支持模型驱动开发的飞控系统数字样机设计

针对飞控系统设计面临的各种问题,研究了一种基于图形化建模语言、支持模型驱动开发的飞控系统数字样机设计技术。基于Rhapsody,STATEMATE,Simulink等搭建了用于飞控系统数字样机设计的支撑平台,研究了基于支撑平台的飞控系统数字样机设计流程及数字样机的四个不同侧面;以一小型无人机飞控系统为例,详细介绍了其数字样机设计,并进行了两个层次的检查和仿真验证。设计实践表明该方法能有效缩短设计时间,提高设计质量,支持后期软件的模型驱动开发,适用于各类飞行器控制系统数字样机的设计。     

Web的多学科协同设计与仿真平台及其关键技术

虚拟样机多学科协同设计与仿真平台是虚拟样机支撑环境的重要组成部分，在航空、航天、造船、汽车等复杂产品虚拟样机开发中有着广泛的应用。通过对虚拟样机开发环境中多领域建模与仿真技术的需求分析，研究了协同设计与仿真平台的系统构成、关键技术和实现方案，支持跨平台和网络环境下对各设计与仿真工具之间的数据共享和各类工具的应用集成，并开发了基于Web的原型系统。通过初步应用实践，表明该系统能有效地支持复杂产品虚拟样机的协同开发。     

复杂产品虚拟样机元建模

为了有效地支持复杂产品虚拟样机的信息交换、共享、模型重用,以提高产品质量和效率,基于元建模理论,建立了复杂产品虚拟样机,设计了元模型。分析设计了元模型与学科元模型的映射关系,并实现了二者的转换,实例化得到虚拟样机运动仿真模型和优化模型。以某车辆自动变速器统一建模为例,说明了元建模在复杂产品建模中的应用,验证了统一集成建模的正确性、有效性与实用性。     

仿真网格中协同建模网格服务研究及实现

为了将建模/仿真/项目管理技术协同,集成地应用于复杂系统虚拟样机的全生命周期,给出了仿真网格原型系统体系结构.介绍了六类典型协同建模网格服务及其应用门户的实现方案及应用方式,实现了协同建模环境中计算资源、模型资源、数据资源的共享,以及多媒体研讨厅环境和二维/三维可视化功能的网格化集成,以此支持基于广域网的复杂产品虚拟样机协同设计过程.该原型系统已在有关项目中得到应用验证.     

面向锅炉虚拟样机的研发环境集成研究与实现

针对锅炉产品设计从传统二维设计到基于三维模型的锅炉虚拟样机设计转变所面临的问题,研究了锅炉虚拟样机设计流程与涉及的资源,提出了锅炉虚拟样机研发环境集成的整体解决方案,实现了Auto CAD、PDMS与PDAE(含ANSy S、Nastran)等系统的集成,并对后续研究工作进行了展望。     

一种新型串列式双旋翼飞行器

提出了一种新型串列式双旋翼飞行器。该飞行器采用上下串列螺旋桨设计,其中的一个螺旋桨固定,而另外一个螺旋桨可以摆动,以调整飞行器飞行姿态,达到控制飞行器飞行及保证稳定的目的。分析了国际上类似飞行器的发展概况及其特点,介绍了串列式双旋翼飞行器的机械结构设计方案。对飞行器的姿态控制问题进行了相应的理论分析,建立了动力学模型,并针对模型的特点改写了开源飞控APM。通过对控制系统及实际机械结构的试验,验证了方案的可行性。     

基于虚拟样机技术的混凝土泵车臂架的仿真研究

建立了混凝土泵车臂架系统的虚拟样机模型,建模过程中实现了Pro/E-ADAMS-ANSYS的仿真环境相互集成,利用软件的各自优势完成了虚拟样机的动力学特性分析,仿真结果验证了初始设计的可行性,确立了在物理样机设计中的关键设计参数,为进一步的泵车臂架系统的优化设计和轻量化设计提供了依据.     

虚拟样机多学科协同设计与仿真平台实现技术

在分析产品协同开发平台的功能框架以及主要协同模式的基础上，深入研究了虚拟样机多学科协同设计与仿真平台的分布式计算模型，及其协同运行管理、协同产品开发资源库管理、分布数据的协同交互管理与系统实现技术。基于COM／DCOM的建模与仿真工具协同、支持仿真联邦管理的数据库设计和CORBA的应用实现技术，开发了原型系统。该系统支持Internet网络环境下各种建模与仿真工具跨平台、分布交互与异构集成，可有效支持复杂产品虚拟样机的协同开发。     

超小型无人旋翼飞行器减振增稳云台的设计

旋翼飞行器在飞行过程中,由主旋翼、尾翼、发动机等产生的振动,将对整个飞控系统的控制产生很不利的影响,容易使传感器产生错误信号.设计了一种橡胶隔振器,能有效隔离飞行器传递到飞控盒的振动,使飞行器的控制更稳定.此外旋翼飞行器在飞行过程中的不平稳,将对摄像机拍摄画面的稳定性造成很大影响,为此设计了增稳云台.     

铁路机车车辆虚拟样机数据协调关键技术研究

铁路机车车辆虚拟机机系统为产品设计和生产过程的优化提供了集成的建模和仿真环境。该系统的关键环节在于实现分析数据的协调与集成。为支持开发环境中不同领域、分布、异构的仿真系统间的数据共享，提高仿真平台的可扩展性和灵活性，按数据产生的先后，提出了产品模型数据的分层框架，并研究了每一数据层中关键问题的解决方法。初步实践表明，基于上述研究的虚拟样机系统能有效地支持铁路机车车辆产品的开发。     

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.