一种手腕同步驱动码垛机械手设计

根据啤酒箱码垛系统工艺流程要求,对码垛机械手运动轨迹进行了设计,在此基础上建立码垛机械手模型;设计了一种手腕同步驱动机构,对同步驱动机构进行动力学分析并对驱动转矩参数进行优化。最后,利用ADAMS软件对该机构进行仿真分析。     

新型三指灵巧机械手的研究

介绍了新型三指灵巧机械手,包括研究背景、研究成果以及三指灵巧机械手的各组成部分。详细介绍了灵巧机械手的机械配置,并根据最优抓持的力学理论分析了手的机构配置原理;对新型三指灵巧机械手的驱动原理以及驱动系统的创新和独特之处进行了分析说明;对控制系统的硬件包括轴运动控制器、数据采集板以及功率放大板都从构成到工作原理进行了详细介绍并给出了原理图。对控制系统软件以及控制算法进行了详细说明。     

模块化水下电动机械手设计与运动学分析

为了满足水下作业的多样性需求并提高水下机械手的通用性,对水下电动机械手进行模块化设计,机械手模块分为具有俯仰和腕转两个自由度的基本运动驱动模块和手爪模块,手爪模块采用旋转驱动凸轮机构实现。机械手模块设计实现了控制器内置和内部走线,并且选择适用于深海作业的元器件,不同模块的快速组合可以满足不同的作业需求。利用三个基本运动驱动模块和一个手爪模块搭建了七功能电动机械手,对七功能机械手进行了运动空间分析及运动学仿真。     

六自由度钻杆装卸机械手运动学研究

现有工程钻机机器人采用人工装卸方式换接钻杆,其工作效率较为低下且存在安全隐患。为提高钻机的钻杆换接效率,设计了一种六自由度钻杆装卸机械手。在此基础上,利用笛卡尔坐标系建立了机械手的运动学方程,并采用遗传算法运动学方程进行了求解。进一步通过UG软件建立了钻杆装卸机械手虚拟样机模型,并提出了同步驱动和依次驱动两种驱动方案,同时在两种方案下对钻杆装卸机械手的运动学进行了仿真分析,分析结果表明:运动学方程逆解和连杆参数设计正确;机械手同步驱动方式在运动特性方面优于依次驱动方式。研究成果为实现工程钻机人钻杆的自动装卸提供理论基础。     

搬运机械手控制系统的研究

对机械手的机械结构、驱动机构和控制系统分别进行了分析。本设计中的机械手有5个自由度,其中手臂的上下和伸缩运动由二相混合式步进电动机驱动,手腕的旋转与底盘的旋转由直流电动机驱动,手爪夹取则采用气压驱动。设计了以ATMEL公司的8051单片机为核心的控制系统,并绘制机械手单片机控制程序流程图,形成一套完整的搬运机械手模型单片机控制系统。     

水下欠驱动机械手结构设计与仿真分析

面向水下机械手深海作业环境,研究设计了一种可用于水下环境的欠驱动机械手,机械手共有3个手指,每个手指有3个关节,是由连杆传动的欠驱动手指,欠驱动使手指抓取具有自适应性。分析了手指运动机理,研究设计了手指模块和整体结构,对手指进行了抓取静力学分析,在ADAMS软件中对机械手进行动力学仿真,验证了机械手结构的合理性与可行性。     

多模式抓取欠驱动手的机构设计与力学分析

针对机器人末端执行器机械手多功能化的需求,提出了一种多模式抓取欠驱动手.该机械手基于欠驱动理论,解决了传统复合欠驱动手存在的结构复杂、控制元件多、适应能力不强等缺点.介绍了多模式抓取欠驱动机械手的结构组成和运动过程,建立了欠驱动手的数学模型;根据几何关系对机械手进行运动分析与适应性分析,并求得机械手抓取的参数范围;在不同的抓取模式下,分别对机械手进行受力分析,利用虚功原理,计算出理论输出力.虚拟样机仿真实验表明,该机械手无需安装受力传感器及复杂的控制系统,可实现平夹和包络两种抓取模式,验证了设计的可行性.     

驱动平面机械手的液压系统建模及CMAC-PID控制研究

为了提高平面机械手运动的稳定性和轨迹跟踪精度,采用小脑模型神经网络(CMAC)控制液压驱动系统,并对机械手运动轨迹响应速度和误差进行仿真.建立液压驱动机械手简图装置,给出机械手液压驱动控制流程图.创建了液压动力装置、控制阀、液压油缸及机械手键合图模型,推导出液压驱动机械手控制方程式.设计了机械手液压驱动CMAC-PID控制结构图,利用系统仿真软件Matlab对机械手运动轨迹进行仿真;同时,与常规PID控制仿真结果进行比较.结果表明:采用常规PID控制液压驱动机械手运动轨迹,响应时间大约为0.4s,产生的最大误差大约为1.4cm;采用CMAC-PID控制液压驱动机械手运动轨迹,响应时间大约为0.1s,产生的最大误差大约为0.75cm.采用CMAC-PID控制平面机械手液压驱动系统,能够提高机械手运动轨迹响应速度和跟踪精度.     

绳驱动式四指机械手的虚拟设计

根据功能需求的变化,从仿生学角度出发,设计一种绳驱动式四指机械手,该机械手共有十三个自由度,通过电机驱动及绳索传动来控制机械手的十三个自由度。该机械手通过耦合连接方式实现远指节的弯曲。详细介绍机械手的组成情况及工作原理,应用三维软件设计机械手的三维实体模型,并对三维模型进行虚拟装配及运动仿真分析,该机械手的研究可为绳驱动式多指机械手的实际应用提供一定的理论参考。     

基于欠驱动机构的水下作业机械手仿真研究

建立了机械手的三维模型,对机械手运动学和动力学性能进行了仿真研究,分析了运动部件之间的相对关系,完成了机械手抓取不同目标物时的运动学、动力学仿真;机械手采用液压驱动方式,驱动力大、结构简单;机械手有3个手指,采用4个驱动元件实现对机械手11个自由度的驱动,3个手指之间的相对位置可根据抓取目标物的形状而改变,抓取物体时具有形状自适应能力.     

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.