Fuzzy Theory Based Control Method for an In-pipe Robot to Move in Variable Resistance Environment

Most of the existing screw drive in-pipe robots cannot actively adjust the maximum traction capacity, which limits the adaptability to the wide range of variable environment resistance, especially in curved pipes. In order to solve this problem, a screw drive in-pipe robot based on adaptive linkage mechanism is proposed. The differential property of the adaptive linkage mechanism allows the robot to move without motion interference in the straight and varied curved pipes by adjusting inclining angles of rollers self-adaptively. The maximum traction capacity of the robot can be changed by actively adjusting the inclining angles of rollers. In order to improve the adaptability to the variable resistance, a torque control method based on the fuzzy controller is proposed. For the variable environment resistance, the proposed control method can not only ensure enough traction force, but also limit the output torque in a feasible region. In the simulations, the robot with the proposed control method is compared to the robot with fixed inclining angles of rollers. The results show that the combination of the torque control method and the proposed robot achieves the better adaptability to the variable resistance in the straight and curved pipes.

Unilateral self-locking mechanism for inchworm in-pipe robot

A unilateral self-locking mechanism(USM) was proposed to increase the tractive ability of the inchworm in-pipe robots for pipeline inspection.The USM was basically composed of a cam,a torsional spring and an axis.The self-locking and virtual work principles were applied to studying the basic self-locking condition of the USM.In order to make the cooperation between the crutch and telescopic mechanism more harmonical,the unlocking time of the USM was calculated.A set of parameters were selected to build a virtual model and fabricate a prototype.Both the simulation and performance experiments were carried out in a pipe with a nominal inside diameter of 160 mm.The results show that USM enables the robot to move quickly in one way,and in the other way it helps the robot get self-locking with the pipe wall.The traction of the inchworm robot can rise to 1.2 kN,beyond the limitation of friction of 0.497 kN.

定题搜索引擎Robot的设计与算法

定题搜索引擎将信息检索限定在特定主题领域 ,提供特定主题的信息检索服务 ,是新一代搜索引擎的发展方向之一。该文介绍了一个定题搜索robot系统NetBat2 .0 2版 ,它可以实现在web上爬行下载主题相关网页。定题搜索的关键技术是主题相关信息的搜索及网页相关度分析。该文分析了传统定题搜索算法的优缺点 ,提出了基于反向链接结合超链文本分析的定题搜索算法。文章还对基于内容的网页相关度分析算法进行了详细的论述。对比搜索实验表明系统有着较好的性能 。

Wheel-legged In-pipe Robot with a Bioinspired Hook and Dry Adhesive Attachment Device

In-pipe robots have been widely used in pipes-with smooth inner walls.However,current in-pipe robots face challenges in terms of moving past obstacles and climbing in marine-vessel pipeline systems,which are affected by marine biofouling and electrochemical corrosion.This paper takes inspiration from the dual-hook structure of Trypoxylus dichotomus’s feet and gecko‑like dry adhesives,proposing an in-pipe robot that is capable of climbing on rough and smooth pipe inwalls.The combination of the bioinspired hook and dry adhesives allows the robot to stably attach to rough or smooth pipe inwalls,while the wheel-leg hybrid mechanism provides better conditions for obstacle traversal.The paper explores the attachment and obstacle-surmounting mechanisms of the robot.Moreover,motion strategies for the robot are devised based on different pipe structural features.The experiments showed that this robot can adapt to both smooth and rough pipe environments simultaneously,and its motion performance is superior to conventional driving mechanisms.The robot’s active turning actuators also enable it to navigate through horizontally or vertically oriented 90°bends.

NEW KIND OF WIRELESS MICRO ROBOT ACTUATED AND CONTROLLED THROUGH OUTSIDE MAGNETIC FIELD

A new method to drive and control micro in-pipe robot by means of magneticfield outside pipe is put forward, in which wireless micro robot can move forward driven by thevibration of its legs through converting magnetic energy into mechanical one under the action ofpiezomagnetism and magnetomechanical coupling of its micro GMA, when time varied oscillatingmagnetic field with different frequency applied outside pipe. Firstly its systematical structure andoperation principle are introduced, and energy converting process from outside magnetic one intomechanical one is analyzed through setting up the magnetic and mechanical dynamic model of GMA andestablishing dynamic model of two stage amplifier of mobile earner. Robot systematical experimentsshow the correctness of the theoretical analysis and its feasibility. As a result, drive and controlmethod without cable through outside magnetic field is realized.

Research on a New-style Pipeline Inspection Robot System

The pipe inspection robot system is developed for automatic inspection of gas pipeline with pipe diameter between 400 mm and 650 mm. It is composed of a pipe robot crawling mechanism controlled by remote network system, nondestructive examination sensor system, ground working station and so on. This paper presents the pipe inspection robot system design, the Key technique and the performance experiment of the robot. The main performance index of the pipe robot system prototype has reached domestic advanced level. The prototype has also the technical potential to be developed as a product used in industry for periodic check of main gas/oil pipe.

昆虫级微型爬行机器人的研究综述

爬行作为动物的一种有节律的运动行为,众多学者对其潜在机理的研究已经持续了一百多年。随着计算机集成技术、材料科学、空气动力学、微纳制造与人工智能技术的不断进步,对仿生爬行机器人的研究正朝着微型化和智能化的方向发展。本文对昆虫级微型爬行机器人的前沿动态发展进行了综合评述,并结合当前发展态势给出了微型爬行机器人未来发展的建设性意见。首先介绍了微型爬行机器人的研究背景和基本概念,对微型爬行机器人的运动机理和稳定性判据进行了简单分析。然后分析了微型爬行机器人的驱动方式并比较了各种微型爬行机器人的性能。最后,从供能、制造和设计3方面对微型爬行机器人的关键技术进行了总结,探讨了微型爬行机器人研究面临的问题,并提出了微型爬行机器人未来的应用前景和发展方向。

管桁架焊缝检测机器人夹紧机构瞬态振动特性分析与试验

为保证管桁架焊缝检测机器人夹紧瞬间的稳定性,对机器人夹紧瞬间的振动特性展开研究。根据夹紧机构零部件配合方式构建夹紧机构振动模型,对机器人夹紧瞬间进行仿真,分析夹紧瞬间夹紧机构的响应情况,研究夹紧机构对模型参数的敏感程度。对夹紧机构进行改进,提高弹簧刚度,增加动态吸收器,建立改进后的夹紧机构瞬态振动模型,并在MatLab中进行仿真分析。开展夹紧机构振动测试试验,测量原始与改进后机构的振动情况,对比弹簧支撑振动测试结果与仿真结果。结果表明:弹簧刚度对弹簧压缩量影响最大,弹簧阻尼对调整时间影响最大;机构改进后,调整时间缩短,弹簧压缩率显著降低,稳定性优于原始机构;试验结果与仿真结果的瞬态性能指标误差均小于5%,试验结果与仿真结果具有一致性。

基于Halbach阵列的新型吸附结构设计及其优化

为解决目前爬壁机器人永磁式吸附结构难以改变吸附力大小的问题,提出了一种基于Halbach阵列的新型永磁式吸附结构,该结构由方形永磁体和圆柱形永磁体按一定的充磁方向排列组合而成,通过转动圆柱形永磁体改变充磁方向,从而改变吸附力大小.采用ANSYS Maxwell软件研究了吸附结构各参数(永磁体数量、轭铁厚度、气隙大小)对吸附力和单位吸附力的影响,并对以上参数进行优选;以单位吸附力为目标参数,基于粒子群算法对两种永磁体尺寸进行优化,优化前永磁体体积为219823 mm^(3),吸附力为744 N,永磁利用率为0.00352N/mm^(3),优化后永磁体体积为160027.4 mm^(3),吸附力为819.7 N,永磁利用率为0.00510 N/mm^(3).研究结果表明:吸附结构优化后节省了27.2%所占据的空间,增加了15.1%的总体吸附力,提升了45.5%的永磁利用率,优化后吸附结构的吸附性能有了显著提高,可为永磁式吸附结构的设计及优化提供参考.

Axiomatic design method to design a screw drive in-pipe robot passing through varied curved pipes

A screw drive in-pipe robot is promising inspection equipment for small pipes. However, most of the existing screw drive in-pipe robots have problems of motion interference and slipping inside curved or irregular pipes. These problems result from the coupled relations among the steering motion, the motion speed and the load ability of the robot. In order to deal with the problems, the axiomatic design （AD） theory is applied to evaluate and analyze the existing designs. Then an uncoupled con- cept design based on the AD theory is proposed and the complete AD decomposition process is presented. After that, the pro- posed robot based on a tri-axial differential angle modulation mechanism is designed to realize the uncoupled concept. Finally, the uncoupled property is verified in a dynamics simulation system. The simulation results indicate that the mc tion speed, load ability and steering motion of the proposed robot can be adjusted individually compared with the robots taat have inclin- ing-angle-fixed rollers. Owing to the uncoupled design, the proposed robot can mechanically adapt to straight pipes and curved pipes with less roller slipping.

A wheel-type in-pipe robot for grinding weld beads

To improve the safety and efficiency of polishing operations in circular boiler headers, a new type of wheel-drive polishing robot was developed in this study. The robot was designed to grind weld beads on the inner walls of pipes in diameter between 550 mm and 714 mm. The robot consists of a moving structure, a positioning structure, and a polishing structure. Charge coupled device （CCD） cameras and line lasers are used in the robot＇s vision system, thus the robot can be manually controlled to move, locate, and grind quickly and accurately. The experimental results showed that the robot performed well in practical applications.

Modular crawling robots using soft pneumatic actuators

Crawling robots have elicited much attention in recent years due to their stable and efficient locomotion.In this work,several crawling robots are developed using two types of soft pneumatic actuators(SPAs),namely,an axial elongation SPA and a dual bending SPA.By constraining the deformation of the elastomeric chamber,the SPAs realize their prescribed motions,and the deformations subjected to pressures are characterized with numerical models.Experiments are performed for verification,and the results show good agreement.The SPAs are fabricated by casting and developed into crawling robots with 3D-printing connectors.Control schemes are presented,and crawling tests are performed.The speeds predicted by the numerical models agree well with the speeds in the experiments.

A Novel Worm-like In-Pipe Robot with the Rigid and Soft Structure

Soft in-pipe robot has good adaptability in tubular circumstances,while its rigidity is insufficient,which affects the traction performance.This paper proposes a novel worm-like in-pipe robot with a rigid and soft structure,which not only has strong traction ability but also flexible mobility in the shaped pipes.Imitating the structure features of the earthworm,the bionic in-pipe robot structure is designed including two soft anchor parts and one rigid telescopic part.The soft-supporting mechanism is the key factor for the in-pipe robot excellent performance,whose mathematical model is established and the mechanical characteristics are analyzed,which is used to optimize the structural parameters.The prototype is developed and the motion control strategy is planned.Various performances of the in-pipe robot are tested,such as the traction ability,moving velocity and adaptability.For comparative analysis,different operating scenarios are built including the horizontal pipe,the inclined pipe,the vertical pipe and other unstructured pipes.The experiment results show that the in-pipe robot is suitable for many kinds of pipe applications,the average traction is about 6.8N,the moving velocity is in the range of 9.5 to 12.7 mm/s.

Research on Piezoelectric Driving Microminiature Three-Legged Crawling Robot

Micro-robots have the characteristics of small size,light weight and flexible movement.To design a micro three-legged crawling robot with multiple motion directions,a novel driving scheme based on the inverse piezoelectric effect of piezoelectric ceramics was proposed.The three legs of the robot were equipped with piezoelectric bimorphs as drivers,respectively.The motion principles were analyzed and the overall force analysis was carried out with the theoretical mechanics method.The natural frequency,mode shape and amplitude were analyzed with simulation software COMSOL Multiphysics,the optimal size was determined through parametric analysis,and then the micro three-legged crawling robot was manufactured.The effects of different driving voltages,different driving frequencies,different motion bases and different loads on the motion speed of the robot were tested.It is shown that the maximum speed of single-leg driving was 35.41 cm/s,the switching ability between different motion directions was measured,and the movements in six different directions were achieved.It is demonstrated the feasibility of multi-directional motion of the structure.The research may provide a reference for the design and development of miniature piezoelectric three-legged crawling robots.

基于立体视觉技术的岔区钢轨爬行检测方案

道岔区钢轨爬行病害会对铁路运营安全带来不利影响,当前人工检测手段存在巡检效率低、精度不高等问题。本文将立体视觉检测系统搭载到移动平台,开发钢轨爬行自动检测机器人、算法模型和检测标靶,通过定位钢轨标靶并利用立体视觉系统拍摄路旁标靶计算坐标的方式,实现了视觉系统在运动状态下的高精度检测。针对道岔结构特性设计了道岔区钢轨爬行检测方案。道岔区尖轨爬行检测试验表明,在5 km/h速度条件下,重复性试验最大误差为0.19 mm,准确性试验最大误差为0.54 mm,满足毫米级检测精度要求,可在2 min内完成整组道岔的检测。钢轨爬行检测机器人具有运行速度快、检测精度高的特点,可实现铁路钢轨爬行的大范围巡检,具有良好的应用前景。

Design and Experimental Validation of a Worm-Like Tensegrity Robot for In-Pipe Locomotion

Traditional rigid-body in-pipe robots usually have complex and heavy structures with limited flexibility and adaptability.Although soft in-pipe robots have great improvements in flexibility,they still have manufacturing difficulties due to their reliance on high-performance soft materials.Tensegrity structure is a kind of self-stressed spatial structure consisting discrete rigid struts connected by a continuous net of tensional flexible strings,which combines the advantages of both rigid structures and soft structures.By applying tensegrity structures into robotics,this paper proposes a novel worm-like tensegrity robot for moving inside pipes.First,a robot module capable of body deformation is designed based on the concept of tensegrity and its deformation performance is analyzed.Then,the optimal parameters of the module are obtained based on the tensegrity form-finding.The deformation ability of the tensegrity module is tested experimentally.Finally,the worm-like tensegrity robot that can crawl inside pipes is developed by connecting three modules in series.Motion performance and load capacity are tested on the prototype of the worm-like tensegrity robot by experiments of moving in horizontal pipe,vertical pipe,and elbow pipe.Experimental results demonstrate the effectiveness of the proposed design and suggest that the robot has high compliance,mobility,and adaptability although with simple structure and low cost.

架空高压输电线自动爬行机器人的研制

研制了一台沿架空高压输电导线自动爬行和跨越障碍物的机器人。机器人的承重行走采用伞形轮来实现,伞形轮的越障运动由槽凸轮机构控制。机器人的爬行运动采用行程放大机构和抓握机构来实现,爬行的协调运动和抓紧力的自适应控制由集成电液伺服系统实现。机器人可携载检测和通信设备,对输电线路进行巡检作业。

一种多吸盘爬壁机器人原型的研制

介绍了一种仿坦克的爬壁机器人原型设计 ,该机器人新颖之处在于采用多个吸盘组成的吸附机构和单链条爬行及转向机构 ,它可以在玻璃幕墙和船壳等墙面上连续爬行 ,并有一定的越障能力。主要阐述了爬壁机器人关键结构的设计、安全性分析、转弯技术和越障实现的设计思想 。

基于PLC控制的爬行式智能弧焊机器人系统的研制

为实现大型工件的自动焊接而开发了爬行式智能弧焊机器人系统 ,详细论述了该系统的组成、工作原理和特点 ,对其跟踪机构提出了一种协调控制的方案 ,并通过实验得到了爬行小车的控制规律。焊接实验表明 ,该系统具有较好的稳定性、可靠性 ,跟踪精度高 ,可达到± 0 .5 mm,焊接质量能够达到工业生产的要求 ,在大型球罐和船体的焊接中有良好的应用前景。

无轨导全位置爬行式弧焊机器人系统

介绍了一种采用新型轮履复合式爬行机构的全位置爬行式弧焊机器人系统,详细地阐述了系统的组成和工作原理。该系统由爬行机构、焊接系统、视觉跟踪系统以及控制系统组成,是一种既无需轨道也无需导向的自动焊接系统。爬行机构具有负重能力强、运动灵活等特点,满足机器人在大型工件上全位置爬行焊接要求。通过大量试验对爬行机构进行了运动分析,建立了机器人运动模型。针对系统的复杂性设计了开关控制器,实现了爬行机构及十字滑块的协调控制,达到焊缝精确跟踪的目的。进行了焊接条件下的跟踪性能试验、全位置多层多道焊接试验,取得了满意的效果,实现了大型工件焊接过程自动化。