Delta机器人期望工作空间求解算法研究

针对并联机器人工作空间存在一些病态的不连续空间,提出来了一种Delta机器人期望工作空间的求解算法。首先,由Delta机器人运动学出发,给出了机器人实际工作空间的表达式,并将工作空间分成上下界进行求解;然后,通过将给定形状的规则期望工作空间的上下界与机器人实际工作空间的上下界进行比较,从而得到期望工作空间;最后,在Matlab软件上对算法进行了验证。所提出的算法可适合于不同形状期望工作空间的求解,并且较几何分析法更简便、更易于编程实现。     

基于运动学正解的Delta机器人工作空间分析

基于并联机器人机构学理论,对Delta机器人机构进行位置分析,建立Delta机器人运动学逆解模型,并通过几何法求得Delta机器人运动学正解。在运动学正解的基础上,分析了Delta机器人的工作空间,并利用MATLAB的计算与绘图功能,画出Delta机器人的工作空间,为Delta机器人的应用提供了重要参考依据。     

一种Delta机器人定位技术

相较旋转型Delta机器人,直线型Delta机器人具有更高的控制精度和更大的工作空间,是机器人应用的典型代表。定位技术是机器人应用的基础,但当前对直线型Delta机器人定位技术的研究较少,且方法复杂。针对上述问题,提出一种Delta机器人定位技术。该方法在矢量分析运动学的基础上,将结构关系转换成数值关系,建立了伺服电机进给量与动平台空间位置之间的联系。通过对约束条件的限定,有效地解决了逆运动学多解问题。因简洁的数学分析及逆运动学多解问题的有效解决,所以更利于结构化编程。实验结果证明了该方法的可行性与准确性。与传统方法相比,该方法省去了复杂的坐标系变换及矩阵运算,因而适用于工程应用。     

基于遗传算法3-RCR并联机器人的结构参数优化设计

确定机器人机构结构参数是并联机构优化设计的难题,因为并联机器人的机构结构参数优化属于多维,多目标和多约束条件优化问题。基于3-RCR并联机构的工作空间体积,分析了机构结构参数对工作空间体积的影响。运用坐标变换法对机构的位置反解进行求解;利用极坐标边界搜索法通过具体算例确定了机构的工作空间及其边界,以工作空间为目标利用遗传算法对机构进行了结构参数优化,获得了性能优良的结构参数,运用MATLAB软件编程得到了该并联机构的工作空间图谱。为该类并联机构的进一步研究和推广应用奠定了基础。     

关节型工业机器人工作空间及结构尺寸参数的一种确定方法

提出了一种适用于工程设计的确定关节型工业机器人工作空间及结构尺寸参数的简易而又实用的方法。根据机器人工作空间主视图边界曲线上特定的三点座标值，利用数值计算方法就可以确定机器人的结构尺寸参数（大小臂长度Ｌ１和Ｌ２的值，及其旋转角θ１和θ２的极限值），再根据这些结构尺寸参数确定机器人的工作空间。另外依此编制了相应的软件Ｒｏｂｓｐａｃｅ，只要输入三点的座标值及机器人机座的高度和机座旋转角度，便能确定机器人结构尺寸参数及其工作空间，并能显示、打印结构尺寸参数结果及工作空间边界曲线。     

平面冗余与非冗余并联机器人工作空间图谱的比较研究

并联机器人的结构参数决定其工作空间的特性。本文对并联机器人的杆件尺寸参数采用无量纲处理方法,建立了平面冗余与非冗余并联机器人的结构参数与工作空间形状的函数关系,绘制了两者基于无量纲参数的工作空间图谱,比较了两类工作空间的特点与优缺点,为并联机器人的机构设计提供了系统的参考依据。     

基于运动学的Delta机器人优化设计

机器人雅克比矩阵最小奇异值与条件数是其工作性能的重要评价指标。因此,针对研发的Delta机器人进行运动学分析,根据Delta机器人雅克比矩阵奇异值随尺度参数的变化规律曲线,确定一组最优设计尺度参数。同时对该Delta机器人进行全域条件数分析,得到Delta机器人操作性能在全域的变化规律,根据这一变化规律能有效地提高Delta机器人的工作性能。通过上述分析能够很好地对Delta机器人进行优化设计。     

平面三自由度并联机器人理论工作空间与机构尺寸关系研究

以一种平面三自由度并联机器人机构为研究对象,对其机构尺寸进行量纲一划,给出反映机构尺寸参数变化范围的设计空间,求得其封闭运动学反解。利用运动学反解存在条件和设计空间,计算该机器人机构理论工作空间并绘制理论工作空间性能图谱,建立了机构理论工作空间与机构运动学尺寸之间的一一对应关系。总结该机器人理论工作空间性能指标在设计空间内的分布规律,给出了理论工作空间较大的机构尺寸范围。这些图谱是该机器人机构优化设计的重要参考依据。     

Delta机器人分拣平台的机构尺度综合与分析

Delta机器人以其刚度大、精度高、速度快等优点在轻载分拣领域有着庞大的市场需求,其尺度综合是产品设计的重要环节.针对3自由度Delta机器人基于矢量法,建立了单支链运动约束方程,进而推导出其逆解、雅可比矩阵及可达工作空间边界的解析方程.为满足实验平台作业现场的分拣需求,以设计工作区域与可达工作空间边界的距离权值最小为...     

一种关节型串联机器人工作空间边界提取的新方法

利用杆件极限组合原理,结合定步距角法可固定关节变量的特点,提出一种提取工作空间边界的新方法--“极限定步距角法”,阐明思路并给出其具体实施步骤。以某型ABB机器人为例,利用D-H法设定机器人连杆参数及关节变量,并建立机器人坐标系与D-H坐标系间的转换关系,获得机器人边界关键点位置,进而借助MATLAB软件绘制机器人手腕处三维透视工作空间,对比分析表明所获边界关键点精度完全满足商用机器人标准。所提出的方法简单有效、计算便捷、利于操作,对串联机器人工作空间的研究具有理论指导意义和实践应用价值。     

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.