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设计了一种新型的组合式串口服务器,将以太网有线通信功能与射频无线通信功能组合在一起形成一种新型的集成DNC系统.详述了该集成DNC系统的硬件构成及其硬件接口,并在此硬件基础上,开发了相应的DNC通信软件功能模块.实验表明,组合式的集成DNC系统相比于其它DNC系统,具有便捷、灵活、扩充性强、开放、可靠、能远距离传输等优点. 相似文献
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把热电偶从高速旋转刀具上采集到的热电势信号传输到静态测温设备一直是个难题,为此采用以下两种方法来达到这一目的。一种叫信号暂存法,该方法把热电偶采集到的热电势信号暂时存储在随铣刀一起旋转的热电势采集卡中,等一次切削结束后,再通过有线的方法传输到静态测温设备。这种方法优点是信号传输稳定,缺点是采集到的信号不能适时显示;另一种方法是热电偶无线传输,这一方法通过无线的方式把信号适时传输到测温系统的PC机,并把热电势信号转换为温度值,实现切削温度的适时显示。制造了两套测温系统,并通过实验验证热电势无线传输的稳定性。 相似文献
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Zeithain无缝钢管厂顶管车间配置了一套自动化钢管精整加工系统,由计算机控制钢管矫直到成品包装入库的全过程。该系统具有设备优化、传输准确、加工周期短以及产品质量高等特点。介绍了该加工线的主要技术数据、工艺特点、设备布置概况和自动化系统。 相似文献
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基于虚拟仪器技术和互相关原理,研制出一种新型喷气织机主喷嘴气流流速测量系统。该系统采用一种新的流速测量方法,即应用DAQ集成板卡完成上下游流动信号的采集,对它们进行互相关运算,采用优化算法计算渡越时间,间接测出流速,最后将处理结果传输给上位机。动态实验结果表明:该测试系统工作稳定可靠、灵敏度高、误差范围小。 相似文献
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《组合机床与自动化加工技术》2017,(9)
文章设计并研制了8英寸硅片真空传输平台,介绍了该传输平台的整体结构,并对关键模块前端传输腔室VCE中的CTA传输手托盘系统进行了选型设计、机构分析。垂直升降系统采用丝杠传动,CTA传输手采用平面四连杆机构增大刚度。对传输手主动杆强度和变形量进行了有限元仿真分析。经过重复运行精度实验测试,整个平台达到了硅片制造要求。 相似文献
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基于有限元和最优化方法的淬火冷却过程反传热分析 总被引:7,自引:0,他引:7
淬火过程换热系数的求解是反向热传导问题中的一种不适定和非线性问题.本文提出了一种求解淬火过程随温度变化的换热系数的新方法,该方法把有限元方法引入反向热传导问题,根据实验测量的温度曲线,结合使用最优化方法中的进退法和试探法确定合理的边界换热系数.为了使进退法适用于该类反传热问题,对其算法进行了改进,并用其确定换热系数优化的搜索区间,然后用试探法(黄金分割法)在搜索区间内找到换热系数的最佳值.在计算过程中,利用有限元法可以方便地计算出各个单元在整个过程的相变情况,得到各单元在相应时间段所产生相变潜热,并将各单元的相变潜热与单元温度场进行耦合计算. 相似文献
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李钟慎 《组合机床与自动化加工技术》2006,(10):62-63,66
针对一阶加纯滞后(FOPDT)模型,基于最优传递函数,提出了Smith预估控制系统的PI参数整定方法。首先介绍了Smith预估控制方法,然后对比Smith预估控制系统的闭环特征方程式和二阶最优传递函数的特征方程式,得出PI控制器的参数整定公式,最后基于ITAE最优传递函数或Butterworth最优传递函数,给出了PI控制器的设计实例,并进行了相应的仿真。仿真结果表明,按该方法设计的Smith预估控制系统的动态性能和抗扰动性能都取得比较好的效果。 相似文献
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《Science & Technology of Welding & Joining》2013,18(4):221-226
AbstractA method is developed to compute the stability of droplets detaching from the consumable electrode in gas metal arc welding. An aluminium electrode is used as the model system. Theoretical predictions and supporting experiments are used to ascertain the rate of transfer of droplets for a range of current encompassing globular and spray transfer, and to examine the transition between these distinct modes of metal transfer. The method uses dimensional analysis to correlate the mass, rate of transfer, and force acting to detach droplets. The correlation is found to undergo a notable change in slope at the transition between globular and spray transfer. The accuracy of the correlation is assessed by comparing the theoretical and measured rate of transfer of droplets in gas metal arc welding using aluminium electrodes of variable diameter. 相似文献
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This article deals with the application of the stochastic Exodus method for modelling of thermal spraying heat transfer processes and for solving direct and indirect problems. The Exodus stochastic method has an advantage in straightforward solving of the transient inverse heat transfer multi-dimensional problems over other methods based on iterative fittings procedures used for example by finite element methods (FEM). Theoretical background of the method is introduced. Application capabilities of the method are shown on the example of high velocity oxygen fuel thermal spraying heat transfer process analysis. Comparisons with results of FEM computational method application are presented. 相似文献
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A relatively simple method for controlling electrode metal transfer improving the parameters of the welding process in comparison with uncontrolled transfer is proposed. 相似文献
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High-quality solidification microstructure during directional solidification relies on precise temperature gradient control, so accurate calculation of the temperature field is critical. In this study, a 3D transient global heat transfer model of directional solidification by the Bridgman method based on the finite difference method is developed. The radiation heat in this model is calculated by the discrete transfer method, and a modified method of external surface area for irregular geometric models is proposed to reduce the zigzag shape caused by finite difference grids. Considering the radiative heat transfer between any surface elements of all materials in the directional solidification furnace, a dynamic ray tracing algorithm is developed to simulate the entire process of directional solidification. Then, the simulated results are compared with the theoretical results and experimental results, respectively. Finally, based on the present model and method, the simulation program developed is applied to the directional solidification of actual castings. The simulated results are in good agreement with the experimental results, which indicate that the model and method developed in this study is effective and practical. 相似文献
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1 INTRODUCTIONThetechnologiesofthe 16 0kA prebakedanodealuminumreductioncellofGuizhouAluminumSmelter,China ,wereintroducedfromJapaninthe1970 s .Ithasbeenfoundintherealoperationthatthetargetindexesarenotasgoodasexpected .Forexample ,thecurrentefficiencyislowerthan 88%andtheDCpowerconsumptionforproducingAlishigherthan 14 0 0 0kWh/t .Meanwhile ,becauseofthebiggersidechannel,sideledgecannotbefullyformed .Itisanalyzedthatpoorbusbararrangementsandinnerliningstructureaswellasoperationallha… 相似文献
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获得熔滴过渡的信号是MIG焊熔滴过渡控制的关键,这已成为目前亟需解决的问题。文中介绍了以电弧光谱手段检测熔滴过渡的试验装置、原理和方法。通过试验测试及数据分析发现,通过熔化极电弧的光谱信号可以检测出MIG焊喷射过渡的过渡过程、过渡形式,测量过渡参数。信号幅度大,品质好;不同的过渡形式具有不同的典型信号模式;信号脉冲的形态与熔滴过渡的发展过程具有明确的对应关系。熔化极电弧光谱信号的诸特征可方便地应用于MIG焊熔滴过渡的过程控制、过渡形式的模式识别与稳定化以及过渡参数的测量。 相似文献
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为研究火车轮在模锻成形过程中内部金属流动及淬火加热、踏面淬火中的换热系数和温度变化,利用有限元软件对其模锻成形及热处理过程进行数值模拟分析,并结合黄金分割优化法对综合换热系数进行了反传热计算。结果表明:模锻过程中,辐板与上模接触区域的等效应变最大,轮辋外侧变形相对较小,踏面附近区域变形较均匀;在淬火加热过程中,换热系数随工件表面温度升高而增加,当温度在500℃以下时,换热系数随温度的升高而快速增加,500℃以后,增速缓慢,800℃时,换热系数达0.15 kW·(m^2·℃)^-1;踏面淬火时,在700℃以下,随温度下降,换热系数迅速增大,300℃时达到峰值3.1 kW·(m2·℃)^-1,在250℃以下,换热系数稍有下降,100℃时换热系数为2.5 kW·(m2·℃)^-1。 相似文献