一种高性能花瓣廓形胶囊机器人

为提高肠道内综合驱动性能,提出一种新型花瓣状结构胶囊机器人,机器人表面四块偏心花瓣廓形与管壁形成四个收敛楔形空间,使流体运动路径发生改变并产生多楔形效应。根据库埃特流动理论,借助牛顿内摩擦定律建立花瓣型胶囊机器人流体动力学模型,在求得机器人稳态游动速度、流体动压力和液体扭转力矩解析解的基础上,对花瓣型胶囊机器人综合性能进行研究。理论与试验证明花瓣型胶囊机器人表面流体动压与稳态游动速度更大,流体扭转力矩更小。花瓣型胶囊机器人的综合性好,实现机器人在管道内全悬浮式非接触游动,诊断遍历时间更短,对肠道的扭曲作用更小,安全性更高,在胃肠道诊断领域实用前景良好。     

花瓣廓形胶囊机器人的流体动态性能

提出的新型花瓣状结构胶囊机器人可提高驱动性能,其表面偏心花瓣廓形与管壁形成四个收敛楔形空间,使流体流线方向发生改变并产生多楔形效应。根据建立的流体动力学模型,求得机器人流体动压及稳态游动速度解析解。运用数值模拟方法对机器人外围流体流动特性进行了可视化分析,理论推导与仿真试验均表明:花瓣型胶囊机器人的表面流体动压与稳态游动速度更大,综合性能更好。     

二次曲线廓形胶囊机器人速度分析

在圆柱机器人基础上提出一种二次曲线廓形胶囊机器人,表面二次曲面与管壁形成四个收敛楔形空间,使流体运动路径发生改变并产生多楔形效应。建立流体动力学模型,对机器人稳态游动速度进行求解分析。研究结果表明,二次曲线廓形胶囊机器人稳态游动速度更大,提高了肠道内驱动性能、安全性与作业效率,实用前景良好。     

粘性流体内花瓣型胶囊机器人驱动特性

以花瓣型胶囊机器人为模型,推导机器人表面流体运动规律。通过解析法求得机器人外围流体动压力表达式,以牛顿内摩擦定律为基础得到液体阻力矩模型,对比研究花瓣型和圆柱形两种胶囊机器人管道内悬浮能力,分析流体粘度对不同廓形胶囊机器人液体阻力矩的影响,得到花瓣型胶囊机器人能够悬浮在管道中避免与管道接触,同时可以降低磁场线圈功耗,且流体环境适应能力强,提高了临床应用的可行性。     

肠道胶囊式微机器人轴向磁拉力特性

提出一种以径向磁化的瓦状多磁极组成的圆筒式永磁体为外驱动器，以嵌入机器人本体内与外驱动器同磁极结构的永磁体为内驱动器的非接触式驱动控制方案。通过外驱动器的旋转产生旋转磁场，借助于磁机耦合作用，驱动机器人旋转并在其外螺纹表面形成的流体动压力作用下产生轴向推力，进而实现胶囊式机器人在肠道内旋进。基于等效磁荷理论，采用磁荷积分法建立了驱动器的轴向磁拉力模型，对驱动器磁极结构参数与磁拉力的关系特性以及磁拉力与机器人游动关系特性进行了理论与试验研究。     

磨削区流体速度场建模与实验研究

根据Navier-Stokes方程和流体流动的连续性方程,建立了砂轮/工件楔形接触区流体速度场的数学模型并进行仿真.结果表明,流体速度随砂轮速度的提高而增加,在砂轮宽度方向除在砂轮边缘产生突起外,流体速度分布规律相同;对砂轮与工件之间楔形区域形成的流体速度场进行了实验研究,实验结果表明,依据Navier-Stokes方程和流体流动的连续性方程建立的速度场理论模型与实验结果吻合,理论模型能很好地预测接触区流体速度场分布.     

新型肠道胶囊式微型机器人的运动特性

提出一种胶囊微机器人的外旋转磁场驱动方法,原理是以径向磁化瓦状多磁极构成的圆筒形NdFeB永磁体为外驱动器,以胶囊微机器人内嵌同磁极结构NdFeB永磁体为内驱动器,通过外驱动器旋转产生旋转磁场的磁机耦合作用,形成内嵌驱动器对胶囊微机器人的驱动力矩,在胶囊表面螺旋与流体形成的动压力作用下,实现胶囊微机器人在肠道内旋进。首先介绍胶囊微机器人系统的结构,然后根据雷诺和Navier-Stokes方程建立管道环境内胶囊微机器人的运动数学模型,对其螺旋参数与速度的关系进行理论与试验研究,并发现了临界间隙现象。试验表明,该胶囊微机器人具有驱动力矩大、适合大粘度液体封闭管道内行走等特点,在人体肠道和血管内具有很好的应用前景。     

砂轮/工件楔形区流体动压力的建模与实验验证

基于Navier-Stokes方程和流体流动的连续性方程,建立了浇注式供液方式下,考虑砂轮、工件表面粗糙度的砂轮/工件楔形区流体动压力数学模型。在平面磨床上进行了流体动压力的实验研究,结果表明,实验中测量的动压力值与相同条件下模型理论值基本吻合,理论模型可很好地预测粗糙表面间楔形区压力场的分布;考虑粗糙度的楔形区流体动压力的理论曲线是不光滑的;楔形区流体动压力随着砂轮速度的增加、最小间隙的减小而增大,最大压力峰值分布在砂轮、工件最小间隙区域,且在该区域压力梯度变化明显。     

一种医用肠道机器人的理论分析与试验研究

提出一种结构简单的医用肠道机器人的驱动机构。利用弹性流体动压润滑理论,详细分析计算了肠道机器人在不同弹性模量、不同半径和不同粘液粘度的肠道内的轴向运行速度和形成的粘液膜厚度。结果表明,此种肠道机器人能以较快速度在肠道内悬浮运行。上述分析结果已被肠道试验研究所证实。     

医用微型机器人蠕动肠道中的驱动力计算及实验研究

提出了一种新型的可进入人体内腔和微型机器人驱动机构。此种微型机器人能够在充满液体的弯曲的人体肠道内运行。当机器人在充满液体的微型管道内运行时，在其周围会自动形成一层液体动压润滑膜，此润滑膜能避免机器人与管道壁发生直接接触。结合人体肠道的蠕动方程和N－S方程利用有限元分析计算了此种微型机器人在蠕动肠道中的驱动力和运行速度，进行了机器人的运行实验，结果表明，机器人能以较快速度在肠道内悬浮运行。     

Minimal Realization of Linear Graph Models for Multi-physics Systems

An engineering system may consist of several different types of components,belonging to such physical"domains"as mechanical,electrical,fluid,and thermal.It is t...     

INTEGRAL EQUATION METHOD＇S APPLICATION IN HOLE-EDGE STRESS OF COMPOSITE MATERIAL PLATE WITH DIFFERENT SHAPED HOLES

The strength of composite plate with different hole-shapes is always one of the most important but complicated issues in the application of the composite material. The holes will lead to mutations and discontinuity to the structure. So the hole-edge stress concentration is always a serious phenomenon. And the phenomenon makes the structure strength decrease very quickly to form dangerous weak points. Most partial damage begins from these weak points. According to the complex variable functions theory, the accurate boundary condition of composite plate with different hole-shapes is founded by conformal mapping method to settle the boundary condition problem of complex hole-shapes. Composite plate with commonly hole-shapes in engineering is studied by several complex variable stress fimction. The boundary integral equations are founded based on exact boundary conditions. Then the exact hole-edge stress analytic solution of composite plate with rectangle holes and wing manholes is resolved. Both of offset axis loadings and its influences on the stress concentration coefficient of the hole-edge are discussed. And comparisons of different loads along various offset axis on the hole-edge stress distribution of orthotropic plate with rectangle hole or wing manhole are made. It can be concluded that hole-edge with continuous variable curvatures might help to decrease the stress concentration coefficient; and smaller angle of outer load and fiber can decrease the stress peak value.     

Non-monotonic material contrast in scanning ion and scanning electron images

30 keV Ga⁺ focused ion beam induced secondary electron (iSE) imaging was used to determine the relative contrast between several materials. The iSE signal compared from C, Si, Al, Ti, Cr, Ni, Cu, Mo, Ag, and W metal layers does not decrease with an increase in target atomic number Z₂, and shows a non-monotonic relationship between contrast and Z₂. The non-monotonic relationship is attributed to periodic fluctuations of the stopping power and sputter yield inherent to the ion–solid interactions. In addition, material contrast from electron-induced secondary electron (eSE) and backscattered electron (BSE) images using scanning electron microscopy (SEM) also shows non-monotonic contrast as a function of Z₂, following the periodic behavior of the stopping power for electron–solid interactions. A comparison of the iSE and eSE results shows similar relative contrast between the metal layers, and not complementary contrast as conventionally understood. These similarities in the contrast behavior can be attributed to similarities in the periodic and non-monotonic function defined by incident particle–solid interaction theory.     

Application of Feature Extraction through Convolution Neural Networks and SVM Classifier for Robust Grading of Apples

This paper proposes a novel grading method of apples,in an automated grading device that uses convolutional neural networks to extract the size,color,texture,an...     

分布动态载荷识别的抗噪处理

针对正交多项式频域法在用多种响应对矩形薄板进行载荷识别中抗噪性较差的问题,综合运用平均法、矩阵预处理和奇异值截断法等方法对之进行改善,并引入空间映射的思想,将该方法的应用范围拓展为复杂的模型.利用仿真算例,证实了该方法具有较好的抗噪性.     

Short-Term Relay Quality Prediction Algorithm Based on Long and Short-Term Memory

The fraction defective of semi-finished products is predicted to optimize the process of relay production lines, by which production quality and productivity ar...     

End-to-End Multiview Gesture Recognition for Autonomous Car Parking System

The use of hand gestures can be the most intuitive human-machine interaction medium.The early approaches for hand gesture recognition used device-based methods....     

基于MELTAC-N平台的核电厂安全级DCS环网研究与测试

针对工程实践中环网通讯相关问题的处理缺乏理论基础及国产化安全级DCS平台的开发缺乏成熟经验借鉴问题,对基于MELTAC-N平台核电厂安全级DCS环网的软硬件实现进行了研究。提出了安全级DCS环网双环网冗余设计、光切换开关设计等硬件设计方法,以及以RPR协议为基础,采用全数据收发策略的软件设计方法。在CPR1000安全级DCS平台上对安全级DCS环网的可靠性及实时性进行了评价,并进行了容错能力、响应时间及响应时间稳定性测试验证实验。结果表明,基于MELTAC-N平台安全级DCS环网软硬件设计具有较好的容错能力及响应时间稳定性。     

The laboratory simulation of abrasive wear

Abrasive wear has long been recognised as one of the most potentially serious tribological problems facing the operators of many types of plant and machinery; several industrial surveys have indicated that wear by abrasion can be responsible for more than 50% of unscheduled machine and plant stoppages. Locating the operating point of a tribological contact in an appropriate operational ‚map’︁ can provide a useful guide to the likely nature and origins of the surface degradation experienced in use, though care must be exercised in choosing the most suitable parameters for the axes of the plot. Laboratory testing of materials and simulations of machine contacts are carried out for a number of purposes; at one level for the very practical aims of ranking candidate materials or surface hardening treatments in order of their wear resistance, or in an attempt to predict wear lives under field conditions. More fundamentally, tests may be aimed at elucidating the essential physical mechanisms of surface damage and loss, with the longer term aim of building an analytical and predictive model of the wear process itself. In many cases, component surface damage is brought about by the ingress of hard, particulate matter into machine bearing or sealing clearances. These may be running dry although, more usually, a lubricant or service fluid is present at the interface. A number of standardised wear test geometries and procedures have been established for both two- and three-body wear situations, and these are briefly described. Although abrasive wear is often modelled as following an ‚Archard’︁ equation (i.e. a linear increase in material loss with both load and time, and an inverse dependence on specimen hardness) both industrial experience and laboratory tests of particularly lubricated contacts show that this is not always the case: increasing the hardness differential in an abrasively contaminated lubricated pair may not always reduce the rate of damage to the harder surface.     

ANGULAR DISTORTION ALLOWABLE VALUE AND ASSESS METHOD OF WELD ON COKE TOWER

A graph as the new engineering method for estimate the safety of bulging deformation of coke tower is proposed. Through stresses analysis of circumferential weld of coke tower and comparing the stresses produced by pressure with heat stress of steady state, residual stress, bending stress produced by both itself weight and wind loads, it showed that the stresses produced by pressure on the angle distortion are the main factor of equivalent stress of the combined stress. After comparing four kinds of stress controlling conditions, the relation to stress with depth of angular distortion, grade of curvature of angular distortion and half of region of angular distortion has been inferred. Graph of deformation allowable value of coke tower for different condition by angular distortion and half of region of angular distortion has been plotted. The five steps for its engineering use have been explained. The lighter the grade of curvature is, the larger of bulge allowance, may be, and the bigger of depth of angular distortion may pose too. For the coke tower with a popular structure of Dg 5 400 mm×28 mm, the result by graph is nearly more than the result of two formulas formed by other research, the error is less than 7.0%. But, the graph can be easily applied to different size of angular distortion.