基于BPMN的数控机床能耗多源动态特性建模及应用

针对数控机床能量源多、能量消耗动态变化复杂的特点,提出了一种基于业务流程模型和符号(Business process model and notation,BPMN)的数控机床多源动态能耗建模方法。依据数控机床不同子系统的功率特性,将其划分为时变能耗单元和非时变能耗单元,分析了其工作状态及耦合关系对数控机床能耗的影响;基于BPMN2.0规范,构建了能耗单元工作状态BPMN流程模型和BPMN耦合模型,提出了能耗单元工作状态能耗数据及耦合关系时序数据与BPMN模型的数据集成方法,构建了数控机床能耗多源动态特性模型。以某数控铣床加工过程为例验证了所述模型及方法的有效性。     

机床多源能耗状态在线检测方法及检测系统

针对目前缺少多功能且实用有效的机床多源能耗状态在线检测方法的问题,分析了机床多源能耗状态的构成,提出了在线检测指标体系;研究了机床多源能耗状态信息在线检测方法,包括机床多源能耗分组方法和关键能耗参数指标获取方法;研发了相应的检测系统。该系统能在线检测和监测机床与工件加工全过程的输入能量、有效能量、瞬态效率、能量利用率以及能量比能效率、设备有效利用率等信息;通过在数控机床PL700上进行的大量实验,验证了上述方法及检测系统的有效性,表明其可广泛运用于机械加工过程能量消耗与能量效率的状态信息分析、管理控制和节能优化研究中。     

数控机床多源能耗模型及其应用

数控机床能耗部件数量多,能耗类型涵盖机电液领域,因此对其建立能耗模型比较困难.针对数控机床难以建模的问题,建立了一个数控机床能耗集成模型.该模型先将其能耗分为负载无关和负载相关两个能耗部分.其中负载无关的部分能耗采用开关函数和常量函数描述,负载相关的能耗部分用功率平衡方程描述.该模型既包含了机床状态又包含了机床实时负载,将定性的能耗描述转化为能耗的定量计算,为预测和实时监测机床能耗提供了依据.最后用该模型对一台数控车床的能耗状况进行了预测实验,结果表明该模型是有效的.     

[绿色制造工艺和系统]面向节能高效需求的数控加工系统多目标优化模型

针对数控加工系统复杂的多源动态能耗特性,提出了一种基于单元工作状态的能耗建模与优化方法。首先,对数控加工系统能耗单元及其工作状态的能耗特性进行分析,建立了时变能耗单元和非时变能耗单元的工作状态能耗模型;其次,构建以切削速度和进给量为变量,以最小系统能耗和最短加工时间为目标的数控加工系统节能高效多目标优化模型,提出一种基于小生境遗传算法的模型求解方法;最后,通过某机床中心架底座加工案例对所提方法和模型进行了验证,并对优化结果、算法性能进行了对比分析,说明了上述模型和方法的有效性。     

面向节能高效需求的数控加工系统多目标优化模型

针对数控加工系统复杂的多源动态能耗特性,提出了一种基于单元工作状态的能耗建模与优化方法。首先,对数控加工系统能耗单元及其工作状态的能耗特性进行分析,建立了时变能耗单元和非时变能耗单元的工作状态能耗模型;其次,构建以切削速度和进给量为变量,以最小系统能耗和最短加工时间为目标的数控加工系统节能高效多目标优化模型,提出一种基于小生境遗传算法的模型求解方法;最后,通过某机床中心架底座加工案例对所提方法和模型进行了验证,并对优化结果、算法性能进行了对比分析,说明了上述模型和方法的有效性。     

基于BPMN2.0的数控机床主传动系统动态能耗建模

选取数控机床的主要耗能子系统即主传动系统进行研究,针对其加工过程中能量消耗动态变化且难以规范化描述的特点,通过主传动系统能量消耗动态性的分析,提出了一种基于业务流程建模规范BPMN2. 0的数控机床主传动系统动态能耗建模方法。该方法利用BPMN2. 0的符号和语义对主传动系统不同能耗单元的执行流程、配合关系进行描述,并利用数据关联集成建立的业务流程建模规范(BPMN)能耗模型,实现了制造过程中数控机床主传动系统能耗动态性的图形化表达与能耗计算。最后,以某数控铣床加工过程为例,对所述模型及方法进行了应用,验证了其有效性与准确性。     

智能数控提高机床能效的研究

为了研究数控机床的能耗问题,设计了机床能耗的整体测试方案,对数控机床能耗进行分析,确定机床各个相关部件的能耗情况,采用Matlab工具建立机床能耗仿真模型。在加工循环中,测量机床运行总能耗,根据加工循环及相关参数,利用能耗仿真模型对机床能耗进行仿真,将仿真结果和实际测量能耗进行了对比,验证了模型的准确性。研究了在数控系统中集成能耗的监视及预测等功能,并给出了基于能耗的智能化数控系统的架构,该架构为进一步研究提高智能数控机床能效提供了依据。     

一种数控切削机床运行能耗状态在线判别方法

机床运行能耗状态由一系列的能耗状态节点和能耗过程构成。针对至今仍存在一些关键状态节点无法判别等问题,提出了一种数控机床运行能耗状态在线判别方法。该方法基于数控机床运行能耗状态和状态节点的系统分析,并综合机床功率信息和数控系统通信信息,提出关键节点状态与过程状态在线判别方法,解决了切削加工开始、完成等关键节点和精加工状态判别等难题,从而实现了数控机床全部运行能耗状态的在线判别。在FANUC数控机床上进行的案例研究验证了该方法的有效性和实用性。     

机床动力学建模的拓展传递矩阵法

针对现代高性能数控机床动力学建模与优化问题,提出一种适合机床动态分析的拓展传递矩阵法,该方法将机械系统划分为刚体、柔体和结合面三类元件,并以矩阵的形式给出元件数学模型.而整机的动力学模型则是由这三类元件组成的复杂网络,应用状态矢量传递思想对元件网络进行整合,最终得到用一个高维矩阵表示的整机模型,求解该高维矩阵能够方便地得到整机的动态特性.最后应用该建模方法对数控机床中一种直线电动机驱动进给功能部件进行动力学建模与分析,给出该功能部件频响函数的仿真与试验对比,并作了相应的分析.分析表明该方法对于数控机床整机的建模、动态特性分析具有很好的建模精度.该方法简化机床动力学的建模过程,更适合于工程应用.     

数控机床能耗建模与测试技术研究进展

数控机床作为制造业重要的"工作母机",节能降耗潜力巨大。针对数控机床的能量特性,国内外学者开展了大量的研究工作以提高机床能量利用率,降低机床能量损耗。综述了数控机床能耗的影响因素、能耗分析建模技术以及能耗测试方法等方面的研究现状,并就这一方向的深入研究工作做了展望。     

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.