基于DMC的机器人轨迹规划研究与实现

在分析6自由度机器人运动控制系统架构的基础上,提出基于DMC(digital motion controller)的开放式运动控制系统的6自由度机器人轨迹插补算法.主要研究在笛卡尔空间规划中直线的插补算法.同时介绍了插补算法在DMC上的具体实现方式.实验证明了控制器能可靠精确地实现机器人轨迹运动.     

工业机器人笛卡尔空间轨迹规划

研究了在笛卡尔坐标系中工业机器人空间直线及圆弧轨迹规划问题,提出利用抛物线过渡的空间直线插补算法和基于局部坐标系的空间圆弧插补算法。以上算法在自行设计的五自由度喷涂机器人上进行了实验验证。实验结果表明,该直线和圆弧插补算法能保证机器人运行平稳,轨迹衔接平滑。     

基于VC的逐点比较空间直线插补算法改进与仿真

针对传统逐点比较空间直线插补方法存在插补误差大、直线光滑性差等问题,提出了一种基于基础坐标概念的逐点比较空间直线插补算法。在三维空间划分为24个区域的基础上推导该算法的插补原理,得到了各区域的插补公式。基于VC++6.0软件进行了模拟仿真,该算法可以实现串联机床三轴联动、六轴并联机床六轴联动功能,进一步提高了数控系统的插补速度,有效地提高了逐点比较空间直线插补精度和刀具半径补偿精度。     

基于实时以太网的高速精插补算法及其实现

为提高数控机床的轮廓控制精度和加工速度,在基于实时以太网的运动控制平台上,提出了一种高速精插补算法。该算法采用在一个通讯周期中发送多个插补周期数据,然后在插补周期内部进行多次等时插补的机制实现。每个通讯周期内大量插补数据的传递由实时以太网保障。这种机制能够更充分地利用计算机强大的运算能力和底层可编程控制器的并行处理功能,可以实现微秒级时间尺度上的精插补周期控制。     

基于DSP的数控插补平台研究

介绍了一种基于DSP的数控插补平台。该平台由上位机以及基于DSP和FPGA的运动控制器组成。上位机进行G代码的解析处理,通过ISA接口传输给DSP,在DSP中完成多轴运动控制,包括插补预处理、多轴插补运算、伺服控制、数据采集和实时轮廓误差的计算等。插补算法中,采用前瞻控制和柔性的加减速控制,实现了多段直线或圆弧的连续插补控制。由于DSP运算速度快,插补周期可以达到1ms以内,因此,该平台可达到很高的插补精度。实验验证表明,该平台运行稳定,功能完备,同时具有较高的轮廓精度,适合各种插补算法的研究。     

智能协调n分步长抛物线插补算法的研究

提出基于时间分割法的智能协调n分步长抛和线插补算法,该算法根据抛物线特性采用了智能协调控制器在线选择插补过程中步长的n等分。文中对该插科精度和插科运算时间两方面与传统算法进行了比较分析。     

基于运动控制卡的PVC软标机控制系统

为了实现皮标自动化,以填补国内空白,设计了一种基于运动控制卡的PVC软标机控制系统方案。介绍了整个系统的硬件构成和软件设计流程,并详细阐述了直线插补算法。系统软件使用DDA直线插补算法控制伺服电机按预定轨迹运行,有效地提高了加工精度和效率。样机试验结果表明该控制系统达到了设计精度和速度的要求,实现了预期的各种功能。     

机器人的三种规则曲线插补算法

针对机器人末端执行器在笛卡尔空间中的轨迹规划方法,研究了空间直线、平面圆弧、空间圆弧等三种基本规则曲线的插补算法.此算法在理论上可使所有插补点均落在所要求的曲线上,算法精简且无累积误差.研究成果已在实际机器人中得到实现.     

基于NURBS曲线的工业机器人位置插补算法研究

针对直线圆弧插补在线计算量大,样条插补不能描绘自由曲线,提出了一种将NURbS算法应用于工业机器人控制系统的描绘自由曲线的实时高精度插补算法。该算法基于NURbS曲线矩阵表达式,利用插补前分段加减速控制的对称性反向插补预测减速点,整合了Taylor展开式和Adams方法预估曲线参数,通过加减速、弓高误差和法向加速度进行实时步长自适应控制,并由预估-校正进行精度控制。仿真与实验结果表明,该插补算法实时性好,精确度高。     

刀具插补算法的优化设计

逐点比较法以折线来逼近直线或圆弧,只要将脉冲当量(每走一步的距离)取得足够小,就可达到精度要求.基于逐点比较法原理,提出中点插补算法作为数控系统控制步进的偏差判别依据,建立插补算法的数学模型,对插补算法偏差判别函数进行改进和完善.实例分析结果表明,中点插补算法,使插补精度由原来的小于等于一个脉冲当量提高到小于等于0.5个脉冲当量,插补点大幅度下降,系统的响应速度加快和插补精度提高.     

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.