IPMC型柔顺手爪作动器的设计与性能测试

为克服传统手爪机构传动链多,耗能大,结构复杂等缺点,设计并制作了一种应用电致动智能材料(IPMC)的柔顺手爪。运用Pro/E软件设计IPMC手爪的主体结构,并分析其运动过程,最终装配完成IPMC手爪;运用激光位移传感器,精密电子秤和Canon相机测试了研制的4片IPMC驱动薄膜的末端位移,端部力和平均运动速度,并通过Labview测试系统对其进行采样和分析。实验结果表明:IPMC手爪驱动元件的角位移在3V电压激励下超过了180°(-3V电压下负向位移与+3V电压下正向位移之和);其末端位移大小为其自身(除固定部分外)总长;手爪驱动薄膜每片重量约为0.5mg,可抓握质量为1.6g左右的物体。该手爪结构简单、位移大、耗能低;同时,由于IPMC的柔顺特性,在抓取物体时它会贴附在其表面,而不破坏其表面精度。因此,这种手爪适用于抓取表面粗糙度要求高的物体。     

杠杆式尺蠖压电直线驱动器

设计了一种基于尺蠖运动原理的压电直线驱动器,用于解决光学领域中的精密定位问题。该驱动器采用了对称杠杆式位移放大机构,在保证钳紧力的同时,可以获得较大的驱动位移。阐述了尺蠖式压电驱动器的工作原理,对杠杆式柔性放大机构的位移损失、压电陶瓷与柔性机构的耦合特性及箝位机构与中间驱动机构的刚度进行了分析。利用有限元软件Ansys对钳位机构和驱动机构的变形、应力、输出位移和固有频率等参数进行了仿真分析。最后,搭建了实验平台,测试了驱动器的各项性能。测试结果显示,该驱动器的行程为±25mm,钳紧力为17N,承载力为11N,最大和最小步距分别为55μm和60nm。当驱动电压为150V时,驱动器的最高驱动速度为1.259mm/s。得到的性能指标满足光学领域精密定位需要。     

形状记忆合金丝驱动的微型机械手

文章介绍了以形状记忆合金丝为驱动材料,以弹簧钢为基体研制的微型机械手。它抓取零件的直径范围为φ0.5-1mm,最大抓取重量为50g。文章讨论了所设计微型机械手的结构。形状记忆合金驱动的特点及控制原理、柔性铰链应用以及机械手进一步微型化的条件。     

精密小转矩加载机构的研制

研制了一种压电驱动的柔性铰链微位移放大机构，以满足航天微型扭杆刚度测试装置中实现精密小转矩加载的要求，时这种机构建立了精确的有限元模型，运用有限元方法对这种的机构的强度和放大比进行了校核和分析。该机构具有350μm的行程，位移分辨率大于0．25μm，最大输出力不低于4N，满足了测试装置的要求。     

一种新型柔性气缸驱动手爪

提出一种新型柔性气缸驱动手爪,具有抓取柔顺性和较大的抓取力,可用于抓取易碎易损品.介绍柔性气缸驱动手爪的整体结构方案,给出柔性驱动气缸的静态结构性能分析及输出力试验结果.对手爪的抓取能力和实物抓取进行试验,手爪在70 kPa的工作压力下最大抓取力为122 N,比一般柔性手爪的35 N抓取力提高了约2.4倍,并且保持了抓...     

超磁致伸缩驱动镜放大机构设计与仿真

为满足超磁致伸缩驱动镜对天文望远镜的输出位移需求,设计了一种基于杠杆式柔性铰链的二级微位移放大机构.通过对柔性铰链转动中心偏移量的分析,推导出放大机构放大率公式;使用ansys有限元软件对其进行静态位移输出特性分析并计算放大率;通过实验对理论分析、有限元仿真进行验证.结果 表明三者的放大率基本吻合,相对误差不超过3％,位移放大率接近8倍;放大机构结构简单紧凑、设计合理、可以满足超磁致伸缩驱动镜的输出位移需求.     

微型可变形轮式机器人研究

面向微型机器人未来在地外探测上的潜在应用,提出了一种手掌尺度可变形轮式机器人的整体设计与制造方案。基于多层材料叠合加工工艺将探测机器人主体材料与柔性薄膜电路叠合在一起构建复合结构;基于平面一体式成形制造方法加工出探测机器人的可折叠主体结构。基于一体化集成方法设计了包含运动驱动电机、变形驱动机构、传动系统及电池等部分的一体化车轮并在此基础上与主体结构进行结合。开展了微型可变形轮式机器人的系统设计与加工测试。总重约300 g的可变形轮式机器人样机在内置7 V电压下完成了运动与变形测试,验证了可变形轮式探测机器人设计方案的可行性。     

基于柔性铰链的微操作执行器的设计和分析

为了满足微型机电系统研究和测试的要求，设计了一种压电驱动的基于柔性铰链的微操作执行器。该微操作执行器采用组合杠杆原理将压电驱动器的微小位移放大。用简化方法和有限元方法分别对该柔性铰链微操作执行器进行了分析，发现简化方法可以用在初步设计中，而最终需要用有限元方法进行校验。在柔性铰链微操作执行器的设计中，加强杠杆的支点和杠杆臂的刚度，能有效地提高系统的运动放大倍数，并且使简化分析的结果和有限元分析结果更接近。     

仿鸟喙微型气动软体机械手爪的设计及优化

为实现微型易碎、不规则物体的稳定抓取,结合软体材料的柔顺性和鸟喙结构抓取的准确性,提出一种仿鸟喙微型气动软体机械手爪,该机械手爪不仅具有一般软体手爪良好的环境适应性,而且结构更加简洁,对微型物体尤其适用。利用Yeoh本构模型和Ansys软件,对手爪的弯曲特性做了有限元仿真,并根据仿真结果进行变壁厚和局部填充的优化。对优化后的手爪进行了弯曲特性、抓取力测试试验和适应性试验,验证了仿鸟喙微型气动软体机械手爪的可行性。     

轮式直线型超声电机定子的动态设计和分析

利用非统一截面梁在正交方向上的2个同形弯曲振动模态作为工作模态,设计了一种新型直线超声电机.基于有限元理论叙述了该定子的动态设计过程,对定子驱动足位置、压电陶瓷安装位置和定子的不同夹持方式进行了仿真计算,分析了不同阶次弯曲振动模态作为定子工作模态的优缺点以及不同支撑方式对定子振动模态的影响.制造了一台原理性样机,样机定子直径为10 mm,长为55 mm,重为30 g.在驱动电压峰峰值为200 V,驱动频率为49.52 kHz,摩擦副为陶瓷摩擦材料对不锈钢的情况下,电机空载速度为374 mm/s,最大推力为13 N,推重比达到了43: 1.     

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.     

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。     

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....     

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.