Design of wake-adapted contra-rotating propellers for high-speed underwater vehicles

Based on the lifting-surface vortex lattice model, a numerical design method of wake-adapted contra-rotating propellers (CRPs) for high-speed underwater vehicles is proposed. According to the given radial circulation distribution, the method can use prescribed camber line shapes to design maximum cambers and pitches of blade sections by controlling circulation at the leading edge, which makes the chordwise distribution of blade loading similar to that of NACA a = 0.8. It also can be performed under prescribed chordwise circulation distributions, where camber line shape and blade section pitch are designed. The Newton–Raphson iterative algorithm is utilised in the design of the pitch and camber. The radial circulation distribution of a set of CRPs for an underwater vehicle is used to redesign CRPs by the proposed method, and the design results are then validated via numerical simulations by solving the Reynolds-averaged Navier-Stokes equations. The results indicate that the proposed method is suitable for the design of CRPs with tapered hubs and skewed blades, and it also exhibits good mesh convergence. The CRPs designed with the given camber line shape and the given chordwise loading distribution both have relatively uniform pressure distributions, with the latter being superior.     

水下机器人光纤微缆动力学研究

讨论了水下机器人远程通信光纤微缆的动力学问题,研究分析了在海洋层流条件下水下机器人的运动对光纤微缆张力的影响,在仿真分析的基础上提出了对光纤微缆收放系统的设计要求并给出了概念设计方案。     

Pseudo long base line navigation algorithm for underwater vehicles with inertial sensors and two acoustic range measurements

This paper presents an integrated navigational algorithm for unmanned underwater vehicles (UUV) using two acoustic range transducers and strap-down inertial measurement unit (SD-IMU). A range measurement model is derived for a UUV having one acoustic transducer and cruising around two reference transponders at sea floor or surface. The proposed algorithm, called pseudo long base line (PLBL), estimates the position of the vehicle integrating the SD-IMU signals corrected with the two range measurements. Extended Kalman filter was applied to propagate error covariance, to update measurement errors and to correct state equation whenever the external measurements are available. Simulations were conducted to illustrate the effectiveness of the PLBL using the 6-d.o.f. nonlinear numerical model of a UUV at current flow, excluding bottom-fixed DVL. This paper also shows the error convergence of the vehicle's initial position by the additional range measurements without velocity information.     

Autopilot control synthesis for path tracking maneuvers of underwater vehicles

This paper is concerned with the robust control synthesis of autonomous underwater vehicle(AUV) for general path following maneuvers.First,we present maneuvering kinematics and vehicle dynamics in a unified framework.Based on H∞ loop-shaping procedure,the 2-DOF autopilot controller has been presented to enhance stability and path tracking.By use of model reduction,the high-order control system is reduced to one with reasonable order,and further the scaled low-order controller has been analyzed in both the frequency and the time domains.Finally,it is shown that the autopilot control system provides robust performance and stability against prescribed levels of uncertainty.     

基于层次模型定量推理机制的潜水器故障诊断系统设计

基于智能信息处理故障诊断方法,描述和分析了用于潜水器一类的复杂动态系统。通过引入概率信息的方法对其推理机制进行量化,实现了诊断结果的精确度量以及诊断过程的精确控制;针对系统不同层次间的检测和诊断进程建立了信息交换和综合设计方法,提高了各模块的检诊能力和检诊效率,可以从总体上提高处理复杂故障情况的水平。     

A novel maneuverable propeller for improving maneuverability and propulsive performance of underwater vehicles

The existing propulsor that can perform both propulsion and maneuvering along axis of rotation is propeller/rotor for a helicopter. Helicopter propellers when maneuvering increase or decrease their blades’ pitch cyclically to create imbalanced thrust and hence maneuvering force/torque. A “maneuverable propeller” was developed and its performance on both maneuvering and propulsion is assessed. The “maneuverable propeller” is an alternative of the existing helicopter rotors. The novelty of this propulsor is that the imbalanced thrust force/torque is created by cyclically increasing or decreasing the angular speed of their blades relatively to the hubs/shafts, to provide the desired maneuvering torque. This maneuverable propeller is hence defined as the Cyclic Blade Variable Rotational Speed Propeller (CBVRP). One of the best advantages is that the maneuvering torque created by the “maneuverable propeller” is much higher, about 5 times of the shaft torque of the same propeller at thrust only mode. The “maneuverable propeller” has wide applications for both surface ships and underwater vehicles that require high maneuverability for cruising inside the narrow passage.     

水下机器人主动升沉补偿系统研究

介绍一种基于水下机器人常规液压收放绞车的主动升沉补偿系统,利用加速度传感器获得母船的升沉运动信号,控制绞车的运转来降低母船的升沉运动对水下机器人的影响。通过理论计算建立主动升沉补偿系统的数学模型,仿真分析绞车运动对水下机器人升沉运动的补偿效果,并利用主动升沉补偿系统实验台验证基于常规液压收放绞车的主动升沉补偿方案的可行性。     

Design and implementation of time efficient trajectories for autonomous underwater vehicles

This paper discusses control strategies adapted for practical implementation and efficient motion of autonomous underwater vehicles (AUVs). For AUVs we would like efficiency in both the measured time and the energy consumption, the mission dictating the weight to put on each of these cost. As a first approach to this problem, we focus in this paper on time minimization. Based on the structure of the time optimal trajectories and of the pure motions, we develop an algorithm to design time efficient trajectories corresponding to piecewise constant thrust arcs with few actuator switchings. We do that by solving a new optimization problem where the unknowns are the time period between two actuator switchings as well as the values of the constant thrust arcs. We apply a direct method to compute the solutions numerically. With our algorithm, we gain considerable computational time. Moreover, with as few as three actuator switchings, the duration of our trajectories is within 10% of the optimal trajectories. Since our control strategies have a simple structure they can be implemented on a test-bed vehicle. For the experiments displayed in this paper we use a spherical underwater vehicle which exhibits with almost no preference of direction or orientation for movement; this gives us a very controllable and versatile vehicle.     

水下机器人耐压舱优化设计与结构分析

水下机器人的耐压舱设计要求在满足总体指标的前提下,最大限度地提高设计强度与稳定性,同时尽可能降低质量。本文使用ANSYS Workbench中的Design Explorer模块,对耐压舱进行快速优化设计,一次获得多个优化候选结果,经过对比分析得到最优设计方案。然后,针对装配形式进行接触分析,确保大压力条件下结构不会在接触面发生失效破坏。最后,对舱体结构进行稳定性分析,确保结构能够在大深度环境中不发生失稳破坏。本研究为水下机器人耐压舱体快速优化设计、强度和稳定性校核提供了参考。     

潜水器控制系统层次故障诊断模型设计

在潜水器控制系统的基础上,按照结构、功能和组件的关系,为潜水器控制系统进行故障诊断建模。依据基于模型的层次故障诊断技术,建立了适用于潜水器控制系统故障诊断的具体诊断和推理策略,开发了故障诊断软件系统,描述了故障诊断具体过程,并利用数字仿真验证系统设计的有效性。     

浅海管线检测维修潜水器控制系统自航模试验

浅海海底管线检测维修潜水器是具有复杂动力特性和作业方式的特种载人潜水器，其作业需配备姿态及航行自动控制系统。为了保证其自动控制系统研制成功，研制了1：8缩尺的自航模作为平台，将实际控制系统方案遵循相似性准则改造为自航模控制系统，包括校正与补偿回路、指令分配器、姿态控制回路、航行控制回路。在海洋工程水池模拟风浪流等海洋环境，进行各种情况下的控制试验，对实现的控制律加以验证和改进，这些改进又按照相似性准则反映到实际控制系统方案的修正中。控制系统的设计方案由此得到全面验证和改善。     

海底管线检修潜水器垂直面控制及自航模试验

论述了纵倾控制律设计及自航模试验。首先选择一系列深度,对同一深度采用频域校正法单独设计控制律,使之对不同的速度和漂角具有足够的稳态精度和抗干扰性,这些控制律被集成统一为纵倾控制器,并根据潜深变化进行切换,对于其它深度采用同样的方法设计。控制器首先通过计算机仿真,然后进行自航模试验验证。设计的纵倾控制系统同时在其他试验项目中(水下管线跟踪和动力定位)发挥了重要的作用。     

“海底管线检修潜水器”管线位置信息重构及其自航模试验

海底管线检修潜水器主要依靠管线探测系统给出的管线位置信息完成水下自动跟踪巡线、定位和作业。针对管线探测系统信息不佳甚至丢失问题 ,建立了基于扩展卡尔曼滤波的信息重构算法 ,通过对来自管线探测系统、惯导和GPS系统以及管线位置历史数据库的信息进行融合 ,不仅提高了管线位置信息的稳定性 ,而且可以在管线探测系统信息丢失的情况下短时间内重构管线位置信息 ,供自动控制系统使用。运用该算法进行了计算机仿真和自航模试验 ,试验结果验证了该算法的有效性     

海域无人机监视监测业务流程设计

文章主要探讨海域无人机监视监测业务流程,针对目前海域动态监视监测工作中无人机管理模式及作业流程的现状,结合海域资源开发管理业务需求,阐述规范无人机作业流程的必要性。按照无人机监测任务的紧迫程度分为常规监测任务和应急监测任务,以规范无人机业务流程、提高无人机作业效率、保障无人机作业安全为目的,并结合无人机业务工作中的实际情况对两类监测任务的无人机作业流程进行了探讨与设计。     

基于水下自主航行器（AUV）的神狐峡谷谷底块体搬运沉积特征及其对深水峡谷物质输运过程的指示

海底峡谷是陆源物质向深海运移的重要通道。对于远离陆地的海底峡谷,通常认为浊流是物质搬运的主要营力。受限于探测精度和复杂作业环境影响,使用常规地球物理资料对深水海底峡谷尤其是对谷底沉积体的形态和结构特征的刻画不够精细。基于水下自主航行器（AUV, Autonomous Underwater Vehicle）采集的高分辨率多波束、旁扫声呐和浅地层剖面资料,对神狐峡谷群中的一条峡谷的谷底表面及部分浅部地层的沉积特征进行了分析。结果表明,峡谷谷底浅部地层并不像它平滑的表面那么简单,而是由大量内部杂乱弱反射、厚度在8.4 m及以下的块体搬运沉积体组成。峡谷中下游块体搬运沉积体大都沿峡谷走向整体呈条带状展布,不是直接来源于相邻的峡谷脊部。研究认为在特定沉积环境下（例如高海平面时期）,陆坡限定性峡谷谷底的块体搬运沉积过程的重复进行是峡谷谷底物质输运的重要途径,与浊流共同雕刻了峡谷的地形地貌。基于AUV的地球物理探测技术将是研究海底浅表层沉积过程和保障海底工程施工的重要手段。