六自由度运动模拟器的动感模拟算法研究

为了模拟运动对人产生的影响，针对已建成的大型六自由度运动模拟器，建立了复现运动加速度的基本处理方法，研究了相应的动感模拟算法，并对一组真实的舰船运动数据进行了仿真和实验，验证了文中的算法，提高了系统的运动模拟能力。     

海浪扰动下电液3-UPS/S舰船并联稳定平台振动特性分析

针对电液驱动的舰船并联稳定平台在实际工况下的振动问题，以电液3-UPS/S舰船并联稳定平台为研究对象，在考虑铰链刚度的基础上应用虚功原理建立稳定平台的动力学模型；通过海浪谱函数，计算了随机海浪激励下船舶的运动响应，进而得到稳定平台跟踪舰船运动的响应规律；分析了稳定平台在随机海浪激励条件下和初始工作空间内的固有频率变化特性；最后，为验证动力学模型的正确性，采用脉冲激励法对稳定平台样机进行模态试验，固有频率理论值与试验值的最大误差为4.66%,可以验证动力学模型的正确性。     

飞行模拟器六自由度运动系统负载交联耦合的研究

以所研制的飞行模拟器液压六自由度运动系统试验样机为研究对象 ,通过建立运动系统的多通道数学模型 ,对并联六自由度运动系统的耦合特性作了定性分析 ,探讨了该类控制系统的特点和适用的控制策略 ,并在试验样机上作了实验研究 ,从理论和实践上对并联六自由度运动系统的负载交联耦合特性作了深入的研究。     

3UPS/S舰船稳定平台非惯性系动力学建模

舰船稳定平台实时检测并补偿船体在海浪中运动,为舰载设备提供对地稳定空间。稳定平台处于不断运动着的工作环境,准确高效的非惯性系动力学模型是提升稳定控制品质的重要前提。借鉴串并混联机构动力学建模过程,通过虚拟低阶参考系机构,将惯性系动力学研究方法扩展非惯性系当中,利用凯恩方法建立3UPS/S并联稳定平台非惯性系下动力学模型。为了验证建模方法的正确性,分别搭建Simulink/SimMechanics多体动力学仿真模型以及非惯性运动试验平台。试验结果表明,计算驱动力与实测驱动力在量值上相近且变化趋势一致,验证了动力学模型的合理性。     

基于干扰观测器的舰船运动模拟器非线性控制

舰船运动模拟器在使用中会受到来自被测设备的干扰力,该干扰力对模拟器的精确控制存在较大影响。针对此问题,根据系统动力学模型,提出一种自适应干扰观测器,在线观测模拟器所受干扰力,并在控制器中进行补偿。分析液压驱动的舰船运动模拟器在精确控制中的困难,使用鲁棒控制器克服参数不确定性和未建模不确定性引起的干扰。利用反步法推导出综合非线性控制器,并通过Lyapunov方法证明了该控制器是渐近稳定的。试验证明,该控制器在存在较大外干扰情况下能够平稳运行,且与普通比例积分微分(Proportional integration differential,PID)算法相比,有效地提高了系统的动态跟踪性能。     

水平运动模拟器复演随机海浪谱实验

设计了一种水平随机运动模拟器,并基于模型实验研究了该水平运动模拟器复演宽频带Bretschneider谱(B谱)与窄频带JONSWAP谱(J谱)所生成随机运动位移的能力及其关键影响因素。通过改变谱峰周期和有效波高讨论了两种海浪谱所生成水平随机运动位移的极值及与随机运动位移相应的频谱密度特征,确定了谱峰周期及有效波高对水平运动模拟器冲程的影响规律。基于实测频谱密度与理论谱之间的拟合优度,发现该模拟器对宽频带的B谱具有较高的复演精度,而对能量分布相对集中的窄频带J谱的复演精度相对较低,并且发现谱峰周期是影响J谱实测谱与理论谱拟合优度的主要因素,同时由J谱生成的随机运动位移的标准差及相应频域中能谱密度的方差均大于B谱,表明J谱相对B谱而言是一种高离散度的谱型,在运动模拟器中很难被精确复演为随机运动位移。     

六自由度直升机运动模拟器结构参数优化方法研究

本研究广泛用于直升机模拟训练的六自由度运动模拟器参数优化的方法。以液压作动筒驱动力均值最小为优化目标,采用两种方法进行六自由度运动模拟器结构参数优化。首先通过牛顿-欧拉法建立单体动力学模型,优化运动模拟器结构参数并采用Adams优化验证,然后采用Adams进行运动模拟器多体动力学结构参数优化。优化结果对于指导机构尺寸详细设计、降低成本和提高运动模拟器动态性能具有重要作用。     

用于机载火控性能测试的六自由度运动模拟器参数设计

文章从机载火控模拟测试的需求出发，根据相关的技术指标要求，对六自由度运动模拟器进行了详细的动力学分析和运动学分析，给出了运动模拟器的结构参数和液压参数的设计过程，并对六自由度的运动精度进行了简要的分析。     

一种新型3自由度并联运动模拟器的设计与分析

提出了一种新型两转一移3自由度并联运动模拟器,该运动模拟器能够完成升降、侧倾、俯仰3种运动,可以用来模拟飞行器、船舶、驾驶场景或应用在动感座椅等其他民用娱乐设备上.基于螺旋理论,分析了该机构的自由度,求解了该并联机构的运动学正反解;对工作空间和奇异位形进行了分析;利用SolidWorks和Recurdyn联合仿真,建立虚拟样机模型,验证了该机构是一个完全对称的空间3自由度并联机构,自由度与螺旋理论运动分析一致,对运动性能进行仿真分析,经验证满足设计指标,为后期样机的加工、控制奠定了基础.     

飞行模拟器运动平台中单缸系统的性能改善研究

六自由度飞行模拟器运动平台的单出杆缸系统在运动换向时存在冲击，这一问题将影响飞行模拟器的真实性，本文由此提出了“数字负载压力补偿”方法，可以消除这一问题。     

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...     

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.     

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。     

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。     

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。     

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.     

交通荷载作用下桥梁结构参数识别方法

应用动力节点加载法,将作用在桥梁上的交通荷载转化为等效节点荷载,再用两步构造法识别结构物理参数.第1步,用Newmark-β方法变换结构运动方程,并用结构的加速度响应求得变换空间内的位移、速度和加速度响应;第2步,基于最小二乘原理,构造出变换空间内求解结构参数的递推式,进行结构物理参数识别.数值模拟结果表明,在交通荷载作用下,该方法能够快速、准确地进行桥梁结构参数识别.     

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...