电力铁塔攀爬机器人工作空间的3种求解方法

在对现有的机器人工作空间求解方法分析总结的基础上,分别采用蒙特卡洛法、定步距角法及仿真法求解电力铁塔攀爬机器人工作空间,并从图形效果、分析方法、用时及适用场合4个方面对其进行了比较,选择定步距角法为求解攀爬机器人工作空间的最优方法。通过对工作空间降维提取二维边界曲线并生成三维曲面的方法分析机器人工作空间边界,采用数值法求解了工作空间体积,为机器人结构优化设计、路径规划及运动控制提供了理论依据。     

6-DOF工业机器人逆解优化及其工作空间的研究

为实现6-DOF工业机器人的精确控制,对其运动学逆解进行了分析以及工作空间予以仿真研究。据D-H法建立机器人运动学模型,得出正逆解,并提出了基于最短行程原则的运动学逆解优化方法,确保机器人系统取得合适的逆解。最后基于Matlab的数值解法对工业机器人的工作空间进行求解并进行了仿真,结果切实有效。     

基于三种方法的油罐清洗机器人工作空间分析

根据油罐清洗机器人的结构特点和各种工作空间求解方法的优缺点,分别采用图解法、蒙特卡洛法和仿真法求解了油罐清洗机器人的工作空间,并从不同角度对3种方法进行了分析比较。结果表明:不同的方法在求解机器人工作空间时适用情况不同,得到的结果也存在误差,在此基础上筛选了不同情况下求解油罐清洗机器人工作空间的优先方法。工作空间的求解为机器人结构优化设计、避障及运动控制提供了理论依据。     

基于蒙特卡洛法的混凝土布料机器人工作空间分析

以天津市智能制造科技重大专项(15 ZXZNGX00260)——混凝土智能布料机器人系统研发项目为背景,分析了混凝土智能布料机器人的工作空间。采用D-H参数法建立混凝土智能布料机器人的运动学模型;基于蒙特卡洛法,并利用Matlab软件编程,进行了该机器人工作空间的分析与仿真。仿真与分析结果为该机器人机械结构优化、工作站搭建及路径规划奠定了基础。     

2自由度手臂康复机器人运动学及动力学分析

针对上肢康复训练需求,设计一种采用二连杆串联结构的2自由度手臂康复机器人。基于D-H法对机器人的正、逆运动学进行理论分析,采用Matlab/Simulink和SimMechanics工具箱分别搭建机器人的正逆运动学理论模型与机构模型进行仿真对比,分析结果验证了机器人运动学建模的正确性。结合人体工程学相关标准和手臂关节运动范围要求,建立机器人与手臂机构的联合仿真模型,确定机器人的工作空间;并完成机器人进行画圆训练的轨迹规划,为机器人运动控制奠定了基础。基于联立约束法建立机器人的动力学模型,确定了机器人各关节驱动力矩大小,为驱动电机选取和控制器参数选择提供了依据。     

基于matlab的六自由度机器人运动特性分析

应用Denavit-Hartenberg法建立6R机器人的关节坐标系并确定杆件参数,建立机器人的正逆运动学模型,在Matlab环境下利用Monte Carlo法计算出机器人的工作空间,并用Robotics Toolbox对机器人正逆运动学进行仿真,并对工作空间及关节空间的运动轨迹进行规划,从而验证机器人结构设计的合理性。为动力学分析、离线编程、基于力反馈机器人动态控制以及机器人结构的动态设计的研究奠定必要的基础。     

机器人工作空间求解方法研究及应用

针对机器人工作空间的求解问题,在现有研究方法基础上,将蒙特卡洛法的优点和Matlab的仿真建模功能相结合,提出了一种新的求解工作空间的方法;以Staubli TX60L六轴串联机器人为例,分别用数值法、几何绘图法和本文提出的方法求解出工作空间,进行对比分析,结果证明,此方法不仅不需要考虑复杂的运动学方程,且准确度高、运算速度快。     

2P3R型机床上下料机器人工作空间分析

针对自主创新设计的2P3R型机床上下料机器人,给出了该机器人运动学方程的完整推导过程;采用蒙特卡洛法与碰撞检测算法相结合的方法,对该机器人工作空间进行仿真分析,得到基座与杆件及末端无碰撞点云图;同时提出图解法与数值仿真验证相结合的方法确定并验证了工作空间剖截面边界。该方法利用了数值仿真分析使用简单、适用于各种结构机器人的优点和图解法能够确定准确工作空间边界的特点。结果表明:提出的方法可以有效获取机器人无碰撞工作空间及确切边界。     

压力容器检测机器人的灵活性分析

针对某一种密闭压力容器检测机器人工作空间灵活性的问题,首先运用D-H法对该机器人进行建模,利用Monte Carlo法对机器人的工作空间进行Matlab仿真;然后借用服务球的概念建立了机器人工作空间任意点的灵活度的计算方法,利用灵活度的概念对机器人工作空间内给定点的灵活度进行了求解,对机器人给定工作空间截面上的灵活度分布进行了仿真与分析;最后研究了关节尺寸对机器人工作空间中给定点灵活度的影响。结果表明,机器人在工作空间满足任务需求的前提下,关节尺寸越小,灵活性越好。此研究为关节型机器人的尺寸优化、路径优化、灵活性分析提供了参考。     

多机械臂协作空间分析与仿真

针对多机械臂协作系统模型的协作空间及奇异点问题,采用蒙特卡罗法和包络法进行分析。采用标准D-H参数法建立坐标系,在Matlab中建立机器人运动学模型,求出机器人的正运动学方程;采用蒙特卡罗法得到各机械臂的工作空间,采用包络法提取公共区域点,得到多机器人协作系统的协作空间及各个机械臂在协作空间内的关节角范围;提出了一种计算可操作度的算法,根据该算法计算分析了多机械臂在协作空间内的奇异点分布情况。采用Matlab/Robotics工具箱搭建仿真平台,并编写算法进行仿真分析,验证了多机器人协作系统运动学模型的正确性和合理性,证明了所提出的算法的可行性;为后续的协调操作和规避奇异点的轨迹规划奠定基础。     

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.     

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.