共查询到17条相似文献,搜索用时 171 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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基于信息融合的电解加工间隙检测 总被引:2,自引:0,他引:2
目前,在电解加工中还没有有效的加工间隙在线检测方法[1]。本文通过采集真实电解加工中阴极表面上来自电解液的平行于机床主轴的力和加工电流,利用小波变换对采集的信号进行处理,提取趋势项。结果发现:随着间隙减小力和加工电流都增大,可以据此间接实现间隙的测量。用力和加工电流经过小波变换提取的趋势项进行信息融合来更好地反映间隙,将它用于方坯加工叶片时采用的全程控制。用神经网络建立数显进给位置与力和电流融合信号之间的非线性映射,使它作为标准曲线以对间隙进行自动的全程控制。 相似文献
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基于力外环的模糊灰色预测力控制器 总被引:2,自引:1,他引:2
在基于位置环的显式力控制方案的框架内,提出一种新型模糊灰色预测力控制策略。采用灰色预测器来预测将来的接触力,通过模糊增益调节器将预测的接触力误差和实际测得的当前接触力误差进行合成形成一个综合接触力误差,综合接触力误差作为PID或PI力补偿器的输入变量,力补偿器生成位置控制系统的输入指令。这样该控制器可以利用过去、当前和将来的接触力信息来计算合适的控制校正量来对接触力误差进行预补偿,使控制器可以同时获得超调量小和响应快速的性能。而且,该控制器可以按照当前和将来的接触力状态来调节预测的接触力误差和实际测得的当前接触力误差的权值,使控制器对机器人和环境之间的动态接触过程具有适应性。最后用仿真试验证明所提出的模糊灰色预测力控制器的有效性。 相似文献
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旋转阴极展成电解加工主要用于型面的光整加工,其最终加工间隙决定了型面精度,对进给速度,初始切深,阴极半径这3个影响最终加工间隙的关键因素进行了试验研究,结果表明旋转阴极展成电解加工具有相当好的间隙稳定性和整平能力,并且由于间隙和阴极半径小,用其光整加工直纹面产生的几何误差远小于铣刀加工,对此进行了理论计算。 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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针对工业机器人进行接触式作业过程中对末端接触力的要求,提出了一种基于力控法兰的末端恒力控制方法。对力控法兰进行了分析建模与参数辨识,设计了模糊控制与比例积分微分(proportion integral derivative,简称PID)控制并行的模糊PID控制器,通过Matlab仿真对纯模糊控制与模糊PID控制效果进行了对比,并研究了模糊PID控制器各参数对控制性能的影响。最后,搭建了基于Labview和外部设备互连(peripheral component interconnect,简称PCI)总线数据采集卡的实验平台,对力控法兰末端输出力进行了实验验证。仿真结果表明,纯模糊控制可提高系统响应性能,但存在一定的稳态误差。加入PID控制与模糊控制并行控制后,仿真与实验证明,阶跃响应的稳态误差消除,正弦跟随效果明显改善,恒力控制输出力在期望力F=10N时波动误差为±0.8N。因此,通过模糊PID控制可实现力控法兰末端的恒力控制,具有较好的动态响应性和跟随鲁棒性。 相似文献
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This study compares three different control algorithms for a muscle-like actuated arm developed to replicate motion in two
degrees-of-freedom (df): elbow flexion/extension (f/e) and forearm pronation/supination (p/s). Electromyogram (EMG) is employed
to help determine the control signal used to actuate the muscle cylinders. Three different types of control strategies were
attempted. The first algorithm used fuzzy logic with EMG signals and position error as control inputs (Fuzzy Controller).
The second algorithm incorporated moment arm information into the existing fuzzy logic controller (Fuzzy-MA Controller). The
third algorithm was a conventional Proportional-Integral-Derivative (PID) controller, which operated solely on position and
integration error (PID Controller). Overall, moment arm scaling aided the fuzzy logic control algorithm by improving movement
accuracy as determined by relative error and correlation. The PID controller resulted in the most accurate movement tracking
after fine tuning the control gains. This study implies that moment arm scaling is an effective tool for improving motion
tracking accuracy of the fuzzy controller in the mechanical arm. The study also implies that PID controller can be used as
a substitute for the fuzzy based controller once the desired motion is prescribed. 相似文献
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基于模糊BP网络的自适应PID控制 总被引:4,自引:0,他引:4
针对经典PID控制的参数不能在线调整的缺陷,提出了一种基于模糊BP神经网络的PID控制算法,采用模糊规则自动地调节BP神经网络训练过程的学习参数,利用神经网络较强的学习能力和模糊控制在模型未知或不精确前提下的控制能力,将其应用到PID控制中[1],实现了PID控制参数的在线调整和优化,并对其在非线性离散系统中的应用进行了仿真。实验结果表明该算法性能优良,加快了系统响应速度,减少了超调量,适用于纯滞后非线性系统。 相似文献