新型并联数控铣床手轮模块功能的实现

针对一种新型并联数控铣床的非线性映射运动控制特点,实现了该型铣床手轮模块的设计,详细讨论了手轮模块的硬件结构和软件结构。实际应用结果,表明该模块能够准确快速地控制动平台的运动,该项技术对并联机床手轮功能的设计具有一定的参考价值。     

并联机床手轮功能的实现

手轮和点动等基本功能的实现一直是并联机床数控系统开发中的技术难点之一,也是并联机床实用化的关键.针对并联机床非线性映射的运动控制特点,提出了基于"PC+PMAC"的硬件结构,结合PLC技术与中断技术,采用实时多任务调度策略开发并联机床手轮功能的方法.实际应用结果验证了该方法的有效性和实用性.该项技术对促进并联机床的实用化起到了很大作用.     

EMC2中HAL实现机理和应用研究

本文在对开源数控系统EMC2中的HAL框架的概念和实现机理分析的基础上,结合HAL中直流伺服电机PID控制实例说明了卜LAL中元件复杂组合的设计和实现过程.分析了HAL跟EMC2中其他重要模块的关联,应用HAL进行了电子手轮和虚拟电子手轮的设计.     

基于PMAC的数控机床手轮功能的实现

PMAC是当今工业领域最常用的运动控制器之一,而在基于PMAC的数控系统开发过程中手轮功能的实现是常见问题.文中在基于PMAC所提供的位置跟随功能的基础上,提出了基于＂PMAC＋PC＂的硬件结构,并结合PLC技术与Visual C＋＋技术,设计了手轮的控制程序,实现了手轮的位置和速度跟随功能.     

火炮高平机复杂系统参数优化

为解决超轻型大口径火炮手轮力较大的问题,利用参数优化设计方法,进行高平机复杂系统寻优设计。建立高平机结构、位置、特性等参数的数学关系,通过Matlab编程计算全射程范围内手轮力。建立以手轮力最大值最小为优化目标的单目标优化模型,采用多岛遗传算法与胡克基夫组合优化算法,通过多学科优化软件i Sight集成Matlab进行寻优,得到使手轮力最大值最小时的参数值。优化结果对超轻型火炮高平机设计具有指导意义,使其符合实际可操作性,达到了改进设计目标;该优化模型的建立为传动系统的优化问题提供了一种新思路。     

基于PCI-1240U的数控机床手轮功能的实现

在基于PCI-1240U的脉冲伺服运动控制功能的基础上,阐明了基于“PCI-1240U+PC”的硬件结构,利用Visual C++编程技术,设计了手轮的控制程序,实现了手轮模式切换、控制轴切换和倍率切换等功能.     

Mahr891E齿轮测量机电子手轮倍频鉴相电路研制

介绍了M ahr891E齿轮测量机改造中电子手轮倍频鉴相电路的研制。利用纯逻辑电路实现了电子手轮脉冲的4倍频鉴相,借助EDA工具Q uartus II 4.0对上述电路进行了设计和仿真,并在CPLD器件中实现了该电路。分析了电子手轮操作过程中造成鉴相电路输出信号不稳定的原因,给出了解决该问题的方法。讨论了电子手轮脉冲在进行4倍频之后还需进行高倍频的必要性。介绍了锁相环及其倍频技术,运用集成CM O S锁相环CD 4046结合CPLD器件设计了100倍频电路。以上电路均已应用于M ahr891E齿轮测量机新测控系统中,使用效果良好。     

关于室内消火栓手轮问题的分析和探讨

详细分析了现行标准、规范、图集对室内消火栓手轮的材质和参数要求的差异,以及消火栓手轮产品存在的问题,并提出了统一手轮的材质和公差尺寸、提高消火栓手轮质量的具体措施,提升消火栓产品的质量水平。     

新型扭矩手轮

本文针对目前国内外手动阀门工作时,操作力较难控制的情况,设计了新型扭矩手轮。实践证明,这种新型扭矩手轮使用方便,成本低廉,可提高密封可靠性,延长阀门使用寿命,对中低压明杆式大口径阀门尤其适用。扭矩手轮如图1所示,关闭扭矩由手轮4通过钢球5作用到阀杆螺母3V形槽斜面上。当扭矩超过规定值时,V形槽斜面克服弹簧6压力将钢球推入孔内,使手轮5阀杆螺母打滑,防止产生过大的密封应力,减     

快速切断阀用气动活塞式直行程装置手轮机构的设计

介绍了气动活塞式直行程装置手轮机构的工作原理、结构特点和传动副的设计。     

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。     

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。     

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。     

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.     

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.     

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.