4-UPS-CPC并联机构运动学分析

并联机构的运动学分析是并联机构研究的重要对象之一,是进行优化分析的重要依据。目前,国内外许多知名学者通过理论求解和软件仿真分析对并联机构进行了多方面的研究。以4-UPS-CPC并联机构为研究对象,建立机构模型和数学模型,进行了位置、速度及加速度分析,建立了机构输入输出的速度、加速度映射方程。在建立机构运动学模型基础上,用数学编程软件Matlab对机构进行了运动学数值仿真分析;基于动力学仿真软件Recur Dyn,实现了4-UPS-CPC并联机构的运动学仿真分析;利用Recur Dyn仿真结果对理论数值仿真的正解、逆解进行了验证。研究结果表明了运动学理论求解的正确性和仿真验证的可行性。     

夹钳机构的优化设计

在Pro/E环境下对初步设计的夹钳机构进行建模、装配及运动学仿真分析,发现模型运动学特性较差。为改善机构的运动学特性,将模型通过M echan ism/Pro接口程序导入ADAMS中进行优化设计,得到了改进机构运动特性的方法。在Pro/E下改进机构模型并再次进行运动学仿真,验证了改进结果的合理性。最后,通过平面几何知识对改进方法的合理性进行了证明。仿真结果表明,利用Pro/E和ADAMS联合仿真的方法可以为机械系统结构的优化设计提供一条有效途径。     

3-(P-)RS并联机构主轴的运动学研究与仿真

建立了3-PRS并联机构主轴的结构模型，通过运动学分析导出其运动学模型，并讨论了运用OpenGL图形库对主轴进行几何建模和运动学仿真。     

空间弱撞击对接机构对接过程运动学分析

以空间弱撞击对接机构（LIDS ）对接过程为研究对象,通过运用Pro/ENGINEER软件建立机构的三维模型,采用矢量方法建立运动学模型,对其位置和姿态进行了分析。运用Newton -Raphson迭代法对空间弱撞击对接机构进行了位置正解分析,表明该方法可以迅速求解。以对接机构的三维模型和运动学模型为基础,通过MATLAB和ADAMS软件进行联合仿真分析,得到了满足设计要求的运动轨迹曲线,从而验证了运动学模型。对弱撞击对接机构进行了动力学仿真,得到了机构传力构件的最大受力情况。     

ADAMS在并联机构运动学分析中的应用

针对并联机构的运动学分析计算,以3-UPS/UP型并联机构为例,介绍了应用动力学仿真分析软件ADAMS对其进行运动学仿真的方法与步骤。采用三维CAD软件Inventor建立了几何模型,以Parasolid格式导入ADAMS环境,对几何模型施加约束与激励,建立了并联机构的虚拟样机模型。并对模型进行了逆向与正向运动学仿真,快速准确地求得了并联机构的运动学反解与正解,大大简化了计算过程,为并联机构的运动学分析及机构设计提供了借鉴。     

基于ADAMS对下摆式递纸机构的动力学研究

对现有平版印刷机的下摆式递纸机构进行动力学研究并进行了重新设计.通过三维软件建立了递纸机构仿真模型.利用动力学分析软件ADAMS的测量输出和仿真分析功能,对它进行了运动学分析和仿真,并与原平版印刷机的递纸机构进行比较.仿真结果表明重新设计的递纸机构运行平稳,冲击力更小,符合设计要求.     

3-■RS并联机构主轴的运动学研究与仿真

建立了3-■RS并联机构主轴的结构模型,通过运动学分析导出其运动学模型,并讨论了运用OpenGL图形库对主轴进行几何建模和运动学仿真。     

基于Pro/e的送瓶机构的改进与运动仿真

介绍和分析了一种新的洗瓶机的送瓶机构,同时利用Pro/e对机构进行了建模和运动学仿真,通过对仿真结果的分析,提高了机构设计的准确性,为洗瓶机传动系统的优化设计提供了研究基础.     

基于ADAMS的一种新型六自由度并联机构的参数分析与仿真

通过ADAMS虚拟样机的试验和测试,可以在研究机构性能的同时发现设计中存在的问题并提出改进方法.为了充分阐述3-PRPS并联机构的运动学本质特性,利用线几何的有效方法对机构模型运动学进行了分析,求解了逆运动学关系,并应用ADAMS软件进行运动学仿真分析.其中通过定义已经建立的实体模型参数变量,合理规划选取动平台的运动轨...     

一自由度腿式行走机构的研究与设计

设计了一种一自由度腿式行走机构,机构由平面四杆机构和放大机构组成。首先基于契贝谢夫平面四杆机构特点,利用解析法,建立相应数学模型,得出运动学方程。其次利用Adams对行走轨迹进行仿真分析,讨论了连杆长度对运动轨迹的影响,并进行了运动学仿真研究。最后,通过系统仿真和搭建原型,验证了方案的正确性及机构设计的合理性。该机构的设计为开发新型的低功耗、低成本、易控制的腿式机器人提供设计了依据,实用可行。     

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...     

Quantum Cooperative Robotics and Autonomy

The intersection of Quantum Technologies and Robotics Autonomy is explored in the present paper.The two areas are brought together in establishing an interdisci...     

考虑进油孔有限长滑动轴承油膜力的近似解析解

针对具有进油孔的有限长滑动轴承油膜力求解问题,采用变分原理和分离变量法,求得了有限长滑动轴承油膜压力分布的近似解析表达式。将油膜压力分布的近似解析表达式在油膜存在区域上进行积分,即得到了油膜力。将提出的计算有限长滑动轴承油膜力方法与无限长轴承模型、有限元方法的计算结果进行了比较,发现了提出的方法与有限元方法的计算结果很接近。最后,研究了进油孔位置和进油压力对油膜存在区域、油膜力等的影响,研究结果表明进油孔位置和进油压力对油膜存在区域和油膜力有较大的影响。     

三绕组变压器的双绕组等效建模及在Matpower中的应用

针对实际电网存在着大量的三绕组变压器,但国际上一些著名商业软件,如BPA仿真软件、Matpower这一权威潮流计算开源软件,均只提供双绕组变压器模型,限制了其在具有三绕组变压器的电力系统中的应用的问题,潮流计算是自主开发的电力系统各种应用软件的核心模块,因此依托国际权威开源程序进行二次开发,是一种较好的选择。对Matpower要求的数据格式进行了归纳,对变压器的一般的等值电路及带理想变压器的等值电路和带标幺值的等值电路进行了分析研究,提出了三绕组变压器转换为双绕组等效模型的建模方法,使得原先只适应双绕组变压器的潮流计算软件可以适用于三绕组变压器电网的潮流计算;最后以Matpower软件为例进行了案例计算,并用PSASP仿真软件进行对比验证。研究结果证明,所提出的建模方法是有效的。     

On the Relation of Load to Average Gap in the Contact Between Surfaces with Longitudinal Roughness

A computer simulation model for the contact between longitudinally-oriented rough surfaces has been formulated. This model closely duplicates the actual surf ace contact deformation behavior by taking into account the elastic interactions between the asperities. There were no assumptions made about the shapes, or any deformation behavior of the asperities, except for their obeying the laws of elasticity. The plastic deformations on the high asperity peaks were taken into account by setting a ceiling on their contact pressures at the material hardness value. The simulations used real surface profiles which were digitized from unworn circumferentially ground steel surfaces. Each pair of these profiles was mathematically combined to form an equivalent rough profile pressing against an infinitely rigid flat and having the appropriately adjusted elastic modulus. A total of 28 different pairs of profiles were used in the simulations. Each contacting pair was subjected to 30 different load levels and the local contact pressures and deformations were calculated. The contact simulations yielded some important mathematical relationships between parameters, such as the real area of contact, average gap, and average asperity load through statistical curve fitting. Two analytical functions were generated to relate the average load to average gap and the real area of contact to load.     

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.     

电站锅炉模糊风险评价方法研究与应用

针对电站锅炉风险等级评价问题,将模糊综合评价技术应用到电站锅炉风险等级评价中。开展了电站锅炉失效影响因素及模糊评价因素的重要程度分析,建立了一套科学合理适于在线评价的电站锅炉风险评价体系,提出了模糊综合评价技术与改进的模糊层次分析法相结合的模糊风险评价方法,利用改进的模糊层次分析法计算了指标体系中各层指标权重。对某一台电站锅炉的实际运行工况影响子因素进行了模糊风险评价,采用模糊合成算子进行模糊综合运算得到电了站锅炉运行工况影响子因素的评价向量。研究结果表明:电站锅炉的运行工况影响子因素的风险评价等级为第6级,失效可能性等级为小,该电站锅炉运行工况良好。     

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.     

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....