3D track-keeping method for autonomous underwater vehicle

In this paper, 3D track-keeping control method for autonomous underwater vehicle (AUV) with and without the influence of ocean current is investigated. Because the system to be controlled is highly nonlinear and strong coupled, an approach is used to divide it into two subsystems. One is to control the heading and the track error on the horizontal plane. The other is to control the pitch and the track error on the vertical plane. The results of computer simulation show that the autopilot works properly, it can capture the current waypoint and turns to track the next path automatically.     

Simulation platform of navigation system for autonomous underwater vehicle

1 Introduction1 It is hoped the Autonomous Underwater Vehicle (AUV) can be fully autonomous, but the basis of this hope is that AUV can navigate and position accurately.Inertial navigation is the main navigation method for AUV, but accumulative error of t…     

Design and evaluation of a hierarchical control architecture for an autonomous underwater vehicle

This paper researches on a kind of control architecture for autonomous undelwater vehicle （AUV）. After describing the hybrid property of the AUV control system, we present the hierarchical AUV control architecture. The architecture is organized in three layers： mission layer, task layer and execution layer. State supervisor and task coordinator are two key modules handling discrete events, so we describe these two modules in detail. Finally, we carried out a series of tests to verify this architecture The test results show that the AUV can perform autonomous missions effectively and safely. We can conclude the control architecture is valid and practical.     

水下无人航行器主动目标自动检测方法研究

水下主动目标自动检测是反映水下无人航行器目标探测能力的一项重要指标,混响背景下的主动目标自动检测是其中的难点之一。该文将主动目标自动检测转换为图像分割问题,先用形态学重建或低通滤波算法预处理声图,再用分水岭算法从梯度图像中分割出目标。在此基础上提出了一种自适应阈值选取方法。经过海试数据的检验,文中方法具有较强的稳定性,与传统的恒虚警算法相比,可以有效降低虚警率。     

水下多智能体群协调控制仿真分析

基于一致性理论研究了水下智能体群的运动稳定性问题.在具有通信约束的情况下,对每个智能体设计一个分布式控制器.在系统的通信网络拓扑结构为连通图的情况下,给出了系统时滞上界的具体解析表达式.通过仿真示例验证了当个体间的通信时滞在给定范围内,所有的AUV仍然能全局渐近地收敛至期望速度和期望队形.     

自主式无人水下航行器航向自适应滑模控制

无人水下航行器是未来水下战场的重要武器装备,对其运动控制的研究得到广泛关注,其中航向控制的实现是研究的热点问题。对无人水下航行器六自由度动力学方程进行简化,得到横向运动动力学方程,并将偏航角作为控制对象,采用滑模控制的方法实现对航向角的跟踪控制,并引入自适应机制在线估计未知参数,减小参数不确定性对稳定性的影响。通过对控制算法的仿真,结果表明了控制器设计的正确性。     

智能水下机器人路径规划方法综述

路径规划方法是智能水下机器人技术研究的核心内容之一,是实现自主航行和作业的关键环节。本文将水下机器人的路径规划方法按智能程度分为传统和智能两大类。传统方法包括基于路线图构建的路径规划方法、基于单元分解的路径规划方法以及基于人工势场的路径规划方法,智能方法包括基于群智能的路径规划方法和基于机器学习的路径规划方法。针对水下机器人规划环境的特点,分别对这几类典型方法进行总结与评价,重点分析了智能方法的优缺点和关键问题,最后展望智能水下机器人路径规划的未来研究方向。     

Mooring cable tracking using active vision for a biomimetic autonomous underwater vehicle

This study presents a localization system using visual information for guidance and navigation of a biomimetic autonomous underwater vehicle (BAUV). The BAUV tracks a mooring cable using two cameras and sonar. Sonar has good accuracy in detecting longitudinal distances but is poor in detecting lateral distances. Since a stereo image has quantization errors, for the cameras, measurement errors in lateral directions are less than those in the optic-axis direction. An extended Kalman filter was employed to combine observational information derived from the cameras and sonar of the mooring cable position with the navigation data of the BAUV. This work demonstrates, using water tank experiments, the effectiveness of the proposed tracking technique in decreasing uncertainty in position estimations of the BAUV and mooring cable.     

负浮力四倾转推进器水下机器人姿态跟踪控制

负浮力四倾转推进器水下机器人(NQTAUV)的姿态控制受到各种干扰的影响,导致姿态跟踪误差。为了实现干扰的估计与补偿,进行精确的姿态跟踪,设计干扰观测器和姿态控制器。首先,建立姿态跟踪误差模型,基于抗干扰控制理论,设计干扰观测器估计干扰,然后设计姿态跟踪控制器,并在三自由度实验平台上进行姿态跟踪实验。比较干扰观测器激活和关闭情况下,跟踪正弦信号的性能。实验结果表明,干扰观测器能够准确估计干扰,控制器能够对干扰进行补偿,实现了高精度的姿态跟踪。研究结果显示,基于干扰观测器的姿态跟踪控制能够对干扰进行补偿,提高了姿态跟踪精度。     

深水欠驱动自主水下航行器分布式控制方法

针对传统CAN总线控制方法在欠驱动状态下,出现的控制指令响应速度慢、欠驱动状态下控制指令下达滞后等问题。提出深水欠驱动自主水下航行器分布式控制方法,在传统CAN总线控制方法的基础上建立欠驱动信号指令识别单元与分布式控制指令识别传输单元,实现分布式控制的效果。通过对比实验证明:提出的深水欠驱动自主水下航行器分布式控制方法,能够准确识别航行器的欠驱动状态,并通过分布式控制指令传输方式,完成对欠驱动状态下航行器的稳定、准确控制。     

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.     

Coordinate control of initiative mating device for autonomous underwater vehicle based on TDES

A novel initiative mating device, which has four 2-degree manipulators around the mating skirt, is proposed to mate between a skirt of AUV （autonomons underwater vehicle） and a disabled submarine. The primary function of the device is to keep exact mating between skirt and disabled submarine in a badly sub sea environment. According to the characteristic of rescue, an automaton model is brought forward to describe the mating proceed between AUV and manipulators. The coordinated control is implemented by the TDES （time discrete event system）. After taking into account the time problem, it is a useful method to control mating by sinmlation testing. The result shows that it reduces about 70 seconds after using intelligent co-ordinate control based on TDES through the whole mating procedure.     

Biogeography-based combinatorial strategy for efficient autonomous underwater vehicle motion planning and task-time management

Autonomous Underwater Vehicles (AUVs) are capable of spending long periods of time for carrying out various underwater missions and marine tasks. In this paper, a novel conflict-free motion planning framework is introduced to enhance underwater vehicle’s mission performance by completing maximum number of highest priority tasks in a limited time through a large scale waypoint cluttered operating field, and ensuring safe deployment during the mission. The proposed combinatorial route-path planner model takes the advantages of the Biogeography-Based Optimization (BBO) algorithm toward satisfying objectives of both higher-lower level motion planners and guarantees maximization of the mission productivity for a single vehicle operation. The performance of the model is investigated under different scenarios including the particular cost constraints in time-varying operating fields. To show the reliability of the proposed model, performance of each motion planner assessed separately and then statistical analysis is undertaken to evaluate the total performance of the entire model. The simulation results indicate the stability of the contributed model and its feasible application for real experiments.     

水下拖曳体自主布放回收装置设计与研究

为了保证搭载于水面无人艇(Unmanned Surface Vehicle)的水下拖曳体(Underwater Towed Vehicle)能够正常工作,并且能够自主布放和回收水下拖曳体,设计了一种基于无人水面艇的水下拖曳体自主布放回收装置。该装置主要包括绞车、液压系统、滑台、滑轨、起升架以及其他辅助机构,通过液压驱动绞车实现缆绳的收放,通过液压缸驱动起升架、滑轨和滑台实现3级布放回收。整套装置采用液压驱动,滑道式布放回收,该自主布放回收装置可靠性高,占用甲板空间小,满足无人条件下作业,提高了工作效率,工程应用价值高。     

水下航行体非定常垂直空泡长度的计算

带空泡航行体从水下朝水面运动时,空泡将受到重力梯度和空泡记忆效应的耦合影响而呈现出特殊的非定常特点。为了计算有限水深重力场中的空泡长度,文章在Paryshev空泡动力学数学模型(Delay Differential Equations,DDEs方程)基础上,增加了重力影响项;同时为了快速求解上述空泡DDEs方程,对DDEs的数值方法进行了改进,提出了一种效率更高的对延迟时间点进行局部拟合的方法。最后利用新方法求解了带重力影响的空泡DDEs方程,计算结果与试验结果吻合。     

新型自主水下航行器的运动控制研究与应用

针对与上海交通大学共同研制的ZY-1型自主水下航行器,本实验室承担了其动力推进装置设计与优化任务。本文首先综合水动力特性和新型后置推进器的设计,分析此新型AUV后置X型推进器的推力模型,对AUV在水平面与垂直面的运动方式和相应的控制算法进行阐述,并设计了PID控制器。接下来在搭建的实验平台上对PID控制参数进行整定。最终在拖曳水池试验中验证了所述方法的合理性,并且在后期的湖试中得到了满意的试航结果。     

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.     

一种基于行为的自主/遥控水下机器人共享控制方法

自主/遥控水下机器人(ARV)是一种综合自主水下机器人和遥控水下机器人特点的新型水下机器人,融合ARV自主控制和操作人员遥控的共享控制是ARV控制的关键问题。针对ARV在环境探索任务中和目标观察任务中的共享控制,采用基于行为的控制思想,提出一种基于行为的ARV共享控制方法,包括实现环境探索的遥控行为、自主避障行为、以及实现目标观察的人机协同路径跟踪控制行为,通过设计的基于优先级的行为组织和融合方法,实现了ARV基于设计的行为以"人主机辅"模式执行环境探索继而以"机主人辅"模式执行目标观察过程的有效共享控制。基于构建的水下机器人共享控制仿真环境对设计的共享控制方法进行仿真实验,验证了提出的共享控制方法的有效性。     

水下航行体垂直发射筒口压力场 L/E耦合数值模拟

采用 Lagrange 结构网格和 Euler 流场网格（L/E）耦合的数值仿真方法,对潜射航行器出筒后筒口压力场进行三维数值仿真分析。计算模型考虑海水的横向来流和航行体出筒过程对筒口气泡脉动的影响。仿真计算获得了筒口压力场气泡脉动主要特征,试验与计算的2个主要压力波峰曲线形状基本一致。通过对比计算表明,考虑横向流作用可以有效减少筒口压力场计算偏差。本文的计算方法及结论可为发射筒口压力场分析提供有益指导。