基于xPC技术的液压伺服系统模型辨识研究

利用xPC技术建立了阀控缸实时电液伺服控制系统。为了获得系统准确的数学模型,文章借助于xPC实时系统的半实物仿真环境和MATLAB系统辨识工具箱,对电液位置伺服系统进行了系统模型辨识实验研究。通过改变工况以及设计控制器进行辨识模型的数字仿真和半物理仿真,验证了该辨识模型的准确性。该研究对电液伺服系统建模及控制系统设计具有参考价值。     

基于半物理仿真技术的机电伺服系统模型辨识研究

系统模型是进行系统性能分析与设计的基础。为了获得准确的系统数学模型,文章借助于dSPACE实时系统的半物理仿真环境和MATLAB系统辨识工具箱,提出了一种适用于机电伺服系统的模型辨识方法,并以机器人关节伺服系统为对象进行了系统模型辨识实验研究,通过对比离线仿真和半物理仿真结果验证了该方法的有效性。该研究对机电系统建模及控制系统设计具有参考价值。     

网络协同工艺设计系统研究与实现

针对网络协同工艺设计的特点,结合自主开发的网络化制造平台eCWS,提出了一个基于多Agent的网络协同工艺设计系统架构.根据协同工艺设计的需要,对协作企业共享资源进行分类,并建立了资源对象模型,该模型可根据不同的协同过程进行重组和扩展.研究了支持协同工艺设计的分层决策机制和数据管理模型,开发了协同工艺设计系统e-CAPP.实例表明,该系统能使异地协作人员通过网络协同对产品工艺进行设计、分析与优化.     

基于Multi-Agent分层协作的数据采集系统

为解决数据采集系统协议解析并发度不高、多接口设计、软件灵活性不佳等问题,将Multi-Agent技术应用到数据采集系统的设计实现中。在对软件业务需求以及Multi-Agent通信协作技术进行研究的基础上,提出了基于Multi-Agent分层协作的软件框架;按照该模型设计并实现了数据采集系统。最后,在该系统上进行了运行试验。运行结果表明,该模型的设计原理与思想正确,提升了数据采集系统的业务处理能力和灵活性。     

基于LabVIEW的气动力伺服系统模型辨识与实验

气动力伺服系统能够对输出力大小进行准确控制,可应用于机器人自动打磨抛光中,提高工件表面修形质量。目前该系统本身难以建立准确的数学模型,然而模型对力控算法设计与改进具有很大的帮助。首先分析了系统机理建模过程,然后对搭建的一套气动力伺服系统平台采用系统辨识的方法获取该系统的最佳数学模型:设计了基于Lab VIEW的系统实时在线辨识平台,采用最小递归二乘法作为辨识算法对搭建的平台系统进行了模型辨识,最后对该模型进行了实验验证,结果表明辨识所得模型能很好地表征该系统的特性,为气动力伺服系统的输出力控制算法设计研究奠定基础。     

基于虚拟样机的刚柔耦合系统的设计研究

对刚柔耦合系统的设计提供了一种基于虚拟样机的方法。ANSYS中建立柔性体模型，再导入到ADAMS中进行设计研究，进行动态特性分析和设计研究。该方法把ADAMS中的刚体模型传到ANSYS，并在使用该方法可以直观、迅速、简单地对刚柔耦合系统     

机械产品经验、教训重用研究

为了将企业资源更好地应用于机械产品创新设计平台,在对设计实践和设计重用分析的基础上,对经验教训重用系统建模、设计经验重用过程模型流程进行了研究,提出了由设计支持库和设计重用于系统构成的设计经验重用模型,并给出了相应的模型流程。该研究为机械产品创新设计平台的建立与完善奠定了坚实的基础,为制造业设计人员更充分、合理地利用企业资源提供了理论依据。     

基于模板的减速机参数化设计系统

介绍了一种SolidWorks二次开发的减速机三维设计系统,该系统结合模板思想对不同类型的减速机分别进行参数化设计,利用VB语言对减速机关键零部件的设计计算过程进行编程计算,得到模型驱动参数驱动模板模型,该系统将减速机的设计计算、模型驱动、出图集于一体,有效地提高了设计效率,保证了产品的质量,降低了劳动强度。     

电液主动悬架控制系统设计与仿真

对一个电液主动悬架装置进行了研究.首先对该装置进行了分析并建立了该主动悬架系统的动力学模型,然后以装配该悬架装置的1/2车辆模型为控制对象,设计了一个力追踪控制系统.最后,采用MATLAB/SIMULINK对该控制系统进行仿真,结果表明,所设计的控制系统能够保证悬架具有良好的控制效果.     

某型增压柴油机排气系统的仿真研究

排气系统设计是否合理对柴油机的性能有着重要影响,为了探求某型增压柴油机采用不同排气系统的优越性,本文以内燃机性能仿真软件GT-Power为平台,建立了工作过程仿真模型,利用试验数据验证了模型的可靠性。柴油机采用脉冲增压系统,针对定压增压系统和MPC增压系统对原机的排气系统进行了重新设计,建立了定压增压系统和MPC增压系统的柴油机模型,并分别对其进行了稳态工作过程计算,着重分析研究了采用不同排气系统对该柴油机性能的影响,为该柴油机排气系统的改进提供了参考依据。     

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.     

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....     

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。     

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.