基于ROS的室内导航机器人设计研究

采用基于机器人操作系统（ROS）的设计方案开展了机器人在自主导航中的应用研究,设计了一款集定位、SLAM建图、路径规划、驱动控制于一体的机器人综合系统。系统利用激光雷达扫描获取环境实时数据和里程采集信息,通过Gmapping算法对数据进行融合,以及采用自适应蒙特卡洛定位（AMCL）方法实现了环境地图绘制与定位。通过matlab对路径规划算法进行对比研究发现,路径规划任务中Djakarta算法更适应在室内多障碍物场景。而实验结果显示在模拟环境中利用Dijkstra算法和DWA算法进行避障更加有效。仿真实验结果也表明,该系统可构建高精度环境地图,并对机器人进行定位和导航,实现了在实时路径规划中成功避开障碍物到达目标点。以上研究表明在室内定位和导航任务中该机器人系统框架具有良好的可行性和稳定性。     

雨污管道巡检机器人嵌入式系统的设计与实现

城市雨污排水管道的巡检主要以人工为主,但由于地下管道环境错综复杂并存在有毒可燃气体,人员下井存在很大危险.虽然有部分巡检工作尝试采用巡检机器人代替人工,但这些机器人采用的有缆方式,存在巡检距离受限、操作繁琐、能耗高等问题,导致巡检效率低下,智能化程度低.针对上述问题以及巡检机器人的任务需求,设计并实现了一种更加安全可靠与智能的雨污管道巡检机器人嵌入式系统.该设计基于CCTV巡检方式,采用STM32作为主控芯片,搭载工业摄像头、传感器组等模块采集数据,并采用无线通信的方式与上位机进行连接,之后通过YOLOV5s自主判断所采集的视频流中是否存在淤积物堵塞问题.通过在广州市番禺区的实地试验,结果表明,嵌入式系统设计合理,管道巡检机器人能够实现各项功能与技术要求.     

校园巡检机器人智能导航与控制

针对校园巡检需求设计机器人本体结构,采用了GPS导航作为全局路径规划和模糊控制算法作为局部路径规划的机器人组合控制策略,提出了借助NI myrio作为控制核心和LabVIEW图形化编程的巡检机器人控制系统构建方法,研究了巡检机器人在校园环境下的导航、控制、多传感器融合等问题。结果表明:该套控制系统的研发有效解决了校园巡检机器人的智能导航与控制系统构建编程效率低、开发周期长等问题。通过采用二级分布式结构,保障了整个系统的实时性,实现了机器人复杂的人机交互和环境交互。同时提高了机器人控制系统的自适应性和鲁棒性,为巡检机器人的智能化研究提供了一种高效可靠的方法。     

巡检机器人中二维条码的设计与应用

提出了一种巡检机器人中应用二维条码的视觉定位与任务给定及辅助导航的方法.通过在机器人巡检路线中的关键点设置二维条码标记,将巡检机器人大范围的绝对定位问题转化为小区域的相对定位,消除了里程计的累积误差.通过传递导航与命令信息,使巡检机器人的可操作性与可维护性大大提高.详细分析了二维条码图的设计方法,通过图像预处理、图像的矢量中值滤波、条码数据区定位等步骤得到了二维条码的读取算法.分步调试与在变电站设备巡检机器人系统中的应用表明,该算法实现简便,处理速度快.     

基于机器人操作系统的移动机器人激光导航系统

为了验证激光导航的先进性及机器人操作系统(robot operating system,ROS)的便捷性,进一步对机器人导航机理进行研究,提出了改进粒子滤波算法及改进A*路径规划,分别应用于地图构建和路径规划,并搭建了基于ROS平台的移动机器人导航试验平台,该平台具有低成本、高性能的特点。试验平台由上位机和移动机器人组成,上位机实现对机器人的控制,移动机器人配置有工控机和激光传感器,机器人通过激光传感器采集环境信息,为实现即时定位及地图构建功能提供数据支撑。研究并构建基于ROS的地图构建和自主导航功能包并通过实际环境进行试验验证。试验结果表明:构建功能包可用于机器人的激光导航中,该激光导航系统的可行且具有一定的稳定性与可靠性。     

基于单线激光的果园机器人自主导航方法

以四轮差速机器人作为试验平台,提出一种基于单线激光雷达获取环境信息的方法,研究机器人在树行中心线的导航性能以及机器人到达行尾进行自主换行的能力.首先,由单线激光雷达获取环境信息,利用距离阈值法、自适应密度聚类算法、改进的最小二乘法等算法处理激光数据,得到树行中心线作为机器人理论导航路径,以机器人与导航路径的横向偏移量、航向偏角和线速度作为输入量来设计控制模型实时跟踪导航路径,到达行尾时能够自主感知并执行掉头转弯至下一行动作;行间自主导航试验中,机器人线速度分别为0.2、0.4和0.6 m/s,且机器人初始位置横向偏移量不大于0.8 m、航向偏角不大于15°时,导航轨迹与树行中心线的平均横向偏差为3.69 cm,最大横向偏差为11 cm;在自主换行测试中,机器人能够准确进行掉头转弯到下一行,然后继续进行行间导航.果园自主导航系统具有良好的运行稳定性和较高的导航精度,能够满足果园作业机器人的自主行驶精度要求.     

基于声纳的智能机器人自主定位算法研究

为了解决声纳传感器探测信号的不确定性问题并消除在定位过程中存在的噪音 ,以P2 DXe机器人为实验主体 ,根据声纳传感器在机器人定位中的特性 ,对声纳传感器在机器人自主定位应用中的相关算法作了系统的分析和研究 ,比较各种算法之间的联系和区别 .利用机器人Saphira8.0仿真平台对算法进行了仿真 ,证明了该算法的可行性 .     

基于异质传感器信息融合的移动机器人SLAM研究

针对采用单一传感器在移动机器人同步定位与构图(SLAM)中存在定位精度低、构图不完整等问题,提出一种基于Kinect视觉传感器和激光传感器信息融合的SLAM算法。首先将Kinect传感器获取的深度图像经过坐标系转换得到三维点云、通过限制垂直方向滤波器过滤三维点云的高度信息、再将剩余三维点云投影到水平面并提取边界点云信息转化为激光扫描数据;然后与激光传感器的扫描数据进行数据级的信息融合;最后输出统一数据实现移动机器人的构图及自主导航。实验结果表明,该方法能够准确的检测小的及特征复杂的障碍物,能够构建更精确、更完整的环境地图,且更好地完成移动机器人自主导航任务。     

变电站巡检机器人导航方法研究

随着移动机器人技术的发展和变电站无人值守的开展,变电站巡检机器人应运而生。稳定的导航是巡检机器人能够正常工作的前提保证,因此针对变电站巡检机器人的导航方法进行研究。影响导航的关键因素有导航方式和导航算法,变电站巡检机器人采用视觉与电磁融合的导航方式,运用自适应位置型PID控制算法,对于脱离导航线的错误处理采用模糊控制的思想,实现了巡检机器人的导航并得到了实际应用,实际运行的结果说明此种方法抗干扰能力强、收敛性好。     

室内机器人导航系统的设计及仿真验证

针对室内机器人在未知环境下的自主导航问题,以机器人操作系统ROS为开发平台,基于Gmapping、Amcl、Move_base等开源功能包设计自主导航系统,使搭载此系统的机器人能够学习未知环境下的地图信息,并基于地图实现定位、路径规划、避障等功能.通过三维物理仿真软件Gazebo模拟环境并加载设计的URDF机器人模型,...     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that     

On the Thermodynamic Limit for Responses to Static Electromagnetic Fields

For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the     

An affordable accurate evaluation of the binding conformations predicted by molecular docking studies in bio-system

Franck-Condon factors bridge the gap between theoretical modeling and experimental observations for molecular electronic spectroscopy and electron transfer.Under the displaced harmonic oscillator approximation,multidimensional Franck-Condon factors are decomposed into a product of many one-dimensional(1D)Franck-Condon(FC)factors,and each 1D-FC factor is associated with one Huang-Rhys factor that determines the leading contribution of     

Call for Papers

<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with