压电石英称重传感器及其在动态公路车辆称重系统中的应用

本文介绍了以石英晶体为敏感元件的压电石英称重传感器的工作原理、结构与特点;石英晶体的压电效应,压电石英晶体片的并联、串联连接方法,电荷电压计算;石英晶体片的装配要求和装配工艺;石英晶体敏感元件与电阻应变计的性能比较。分析利用多个石英晶体敏感元件组装的工字梁型动态称重传感器的结构与技术特点,及其在动态公路车辆称重系统中的应用。     

基于PVDF的新型高速公路压电动态称重传感器

针对高速公路车辆超载严重的问题,提出了一种以压电薄膜聚偏二氟乙烯(polyvinylidene fluoride,简称PVDF)为敏感元件的新型高速公路压电动态称重传感器.分析了该新型传感器的工作原理,采用有限元分析软件ANSYS建立了传感器的机-电耦合模型,模拟得出了单片PVDF、双片PVDF串/并联情况下产生的电荷量.针对该传感器设计了一种简单调理电路,使PVDF的高阻抗输出变为低阻抗输出,并对所采集的电信号进行有效的放大.为验证该压电传感器方案设计的可行性,进行了室内试验和小型乘用车现场动态实测.试验结果表明,压电传感器具有较高的灵敏度,可以对车重进行实时检测和数据分析.     

车辆动态称重技术

随着公路运输业和商业贸易的发展，车辆动态称重技术已成为车辆载荷测量的关键技术和发展方向。文中对车辆动态称重系统的结构和弯板、压电传感器、单传感器及光纤传感器4种常用的动态称重传感器进行了介绍，并对系统产生的轴重信号进行了分析，重点讨论和研究了算术平均、神经网络、系统辨识等运用到车辆动态称重系统中的算法，并且阐述了今后的发展趋势。     

一种基于PVDF的车辆动态称重系统设计

针对高速公路车辆超载问题,设计了一种基于PVDF的车辆动态称重系统。首先介绍了动态称重系统的硬件系统,然后比较了三类压电传感器优缺点,简述了PVDF传感器的安装,给出了电荷放大器以及信号采集器等硬件的选择,并对软件系统的设计流程进行了分析。最后设计了动态称重系统试验,对系统进行了验证。     

基于数据融合的动态称重传感器布局研究

动态称重是汽车在高速路行驶中获取汽车真实重量的有效方法,文中介绍了压电传感器的原理以及简化的动态称重模型.在使用压电传感器的基础上应用数据融合的方法,对传感器进行合理布置,用Gass-newton法来求动态轴重信号模型,得到更接近真实轴重的值.在不同初始相位下,对不同速度时的误差进行仿真,结果显示该方法精度较高.     

并联式轴用压电六维力/力矩传感器

针对巨型重载操作装备极端制造中多维大载荷测量的难题,提出一种利用压电石英作为力敏元件的新型并联式轴用压电六维力/力矩传感器。对比各种力敏元件的性能,选择压电石英作为力敏元件可以实现空间力/力矩的动态测量,分析压电石英晶组不同空间布局方式的测量原理,提出并联式轴用压电六维力/力矩传感器的多点测量原理,分别对其建立空间力学模型,并进行解耦计算。设计出高灵敏度、高刚度、高线性度的非组装整体化六维力/力矩传感器新结构。研究并联式轴用压电六维力/力矩传感器的标定方法,并进行静态和动态标定试验,得到六维力/力矩传感器的标定矩阵和误差矩阵。试验表明,该六维力/力矩传感器可以动态测量空间六维力/力矩,具有量程大、线性好、固有频率高、动态性能好和应用场合多等优点。     

多传感器数据融合技术在车辆动态称重中的应用

针对车辆动态称重系统的结构和特点,采用一种基于神经网络的多传感器数据融合技术处理方法,并将其应用到动态称重系统中。通过对融合前后的数据进行比较分析,可有效地提高车辆动态称重系统抗干扰能力,以保证参数检测的可靠性和准确性。     

压电薄膜微传感器的动态特性分析

论述了压电薄膜微传感器的结构和工作原理,应用有限元方法对压电膜微传感器进行了动力学分析。利用有限元软件ANSYS7．0对压电薄膜微传感器结构的振动模态进行了仿真,并拟合了感应电压和动态外力幅度、频率以及结构几何参数之间的关系,这些分析为此类微传感器的设计提供了理论依据。     

基于光纤光栅的小量程称重传感器设计

设计了一种小量程光纤布拉格光栅称重传感器,采用双孔单槽式悬臂梁型弹性体结构,并利用有限元软件ANSYS对弹性体结构进行优化设计,以满足小量程设计要求。采用四片光纤光栅布片方式,提高了传感器的灵敏度,并利用正应变和负应变的光纤光栅信号进行叠加,以补偿温度的影响。对传感器进行加载卸载实验,并对所设计的传感器进行了整体性能分析,实验结果表明,传感器的称重范围为0-4kg,线性度误差小于0.9%,温度补偿达到了一定效果,性能稳定,证明了设计方法的可行性。     

压电复合薄膜传感器的制备与应用性研究

为了进一步优化压电薄膜传感器的制备工艺,探究压电薄膜传感器在建筑工程领域的应用前景,采用流延工艺制备了碳纳米管改性的0-3型压电复合薄膜,并使用该薄膜制成了压电复合薄膜传感器,将制得的压电薄膜传感器和传统的电阻式应变片同时贴在等强度悬臂钢梁上,通过采用2组不同频率的正弦荷载和1组随机荷载对悬臂梁进行激励,对比研究了压电传感器和应变片在动态荷载激励下的响应。研究结果表明:压电复合薄膜传感器具有更快的反应能力和更高的灵敏度,压电薄膜传感器可以有效地对结构的应力和应变进行实时监测。     

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...     

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。     

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...     

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。     

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.     

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.     

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.