基于CFD不同AUV艇体的阻力性能分析

自主水下航行器（AUV）作为探索海洋、开发资源和军事作战等水下应用的重要手段,其速度和续航力是评价其性能优劣的重要方面。AUV在水下航行时的阻力主要取决于其几何形状和尺寸以及其表面的光滑程度,因此,研究AUV的几何形状和外观尺寸便显得尤为重要。对AUTOSUB,HUGIN,REMUS,BLUEFIN1和BLUEFIN2这5种艇型建立几何模型并进行阻力性能分析。通过采用计算流体动力学（CFD）方法进行数值模拟,并将所得结果与理论结果进行对比分析,以验证CFD模拟的可靠性及模拟的最优模式。通过对比不同直径、不同舵的展弦比、带舵和无舵、有整流罩以及相似径长比的不同艇型来比较AUV的阻力性能,最终得到艇型的阻力性能特点以及最佳艇型。研究表明：在5种艇型中,AUTOSUB型最优,其次是HUGIN型、REMUS型和BLUEFIN1型,最后是BLUEFIN2型,其中AUTOSUB型和HUGIN型适合中、高速航行,REMUS型和BLUEFIN型适合低速航行。     

自主水下航行器发展概述

自主水下航行器（AUVs）因其应用于海洋勘探而逐渐成为一个有趣的研究对象。波浪滑翔机是一种行驶于波浪表面的无人滑行器（SUV）,它借助海洋能来推动自己,这对于典型的AUVs所采用的电机供能以及昂贵的锚链系统浮标供
　　能来说,是一种技术上的重大跨越。该文讨论了最有效率的AUVs类型。第一部分为每一种类型的发展历程,第二部分为它们各自的技术特点。此外,波浪滑翔机作为应用于海洋部门的一种新型水下机器人,文中简要地给出它的过去,现在以及未来的发展概述。研究波浪滑翔机的意义在于证明它的效率以及实用性,进而取代诸多的AUVs来实现各种实际应用。而研究结果也表明波浪滑翔机确实可以应用于众多领域。对于海洋检测而言,相比于其他AUVs,波浪滑翔机提供了更廉价,更经济,更环保的作业模式,同时也不需要缆绳、船舶等海上作业服务。     

Power efficient formation configuration for centralized leader–follower AUVs control

Autonomous underwater vehicles (AUVs) have rapidly developed in the last few decades due to their autonomous properties in the investigation of an underwater environment. The goal of this paper is to develop a power efficient formation control for the cooperative motion of AUVs with a support vessel as a leader. In this paper, a kinematic algorithm for the joint motion of an AUV with a support vessel was developed and that algorithm was expanded for the formation of AUVs. The AUV yaw, surge and sway control loops were designed for that purpose. The complexing navigation system structure for the AUV was also developed. Simulation results demonstrated efficiency of the proposed kinematic algorithm for the joint motion of AUVs. Also, influence of lateral ocean current was considered. After development of the centralized leader?Cfollower formation control for the group of AUVs with a support vessel as a leader, we optimized a formation configuration in terms of power efficiency. Drag forces caused by AUV motion in the water can significantly influence power consumption. We investigated the relationship between the AUV's formation configuration, underwater coverage efficiency, communication quality and power consumption. As a result of research, we proposed a power efficient formation configuration for typical underwater operations. As a result, the effect of the AUV formation configuration on the power consumption was investigated and a trade-off solution for the optimal AUV positions in formation with minimal energy consumption, high coverage efficiency and small communication power consumption was derived.     

Development trend and key technologies of autonomous underwater vehicles北大核心CSCD

为推进和引导我国自主水下航行器(AUV)的发展,总结国内外AUV的研究现状,提出其系列化、集群化、体系化、大型化的发展趋势。重点探讨AUV总体多学科优化设计、结构与材料设计、动力与推进、导航与控制、探测与通信等关键技术,为更好地利用AUV经略海洋,从而实现“进入海洋、探测海洋、利用海洋”的战略目标提出发展意见。     

模糊PID策略在AUV控制中的应用

由于自治水下机器人(AUV)动力学的非线性、模型参数以及海洋环境扰动的不确定性,基于常规PID控制的AUV性能通常不够理想。本文应用模糊控制对PID控制器的参数进行在线调整,从而使PID控制器具有自适应性以适应AUV工况的变化,并应用此策略为小型AUVSubzeroIII设计了自主航行控制系统,仿真结果验证了本策略的有效性。     

Estimation of the hydrodynamic coefficients of the complex-shaped autonomous underwater vehicle TUNA-SAND

Hydrodynamic coefficients strongly affect the dynamic performance of autonomous underwater vehicles (AUVs). Thus it is important to have the true values of the coefficients in order to simulate the AUV’s dynamic performance accurately. Although these coefficients can be predicted by many methods, most are only applicable for AUVs with streamlined shapes. Computational fluid dynamics (CFD) can be applied to estimate the hydrodynamic coefficients of AUVs with complex shapes. In this study, CFD was applied to estimate the hydrodynamic coefficients of the AUV TUNA-SAND (which stands for terrain-based underwater navigable AUV for seafloor and natural resources development), which has a complex block-like structure. First, the validity of the CFD simulation was verified by comparison with experimental results. Second, the relationships between hydrodynamic loads and motions for all six degrees of freedom were analyzed using the simulated results. Third, the importance of each hydrodynamic coefficient was investigated based on these relationships. There are 16 key damping coefficients that relate to viscosity and 12 key inertial coefficients that relate to the potential flow around TUNA-SAND. Finally, the values of all the key coefficients were obtained and verified by comparing the solutions of the simulated dynamics with the experimental results.     

分体式船体设计的水下测绘AUV回转运动的建模和分析（英文）

There is much need for autonomous underwater vehicles(AUVs) for inspection and mapping purposes.Most conventional AUVs use torpedo-shaped single-rigid hull,because of which their manoeuvrability is limited.Moreover,any increase in payload results in a larger hull size and the turning diameter,limiting its operation in constrained areas.As a solution to this problem,we develop M-Hull,a subsurface mapping AUV with a modular-split hull design that provides better manoeuvrability than a conventional torpedo-shaped vehicle.At the same time,it has more agility than an unconventional bio-inspired snake-like vehicle though their designs look similar.This approach makes it a hybrid solution between conventional torpedo-shaped AUVs and unconventional bio-inspired vehicles.We focus on improving the turning diameter during the mapping operation,and hence this paper concentrates on the dynamic aspects of the 2 D turning motion of the vehicle.It will provide the relationship between turning speed,thrust,and joint torque requirements for the multi-hull underwater vehicle.Different turning modes are compared to choose an optimum turning configuration,and the critical speed is calculated for the vehicle's safe operation.In the end,the modelling is verified using the experimental data.One can follow the method followed here for the 2 D motion analysis of similar underwater vehicles.     

AUV cluster path planning based on improved RRT* algorithm北大核心CSCD

[目的]针对微小型欠驱动自主式水下机器人(autonomous underwater vehicle,AUV)集群控制问题,设计一种基于改进RRT^(*)算法的编队控制策略。[方法]RRT^(*)算法规划的路径陡变难以跟踪且收敛速度较慢,针对该问题提出改进方法。首先加入偏置函数使随机采样点靠近目标点,然后采用Dubins曲线平滑连接采样点,通过在可变半径范围内重新布线,并设计有关曲线长度与避障的代价函数,选择最优路径。依据代价和最小值为多AUV分配集结点,协调多AUV速度完成最小集结时间约束,随后设计基于Dubins路径的分段向量场构造方法,使得多AUV跟踪规划路径,到达目标集结点时速度与方向保持一致。[结果]仿真结果表明,多AUV编队平均路径长度缩短26.6%,平均集结时间缩短21.7%。[结论]该算法路径规划质量高,可顺利完成编队集结任务。     

探查水下矿物资源的AUV动力控制系统开发

Valuable mineral resources are widely distributed throughout the seabed. autonomous underwater vehicles (AUVs) are preferable to remotely-operated vehicles (ROVs) when probing for such mineral resources as the extensive exploration area makes it difficult to maintain contact with operators. AUVs depend on batteries, so their power consumption should be reduced to extend exploration time. Power for conventional marine instrument systems is incorporated in their waterproof sealing. External intermittent control of this power source until termination of exploration is challenging due to limitations imposed by the underwater environment. Thus, the AUV must have a power control system that can improve performance and maximize use of battery capacity. The authors developed such a power control system with a three-step algorithm. It automatically detects underwater operational states and can limit power, effectively decreasing power consumption by about 15%.     

Two-Layer Path Planner for AUVs Based on the Improved AAF-RRT Algorithm

As autonomous underwater vehicles (AUVs) merely adopt the inductive obstacle avoidance mechanism to avoid collisions with underwater obstacles, path planners fo...     

自主式水下航行器水下回收融合引导技术方案及算法

[目的]为解决母艇携载的自主式水下航行器(AUV)在水下自主回收和对接的问题,基于惯导(INS)、声学超短基线定位(USBL)、光学等信号引导的多源数据融合,提出一种面向移动平台的AUV水下回收对接引导方法.[方法]为此,设计融合多传感器信息的扩展联邦卡尔曼滤波器,采用分散滤波并再经信息融合方法以提高滤波精度.分别以I...     

开发水下机器人控制器的MDA/MBSE方法的实用专业化研究（英文）

The model-driven architecture(MDA)/model-based systems engineering(MBSE) approach, in combination with the real-time Unified Modeling Language(UML)/Systems Modeling Language(SysML), unscented Kalman filter(UKF) algorithm, and hybrid automata, are specialized to conveniently analyze, design, and implement controllers of autonomous underwater vehicles(AUVs). The dynamics and control structure of AUVs are adapted and integrated with the specialized features of the MDA/MBSE approach as follows. The computation-independent model is defined by the specification of a use case model together with the UKF algorithm and hybrid automata and is used in intensive requirement analysis. The platform-independent model(PIM) is then built by specializing the real-time UML/SysML's features, such as the main control capsules and their dynamic evolutions, which reflect the structures and behaviors of controllers. The detailed PIM is subsequently converted into the platform-specific model by using open-source platforms to quickly implement and deploy AUV controllers. The study ends with a trial trip and deployment results for a planar trajectory-tracking controller of a miniature AUV with a torpedo shape.     

无人表面船在港口信息化建设中的应用与思考

无人表面船（USV）是实现港口信息化的新型技术装备。阐述用于港口的无人表面船的技术要点,分析无人表面船船型和总体设计技术路线、动力系统和推进装置的开发、导航与测量传感器集成技术及智能控制技术。对无人表面船相关法律法规的制定与完善提出了一些建议,对未来发展进行了展望。     

基于蚁群优化的AUV全局路径规划研究(英文)

路径规划是自主式水下潜器(AUV)导航研究的重要课题,AUV可用于未知环境如海洋空间探测.在大范围海洋环境中,应用蚁群优化原理对自主式水下潜器的全局路径规划问题进行了研究.引入栅格建模方法建立了蚁群可视图模型,设计了蚁群信息素更新规则;给出了蚁群全局路径规划的操作步骤;针对蚁群规划路径不平滑问题,设计了切割算予和插点算子.仿真实验结果表明,蚁群全局规划算法非常适合于求解复杂环境中的规划问题,规划时间短、路径平滑,其原型系统可应用于非结构化无人环境监测.     

自主式水下潜器海洋环境监测系统技术概念

介绍了被誉为未来海洋卫星的自主式水下潜器ＡＵＶ（Ａｕｔｏｎｏｍｏｕｓ Ｕｎｄｅｒｗａｔｅｒ Ｖｅｈｉｃｌｅｓ）的国外发展新动态、自主式海洋采样网络ＡＯＳＮ（Ａｕｔｏｎｏｍｏｕｓ Ｏｃｅａｎ Ｓａｍｐｌｉｎｇ Ｎｅｔｗｏｒｋ）和海洋中的“卫星”技术概念和应用前景。     

Robustness of autonomous underwater vehicle control in variable working conditions

The performance of the control systems of autonomous underwater vehicles (AUVs) in the presence of parameter variations was studied. With an AUV working at different operating speeds and in different ocean environments, the physical parameters such as speed, hydrodynamic coefficients, or inertias may be perturbed from their nominal values. The vehicle control systems can be modeled as systems with parameter uncertainty. An existing robust control method, which uses the robustness properties of polynomials, was used for this system to calculate the permissible ranges of variation in the parameters. The method was applied to the Naval Postgraduate School AUV II and the results were verified by simulating the motion control of the vehicle under the influence of parameter perturbations.     

基于EKF的AUV协同定位方法仿真与验证

自主水下航行器（AUV）协同导航定位技术是解决复杂作业环境下导航问题的重要途径,研究了单领航艇的主从式多AUV基于扩展卡尔曼滤波（EKF）算法的协同到导航定位问题。AUV协同定位时,主AUV内部装备高精度导航设备,从AUV内部装备低精度导航设备,外部配有测距装置,舰艇间是通过通信装置来交换自身位置和状态信息并同时测量通信双方的相对距离,通过信息融合对自身定位进行修正,利用EKF算法对系统中传感器所传递信息进行融合,对从AUV进行实时定位。通过仿真验证此算法可以显著提高导航定位精度。     

On the probability of underwater glider loss due to collision with a ship

The demonstrated utility of underwater gliders as measurement platforms for the open ocean has sparked a growing interest in operating them in shallow coastal areas too. Underwater gliders face additional challenges in this environment, such as strong (tidal) currents and high shipping intensity. This work focuses on the probability of losing a glider through a collision with a ship. A ship density map is constructed for the German Bight from observed ship movements derived from automatic identification system data. A simple probability model is developed to convert ship densities into collision probabilities. More realistic—but also more computationally expensive—Monte Carlo simulations were carried out for verification. This model can be used to generate geographic maps showing the probability of glider loss due to collisions. Such maps are useful when planning glider missions. The method developed herein is also applicable to other types of AUVs.     

Market based framework for multiple AUVs cooperation

A“Market” based framework for multiple AUVs team is introduced in this paper. It is a distributed meta-level task allocation framwork. The formulation and the basic concepts of the “Market” such as “goods” and “price” are discussed first, then the basic algorithm of the “auction”. The loosely coupled v-MDTSP tasks are considered as an example of the task allocation mission. A multiple AUV team controller and a detailed algorithm are developed for such applications. The simulation results show that the controller has the advantages such as robustness and low complexity and it can achieve better optimization results than the classical central controller （ such as GA） in some tasks. And the comparison of two different local solvers also implies that we should get the reasonable task allocation even not using the high quality algorithm, which can considerably decrease the cooperation computation.     

基于势流的水下滑翔机的飞行模拟器(英文)

Underwater gliders are recent innovative types of autonomous underwater vehicles (AUVs) used in ocean exploration and observation. They adjust their buoyancy to dive and to return to the ocean surface. During the change of altitude, they use the hydrodynamic forces developed by their wings to move forward. Their flights are controlled by changing the position of their centers of gravity and their buoyancy to adjust their trim and heel angles. For better flight control, the understanding of the hydrodynamic behavior and the flight mechanics of the underwater glider is necessary. A 6-DOF motion simulator is coupled with an unsteady potential flow model for this purpose. In some specific cases, the numerical study demonstrates that an inappropriate stabilizer dimension can cause counter-steering behavior. The simulator can be used to improve the automatic flight control. It can also be used for the hydrodynamic design optimization of the devices.