多功能自助轮椅设计的研究

本文主要设计方便残疾人士的一种多功能自助轮椅。并对轮椅座椅机构部分、转向机构部分、驱动机构部分、座椅升降机构部分、控制机构部分和滚轮机构部分等结构进行设计,实现自动行走、自动上下楼梯、自动升降轮椅、遥控自助轮椅和自动转向等功能,大大的提高了残疾人士的生活质量,也有效的解放了劳动力。     

可升降轮椅的设计与制作

介绍了一款可升降轮椅,该轮椅是在对市场上销售的轮椅进行改造的基础上设计与制作的。它除了具有市场上轮椅普遍具有的多种功能外,还具有升降功能,该功能主要用于减轻护理人员的劳动强度,具有一定发展前景。     

可直立行走的助步轮椅机构设计

助步轮椅是一种可重构机构在助残工具中的应用。设计了一种集轮椅与行走功能于一体的助步轮椅,依靠人体上肢功能完好的力量,可实现路面上为轮椅形态的行进;依靠人体上肢功能完好的力量与楼梯扶手的协助,可实现上下楼梯的动作。解决了轮椅状态下的双摇杆机构与传动的设计、变换为行走状态下的双腿上下楼梯的参数计算问题。     

一种关于新型坐蹲立式代步车的设计研究

通过调查与研究现有代步工具的缺点与不足,研究设计出一种具有创新功能的新型坐蹲立代步车。先简要图文介绍代步车、普通轮椅和可站立电动轮椅这三种常见代步工具,并总结它们的优缺点。接着提出改善这些代步工具缺陷的3种创新功能:(1)车座自动伸缩功能,使操作者简便上下车;(2)具有"坐、蹲、立"三种使用模式且切换简易;(3)具有健身功能,可帮助操作者锻炼身体。然后采用模块化设计方法针对这3个功能对代步车进行座椅移动模块、座椅升降模块、健身康复模块和驱动控制模块设计,并最终运用CAD进行机构设计,利用ANSYS对模型进行力学分析,进行优化设计,从而得到最优产品设计方案。     

一种超市用可升降购物车

提出了一种新型的可升降超市购物车。该购物车利用摇杆滑块结构,通过纯机械操作,在人们购物收银付款时改变以往弯腰拿取购物车车筐里的物品放置在收银台结账的方式。通过下压扶手经传动机构,可快速、省力地升降购物车筐,实现免弯腰取物,从而使购物更加轻松便捷,体现了产品设计的宜人性和舒适性。     

一种多功能越障轮椅的结构设计与仿真分析

针对下肢残障及行动不便的特殊人群出行需求,设计了一种基于人机工程学的多功能越障轮椅。采用电机控制推杆伸缩运动的方式实现越障功能,同时轮椅具有升降、靠背调节、爬坡等功能,对应这些功能设计了执行机构。基于FUSION软件建立了轮椅的三维模型,通过ANSYS对三维模型和推杆进行受力分析,判断其满足强度要求;利用MATLAB软件对3组推杆的空间分布进行优化,使推杆组合运动达到最省力状态;在ADAMS软件上对轮椅进行运动仿真,以确保其可行性。试制的实物样机测试表明,轮椅的各项功能已实现,满足人机工程学,证明设计合理。     

一种星轮式爬楼梯电动轮椅设计

设计了一款三星轮式爬楼梯电动轮椅,其中一个星轮为轮毂电机。采用三星轮机构实现爬楼越障,采用轮毂电机驱动轮椅平地行驶,实现了爬楼功能和电动轮椅功能的有机结合。爬升装置是爬楼梯轮椅的关键,在深入研究爬楼梯轮椅工作机理基础上,充分考虑爬楼梯轮椅爬升装置的结构和尺寸以及爬升功率、安全性等要求,在对爬升装置设计的同时还对轮椅行走环节进行了设计。经过性能分析,设计的爬楼梯轮椅达到了功能要求,并具有乘坐安全、爬楼梯稳定、控制容易以及操作简单等特点。     

基于齿轮传动的结构仿生螃蟹机器人设计

基于螃蟹的结构特性,运用仿生学原理设计了一款由八只足和两只钳螯组成的仿生螃蟹机器人。控制行走步进电机驱动齿轮曲柄摇杆机构实现螃蟹机器人的横向行走、转向等基本动作,控制升降步进电机驱动齿轮齿条机构实现钳螯的升降,控制摆动舵机实现钳螯的左右摆动,控制抓取舵机驱动两不完全齿轮双摇杆机构实现钳螯的抓取。该仿生螃蟹机器人传动灵活、动力传递效率高、维修方便,有很好的路况适应能力。该机器人在复杂路况下进行搜救与探测等方面,具有较好的应用潜力。本文为极端环境下的多足仿生探测机器人的传动设计提供了借鉴和参考。     

一种新型复合式可爬梯轮椅结构设计与分析

为了解决老年人和残疾者上下楼梯困难,设计了一种新型的行星轮-履带复合式可爬梯轮椅结构。采用行星轮-履带复合机构实现爬梯越障的功能,轮椅驱动采用1个电机,星轮采用链传动实现爬梯、平地行驶。该结构结合履带装置,可有效减轻星轮式轮椅振动且提高了传统轮椅的越障能力。在对比现有爬梯轮椅机构特点的基础上,介绍一种星轮-履带结合的新型轮椅机器人的机构方案,并分析轮椅的工作原理,建立数学模型进行爬梯过程运动学与动力学分析。结果表明,轮椅可以安全爬越大部分楼梯。轮椅的结构设计合理,实现爬梯和平地移动功能的结合。     

按许用传动角综合单曲柄双摇杆式翻板机驱动机构

单曲柄双摇杆式翻板机驱动机构,实为两套共驱动轴的正置式曲柄摇杆机构,但两曲柄具有一相位差.在分析驱动机构工作原理的基础上,给出了其综合问题的准确表述,即:已知机架长度和摇杆摆角,按许用传动角综合正置式曲柄摇杆机构.推导出这类机构最小传动角与杆长及摇杆摆角之间的解析关系,分析最小传动角接近其上确界时的杆长及最大杆长比变化趋势,进而建立了按许用传动角综合正置式曲柄摇杆机构的解析法.给出了翻板机驱动机构综合实例,性能参数分析结果验证了综合方法的正确性和可行性.     

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...     

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.     

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.     

Limits of topographic measurement by the scanning tunnelling and atomic force microscopes

Parameters describing the topographic character of a surface (height, surface wavelength, slope and curvature) can be derived from equivalent sinusoidal profiles. The response of a surface-measuring instrument may be modelled in terms of instrument parameters such as stylus radius, and scanning range and resolution. The performance of the instrument may then be mapped as a zone in amplitude-wavelength (AW) space to show the sinusoidal profiles it is capable of measuring. In a first-order analysis the STM and AFM are considered as equivalent to contact-stylus instruments with a notional stylus radius equal to the tip radius plus the gap. Comparisons between different instruments and types of instrument are readily made by mapping in AW space. The error arising from convolution of the sinusoidal profile with that of the finite tip may be quantified and plotted as contours in AW space.     

Fractional order nonsingular terminal sliding mode control for flexible spacecraft attitude tracking

This paper investigates a fractional terminal sliding mode control for flexible spacecraft attitude tracking in the presence of inertia uncertainties and extern...     

奥氏体不锈钢表面双辉等离子渗锆的动力学

利用双辉等离子渗金属技术在0Cr18Ni9Ti奥氏体不锈钢表面制备了一层均匀、致密、呈良好冶金结合的渗锆合金层,并对1 060℃下的渗锆动力学进行了研究。结果表明:随着距锆合金层表面距离的增加,锆元素的含量呈梯度递减,扩散系数逐渐减小,而扩散激活能逐步增大;在1 060℃采用双辉等离子技术渗锆时,渗锆合金层表层的空位密度为2.945×(1012~1013)cm-2,与相同温度下采用常规渗金属工艺相比,提高了1~2个数量级。     

气化炉三维扫描测量与数据处理

以德士古气化炉耐火砖的内壁蚀损检测设备为基础,对采集到的点云数据做了进一步处理.通过对数据的筛选和剔除,实现了数据点的平滑降噪细化和精简.然后利用点云对整、网格划分和分色显示等方法,最终完成了内壁腐蚀情况的三维建模.重点讨论了点云数据的预处理及后处理的方法,并根据内壁耐火砖的腐蚀阈值,提出了一种气化炉内壁腐蚀区域的识别与分割方法.对耐火砖的腐蚀分析、气化炉的生产与维修提供了可靠依据,并在工程应用中获得了一致认可.