多槽锅式茶叶理条机锅体曲线的研究

为了研究不同锅形对茶叶整理成条的效果,建立了多槽锅式茶叶理条机的U型和斜型锅体的曲线模型,在对锅内茶叶进行受力分析和运动学分析的基础上,基于MATLAB编程得到了茶叶在槽锅内的运动轨迹和运动规律。研究结果表明,根据茶叶运动时与锅底面接触的长度分析,斜型锅对茶叶的理条作用较强。该研究提供了多槽锅式茶叶理条机结构参数的一种优化方法。     

基于EDEM的电磁振动给料机参数研究

针对电磁振动给料机无法实现自动化调速加料控制的问题,对不同参数下电磁振动给料机加料性能进行了仿真分析和实验研究。首先,利用SolidWorks软件对电磁振动给料机进行了三维建模,并将其导入离散元分析软件EDEM生成了计算模型;然后,在EDEM软件中分别改变电磁振动给料机的振幅、挡板高度、振动频率、振动方向角参数,对其在不同参数下的加料过程进行了模拟仿真;最后,通过实验验证了挡板高度和振幅变化对电振机物料输送流速影响规律与软件模拟研究规律的一致性。研究结果表明:流速随振幅、振动方向角的增加呈二次曲线变化;流速随挡板高度的增加呈线性增长;流速随振动频率的增加呈二次曲线和线性阶段性变化;通过对电磁振动给料机参数的研究,为电磁振动给料机的参数化设计和自动调速加料控制提供参考。     

纵扭复合超声换能器的频率灵敏度及其结构优化研究

针对现有超声换能器结构设计方法存在效率低、计算繁琐及与实际应用偏差较大等问题,提出了一种基于有限元模态频率灵敏度的结构优化方法.本文以纵扭复合超声换能器为例,从传统解析法与实际应用尺寸边界约束条件相结合角度,初步确定换能器结构参数;在此基础上,采用模态频率灵敏度方法,通过改变对换能器模态频率影响较大的主要结构参数值,优化得到符合实际应用的换能器结构,并通过阻抗分析与振幅测试试验对结构模型进行了验证.试验结果表明,换能器谐振频率为27.6 kHz,纵向振幅为4μm,扭转振幅为1.33μm,纵扭比为33.25％,与仿真值相比误差较小,能够实现纵扭复合振动,且谐振频率、振幅及阻抗均可满足大部分超声加工要求,验证了设计方法的有效性及结构设计的合理性.     

低频扭转振动攻丝基本工艺参数组研究

描述振动攻丝运动形式的参数组很多，不同参数组中影响攻丝扭矩和攻丝效率的参数个数不同，选择对攻丝扭矩和攻丝效率影响因素少的参数组可以大大减少振动攻丝工艺参数选择和优化的难度，在给定条件下，通过试验得到，当以纯切削角，角振幅和振动频率三元素组成工艺参数组时，可以使影响攻丝扭矩的参数由原来的3个下降到2个，因此认为该工艺参数组及其等价的参数组都可以作为低频扭转振动攻丝的基本工艺参数组。     

平贝母收获机振动筛分过程仿真及试验

为了提高平贝母收获过程中的筛分效率和平均运输速度,在传统平贝母收获机的基础上,建立振动筛的仿真试验模型并基于离散元软件进行仿真。对振动筛的三个振动参数：振幅、振动频率以及倾角进行交互试验确定筛分效率与平均运输速度的回归方程,通过3D响应面法优化三个振动参数,得出最优振动参数：振动频率为20 Hz,振幅为3 mm,倾角为15°。最后为验证交互试验的数据是否有良好的预测性,课题组设计制造组装好振动筛试验平台做实物筛分试验,以验证最优参数是否合理。     

仿冲击振动压实的试验研究

利用自主设计的仿冲击振动压实装置,进行了大量的对比性试验。分析了压路机频率、振幅和行进速度等参数对压实效果的影响,确定了仿冲击振动压路机参数的取值范围。试验结果表明:仿冲击振动压实可以在有限的压实遍数下使土壤面层、深层压实度分别达到91.7%和87%;振幅对压实效果的影响比频率更为明显;激振频率在9 Hz~20 Hz、振幅在3 mm~6 mm范围内较为合理。样机产生了明显的冲击压实效应,适于土壤深层压实。     

应用遗传算法对振动平板夯设计参数进行优化选择

要使振动平板夯获得最佳振动压实效果，需合理选择其设计参数，这里在对振动平板夯运动分析的基础上，建立了平板夯的振幅值为目标的优化设计模型，以夯机的重量、振动频率、激振力、移动速度、结构限制等为约束条件。通过遗传算法进行优化求解，获得了满足性能要求的结构参数，为提高振动平板夯的性能设计提供了理论依据。     

双旋筒式茶叶理条机的设计与存在问题分析

介绍一种双旋筒式茶叶理条机,应用自动控制技术和复合运动技术．从根本上改变了传统理条机的工作方式。实践证明,该机在茶叶生产加工中能取得非常好的应用效果。     

电极丝横向振动对电火花线切割加工间隙影响规律研究

以提高电火花线切割加工效率为目的,分析了电火花线切割加工间隙对加工效率的影响,建立了电极丝横向振动数学模型,揭示了各工艺参数对电极丝振幅及加工间隙的影响规律。采用直径1mm的钼丝进行了加工实验,得到了峰值电流、脉冲宽度和脉冲频率等参数对电极丝振幅的影响规律。结果表明所建立的振动模型正确,可为优化电火花线切割加工间隙,从而提高其加工效率提供参考。     

振动对视觉识别效率影响的实验研究

针对振动对视觉识别的干扰,实验研究了振动方向、频率、振幅以及识别对象特征对视觉识别效率(正确识别速度)的影响.根据实验数据,给出了不同振动频率和不同振幅下的识别效率函数,揭示了振动特征与识别对象特征对识别效率的影响及其交互作用.实验结果表明,随着振动频率或振幅的增加,识别效率呈指数趋势递减;振动频率、振幅和识别对象特征对视觉识别效率有显著影响;频率与振幅、振动方向与识别对象特征的交互作用显著.实验结果为振动工况下视觉显示的识别可靠性与舒适性设计提供了依据.     

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...     

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。     

Fifth International Summer School on Screw-Theory Based Methods in Robotics

正3-11 September,2014University of Bologna,Bologna,Italy www.summerscrews.org summerscrews2014.ing.unibo.it SUMMER 20SCREWS 14In 2014,our screw-theory school comes to the world's oldest university.In early September,Summer Screws'14 will gather six experts in the application of screw theory in robotics and up to 40 participants at the University of Bologna,Bologna,Italy.The school will teach attendees how to apply existing methods and empower them to develop new ones in their own research.The basic theoretical notions will be introduced in a rigorous manner,emphasizing examples,applications,and exercises.Scholarships are available.     

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.     

INDUSTRIAL ENGINEERING AND VISUALISATION-A PRODUCT DEVELOPMENT PERSPECTIVE

Taking the actual project of teaching and researching process for example, the relationship between the industrial engineering and product development is discussed. And use the novel visualization technology to support the industrial engineering and product development. How to use the new computer modeling and simulating technologies to support the product development and industrial engineering, is introduced especially. The support includes both domestic products and industrial systems. The visualization and computer technologies take a very important role in some system or multi-direction modeling, those technologies mentioned above can help the industrial engineers study the effect of design on the whole life circle, including the producing steps. So the engineers can avoid making the wrong decision which may cause bad effects on the whole industrial engineering.     

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。     

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...