共查询到17条相似文献,搜索用时 156 毫秒
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在线采集真实电解加工过程中的电流信号,用对实测信号进行小波包分解和重构后的小波系数计算各频段的能量,构造一个由不同频段能量组成的特征向量,发现特征向量的低频分量占总能量的大部分,随着平衡间隙的减小,低频分量能量增大。设计了一个二维模糊控制器,以进给速度的增量为模糊控制器输出,将间隙的误差转化为电流的误差及误差的变化,以此作为模糊控制器的二维输入向量,使加工维持在稳定的小间隙状态。创建了仿真模型,在MATLAB的SIMULINK模块中,通过对模糊控制器和电解加工系统组成的联合模型进行仿真试验来整定模糊控制器的3个增益参数,试验表明,采用此方法进行间隙控制具有较好的快速性、鲁棒性及总体效果。 相似文献
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分析了小波变换和经验模态分解方法 (EMD)提取信号趋势项的理论和算法,并通过对仿真确定信号加趋势项,基于小波变换和经验模态分解两种方法对振动信号趋势项提取分离,将两种方法所得结果进行比较研究。结果表明,EMD方法提取趋势项,过程更简洁,结果更准确、可靠。 相似文献
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短电弧加工(SEAP)是解决特硬、超强、高韧性等难加工材料的表层去除加工难题的有效手段。介绍了短电弧机床电流信号采集系统的结构组成和工作原理,对该系统进行了SEAP电流信号的采集以及电流波形变化规律的初步分析。另外,还介绍了该系统对采集的信号进行滤波处理的两种方法:数字滤波器滤波及小波变换滤波。 相似文献
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自由曲面数控加工中刀具破损的小波分析 总被引:3,自引:2,他引:1
介绍了小波变换的特点,并将其与傅立叶变换及快速傅立叶变换进行了对比,结合刀具破损信号,分析了快速小波变换——Mallat算法.对自由曲面数控加工中主轴电机电流信号的提取技术进行了分析,指出了霍尔电流传感器是行之有效的方法.鉴于刀具破损电机电流信号的瞬时性,采用小波分析方法给出了提取刀具破损信息特征的成功应用实例.研究表明,多分辨(多尺度)分析的方法,对于刀具破损这种突变信号不但具有精确的时-频定位作用,还具有易于监测的优点,说明这种方法能够有效地应用于刀具破损监控的信号处理. 相似文献
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针对脉动态电解加工的电流特性开展多物理场耦合仿真分析,仿真结果显示电流波形以最小加工间隙时刻对称分布。针对在脉动态电解加工实验中观察到的加工电流峰值实际前置于最小加工间隙时刻的现象,采用高速摄像对脉动态电解加工中的产物情况进行观测,并结合图像灰度处理软件对产物在间隙中的比例进行量化分析,分析结果表明产物在加工间隙内的堆积过程特性是引起电流波形峰值前置的主要原因。 相似文献
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为了提高产品加工质量,根据试验测得铣削系统颤振稳定域,制定并采集数控铣削振动信号,以保证采集信号的准确性;融合小波包变换与希尔伯特黄变换,从能量频域分布与幅值概率统计分布两方面提取信号特征值,其中小波包降噪作为信号前置处理能有效降低环境噪声干扰的影响,提高经验模式分解的精度;建立基于模糊支持向量机的颤振诊断模型,将振动信号分为平稳铣削信号、微弱颤振铣削信号、颤振铣削信号及刀具磨损铣削信号。实验结果表明,该模型具有良好的铣削振动信号辨识与诊断能力,预测准确率达97.3%,为数控铣削加工振动信号的准确辨识与诊断提供了一种新方法。 相似文献
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Experimental investigation on monitoring interelectrode gap of ECM with six-axis force sensor 总被引:2,自引:2,他引:0
Yonghua Lu Kai Liu Dongbiao Zhao 《The International Journal of Advanced Manufacturing Technology》2011,55(5-8):565-572
To realize on-line monitoring interelectrode gap, six-axis force sensor was embedded into main spindle of machine tool to measure force signals on cathode exerted by electrolyte. The force signals, three forces, and three moments in X, Y, Z directions, respectively, are considered as research parameters. On one hand, the forces exerted on the tool cathode by electrode are measured with six-axis force sensor as electrolyte flow system is activated and electrode is deactivated. On the other hand, the forces are tested when electrolyte flow system and electrode are both activated. Then, the relation between six force components and interelectrode gap are analyzed. Machining experiments using three types of tool, e.g., plane tool, slant tool, and blade tool, have been carried out to deduct experiential equations between six force components and gap according to least squares method. Furthermore, the experimental data with blade tool are put into experiential equation with slant tool to examine validity of measuring gap in ECM. The relation of parameters in equations is analyzed and a conclusion is drawn: in the range of 15% error, machining experiential equation with slant tool can be used to on-line measure the interelectrode gap in ECM. 相似文献
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基于六维力电解加工间隙在线检测试验研究 总被引:4,自引:0,他引:4
为了实时检测加工间隙,把流体作用在阴极上的六维力作为研究参数:设计通电解液不通电、通电加工两大类工况,从定性和定量两个角度分析六维力与加工间隙之间的关系;并以平面、斜面、叶片型面三种阴极进行试验加工,用最小二乘多变元线性拟合法,分别建立平面、斜面阴极加工的六维力与加工间隙之间的关系方程式,用叶片型面加工数据对建立的关系方程式进行检验与修正,得到最终的修正关系式:分析关系式各参量之间的关系,并得到结论:在15%的误差范围内,关系式可以用于在线检测加工间隙。 相似文献
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针对航空发动机叶片电解加工阴极设计这一具体工程应用,在模型叶片三维实体建模的基础上,着重研究两种阴极设计方法,即基于叶片电解加工实际电场分布的阴极设计有限元数值解法以及同时考虑极间电场和电解液流场特性的阴极设计有限元数值解法。详细地对比了两种阴极设计方法对极间电势分布、间隙分布和阴极边界条件的影响,通过一系列的工艺试验验证了同时考虑电解加工电场和流场特性的阴极设计方法较单纯考虑电场特性的阴极设计方法更全面、更符合电解加工的实际物理过程,因而所设计的阴极更加精确合理。 相似文献
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In this work a theoretical analysis of the ECM process of curvilinear surfaces has been presented. The purpose of this analysis is to predict the shape evolution of the machined object using: a shaping surface of small thickness (flat issue) and a blade of hydrodynamic machine (quasi-three dimensional issue). ECM modeling involves prediction of the machined surface shape evolution and distribution of physical-chemical parameters inside the interelectrode gap. The problem has been solved with the use of an equation of the electrolyte and hydrogen mixture (liquid and gas) flat flow inside the interelectrode gap. After introducing simplifying assumptions for the flow, void fraction distribution and the gap thickness, the equations were solved partly analytically, partly numerically. The obtained solutions for assigned parameters of the machining process are presented graphically in the form of distributions of: static pressure, the mixture flow rate, temperature, void fraction and evolution of the machined surface shape evolution. 相似文献
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ELECTROCHEMICAL MACHINING OF CURVILINEAR SURFACES 总被引:1,自引:0,他引:1
In this work a theoretical analysis of the ECM process of curvilinear surfaces has been presented. The purpose of this analysis is to predict the shape evolution of the machined object using: a shaping surface of small thickness (flat issue) and a blade of hydrodynamic machine (quasi-three dimensional issue). ECM modeling involves prediction of the machined surface shape evolution and distribution of physical-chemical parameters inside the interelectrode gap. The problem has been solved with the use of an equation of the electrolyte and hydrogen mixture (liquid and gas) flat flow inside the interelectrode gap. After introducing simplifying assumptions for the flow, void fraction distribution and the gap thickness, the equations were solved partly analytically, partly numerically. The obtained solutions for assigned parameters of the machining process are presented graphically in the form of distributions of: static pressure, the mixture flow rate, temperature, void fraction and evolution of the machined surface shape evolution. 相似文献