基于大地形管理的水下机器人视景仿真系统

研究水下机器人视景系统优化设计,针对水下机器人的航行环境具有不可接近性和未知性的特点,为创建水下海洋生物和可观世界环境,利用虚拟的计算机仿真环境作为水下机器人初期调试的“平台”具有十分重要的意义.建立了基于大地形管理的水下机器人视景仿真系统.有关大地模型建立、场景效果等,利用函数变量方法自定义机器人运动引擎,采用粒子系统仿真了机器人尾流流场和低噪音的实现.依托软件平台MultiGen Creator和Vega,利用Vega与Visual C++混合编程实现LADBM模块的大地形管理,进行仿真验证.仿真结果表明,视景仿真系统逼真地再现了水下机器人在大范围区域探测目标及自主航行的过程,有效地解决了水下机器人长距离自主航行视景仿真中的大地形管理问题.     

一种基于分布式信息融合技术的水下机器人智能感知系统方案

水下机器人的研究和使用对人类开发海洋资源具 有重大意义．随着海洋探测深度的增加，自治水下机器人（AUV）正成为新的研究热点．为 解决AUV深海域探测所面临的通讯速率低和实时性问题，本文提出了“基于分布式信息融合 技术的水下机器人智能感知系统”的实施方案，并以贝壳抓取过程为实例，解释系统解决实 际问题的过程．     

沈阳自动化所研制成功长航程水下机器人

2月底，由中国科学院沈阳自动化研究所主持研制的远程自治水下机器人演示样机圆满结束湖上试验。经多次试验表明，该样机可连续航行数十小时、续航能力达数百公里，创造了我国自治水下机器人单次航行时间和航行距离的新记录。机器人系统主要技术指标均达到设计要求，并在控制系统体系结构、自主航行控制与精确导航定位、新型声纳、大功率燃料电池和锂电池应用等多项关键技术取得新突破，标志着沈阳自动化所远程自治水下机器人的总体技术跻身于国际先进水平。     

基于柔性长鳍波动推进的仿生水下机器人设计与实现

以基于柔性长鳍波动推进的仿生水下机器人试验模型为背景，主要研究其设计与实现问题．首先，介绍了仿生水下机器人试验模型的设计原则及其系统总体结构，然后重点研究了仿生柔性长鳍、主控模块与通讯系统、运动控制子系统的设计方法、系统构成和工作原理，最后介绍了试验模型的系统测试与航行试验结果及其结论，并指出了仿生水下机器人试验模型的改进重点和柔性长鳍波动推进技术今后的研究方向．基于柔性长鳍波动推进的仿生水下机器人试验模型的研制成功，初步验证了柔性长鳍波动推进方式应用于水下机器人推进控制系统在原理上和技术上是可行的．     

小型自治水下机器人控制系统研究开发

开发了一种性价比高的CAN总线分布式自治水下机器人控制系统结构,并采用了独特的故障处理方法．根据弱耦合简化模型,详细设计了航行控制器,并对航行控制系统进行了仿真研究．仿真与试验结果表明: 控制系统性能可靠、传输率高,并具有很好的鲁棒性与稳定性,能够满足水下机器人工作环境复杂多变的要求．     

业界动态

沈阳自动化所研制成功长航程水下机器人2月底,由中国科学院沈阳自动化研究所主持研制的远程自治水下机器人演示样机圆满结束湖上试验。经多次试验表明,该样机可连续航行数十小时、续航能力达数百公里,创造了我国自治水下机器人单次航行时间和航行距离的新记录。机器人系统主要技术指标均达到设计要求,并在控制系统体系结构、自主航行控制与精确导航定位、新型声纳、大功率燃料电池和锂电池应用等多项关键技术取得新突破,标志着沈阳自动化所远程自治水下机器人的总体技术跻身于国际先进水平。沈阳自动化研究所是我国最著名的机器人研究单位,…     

基于UNITY3D的水下机器人视景仿真方法

水下机器人的视景仿真在整个机器人的研制中占有非常重要的地位.一方面应用在水下机器人航行时,进行实时监控,显示机器人的姿态信息.结合海底信息,为操作员的操控提供了重要的辅助信息;另一方面也应用在测试阶段的仿真航行,它可以反馈海底的障碍信息,提供高程深度数据.本文针对水下机器人视景仿真的需要,设计了水下机器人的视景仿真方法,利用UNITY3D技术进行开发,根据实际地图数据建立海底场景,显示水下机器人在水下航行的姿态,提高了海景的渲染效果和真实程度.本方法已经实际应用于"十三五"国家重点研发计划全海深水下机器人"海斗一号"中和国家重点研发计划全海深AUV中,在论证,测试,实用等各个阶段中,该方法都具有重要意义,为水下机器人的进一步研究提供了有力支撑.     

模块化自主水下机器人的机械设计与实现

介绍了一种具有基本航行能力且可扩展其他功能的模块化水下机器人.利用3维设计软件Solidworks及计算流体力学软件CFX对外形进行分析优化,降低水下机器人的功耗;对各功能舱段及段与段的连接形式采用模块化设计,结构简单,便于更换维修;此外还对耐压壳体强度及稳定性进行了理论计算及软件仿真.湖试证明,该水下机器人利用自身携带的传感器可以完成基本航行功能,包括自主定向航行、自主定速航行、自主定深航行、位置闭环航行等功能.     

带槽道桨水下机器人阻力特性的数值分析

自治水下机器人在低速航行时,单靠操舵方式难以保证其机动性。特别是作业过程中需要进行水下悬停定位时,经常会使用槽道桨。槽道桨在载体上形成贯穿式的孔洞结构,影响水下机器人直航过程中的阻力特性。本文借助流体动力数值仿真计算软件CFX,对槽道孔洞尺度改变、轴向位置改变时,水下机器人航行阻力所受到的影响进行了数值分析。数值分析得到的结论,对水下机器人槽道桨的工程设计和优化具有参考价值和指导作用。     

仿鱼长鳍波动推进水下航行器研究进展与分析

作为一种新型水下机器人,仿鱼长鳍波动推进水下航行器具有噪声低、机动性好等传统水下航行器无法比拟的优点,并得到相关研究人员的广泛关注。本文主要介绍了国内外在仿鱼长鳍波动推进水下航行器推进机理和系统研制方面开展的主要研究工作,在此基础上,分析总结了提升仿鱼长鳍波动推进水下航行器性能需要深入讨论和研究的一些问题。     

Thruster fault-tolerant control of a hovering AUV with four horizontal and two vertical thrusters

This paper deals with the motion control of a hovering autonomous underwater vehicle (AUV) with four horizontal and two vertical thrusters, when one or more thrusters are completely malfunctioned. Three thruster fault cases are considered: one horizontal thruster is faulty; two horizontal thrusters are faulty; and one vertical thruster is faulty. Through a series of simulations and an experiment, it is validated that the AUV can track a planned path in a 3-D space with minimally three thrusters (two are horizontal ones); however, some cases require the changes of the vehicle’s preferred direction of motion and its movement manner. Additionally, when the number of active horizontal thrusters is less than the required degree-of-freedom, a continuous state feedback control law does not exist due to the non-holonomic constraint. This paper highlights that the hovering AUV can overcome the non-holonomic constraint if using the feature that their translational and rotational motions can be controlled independently.     

Sediment penetration performance of a portable underwater robot for core sampling

As described in this paper, we investigate the sediment penetration performance of a portable underwater robot with a helical screw pipe using marine thrusters with limited force. First, we derive a mathematical model based on an empirical and simple method using the undrained shear strength of cohesive soil to provide a rough estimate of maximum penetration depths. Then, we perform numerical analysis for estimating the maximum depth of sediment penetration and for designing a sampling pipe. Additionally, we use experimentation to investigate the relation between the penetration depth of the helical screw pipe and the force of marine thrusters mounted on the portable underwater robot. After testing the penetration performance in a water tank, we conduct a field experiment at Lake Biwa and obtain results of the penetration depths. The maximum penetration into the lake sediment is at least 0.30 m. The results demonstrated the possibility of using the derived mathematical model to make a rough estimation of the maximum penetration depth for clay sediments. Additionally, we can use non-powerful thrusters equipped with small autonomous underwater vehicles (AUVs) and remotely operated vehicles (ROVs) for sediment sampling. The proposed method is also applicable for the installation of underwater sensors using small AUVs and ROVs.     

DC Thruster Controller Implementation with Integral Anti-wind up Compensator for Underwater ROV

This paper presents the implementation and experimental results of different conventional position control schemes for positioning an experimental model, the THETIS Underwater Remotely Operated Vehicle (UROV). To achieve minimum response time and in order to avoid the so-called Integral Wind-up phenomenon, Proportional-Integral (PI) plus integral antiwind-up compensation is used. Hardware implementation of the design is described and experimental results of a digital position control system over one direction using two dc thrusters fed by four quadrant (PWM-Driven) transistor choppers are given. All control algorithms are implemented using a TI's Digital Signal Processor (DSP). The actual position and orientation of the vehicle in a 3-D space is derived through a combination of an ultrasonic scanning system, a direction gyrocompass, and a pressure depth sensor. The vehicle's use at the present stage of development is to perform water pollution measurements.     

Microautonomous Robotic Ostraciiform (MARCO): Hydrodynamics, Design, and Fabrication

Boxfish with multiple fins can maneuver in confined spaces with a near zero turning radius, and it has been found that its unusual boxy shape is responsible for a self-correcting mechanism that makes its trajectories immune to water disturbances. The microautonomous robotic ostraciiform aims to apply these features in a novel underwater vehicle design. Miniature underwater vehicles with these characteristics have a variety of applications, such as environmental monitoring, ship wreck exploration, inline pipe inspection, forming sensor networks, etc. This paper presents the research leading to the design and fabrication of a robotic ostraciiform. Tail fin hydrodynamics have been investigated experimentally using robotic flapper mechanisms to arrive at a caudal fin shape with optimal-shape-induced flexibility. Fluid simulation studies were utilized to arrive at the body shape that can result in a self-correcting vorticity generation. Finally, the robotic ostraciiform prototype was designed based on the previous results. The ostracifform locomotion is implemented with a pair of 2 DOF pectoral fins and a single DOF tail fin. The finalized body shape of the robot is produced by 3-D prototyping two separate halves.     

无人水下航行器推进器故障定位研究

无人水下航行器(UUV)在复杂多变的海洋环境中作业时,推进器的故障可阻挠使命的执行,严重时还可能造成UUV的丢失与损毁。为增强UUV的安全保障能力,针对UUV多台推进器的故障定位问题,采用基于几何相关性分析的方法,设计了UUV同一平面多推进器的故障定位算法,并提出了故障定位约束条件,通过仿真实验验证了所提算法的有效性。     

Controllability of a planar body with unilateral thrusters

Investigates the minimal number of unilateral thrusters required for different versions of nonlinear controllability of a planar rigid body. For one to three unilateral thrusters, one gets a new property with each additional thruster: one thruster suffices for small-time accessibility on the body's state space TSE(2); two thrusters suffice for global controllability on TSE(2); and three thrusters suffice for small-time local controllability at zero velocity states     

采用多齿肋片的电机控制器散热器设计分析

电机控制器作为纯电动汽车的控制核心,其散热性能直接影响到驱动系统的可靠性。以某MOS多管并联的电机控制器样机为研究对象,将原设计的光滑肋片替换为多齿肋片结构,以MOS管芯片温升和肋片散热器重量为评价指标,对原散热器结构进行改进设计,并进行CFD数值分析。结果表明,相对于原设计的光滑肋片,多齿肋片结构增加了对流散热的表面积和换热系数,使得肋片的散热能力得到了提升。通过改变肋片数量、小齿的几何尺寸及位置分布,在不高于原设计的芯片温升的前提下,最优设计方案的肋片散热器重量轻化了6.41%。     

超高速水下航行器纵平面姿态控制研究

超高速水下航行器在水下航行时,由于大部分表面被超空泡所包覆,其纵平面的运动特性发生显著变化,使得控制难度加大.提出把空化器用作控制面,通过操纵其舵角改变量来控制航行器在纵平面的运动,从而达到间接控制航深的目的.最后运用PID算法进行仿真分析,结果表明采用此控制方法所产生的深度负偏差较小,简单易实现、且鲁捧性好.还对航行器直接深度控制进行探讨,考虑到超空泡工况下深度测量的难度较大,姿态控制具有更强的适用性.     

AQUA: An Amphibious Autonomous Robot

AQUA, an amphibious robot that swims via the motion of its legs rather than using thrusters and control surfaces for propulsion, can walk along the shore, swim along the surface in open water, or walk on the bottom of the ocean. The vehicle uses a variety of sensors to estimate its position with respect to local visual features and provide a global frame of reference     

Experimental study on fine motion control of underwater robots

This paper considers thruster dead zones and saturation limits, which are nonlinear elements that complicate fine motion control of underwater robots. If the vehicle is configured with redundant thrusters, the respective dead zones and their surrounding nonlinear regions could be avoided by implementing a null motion solution for the command input of the vehicle. This solution is derived from the vehicle's geometry and is realized before the application of the motion control algorithm. The result is an improvement in system performance exclusive of the implemented controller type. The approach is illustrated through simulation and experiment with an underwater robot, ODIN.