Development of Flexible Spherical Actuator with 3D Coordinate Measuring Device

Rehabilitation devices help to recover the physical abilities of patients. This study aims to develop a portable rehabilitation device that is safe to use when?patients are holding it by hands. In a previous study, to realize a home rehabilitation device, a flexible spherical actuator that can provide motion to patients was developed. In this study, to measure the relative position between both handling stages, a 3D coordinate measuring device using three wire-type linear potentiometers and an embedded controller was proposed and tested. In this paper, the spherical actuator with built-in 3D coordinate measuring device is described. The measuring method and experimental results obtained are also presented. The tracking position control of the actuator using the measuring device was carried out. As a result, the position of the handling stages can be successfully controlled using the feedback signal from the tested?measuring device.

A CONCEPT FOR NEXT STEP ADVANCED TOKAMAK FUSION DEVICE

A concept is introduced for initiating the design study of a special class of tokamak,which has a magnetic confinement configuration intermediate between contemporary advanced tokamak and the recently established spherical torus (ST,also well known by the name "spherical tokamak").The leading design parameter in the present proposal is a dimensionless geometrical parameter, the machine aspect ratio A=R 0/a 0= 2.0,where the parameters a 0 and R 0 denote,respectively,the plasma (equatorial) minor radius and the plasma major radius.The aim of this choice is to technologically and experimentally go beyond the aspect ratio frontier (R 0/a 0≈2.5) of present day tokamaks and enter a broad unexplored domain existing on the (a 0,R 0) parameter space in current international tokamak database,between the data region already moderately well covered by the advanced conventional tokamaks and the data region planned to be covered by STs.Plasma minor radius a 0 has been chosen to be the second basic design parameter, and consequently,the plasma major radius R 0 is regarded as a dependent design parameter.In the present concept,a nominal plasma minor radius a 0=1.2m is adopted to be the principal design value,and smaller values of a 0 can be used for auxiliary design purposes,to establish extensive database linkage with existing tokamaks.Plasma minor radius can also be adjusted by mechanical and/or electromagnetic means to smaller values during experiments,for making suitable data linkages to existing machines with higher aspect ratios and smaller plasma minor radii.The basic design parameters proposed enable the adaptation of several confinement techniques recently developed by STs,and thereby a specially arranged central bore region inside the envisioned tokamak torus,with retrieved space in the direction of plasma minor radius,will be available for technological adjustments and maneuverings to facilitate implementation of engineering instrumentation and real time high field side radiation and particle diagnostics,especially for high field side edge physics and plasma surface interaction studies.

Labyrinth maze-like long travel-reduction of sulfur and polysulfides in micropores of a spherical honeycomb carbon to greatly confine shuttle effects in lithium-sulfur batteries

Polysulfide absorption in a micropore-rich structure has been reported to be capable of efficiently confining the shuttle effect for high-performance lithium-sulfur(Li–S)batteries.Here,a labyrinth maze-like spherical honeycomb-like carbon with micropore-rich structure was synthesized,which is employed as a template host material of sulfur to study the shuttle effects.The results strongly confirm that a diffusion controlled process rather than an absorption resulted surface-controlled process occurs in an even micropore-rich cathode but still greatly inhibits the shuttle effect.Thus,the battery achieves a high initial discharge specific capacity of 1120 mAh g1 at 0.25 C and super cycling stability for 1635 cycles with only 0.035%capacity decay per cycle with 100%Coulombic efficiency.We would like to propose a new mechanism for shuttle effect inhibition in micropores.In terms of the diffusion control process in microporous paths of a labyrinth maze structure,polysulfides experience a long travel to realize continuous reductions of sulfur and polysulfides until formation of the final solid product.This efficiently prevents the polysulfides escaping to electrolyte.The labyrinth maze-like honeycomb structure also offers fast electron transfer and enhanced mass transport as well as robust mechanical strength retaining intact structure for long cycle life.This work sheds lights on new fundamental insights behind the shuttle effects with universal significance while demonstrating prominent merits of a robust labyrinth maze-like structure in high performance cathode for high-performance Li–S batteries.

The design of a novel parallel haptic device

<正> A novel haptic device which is characterized by large workspace,high rigidity,simple kinematicsand easy construction is presented.This device is a parallel mechanism which is composed of a baseplate,three sub-chains,and a mobile plate.Each sub-chain is attached to the base plate through a pinjoint and to the top plate through a spherical joint.The sub-chain is derived from and kinematically e-quivalent to a pantograph linkage but is redesigned to solve the difficult problem of motor-fitting.Thespherical joint is of the ball-in-socket type,but has much larger workspace than its regular counterpart.The kinematics is analyzed,and the inverse kinematics analysis is performed with a geometric approach.The complete workspace is readily obtained with the spherical coordinate system searching method.Theoptimal value of the cone angle of the spherical joint is shown to be 100~.

播种机星齿球面盘式覆土装置设计与试验

针对V型挤压式覆土装置在黏土条件下作业不可靠,种沟闭合不严实,易造成种子“架空”和“晾种”的生产实际问题,设计一种星齿球面盘式覆土装置,提高播种机覆土质量。分析了星齿球面盘式覆土装置的作业原理,通过对覆土作业过程中土壤颗粒的运动学分析,确定了影响覆土作业质量的主要结构参数,并对星齿球面覆土盘主要结构参数和安装参数进行了设计。借助EDEM离散元仿真技术,建立了土壤与覆土装置的互作模型,以星齿球面覆土盘安装倾角、安装间距、入土深度为试验因素,以覆土量与覆土量变异系数为评价指标,分别进行了单因素与Box-Behnken试验,确定了星齿球面覆土盘的最优结构参数组合为安装倾角25.03°、安装间距196.66 mm、入土深度77.65 mm。取安装倾角25°、安装间距197 mm、入土深度77 mm进行了田间验证试验,试验结果表明:最优参数组合下,覆土量平均值为241.46 g,与仿真结果基本一致,相对误差为5.12%,覆土量变异系数为3.71%,覆土均匀,作业质量好,覆土作业后种子播深满足农艺要求,星齿球面盘式覆土装置能有效改善播种机的覆土性能。

基于广义回归神经网络的视觉球形机器人建模

由于球形机器人具有复杂的机械结构和特殊的运动方式,导致其动力学模型具有非线性、多变量、强耦合、参数不确定等复杂因素,因此难以建立精确的数学模型。针对上述问题,设计了一种改进广义回归神经网络(GRNN)对其进行建模。首先,获取基于机理模型的球形机器人实测数据;然后,基于实测数据训练出改进GRNN模型并分析其预测效果;最后,分别基于改进GRNN和机理模型,设计球形机器人的控制器进行自平衡实验,前者比后者受到干扰时的波动幅度更小、调节时间短了近1 s。实验结果证明了所设计建模方法的可行性和有效性。

关节轴承轴向间隙机上原位测量装置设计

面向维修过程中飞机机体关节轴承轴向间隙的测量需求,设计了一款高精度机上原位测量装置。利用其定位机构将轴承外圈和内圈相对位置调正并夹紧,使两者同心。通过微型伺服减速电动机驱动滚珠丝杠,带动轴承内圈相对于外圈沿轴承的轴向作平移运动,利用精密力传感器限制施力幅值,据此确定左右两个极限位置,利用高精度位移传感器测得这两个位置的距离(即关节轴承的轴向间隙)。该装置结构紧凑、精度高、使用方便,可用于飞机结构及其他产品上关节轴承轴向间隙的机上原位测量。

Fertilizer sphericity measuring device based on equatorial and meridian circles

Fertilizer sphericity is an important assessment index of appearance quality that affects the fertilization effect.A fertilizer sphericity measuring device based on machine vision was designed aimed at low precision and heavy workload of manual fertilizer measurement,and high cost and complicated operation of high precision measuring instruments.A fertilizer sphericity measuring method based on equatorial and meridian circles was proposed.The device works in an intermittent static acquisition mode to simultaneously obtain both top and side images of a single fertilizer.First,the method performs gamma correction on the top and side images of the single fertilizer,and uses the Canny operator to detect the edge of the image to obtain the equatorial and meridian circular contour images of the fertilizer.Second,based on the fertilizer equatorial and meridian circular contour,the Least Squares Circle method was used to evaluate the roundness of the single fertilizer.Finally,the average roundness value of the equatorial and meridian circles was used as the final sphericity value of the fertilizer.The sphericity measurement test was carried out on the same batch of compound,organic and biological fertilizers by using the sphericity measuring device.The fertilizer sphericity data were obtained by different measurement and evaluation methods.The variation coefficient was used to evaluate the difference in fertilizer sphericity measured by different sphericity measurement and evaluation methods.The results show that among the different measurement and evaluation methods,the coefficient of variation of fertilizer sphericity measured by the equatorial and meridian circle method was the smallest,and the coefficient of variation of sphericity measured by the Least Squares Circle method was the smallest and accurate.This study shows that the sphericity measuring device and method can accurately measure the fertilizer sphericity,and has a significant potential to facilitate fertilizer production and quality inspection.

Φ8钨球破片速度衰减试验及速度预报方法研究

为建立钨球破片速度预报模型,在通过理论分析得到破片速度衰减规律模型,根据Φ8 mm钨球破片在高速和中速段速度试验,进一步采用非线性分析的方法建立了破片高速和中速的速度衰减模型;由数据融合的方法建立了可预报破片某点处速度的经验公式。计算和试验结果验证了破片速度衰减模型和速度预报经验公式的正确性和实用性,拓展了球形破片速度预报公式的使用范围。

高速铁路大跨长联连续梁桥减隔震方案优化研究

结合某高烈度区高速铁路大跨长联连续梁桥的特点,通过全桥引入粘滞阻尼器、Lock-up和双曲面减隔震支座3种减隔震方案,建立全桥有限元模型,从分散抗震角度出发,采用非线性时程分析法研究3种方案的减隔震效果,总结3种方案的利弊,并基于3种方案提出粘滞阻尼器+Lock-up联合使用的优化方案。结果表明:对于桥墩高矮相差较为明显的高速铁路大跨长联连续梁桥,全桥布置粘滞阻尼器减震效果较差,全桥布置Lock-up方案对较矮墩十分不利,双曲面减隔震支座减震时会产生较大的墩梁相对位移,而粘滞阻尼器+Lock-up装置联合使用的优化方案在实现高效减震的同时很好地控制墩梁相对位移。

球混式精准灌溉施肥系统的设计与试验

针对作物灌溉施肥不均匀,存在多施少施,肥料浓度过高等现象严重,该文设计了一种能实现自动灌溉、施肥、配方、混肥为一体的球混式水肥灌溉系统。该文详细描述了灌溉施肥系统的装置结构、自动控制系统、上位机软件设计,研究了配肥子系统特点和控制算法。根据不同作物的不同需要,对营养液的EC值(电导率间接反映营养液的浓度)和p H值(酸碱度)进行精确控制和实时调节,并利用嵌入式技术、变频技术、自动控制技术以及计算机信息技术开发灌溉施肥自动控制系统,实现灌区的自动灌溉施肥。试验证明,该系统EC、p H值调节品质好,性能稳定可靠,组装简便,操作人性化,实用性强,有利于推广使用。该研究为精准灌溉施肥系统的进一步研究提供了参考。

静压气体球轴承支承球形转子的干扰力矩分析

中心小孔供气单向受载球面气体轴承可以用于球形转子的静平衡测量。对作用于转子上的干扰力矩进行估算是平衡装置设计的重要部分。本文在一定假设条件下推导了由粘性剪切应力和气膜支撑力引起的作用于转子上的干扰力矩。干扰力矩以轴承包角、中心气室张角、气膜压力、转子转速、转子旋转轴位置、失中度、转子非球度表示。以干扰力矩最小为准则分析了这些参数的影响,结论有助于静平衡装置的优化设计以及对精度的进一步分析。

面向iOS的移动端全景地图构建方法

随着移动互联网和街景地图的发展,基于360°全景影像的街景地图服务将成为移动互联网时代位置服务的主流趋势。该文提出了一种面向iOS移动端的全景地图应用构建方法。首先,提出基于球面模型的移动端全景场景构建、纹理贴图和渲染优化的技术方法;其次,针对移动终端应用模式,设计了面向移动终端的全景地图数据服务的技术框架;最后,采用移动端全景地图模型和数据服务框架,实现了iOS下移动端全景地图的开发。实验结果表明移动端全景浏览流畅,可以广泛应用在增强现实位置服务,具有很好的应用前景。

基于响应面方法的甘薯粉尘爆炸研究

为给甘薯粉尘爆炸预防提供依据,用20 L球形爆炸装置进行爆炸试验,研究甘薯粉尘粒径、质量浓度和点火能量3个单因素对爆炸的影响;同时,用响应面方法,通过Design-Expert软件中Box-Behnken试验设计,对影响甘薯粉尘爆炸的因素进行对比分析。试验结果表明,甘薯粉尘最大爆炸压力随粉尘粒径的减小而增大,随粉尘浓度的增加呈现先增加后减小的趋势,随点火能量的增大而增大。同时,由Box-Behnken试验中响应面回归方程知,甘薯粉尘质量浓度对粉尘爆炸影响最大,其次是点火能量,甘薯粉尘粒径对相应粉尘爆炸影响最小。

强震区多跨长联连续梁桥减隔震设计

为了给高烈度地区多跨长联连续梁桥抗震设计提供参考,以一座(55+4×90+55)m的连续梁桥为工程背景.采用ANSYS软件建立全桥分析模型,基于非线性时程分析方法,对比研究结构采用双曲面摩擦摆支座、黏滞阻尼器和速度锁定装置3种减隔震装置下的地震响应.结果表明:黏滞阻尼器在罕遇地震作用下形成了完整的滞回环,每个阻尼器耗能能力明显;采用双曲面摩擦摆支座、黏滞阻尼器和速度锁定装置时,结构的地震响应相对于传统抗震体系都有一定程度地降低,固定墩内力相对减震率分别为63.44%、6.90%、42.32%,位移相对减震率为65.70%、9.34%、43.77%;采用双曲面摩擦摆支座作为减隔震措施时,墩底内力和墩顶位移远小于黏滞阻尼器和速度锁定装置2种减隔震措施.

简化球谐近似模型的图形处理器加速求解

作为辐射传输方程的高阶近似,简化球谐近似模型成为近年光学分子成像研究的重点,但计算效率低限制了它的广泛应用,为此提出一种基于图形处理器的并行加速策略,采用NVIDIA公司推出的统一计算设备架构,对求解过程中耗时最多的两个模块——有限元刚度矩阵的生成和线性方程组的求解进行基于图形处理器的并行加速;根据统一计算设备架构的特点,进行计算任务的分配、存储器的合理使用以及数据的预处理三方面的优化;仿体及数字鼠仿真实验对比刚度矩阵生成时间以及平均迭代时间,以评价所提出方法的加速效果。实验结果表明,该方法可使求解速度提高30倍左右,展示了该方法在光学分子成像中的优势及潜力。

球形环研究概述

球形环是一种先进的磁约束核聚变研究装置 ,它保留了传统托卡马克装置的许多特点 ,比如说封闭磁面系统 ,中等旋转变换磁力线和好的等离子体约束性能等 ,同时又有低环径比 ,低纵向磁场 ,从而具有结构紧凑 ,造价相对低廉等优点 ,是有潜力的磁约束核聚变途径之一。概述了球形环的装置、实验。

非接触式光电液体计量装置设计

针对目前水质在线分析仪器中液体计量方式存在的缺点,提出了一种新的非接触式光电计量装置。该计量装置仅需要一个蠕动泵、一个或多个三通电磁气阀、三通电磁液阀、光电开关和球形石英计量管等相互配合,就可以实现一种或多种不同液体体积的同时计量。通过在石英计量管中设计一个球形腔体,能够有效避免管路中气体对体积测量的干扰,也不必严格控制蠕动泵的转速,大大提高了液体的计量速度。该装置具有计量精度高、稳定好,成本低等优点,具有广阔的应用前景。

SMR靶球与轨道控制点连接装置的设计与精度测试

设计了一款与激光跟踪仪配套的光学反射棱镜SMR靶球的连接装置,并给出了SMR靶球相对于莱卡棱镜的中心位置差异的测试方法,通过测试给出了加工部件的精度指标。

球头超细长轴的大批量加工

提出了用搓削法加工球头超细长轴,阐述了搓削加工原理,重点设计了加工设备中的弧形磨块、送料装置和压紧机构。采用搓削法对球头超细长轴进行加工,不仅易于操作、加工精度高,而且实现了大批量低成本生产。