三轴差动式管道机器人机械自适应驱动特性离线分析系统的研制

为了定量评价三轴差动式管道机器人的机械自适应特性,开发了一套离线分析系统.该系统能够实时采集并记录驱动单元的三组驱动轮及校验轮的速度、机器人负载、驱动电机的电流与电压等数据,计算出机器人的驱动效率、自适应精度、差速特性等评价指标.     

驱动轮转向可控管道机器人的设计与运动分析

为了解决机器人在管道内姿态调节困难、避障能力较弱等问题,文章提出一种通过改变驱动轮转向来快速调节在管道内姿态的轮式管道机器人。该机器人可沿着管道作直线运动,也能绕管道中心轴线沿内壁作螺旋运动和回转运动,同时具有避障能力。通过建立机器人驱动轮转向过程的位姿模型,分析了弹簧以及管道内壁对机器人的正压力的变化过程;建立管道机器人驱动轮转向时的运动学模型,并进行了仿真分析。仿真结果表明了该管道机器人的有效性和实用性。     

微小管道机器人移动机械运动学与动力学特性

微小管道机器人能够帮助人们完成诸如小口径管道内检测等工作，其移动机构是机器人研究领域重要的研究内容之一，在分析研究行星齿轮驱动的微型机器人移动机构的运动学和动力学特性的基础上，详细讨论了移动机构的原理，功能及影响因素，研究表明，通过提高移动机构车轮的附着性和驱动力，减小寄生功率的影响，可较好地实现该微型机器人驱动。     

微管道机器人的脉冲驱动电源

有缆驱动微管道机器人行走时摩擦力大,影响行走效果。利用互补脉冲使螺线管产生交变磁场原理,设计了无电缆驱动电源装置。实验表明,该电源输出的互补脉冲具有较强的驱动能力,螺线管磁场引导机器人可在弯形管道和长距离管道模型中稳定行走,消除了电缆摩擦力对机器人的影响。该电源装置扩展了机器人行走范围。     

改进型管道清灰机器人撑开机构动力学分析及仿真

以改进型管道清灰机器人为研究对象,建立机器人行走装置撑开机构简图.利用动态仿真的联立约束法,将运动约束和牛顿-欧拉方程组成一组联立线性方程组,求解得到各关节的约束反力、加速度和速度.利用Matlab编制计算程序,基于Simulink建立仿真模型,对管道机器人撑开机构动力学进行动态仿真,仿真结果表明:机器人撑开机构滑块速度方向改变时,机构各杆件受力达到最大,且杆件3受力最大.     

四轮管道机器人的通过性能研究

针对市政管道的几何特点,以四轮管道机器人在弯道处的数学模型为基础,设计了四轮管道机器人.利用ADAMS软件对机器人进行了弯道通过性能分析,并绘制出了机器人运动的轨迹曲线.仿真分析结果表明,在满足数学模型的情况下,四轮管道机器人能顺利通过弯道,证明了设计的合理性.其中,过渡阶段轨迹曲线上的20mm微小跳动分析也为机器人的驱动控制研究提供了依据.     

轮式管道机器人过弯动态特性分析

为了详细地了解管道机器人过弯时的动态特性,设计了一种全驱动轮式管道机器人。基于坐标转换法,分析了机器人过弯时质心与管道中线的相对距离Δx发生变化对机器人运动特性的影响;基于力学虚功原理,分析了机器人过弯时Δx发生变化对机器人受力情况的影响。通过Adams软件对机器人过弯过程中的运动状态和受力情况进行了仿真,经分析发现管道机器人在过弯过程中,Δx先快速增大后略低速减小,在运动特性方面,随着Δx增大,外驱动轮运动速度随之增大,内驱动轮运动速度则有所减小。当内驱动轮速度达到最低时,外驱动轮与内驱动轮的速度之比会发生小幅度波动;在受力情况方面,随着Δx增大,内、外驱动轮与管壁的接触力随之增加,此仿真模型中,在入弯阶段外驱动轮和内驱动轮与管壁接触力大小之比为1.4,出弯阶段此接触力之比约降为0.9。从平稳性角度来看,与入弯和出弯两个阶段相比,过渡阶段在运动和受力上均相对不稳定,故当机器人过弯时,将Δx的变化纳入运动分析方程有利于获得其更加精确的动态特性。     

一种新型管道检测机器人系统

摘要：研制了适用于管径为400～650mm的煤气管道内缺陷自动探测系统．该系统由采用远程网络控制技术的管道机器人移动机构、无损检测传感器和地面工作站等组成．综述了管道检测机器人的系统总体设计、关键技术和性能实验．实验结果表明，所研制的管道检测机器人系统在管道中运行平稳，具有稳定的牵引力，其值可达1．404kN，适用于400-650mm管径的油气管道检测．     

新型管道机器人运动学和力学特性分析

目的研究新型步进式管道机器人运动学和力学性能,揭示管道机器人的运动规律,验证其运动状态和工作特性.方法采用理论建模和基于ADAMS软件仿真分析的方法,获得管道机器人相关机构的运动规律曲线以及机器人在管道内步进运动时活塞驱动力变化规律曲线.结果机器人能够适应管道直径范围为750~1 021.5 mm,步距为103 mm,速度和加速度曲线平滑,运行稳定,无震颤现象;当承受负载4 000 N时,伸缩夹紧机构驱动力变化范围为1 407.6~18 113.7 N,步进单元驱动力范围为1 978.46~7 645.38 N,驱动力曲线平滑,无力冲击,可驱动性能良好.结论该新型管道机器人的运动性能满足功能要求,具有适应管径范围大、速度快、运动平稳和驱动性能好等优点.     

管道机器人弯管运动转体原因分析

为避免管道机器人弯管内运行时发生转体现象而影响管内任务的执行,对机器人转体的原因进行了深入研究.以建立的管道机器人弯管运行的位姿模型为基础,对机器人的受力状况进行了分析,建立了机器人过弯时的转体力矩模型.通过对转体力矩的分析,揭示了管道机器人弯管运行时发生转体的根本原因,并指出了管道机器人弯管运行的最佳姿态角.理论计算表明:当机器人以最佳姿态角运行时,机器人转体力矩几乎为0,不发生转体;当机器人以其他姿态角运行时,将出现一个不为0的转体力矩,该力矩使机器人向平衡姿态角方向转体,直至机器人姿态稳定为止.在实际应用时,使机器人在平衡姿态角运行为最佳.仿真结果与理论计算基本一致,该研究为人弯管内的姿态稳定运行提供了一定的理论依据.     

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.     

橡胶颗粒沥青混合料低温抗裂性试验研究

以AC-13级配为基础,将橡胶颗粒代替部分集料掺入混合料中,以低温弯曲试验为评价方法对不同橡胶颗粒掺量下沥青混合料的低温抗裂性进行研究,并引入应变能密度值对混合料的低温抗裂性进行综合评价.试验结果表明:橡胶颗粒沥青混合料试件的破坏微应变均超过2 300,满足冬寒区的技术指标;无论是否掺加橡胶颗粒,随着温度的下降,沥青混合料破坏时的最大弯拉强度增大,弯拉应变降低,劲度模量增大;弯曲应变能密度在胶粒掺量为1%左右时具有较大的弯曲应变能密度值,此时橡胶颗粒沥青混合料具有较好的低温抗裂性.     

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-