank,increasing or decreasing the weight of the manned submersible.A magnetostrictive linear displacement transducer can detect the seawater level in the variable ballast tank.Some seawater valves are used to control pumping direction and control on-off states.The design and testing procedure for the valves is described.Finally,the future development of variable ballast systems and seawater hydraulic systems is projected.

Target Deployment and Retrieval Using JIAOLONG Manned Submersible in the Depth of 6600 m in Mariana Trench

China＇s 7000 m manned submersible JIAOLONG carried out an exploration cruise at the Mariana Trench from June to July 2016. The submersible completed nine manned dives on the north and south area of the Mariana Trench from the depth of 5500 to 6700 m, to investigate the geological, biological and chemical characteristics in the hadal area. During the cruise, JIAOLONG deployed a gas-tight serial sampler to collect the water near the sea bottom regularly. Five days later, the sub located the sampler in another dive and retrieved it successfully from the same location, which is the first time that scientists and engineers finished the high accuracy in-situ deployment and retrieval using a manned submersible with Ultra-Short Base Line （USBL） positioning system at the depth more than 6600 m. In this task, we used not only the USBL system of the manned submersible but also a compound strategy, including five position marks, the sea floor terrain, the depth contour, and the heading of the sub. This paper introduces the compound strategy of the target deployment and retrieval with the practical diving experience of JIAOLONG, and provides a promising technique for other underwater vehicles such as manned submersible or Remote Operated Vehicle （ROV） under similar conditions.

Adaptive Neural Network Control with Control Allocation for A Manned Submersible in Deep Sea

This paper thoroughly studies a control system with control allocation for a manned submersible in deep sea being developed in China. The proposed control system consists of a neural-network-based direct adaptive controller and a dynamic control allocation module. A control energy cost function is used as the optimization criteria of the control allocation module, and weighted pseudo-inverse is used to find the solution of the control allocation problem. In the presence of bounded unknown disturbance and neural networks approximation error, stability of the closed-loop control system of manned submersible is proved with Lyaponov theory. The feasibility and validity of the proposed control system is further verified through experiments conducted on a semi-physical simulation platform for the manned submersible in deep sea.

Multi‑Crack Interaction and Influence on the Spherical Pressure Hull for a Deep‑Sea Manned Submersible

This study investigates the interaction and influence of surface cracks on the spherical pressure hull of a deep-sea manned submersible.The finite element model of the spherical hull is established,and a semi-elliptical surface crack is inserted in the welding toe of the spherical hull as the main crack.Considering the combined effect of external uniform pressure and welding residual stress at the weld toe,the stress intensity factor(SIF)is obtained based on the M-integral method.Inserting disturbing cracks at different positions on the spherical hull surface,the interaction and influence between multi-cracks are revealed by numerical calculation.The results show that the existence of the disturbing crack has a great influence on the stress intensity factor of the main crack,and the influence is different with the different location of disturbing crack.The study of the interaction of multiple cracks under different interference factors and the influence of disturbing cracks on the main crack can provide some reference for future engineering applications.

Metallic Reserves of Submarine Manganese Nodules to be Estimated and Harnessed Prudently: Evidence from China's Jiaolong Manned Submersible

Since the discovery of oceanic manganese nodules during the expedition of the British ocean-going ship Challenger from 1872 to 1876, research and development for seabed manganese nodules have never ceased owing to the huge economic inducements. Manganese nodules are the black or dark brown, spherical or massive Mn-bearing ores, deposits of which are found on the sea bottom. The nodules are a mixture of silicate and insoluble potassium permanganates （also with sub-Ti, Fe and Na permanganates） that contain more than 30 kinds of metallic elements, among which those of greatest economic interest are Mn （27-30%）, Ni（1.25-1.5%）, Cu（1- 1.4%）, Co（0.2- 0.25 %）, Fe, Si, and AI, with minor amounts of Ca, Na, K, Ti, B, H and O.

深海载人潜水器直流无刷电机驱动控制研究

为提高深海载人潜水器电机工作效率和故障诊断能力,并降低系统工作噪声,对直流无刷电机的高效低噪驱动控制技术进行研究。采用具有智能相位控制功能的三相全波正弦波控制芯片TB6605结合智能功率模块(IPM)设计直流无刷电机驱动器。采用单片机对系统的电压、电流、温度、转速、位置信息进行检测,为控制系统提供必要的信息反馈,对应用直流无刷电机的系统状态起到实时信息监测的功能。实验结果表明,研制的直流无刷电机驱动器在电机全转速范围内具有较高的工作效率,额定工况点效率高达90%以上,且在全转速范围内,提高了电机运转的平稳度,降低了系统噪声。研究成果对提高深海载人潜水器电机的工作效率和故障诊断能力,并降低系统工作噪声具有很好的支撑作用。

系统思维在载人潜水器设计中的应用

系统思维以及系统方法论在复杂巨系统的设计上有着极大优势。载人潜水器作为一种大型装备,其设计过程中大量采用了系统方法论。本文对载人潜水器的组成、功能等进行介绍,对系统思维和系统方法论应用于载人潜水器设计的必要性进行分析,对常见的系统方法论进行介绍。并结合具体示例,从载人潜水器总体、载人潜水器分系统之间、载人潜水器分系统自身等层面,对载人潜水器设计过程中所采用的系统方法进行介绍。最后,以生命支持分系统为例,从该系统的运行时长及故障数量角度出发,验证系统思维和系统方法论在该系统的设计过程中发挥的作用。

面向任务的载人深潜人机交互信息重要度评估

为更好地识别复杂任务环境下深海载人潜水器驾驶舱人机交互信息重要度差异,提出一种基于复杂网络的人机交互信息重要度评估方法。以悬停采样任务为研究对象,运用决策阶梯模型及任务-网络建模技术识别复杂任务相关人机交互信息元及逻辑关联,构建交互信息复杂网络模型。基于网络拓扑特征参数,从节点间逻辑影响关系的角度提出节点全局及局部影响效应评估指标,结合解释结构模型层级权重指标对交互信息节点重要度综合值进行计算,得出悬停采样任务人机交互信息重要度排序。将排序结果与其他4种算法进行对比,在证明计算有效的基础上,邀请潜航员结合实际任务流程对交互信息进行主观重要度评估。结果显示,研究所得重要度排序结果与潜航员主观排序结果呈强相关,且对重要交互信息元的识别结果与潜航员主观感知相符合,验证了所提方法识别复杂任务人机交互信息重要度差异的有效性。

深海全通透耐压结构有限元分析

在深海资源开发和发展深海技术的背景下,我国完成了载人潜水器的谱系化建设。近年随着对水下观测需求的增加,全通透载人潜水器引起广泛关注。本文基于有机玻璃试件压缩试验的结果,在LS-DYNA软件中建立有限元模型,通过试件模拟失效模式与试验结果对比,对典型的全透明深海耐压载人潜水器的失效分析进行敏感性研究。在准静态外压下进行极限强度分析之前,进行一阶线性屈曲模态分析以模拟初始几何缺陷。对有机玻璃载人潜水器的耐压壳失效形式和极限载荷进行分析,采用有限元分析方法,研究特定厚度半径比的有机玻璃载人潜水器的临界载荷,为其制造提供技术指导。

载人潜器砰击载荷数值预报方法研究

本文针对载人潜器水面零航速漂浮状态下的入水砰击载荷计算方法进行研究,给出基于频域和时域运动响应结果进行砰击压力预报的计算流程,推导砰击压力极值计算公式,并对某载人潜器进行频域和时域砰击压力预报。根据计算结果发现:频域方法由于未考虑船体运动和波面倾角对入水角的影响,适用于计算船体摇荡对入水角影响不大的船型;对于载人潜器,艇体的大幅运动会使入水角减小,导致砰击压力系数的明显增大,此时应基于时域方法进行砰击载荷计算,以避免砰击载荷的低估;在零航速工况下,潜器在迎浪一侧的砰击压力会明显大于另一侧,因此艉部在随浪下的砰击压力较大,而艏部则在迎浪工况下砰击压力较大。

基于干扰特性指标与推力分配的载人潜水器容错控制

载人潜水器在深海复杂恶劣的环境中运行,容易受到外部环境干扰和推进器故障的困扰,本文将干扰特性指标与基于推力分配的主动容错控制方法相结合,提出了一种新的主动容错控制方法.首先,建立了载人潜水器系统的数学模型;其次,设计非线性干扰观测器估计系统所受的集总干扰,并设计无推进器故障时的控制器;然后,针对推进器故障问题,引入权重矩阵进行推力分配以保护故障推进器,并设计了干扰特性指标表示干扰的性质对跟踪误差和推力损失的影响;在此基础上,给出了一种基于干扰特性指标与推力分配的新型容错控制方法,李雅普诺夫方法保证了该控制算法的理论稳定性;最后,通过数值仿真,验证所设计的控制方法的优越性.其优越性主要体现在:能够利用可用干扰与补偿有害干扰,并将可用的干扰能量用于补偿故障推进器的推力缺失.

深海耐压结构微裂纹损伤识别与定量评估方法

深海耐压壳安全研究主要集中在材料性能本构模型和以疲劳寿命预测为目标的结构参数评估模型上,其损伤识别和定量评估方法的研究尚不成熟。本文针对深海耐压结构,基于电磁感应和涡流热效应,探究瞬态温度响应与微裂纹损伤间的关系,以实现耐压壳关键部位微裂纹的量化研究。项目研究成果将弥补耐压壳服役安全性研究中无损伤监测的空白,为深海耐压壳微裂纹损伤识别提供原创方法及理论依据,保障目前在役深海潜水器的作业安全。

Non-linear buckling analysis of imperfect thin spherical pressure hull for manned submersible

Thin spherical pressure hulls are used as a human occupancy in deep water applications.DNV and other standards specify the imperfection allowed for pressure hulls.Numerical analyses are carried out to find the buckling pressure for both perfect and imperfect thin spherical pressure hulls,considering the geometric and material non-linearities.It is observed that there is a huge variation in the elastic and inelastic buckling pressure in perfect spherical pressure hulls.Moreover,if the manufacturing imperfections are considered in the inelastic numerical analysis,still there is a reduction in the buckling pressure.Design criteria,for deep water pressure hulls,is that both buckling pressure and yield pressure must be greater than the design pressure.In the elastic analysis,if t/D>0.006 buckling pressure is always greater than the yield pressure whereas in the inelastic analysis,the buckling pressure is falling below the yield pressure for all t/D ratios.Hence,inelastic numerical analysis with manufacturing imperfection has to considered in the design of deep water spherical pressure hulls of manned submersibles.

Signal processing in underwater acoustic communication system for manned deep submersible "Jiaolong"

For the first time in the world, underwater acoustic transmission of images, human voice, data and texts between vehicle under 7000 m depth and surface ship was accomplished by underwater acoustic communication system of manned deep submersible Jiaolong＇. In this paper, signal processing in underwater acoustic communication system for manned deep submersible ＂Jiaolong＂ is introduced. （1） Four communication methods are integrated to meet different needs： 1） coherent underwater acoustic communication, with a variable transmission rate from 5 kbps to 15 kbps, to transmit images. 2） Non-coherent underwater acoustic com- munication, with a transmission rate 300 bps, to transmit texts, instructions, and sensor data. 3） Spread spectrum underwater acoustic communication, with a transmission rate 16 bps, to transmit instructions. 4） Underwater voice communication, using single sideband modulation to transmit hmnan voice. （2） Signal processing method in coherent communication mainly consists of concatenation of decision feedback equalizer and Turbo decoder, and wavelet based image compression with fixed length coding. In the equalizer, Doppler compensation, multi- channel combining and equalizer coefficients updating are all using fast self-optimized adaptive algorithm. （3） A linear hydrophone array is lowered from the mother ship to certain depth, and spatial diversity combining technology is adopted. （4） Diving trials of ＂Jiaolong＂ were carried out in Pacific Ocean. The communication range can cover nearly all ocean depth. One optical/acoustic image can be transmitted in 7 or 14 seconds.

Use of the Jiaolong manned submersible for accurate mapping of deep-sea topography and geomorphology

High-resolution bathymetric side-scan sonar(BSSS) performs the functions of traditional side-scan sonar, while also providing a depth-sounding function that allows simultaneous measurement of seafloor topography and geomorphology. Submarine microtopography and microgeomorphology detection ability and advanced underwater acoustic digital communication are important technical capabilities of the Jiaolong manned submersible. High resolution BSSS achieved accurate detection of seafloor topography and geomorphology at a depth of 7000 m, and successful mapping of local microtopography and microgeomorphology in the Mariana Trench.

China’s first deep manned submersible,JIAOLONG

JIAOLONG's function and capability were fully tested during its 37 dives. The longest underwater time was 543 minutes, and the deepest dive of 3759 m was made on its 37th dive. The Chinese national flags and memorial 'Dragon Palaces' were placed on the seafloor. 525 mL of pressure-sustained seawater and two sea cucumbers were sampled. Test results have indicated that all the functions and capabilities were in good agreement with the design data. © 2010 Science China Press and Springer-Verlag Berlin Heidelberg.

Assessment of acoustic backscatter intensity surveying on deep-sea ferromanganese crust: Constraints from Weijia Guyot, western Pacific Ocean

Near-bottom observation data from the manned deep submersible Jiaolong with high-precision underwater positioning data from Weijia Guyot,Magellan Seamounts in the Western Pacific Ocean are reported.Three substrate types were identified:Sediment,ferromanganese crust,and ferromanganese crust with a thin cover of sediment.The ferromanganese crusts show clear zoning and their continuity is usually disturbed by sediments on areas of the mountainside with relatively gentle slope gradients.The identified substrate spatial distributions correspond to acoustic backscatter intensity data,with regions of high intensity always including crust development and regions of low intensity always having sediment.Therefore,acoustic backscatter intensity surveying appears useful in the delineation and evaluation of crust resources,although further more work is needed to develop a practicable methodology.

国外载人深潜技术的创新与发展

海洋尤其是深海已然成为人类生存发展的新空间、科技竞争的新高地,也将成为各国战略利益交汇博弈的主战场。载人深潜技术是海洋高技术领域综合实力的体现,支撑并推动了海洋领域军民两方面的重大进步,正在加速形成“一个核心、多点发力”的新发展格局。本文聚焦载人潜水器技术在载人作业、援潜救生、特种作战3个重点应用领域的创新,从发展需求、技术起源、发展路径、应用模式等角度进行了总结和分析。

基于响应面并行子空间设计的载人潜水器优化

为提高载人潜水器的设计效率和综合性能,确定了一型载人潜水器的设计参数,分析了学科与学科、学科与系统之间的关系,完成了基于多学科设计优化思想的载人潜水器学科分解,建立了载人潜水器结构设计矩阵。利用响应面模型建立了艇型与推进、结构等学科的学科分析模型,利用公式建立了其他学科及系统层分析模型。以艇重为目标函数,分别建立了基于响应面并行子空间设计和基于并行子空间优化的载人潜水器优化框架,可实现优化过程中的近似模型更新,以提高求解效率及精度。利用上述2个框架进行了优化求解,结果表明:相比初始方案,并行子空间设计并行子空间设计减重为7.822%、并行子空间优化减重为7.311%,但并行子空间设计在计算精度、求解效率和最优解获取的概率等方面更具有优势。