2DOF空间3-RPS并联机器人位置运动学混合算法

空间2自由度并联机构可用于高作用力下精确控制姿态的两个分量的工作场合.建立了2自由度3-RPS并联机器人的位置运动学约束方程;对其正逆运动学算法进行了讨论.对求解并联机器人位置正解的杆长搜索法进行了改进,并结合解非线性方程组的拟牛顿法,提出了一种能解决方程组多解并且计算精度较高的混合算法,推导了2自由度3-RPS并联机器人位置反解的求解过程.通过实例验证了算法的正确性和所能达到的精度.     

基于遗传算法的三平动3-PRRRR并联机器人正解位形的研究与仿真

由于并联机器人构型的特点,在其运动学分析中,正解分析较为复杂,也是在研究并联机器人运动学过程中的一个难点.本文采用遗传算法,将并联机器人的运动学正解问题转化为优化问题.利用MATLAB遗传算法工具箱对三平动3-PRRRR并联机器人的正解问题进行求解,得到优化解,并用反解结果与正解结果进行互相印证,证明该方法对于并联机器人正解问题具有较高的实用性.     

一种新型空间三自由度并联机器人的运动学与工作空间分析

提出一种新型三自由度并联机器人机构．该新型并联机器人由定平台、动平台和3个连接支链组成,其动平台相对于定平台具有两个转动和一个移动自由度．各运动支链结构完全相同,且都含有一个闭环子链．该并联机器人只含转动副,具有结构对称和工作空间大的特点．文中对该新型并联机器人的结构进行了详细描述,并应用螺旋理论分析了其运动特性;根据运动链等价替换原理,给出了该并联机器人的运动学反解和正解,并进行了工作空间分析。     

茄子采摘机器人运动学分析与工作空间仿真

为实现4自由度关节式茄子采摘机器人的精确控制,对其进行了运动学分析和工作空间仿真.利用Dellavit-Hartenberg方法建立了机器人运动学模型,得到了机器人的运动学正解;根据机器人的工作特点,采用简化的反变换法求解机器人运动学逆解.采用基于Matlab的数值解法求解了机器人的工作空间,并进行了仿真.工作空问仿真结果表明:设计开发的4自由度采摘机器人结构设计合理,能够满足温室栽培模式下茄子采摘的要求.     

一种空间3自由度并联机器人的工作空间和转动能力分析

研究一种空间3自由度并联机器人(HANA)的工作空间和转动能力.该机器人由定平台、动平台和三个连接支链组成,其动平台相对于定平台具有2个移动和1个转动自由度.该机器人具有以下特性:工作空间内无奇异;单自由度铰链结构和高转动能力.其具有显式封闭解的运动学反解有利于用几何方法表达其工作空间.文中首先分析其定姿态和可达工作空间;然后定义了一种评价转动能力的性能指标,并用该指标详细考查了该并联机器人的转动能力特性;最后得出了转动能力性能指标在其工作空间内的分别,这有助于进一步了解该机器人在工作空间内每一点的转动能力.该并联机器人可以广泛地应用在工业机器人、飞行模拟器、微型机器人和并联机床等行业.     

一种Delta型并联机器人的机构设计与分析

提出了一种应用于产品包装的delta型并联机器人。该机构灵活高效,具有良好的运动和力传递性能。在运动过程中,四个支臂始终保持空间平行四边形且末端执行器只有3个平动自由度。本文对其进行了整体结构设计、自由度分析、位置正解反解的计算,为该机构的应用打下了基础。     

6-RRS冗余驱动飞行模拟器运动学与工作空间分析

提出一种以6-RRS球面并联机构作为运动机构的冗余驱动飞行模拟器.该机构具有3个转动自由度、6个驱动、3个冗余驱动,由2个完全相同的3-RRS球面并联机构构成6-RRS球面并联机构.该机构广义上具有一个定平台和一个动平台,整个动平台即为飞行模式器座舱.在3-RRS球面并联机构运动学分析的基础上,给出了6-RRS球面冗余驱动并联机构的运动学分析,包括机构的方向余弦的建立、反解和正解及该机构的工作空间分析.     

一种大型球冠蜂窝灌注机器人结构设计与分析

针对航天器中大型球冠蜂窝防热层结构自动灌注问题,设计了一种3自由度混联灌注机器人,并建立灌注机器人的机构模型.该混联机器人结构紧凑、驱动简单、占地面积小,末端灌注装置始终垂直于球冠面移动,有利于蜂窝结构的灌注;采用多机器人操作模式,提高了灌注效率.通过建立运动学约束方程,分析了机构的运动学反解,同时建立了机构的速度雅可比矩阵,在此基础上,利用一种高效的数值正解算法分析了运动学正解,并通过对位置正解的分析得出灌注机器人的整个工作空间,并基于速度雅可比矩阵对机构的灵巧性和奇异性进行分析.结果表明灌注机器人能够实现对蜂窝结构的精确定位,且工作空间能够达到整个球冠面,满足蜂窝防热层结构的灌注要求.     

3-RRRT并联机器人的位置正解研究

本文介绍了一种新型3-RRRT并联机器人的特点,推导了该机器人的位置反解方程,获得了其位置反解,采用数值方法给出研究了该并联机构的运动学正解.运用Matlab软件计算进行了验证.     

球坐标式3自由度并联机器人机构的运动学设计

研究一种球坐标式3自由度并联机器人机构的运动学设计,包括运动学反解、速度、考虑铰链转动范围和干涉等条件下的工作空间,和结构参数对工作空间的影响以及灵巧性能指标及其在保角变换平面上的分布特性,这些分析结果和结论对并联机器人机构的设计、轨迹规划和控制等有重要的指导意义.并联机构在并联机床、坐标测量机构和工业机器人等领域有广阔的应用前景.     

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