机器人腕部力传感器的标定

力反馈是机器人控制技术中一种重要的反馈。位于机器人手臂和夹持器之间的腕部力传感器是最重要的力传感器。对力传感器进行标定就是找出其标定矩阵。作者提出了求标定矩阵的方法,并指出Shimino和美国机器人技术公司——RTI的标定方法是错误的。专门设计的实验表明,用作者提出的方法所得的标定矩阵进行计算,测定载荷与实际施加的载荷是相接近的,而RTI公司的结果与施加载荷相差甚大。作者还提出了一种简化的6×6标定矩阵,用其计算的结果也与实际施加载荷接近。     

一种机器人多维光纤光栅力传感器

为实现机器人腕部等结构的多维力传感测量,提出了一种多维光纤光栅力传感器,其弹性体结构主要由2个圆环及4个弓形梁构成,并将光纤光栅分别贴于弓形梁上以实现多维传感.同时,对传感器的理论计算模型及传感原理进行推导,采用有限元分析软件对其弹性体进行力学仿真分析.为进一步分析传感器的基本特性,搭建实验平台并进行了传感器的标定实验.结果表明:所提传感器能准确、有效地完成多维力传感测量,在压力载荷作用下具有良好的线性、重复性和一致性,且灵敏度较高、稳定性较好、抗干扰能力强,能够在恶劣环境下使用.     

双E型膜弹性体六维力传感器静态标定及其性能分析

六维力传感器的静态标定是其在智能机器人应用中准确测量的前提,以双E型膜弹性体六维力传感器为例,设计了静态标定试验,测试了6路静态标定数据,计算并分析了其静态性能指标;并通过采用最小二乘方法进行拟合,得到了维间耦合关系斜率矩阵﹒这是六维力传感器通过耦合分析来进一步提高精度的必要途径﹒     

多维腕力传感器静态解耦的研究

传感器的静态耦合是制约多维力传感器测量精度的一个主要因素。文章总结了腕力传感器静态线性解耦的主要研究内容,提出静态非线性耦合问题,探索静态非线性标定方法,给出了一种非线性解耦方法,仿真结果充分证明其有效性。     

计算机辅助外科中手术与计划空间标定以及视觉空间的误差校正

计算机辅助外科(CAS)系统中,多空间集成在一起,为了提高系统的操作精度,需要有效的标定方法校正空间之间的误差.利用机器人上特征在导航系统中视觉空间的运动误差,建立视觉空间与机器人空间的映射关系,递归校正两空间之间的局部转换矩阵.利用局部转换矩阵建立优化方程,求取全局最优转换矩阵.该方法对所有动态、静态误差进行校正.针对手术与计划空间中存在的耦合误差,利用设计的特殊结构力传感器和标定块解耦标定其误差,并根据求取的转换矩阵,调整计划空间中对象的位姿,保证计划空间与手术空间中的对象位姿一致.实验结果表明,动态标定方法可以使视觉空间中的全局误差减少到5个像素,力控标定方法可以使位置误差减小到0.25mm,姿态误差减小到0.1°.     

三向力传感器标定算法的实验研究

为研究三向力传感器标定算法的有效性,设计一种非对称结构的三向力传感器,并对该传感器采用单向加载的方式进行大样本标定实验,将实验数据代入标定算法,得到该三向力传感器的标定表达式.再对传感器多次进行空间任意方向力加载,记录加载力大小和方向角,将加载时的三个应变输出代入三向力传感器标定表达式,得到标定结果.通过将标定结果与实际加载值进行比较,得出三向力传感器的标定误差.实验结果表明:该三向力传感器标定算法具有一定的标定精度.     

微摩擦测试的微力传感器设计

论述了一种新的应用于微摩擦测试的微力传感器,这种微力传感器能同时测定微小摩擦力及相应正压力的大小,其独特的悬臂结构消除了多维力传感器普遍关注的耦合问题．正压力和摩擦力的测力原理分别基于应变片法和位移法．标定及静态特性的分析表明,该微力传感器具有较高的测力精度和分辨力,适合于mN级的摩擦测试．摩擦测试实验表明,该微力传感器完全能进行各种润滑膜的微摩擦性能评估测试,从而为微摩擦研究提供了一种有效的实验工具．     

基于虚拟仪器的力传感器标定程序

力传感器是目前广泛使用的传感器,在使用过程中,需要对其进行标定,以此保证测量的精度。本文基于LabVIEW,开发了力传感器标定程序。文章主要介绍该程序的设计原理以及软硬件结构。     

基于步行器行走的上肢六维力传感器静态标定研究

本文针对步行器助行过程中上肢力提取问题,研制了一套上肢力提取系统．阐明了该系统的工作原理,通过对六雏力传感器的标定和校准实验,对实验结果的分析表明了该标定系统设计及标定方法的正确性及实用性．     

多维力/力矩传感器动态标定中若干问题的研究

动态标定实验是把握传感器动态特性的基础,是进行系统辨识、补偿和解耦所必需的.文章讨论了六维腕力传感器阶跃和冲击2种动态标定实验的设备和实验过程,求得其动态性能指标,分析了2种标定中存在的问题,并提出了改进多维腕力传感器动态标定实验的建议.     

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.     

An Analysis of Catherine＇s Character——Wuthering Heights

Wuthering Heights, Emily Bronte＇s only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.     

Lower Paleozoic oil relationships within Williston Basin, Canada

The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.     

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.     

Design and analysis of generic LBS application developing platform

Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.     

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