双臂巡检机器人越障能力分析

研究了手臂固定式、手臂移动式和带柔索式三种类型双臂巡检机器人的越障能力,通过理论分析建立了三种类型双臂巡检机器人相应的越障能力数学模型,在设定基本相同的质量参数和结构参数前提下,计算得到了三种类型巡检机器人在不同线路坡度下的最大越障距离.计算结果表明:带柔索双臂巡检机器人的手臂结构运动更为灵活,机器人越障能力更大,且越障距离可根据障碍物大小自由调节,因此带柔索双臂巡检机器人的结构设计具有明显优势,更易实现机器人轻量化设计.     

移动机器人避障路径规划改进人工势场法

针对路径规划中的大型障碍物,机器人、障碍物与目标点三者一线,以及局部最小值等困难问题,提出了相应的改进人工势场算法。针对大型障碍物问题,采用障碍物边界斥力算法改进传统人工势场斥力函数,确保算法的实用性。针对机器人、障碍物与目标点三者在同一条直线时目标不可达问题,应用虚拟子目标引力算法,确保目标点是机器人的势场全局最小点,使得机器人能顺利到达目标点。针对在障碍物环境下的局部最小值问题,采用区域隔离障碍物的方法,使机器人快速走出局部最小值区域。仿真结果验证了改进算法的有效性。     

移动机器人同时定位和地图创建的一种新方法

为了实现室内环境中移动机器人的同时定位和地图创建，提出了一种新方法，该方法应用顺序蒙特卡罗方法，把定位和地图生成分成状态估计和参数估计，应用多粒子滤波器实现同时估计机器人位置和障碍物位置。环境感知采用机器人自身配置的声纳传感器，应用哈夫变换提取环境障碍物边界特征，用直线近似表示，并提出了一种可靠的特征匹配方法。Pioneer 2移动机器人在实际室内环境中完成的实验证明了该方法的可行性。     

双臂机器人机构速度约束方程的快速建立

本文在充分考虑双臂机器人机构结构特性条件下，应用递推算法，建立双臂机器人机构在协调运动过程听速度约束方程并分析了方程特点。     

基于二维激光测距仪的道路可行区域提取

为了使自主移动机器人在结构化和半结构化环境中能快速有效地提取道路的可行区域,采用全局搜索及双阈值的算法.该算法首先采用基于八邻域的全局搜索法搜索激光数据点,再结合角度和高度差双阈值对数据点进行归类并检测道路边界,最后利用障碍物检测原理获取障碍物.实验结果表明:该算法能够检测出路边及障碍物边界,此过程只对机器人感兴趣区域...     

双臂机器人避碰算法研究与实现

以双臂SCARA机器人为研究对象,采用计算机图形学的方法,得出两机械臂在某一时刻的碰撞检测方法。之后采用C空间法对双臂机器人进行避碰路径规划,得出了双臂机器人避碰算法,并对算法进行了仿真,证明了其正确而性。     

基于C空间的双臂机器人无碰撞运动规划

研究了双臂机器人无碰撞运动规划问题,将C空间法成功地应用于双臂机器人的无碰撞运动规划,并提出了从臂从碰撞状态数据库（CSDB）概念,在本算法中,双臂机器人无碰撞运动规划问题被归结为对从臂无碰撞状态数据库的搜索,运用该算法可以找到一条最优的无碰撞运动轨迹,并已在双臂CARATES型机器人上通过试验论证。结果表明,该算法可行且效率较高。     

基于虚拟现实的双臂机器人运动仿真系统研究

随着机器人行业的快速发展,仿人形双臂机器人得到越来越多的应用。根据Baxter双臂机器人的结构,采用D-H方法建立机器人模型,并推导冗余双臂机器人正运动学,并建立逆运动学方程,导入机器人模型到Unity3D中,设置相应的关节约束。通过在Linux系统中创建Baxter机器人控制服务器,Unity3D与之形成双向通信实现双臂机器人的运动仿真。实验结果表明,通过在PC机上操作方便用户对机器人进行运动仿真和轨迹规划,控制仿真方案良好且可视性强。     

适用于双臂机器人机构的动力学方程

在单臂机器人机构动力学基础上,对双臂机器人机构进行运动力学分析,建立双臂机器人机构协运动的动力学方程;并利用奇异值分解方法对这方程的解进行讨论。     

双臂巡检机器人位姿变化下沿悬链线行走能力分析

为解决双臂巡检机器人沿输电线行走过程中存在的行走轮受力不均,易打滑脱线等问题,提出一种移动关节主动调节方法.分别建立了传统的双臂巡检机器人、带柔索双臂巡检机器人和带移动关节双臂巡检机器人行走轮受力模型,对比分析发现:机器人在最佳位姿状态下,受力情况最好,不易发生打滑问题.建立了巡检机器人关节变化的动力学模型并设计主动控制器,对机器人行走越障和沿线行走两种工况进行了仿真模拟.所设计的控制器能够协助机器人完成大坡度巡航与行走越障工作,并能够有效抑制关节振荡问题,缩短响应时间.最后开展了机器人行走越障与不同坡度行走实验,表明所设计的控制器能够辅助机器人完成巡检任务,有效抑制了行走打滑问题.     

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.     

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     

Journal of Donghua University ( English Edition) Contents of Volume 31

正~~