遥控水下机器人系统在水库大坝水下检查中的应用

通过遥控水下机器人系统在水库大坝面板趾板、水库进水口、宋代古陂等工程水下检查中的实际应用,总结遥控水下机器人在清水环境下渗漏点查找、浊水环境水下冲刷检查、流动水环境水下金属锈蚀检查、易缠绕环境条件下水下检查的应用技巧,归纳遥控水下机器人系统的特点、技术优势及适用范围,为解决遥控水下机器人系统应用中出现的线缆易缠绕及难以发现大坝渗漏点等问题积累经验。     

Development of a stable localized visual inspection system for underwater structures

To avert potential crisis from Japan’s aging infrastructure and declining birth rate, the Japanese Government is planning to introduce robotic technology for the inspection of social infrastructure (such as pipes, dams, and bridges). Recording underwater positions is a difficult task for human divers who undertake conventional dam inspections. This study presents the Anchor Diver 5.2 system for efficient and effectual dam inspection. Anchor Diver 5.2 is based on an extended-tether-maneuvered remotely operated vehicle (ROV) equipped with cameras. The ROV is lowered into water by a hoist system from a boat and implements a visual survey of the concrete underwater structure. To improve the visibility of the ROV in murky and cloudy water, a novel concept named Water Loupe is proposed. In addition, a simple boat-fixing method is proposed to provide a stable base on the water surface, and the underwater position of the ROV, which cannot be accessed by global positioning systems, is recorded using a feasible localization method. Finally, the developed system was evaluated in field experiments conducted in the Amagase Dam, Japan, and its merits and problems are discussed.     

In‐water visual ship hull inspection using a hover‐capable underwater vehicle with stereo vision

Underwater visual inspection is an important task for checking the structural integrity and biofouling of the ship hull surface to improve the operational safety and efficiency of ships and floating vessels. This paper describes the development of an autonomous in‐water visual inspection system and its application to visual hull inspection of a full‐scale ship. The developed system includes a hardware vehicle platform and software algorithms for autonomous operation of the vehicle. The algorithms for vehicle autonomy consist of the guidance, navigation, and control algorithms for real‐time and onboard operation of the vehicle around the hull surface. The environmental perception of the developed system is mainly based on optical camera images, and various computer vision and optimization algorithms are used for vision‐based navigation and visual mapping. In particular, a stereo camera is installed on the underwater vehicle to estimate instantaneous surface normal vectors, which enables high‐precision navigation and robust visual mapping, not only on flat areas but also over moderately curved hull surface areas. The development process of the vehicle platform and the implemented algorithms are described. The results of the field experiment with a full‐scale ship in a real sea environment are presented to demonstrate the feasibility and practical performance of the developed system.     

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.     

Development of the multifunctional rescue robot FUHGA2 and evaluation at the world robot summit 2018

Abstract

Robots are needed in rescue activities and the inspection of infrastructure. We developed the rescue robot FUHGA2 so that it has various functions. FUHGA2 has high mobility, with main crawlers covering the body and four sub-crawlers, high dexterity using a long six-axis arm, and high searching ability using various sensors. Furthermore, a novel parallel gripper unit with wire-jamming mechanism is mounted at the tip of the arm, which can change its hardness and fit its shape to an object. Additionally, high Maneuvering is achieved by displaying sensor information to the operator clearly and intuitive operation command design. FUHGA2 won the World Robot Summit 2018 Standard Disaster Robotics Challenge, which is a competition for rescue robots. We achieved high scores in all categories of tasks. In this paper, we describe the development of FUHGA2 and the performance evaluation results from the World Robot Summit 2018.     

Stable camera position control of unmanned aerial vehicle with three‐degree‐of‐freedom manipulator for visual test of bridge inspection

This paper describes a camera position control with aerial manipulator for visual test of bridge inspection. Our developed unmanned aerial vehicle (UAV) has three‐degree‐of‐freedom (3‐DoF) manipulator on its top to execute visual or hammering test of the inspection. This paper focuses on the visual test. A camera was implemented at the end of the manipulator to acquire images of the narrow space of the bridge such as bearings, which the conventional UAV without the camera‐attached manipulators at its top cannot achieve the fine visual test. For the visual test, it is desirable that the camera is above the body with enough distance between the camera and the body. As obvious, the camera position in the inertial coordinate system is effected by the movement of the body. Therefore we implement the camera position control compensating the body movement into the UAV. As a result of an experiment, it is assessed that the proposed control reduces the position error of the camera comparing the one of the body. The mean position error of the camera is 0.039 m that is 51.4% of the one of the body. Our world‐first study enables to acquire the image of the bearing of the bridge by a camera mounted at the end effector of aerial manipulator fixed on UAV.     

基于振弦式传感器的大坝渗压监测系统设计

针对渗压自动化监测系统运行环境恶劣、可靠性要求高的特点,设计了基于振弦式传感器的大坝渗压自动化监测系统。该系统的硬件部分以LPC2368FBD为主控制器,集数据采集、数据存储、数据显示、电源管理于一体。阐述了振弦式传感器的工作原理与特性;介绍了大坝渗压自动化监测系统的硬件、软件结构和设计思想;详细分析了数据采集电路的设计原理与实现过程。将该系统样机在实验室进行了测试和试运行,频率测量精度达±1%;信号和电源防雷击和抗电磁干扰功能强;具有LCD液晶显示功能,可直接显示采集数据,且体积小、造价低,适应现场恶劣环境。     

深海ROV伺服控制方法研究及其仿真

针对深海水下机器人(ROV) 处于深海环境中受到外界干扰的伺服控制这一问题, 首先建立推进器推力分配结构, 推导得出作用在ROV本体上相应的实际推力; 然后依据PID 原理和模糊规则, 构造模糊PID 控制器, 实现ROV消除外界干扰恢复静止稳定状态的伺服控制; 最后通过仿真实验表明了所构造的模糊PID 控制具有较好的动态性能和稳态性能, 显示出良好的伺服控制性能.

     

基于窄带物联网的巡检机器人目标跟踪控制系统设计

目前研究的巡检机器人目标跟踪控制系统存在目标位置误差大、目标跟踪控制效果差、采集的图像模糊等问题。为了解决上述问题,基于窄带物联网的巡检机器人目标跟踪控制系统。系统硬件以窄带物联网无线通信模块为基础,优化设计了Zigbee压力采集器、中央控制器和STM32主控电路,实现了巡检机器人目标跟踪控制系统的数据信息集中调度。Zigbee压力采集器主要由XBee控制模块、压力传感器两部分组成,同时设计了供电电路、晶振电路和复位电路,通过系统硬件,实现了对巡检机器人的跟踪、控制和监控,为系统提供了硬件支持。软件方面给出了系统的控制流程,设计了Zigee组网程序、嵌入式视觉处理程序和巡检机器人自主导航程序。实验结果表明,基于窄带物联网的巡检机器人目标跟踪控制系统目标位置误差较小、控制效果较好、图像更加清晰。     

负压波定位理论在输油管道泄漏监测系统中应用

本文主要讲述了负压波理论在输油管道泄漏监测系统的具体应用情况，分析了采用同压波理论进行泄漏定位的过程中时间差的求解问题，提出了三种求取时间差的方法，通过负压滤理论的定位公式以及时间差对泄漏点进行定位。     

基于负压波法的空调管道泄漏检测系统

管道密封性是评价制冷系统质量的重要技术指标之一。空调管道一旦发生泄漏,将导致空调制冷系统不能有效制冷,甚至无法正常工作。本文在分析国内空调常用的水试漏法、卤素检漏法、氦质谱检漏法的基础上,提出了采用负压波法对空调管道泄漏进行检测,实验表明该方法切实可行有效。     

车牌定位中宇符边缘色彩信息作用研究

研究了字符边缘色彩信息对车牌定位的作用.在HSV色彩空间中,字符边缘处色度、饱和度处于特定的较窄范围,分别提取出车牌底色色彩像素点和字符色色彩像素点,再利用图像水平方向纹理得到车牌底色纹理,最后排除没有字符色像素点相邻的底色纹理像素点.实验结果表明,该方法适应性强、定位速度快,可在定位的同时确定车牌颜色.     

约束条件下的巡线机器人逆运动学求解

高压输电线路巡检机器人是一种多关节悬挂运动机构,要实现其运动控制就需要根据机器人的本身机构特点和悬挂系统的运动约束条件进行运动学分析.本文利用微分扭转法对巡线机器人的正向运动学进行了求解,并通过对机器人悬挂系统的力学分析,得到了机器人运动学的约束条件,并在这种约束条件下,采用了一种可用来进行实时控制的迭代循环坐标下降(CCD)算法,来进行机器人的逆运动学求解.这种迭代算法对于有运动约束系统的逆运动学求解具有较强的适用性,而且它具有较好的收敛性和有效性,适合于在线计算,便于巡线机器人的实时运动控制.     

Development of wheel-less snake robot with two distinct gaits and gait transition capability

Snake robots are mostly designed based on single mode locomotion. However, single mode gait most likely could not work effectively when the robot is subject to an unstructured working environment with different measures of terrain complexity. As a solution, mixed mode locomotion is proposed in this paper by synchronizing two types of gaits known as serpentine and wriggler gaits used for non-constricted and narrow space environments, respectively, but for straight line locomotion only. A gait transition algorithm is developed to efficiently change the gait from one to another. This study includes the investigation on kinematics analysis followed by dynamics analysis while considering related structural constraints for both gaits. The approach utilizes the speed of the serpentine gait for open area locomotion and exploits the narrow space access capability of the wriggler gait. Hence, it can increase motion flexibility in view of the fact that the robot is able to change its mode of locomotion according to the working environment.     

Differential negative resistance effect of output characteristics in deep sub-micrometer wurtzite AlGaN/GaN MODFETs

We obtained the output characteristics in wurtzite Al0.15Ga0.85N/GaN MODFETs with the full band Monte Carlo method. The gate length Lg and the channel length Los in the device are 0.2 μm and 0.4 urn, respectively. In the output characteristics we found a differential negative resistance effect. That is, as VDS is a constant, initially, VDS increases with increasing VDS. When VDS exceeds a certain critical value, IDS decreases with increasing VDS. The analysis for velocity-field characteristics in wurtzite CaN, the distributions of the electric field and the electron velocity in the two dimensional electron gas channel indicates that the differential negative resistance effect of the electron average velocity results in the differential negative resistance effect of the output characteristics. The transient transport also is related to the differential negative resistance effect of the output characteristics. This effect only can be observed in the devices with very short channel.     

节流式差压流量计的新进展之一调整型孔板405C和1595

对节流式差压流量计的发展现状及国际标准ISO5167:2003(E)对直管段要求的变化进行了介绍。介绍节流式差压流量计的新进展之一调整型孔板405C和1595,阐述了该流量计的结构型式、测量原理、性能特点和应用情况,并和标准孔板进行比较。     

一种带负充电泵的IR2110驱动抗干扰电路设计

由于IR2110内部不能产生负电压,因此在采用零电压关断IGBT时容易产生毛刺干扰,对此研究了IGBT体寄生二极管反向恢复过程,并结合IGBT的输入阻抗米勒效应,分析出IR2110零电压关断毛刺干扰产生原因,最后对IR2110典型零电压关断电路进行改进,设计一种带负充电泵的IR2110关断电路.经实验验证,该电路可有效解决IR2110的零电压关断毛刺干扰问题,保证逆变器的工作稳定性.     

加压状态下P-T仪的加速度效应修正方法

针对石油井下射孔压力测试中,承受静液压力的状态下压阻式压力传感器的加速度效应影响了测试精度,提出了在加压环境下进行传感器的加速度效应修正的方法.该方法改进了试验装置,模拟产生静液压力作用于传感器敏感面上,利用摆锤锤击作为加速度冲击的激励源,获得了压阻传感器与加速度的响应关系,从而求得加速度效应灵敏度数学模型来修正实测中的射孔压力值.     

Safety evaluation of Dagangshan arch dam resisting strong earthquakes with a rate-dependency anisotropic damage model

This paper presents a model to simulate the safe behavior of Dagangshan arch dam with a rate-dependency anisotropic damage model. This model considers the damage of asymmetry and anisotropy under cyclic loading of tension and compression, and it is used in the compiled finite element code. The material parameters used in the model can be identified from uniaxial static and dynamic experiments. Thereafter, it is used for analyzing damage and failure patterns of the dam subjected to water pressure and strong ...     

气压变化对极限电流型氧传感器输出特性的影响

对气压变化对极限电流型氧传感器扩散机理的影响进行了研究。实验中将扩散孔径为30μm的极限电流型氧传感器先后放置在不同气压环境中进行了电学性能测试。实验结果显示:在常压下该氧传感器的极限电流IL与氧浓度的对数表达式ln(1-XO2)具有很好的线性关系,呈现正常扩散模型的特征。但在低气压环境下,该传感器的极限电流IL受气压P的影响,并呈现Knudsen模型的某些特征。