便携式双L型测头钢轨外形测量仪的研究

比较分析已有钢轨测量仪器,研究了双L型测头五连杆钢轨外形测量仪,建立测量模型与逆解模型。针对不同测量规格钢轨的需要,对五连杆参数进行优化仿真。用Matlab模拟编码器采样过程,对原理误差、编码器量化误差进行计算。理论分析结果表明:仪器能测量钢轨轨头以及轨头两侧下颚的外形,测量范围宽,为钢轨磨耗的研究提供可靠数据。     

对称 T型钢轨外形磨耗测量仪研究

介绍了对称T型钢轨外形磨耗测量仪的结构及数学模型。用Matlab对其进行运动仿真、参数优化,分析其原理误差及编码器量化误差。理论分析结果表明：仪器选用10000线的光电编码器可满足形状极差要求;仪器测量范围覆盖完整轨头断面,测量范围大,同时体积小,更便携。     

便携式双侧轮轨外形测量仪研究

设计了既能测量车轮又能测量钢轨的双侧轮轨外形测量仪,为轮对与轨道接触几何的研究提供可靠数据。给出机械设计方案和五连杆的数学模型。针对被测轮对和钢轨,对五连杆参数进行优化仿真,以适应量程和精度要求。模拟编码器采样过程,对测量模型误差进行仿真计算。     

对称五连杆下肢康复机构的设计与分析

五连杆机构作为一种特殊的运动机构,有着丰富的运动特点,结合临床康复医学理论对下肢康复机器人方案进行研究,设计了一种针对下肢偏瘫患者的双曲柄对称五连杆康复训练器,推导了五连杆的运动学解析式,通过建立数学运动模型,用Matlab进行仿真,仿真结果表明通过调整该机构两曲柄的相位差或机架的倾角来能实现输出点的运动轨迹的变化,从而达到调整髋关节和膝关节运动范围或最大值的目的,证明了此款下肢康复训练机器人可以满足不同康复阶段的患者的使用需求。     

五连杆非独立后悬架K&C特性仿真研究

利用多体动力学仿真试验技术,发现某SUV后悬架横向刚度偏低容易产生过度转向趋势的问题。针对该后悬架各硬点改变进行运动学仿真研究,将下拉杆前点降低30mm、上拉杆外移130mm及上拉杆后点提高30mm,可以弥补原车过度转向的问题,仿真结果提高了整车的操纵稳定性。通过对原车和改进后车辆进行操纵稳定性主观评价,结果是改进后车辆操纵稳定性得到很大改进,与仿真结果趋势一致,也验证了模型的正确性。该方法可以为新车悬架性能调校提供理论基础。     

多自由度连杆机构的仿真与示教

针对五连杆机构连杆曲线的多样性进行了分析与综合,揭示和确定了五连杆机构有双曲柄的条件.同时采用计算机仿真了五连杆双曲柄机构、带一个移动副的五连杆机构和带一个导块的五连杆机构.通过单片机芯片集成控制五连杆机构,设置4个功能元完成示教动作.从五连杆机构的数学公式出发,对多自由度连杆机构进行了编程和轨迹示教,同时对多自由度机...     

基于L-M算法的五连杆车轮外形测量仪参数标定

介绍了五连杆车轮外形测量仪的结构,推导了测量仪的数学模型,并根据该数学模型建立了测量仪的系统误差模型。采用L-M算法对误差方程进行迭代求解,修正了测量仪的误差参数,使测量精度满足要求。结果表明,该方法可以高效地对五连杆车轮外形测量仪的误差参数进行标定,测量的平均误差由0.121mm降低至0.0039mm。     

确定五连杆悬架虚主销轴线的近似数值方法

使用数值方法确定了五连杆悬架虚主销轴线空间位置的变化,为进一步研究五连杆悬架的运动学特性奠定基础。     

安全钞箱双五连杆机构参数化设计研究

针对安全钞箱创新设计制造,建立了双五连杆结构数学模型,基于模型推导过程及边界条件实现了参数化设计.通过三维设计软件构建的若干算例,验证了模型以及结果的正确性,并成功地应用到安全钞箱的产品设计开发中.     

影响双曲柄铰接五连杆机构连杆曲线的因素

介绍了铰接五连杆机构的连杆曲线的求解方法，分析了影响铰接五连杆机构连杆曲线的因素，绘出了几种特殊的铰接五连杆机构的连杆曲线，并简要介绍了铰接五连杆机构的应用前景。     

Simulation of flow meter calibration factors for various installation effects

The determination of flow meter calibration factors has been made using a computer simulation approach. The proposed technique is based on computational fluid dynamics (CFD). The CFD tools were used to determine the flow field in a flow meter as developed by three different pipe configurations. These flow fields were used to determine the calibration factor for an ultrasonic flow meter. The results have been compared with calibration factors obtained by CFD using detailed LDV input boundary data, analytical calculations and experimental data. Tests were made for reference conditions of 10013 straight-pipe and for single- and double-elbow pipe configurations using Reynolds numbers from 100 to 100,000. For reference conditions good agreement is shown. For disturbed flow conditions the simulations well resembled the experimental data. However we find differences for transitional and swirl flows.     

凸轮轴干切削加工变形仿真研究

针对凸轮轴干切削加工中的变形问题,利用UGNX4.0软件的CAD模块建立凸轮轴三维模型,应用有限元分析模块对其由于切削力引起的变形进行仿真分析,找出影响变形的主要因素,从而进一步提出减少变形、提高加工精度的措施,对保证产品质量具有重要意义.     

混流汽车总装配线上的零部件优化配送方案研究

配送车每次配送的利用率大小是提高配送效率的主要因素,因此设计一种启发式算法使配送车一次装载的标准塑料周转箱尽可能多,提高配送车空间利用率.最后的仿真实验验证了上述配送方法的实用性,提出的零部件配送管理方法,只需使用较少的配送工人,同时降低了线旁库存,能为企业节省人力,降低生产成本.     

自动无线抄表通讯方式研究与实现

本文介绍了当前无线抄表技术中的数据通讯技术,并分析了各种通讯技术的特点,并根据无线抄表系统的实施方案设计了合理的数据通讯方案.     

低功耗预付费热量表的研究

提出了一种基于射频卡的低功耗热量表的软、硬件设计方法。采用了Atmel公司的T5557射频卡实现预付费功能,应用目前国际上功耗最低的MSP430FW425单片机为主控制器,Pt1000为温度传感器,其流量测量部分采用无磁流量计和韦根流量传感器,提高了测量的精度和灵敏度。     

The performance characteristics of a micro-machined Coriolis flow meter: An evaluation by simulation

Micro-machined Coriolis meters will enable measurement of very low flow rates (0.1–500 g/h) and, potentially, ultra-low flows (0.1–100 mg/h). Application areas include the delivery of medical drug infusions to patients, and a wide variety of micro-fluidic devices. An evaluation of the performance of two prototype micro-machined flow-tubes of differing shapes is reported, based upon results obtained from a virtual Coriolis meter. This tool comprises a finite element modelling capability which simulates the meter flow-tube in motion, with the flow represented simply as a continuous string, i.e. 1-dimensional and frictionless, and the model allows the generation of pseudo-data at points on the tube corresponding to sensor locations. Application of signal processing algorithms then enables the representation of an indicated flow time history output by a Coriolis meter in response to a prescribed input flow. Results indicate that the devices investigated were all highly linear and that meter sensitivity is independent of fluid density. One flow-tube shape confers higher stiffness than the other and, for both tube shapes, increasing wall thickness increases tube stiffness at a greater rate than the tube mass. Higher stiffness results in reduced meter sensitivity, but increased drive frequency (hence, faster dynamic response). The spatial averaging resulting from the use of ‘distributed’ internal sensors inevitably yields meter sensitivity values that are lower than the potential maximum value that might be achieved by use of ‘point’ sensors; however there are practical reasons why this latter approach would not work. The dynamic response to a flow step is essentially the same as found for macro-Coriolis meters.     

热释光计量仪在鱼耳石成因矿物学研究中的应用

利用FJ427A1型微机热释光剂量仪对采自河北白洋淀及北京密云水库的45尾野生鲤鱼的鱼耳石进行热释光特征研究。结果表明,以上两个不同水域鱼耳石的热发光曲线的峰高、半高宽、峰位等参数均存在明显差异,与水体的水质特点呈较好的相关性。此外,热释光半高宽,尤其是第二峰半高宽可以作为区分两个不同污染程度水域的生物矿物学标型。     

成形法制备半蜂窝波形条的有限元模拟

航空工业上采用的以成形法成形半蜂窝波形条的方式,成形的波形条结构均匀、精度高、工艺间单.根据某厂生产波形条的工艺,利用非线性有限元法开发了成形法的有限元模型,运用该模型对现场的实际成形过程进行仿真计算,得到与现场实测相吻合的结果.比较板坯在单、双主动辊加栽的条件下,成形结果的优劣性.在此基础上,对影响成形结果的主要因素进行分析.     

新型微型机器人仿真系统建模研究

提出了根据流体润滑理论,建立了微型机器人仿真的系统模型,采用VC 6．0和OpenGL开发了三维动画仿真系统。最后给出了应用该系统进行仿真的一个例子,为微型机器人的研究提供了有效的仿真数据。     

Relationship between velocity profile and distribution of induced potential for an electromagnetic flow meter

This paper investigates the relationship between the induced electric potential and the velocity distribution of the conductive continuous phase in two-phase flows in pipes to which an electromagnetic field is applied, with a view to measuring the continuous phase velocity profile. In order to investigate the characteristics of an electromagnetic flow meter in multiphase flow, an alternating current electromagnetic flow meter was modelled using FEMLAB software. Using the model, electrodes could be placed at any position on the insulating internal surface of the flow meter to satisfy the requirement of measuring the induced potentials at specific locations at the boundary of the flow. The induced electric potential or potential differences from the electrodes were analysed for various simulated flow conditions. The numerical simulation results suggest that electromagnetic flow metering may be an effective novel method for measuring the axial velocity profile of the conducting continuous phase. Furthermore, when combined with the local volume fraction distribution of the continuous phase (obtained, for example, using Electrical Resistance Tomography, also known as ERT), it is expected that the measured continuous phase velocity profile would enable the volumetric flow rate of the continuous phase to be obtained.