Solenoid directional control valve fault pattern recognition based on multi-feature fusion
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摘要:
为提高基于驱动端电流检测的电磁换向阀故障诊断方法的可靠性和识别准确度,开展了电磁换向阀故障模式识别方法研究。提出一种基于多特征融合的方法对电流信号时频分析和时域参数的特征值提取融合;通过设计电磁换向阀驱动端电流信号的采集实验,获取电磁换向阀驱动端电流的时域信号和二阶变化率的多特征曲线,提取时域参数及二阶变化率相应频带能量作为特征值,构建多特征融合的特征向量;采用基于径向基核函数的多分类支持向量机对电磁换向阀进行模式识别。结果表明:基于多特征融合的支持向量机较基于能量特征值的支持向量机可提升8.7%的识别精度和42.11%的验证准确率。
Abstract:In order to further improve the reliability and recognition accuracy of the solenoid valve fault diagnosis method based on current detection at the drive end, a research was conducted on the solenoid valve fault pattern recognition method. First, a method for extracting eigenvalues based on time-frequency analysis of current signals and time-domain parameters was proposed; then, through designing an acquisition experiment of the current signal at the solenoid valve drive end, the time domain signal of the solenoid valve drive end current and the multi-characteristic curve of the second-order rate of change were obtained. Meanwhile, the time-domain parameters and the frequency band energy corresponding to the second-order rate of change were extracted as the characteristic value, in order to construct the feature vector of multi-feature fusion. Finally, a multi-class support vector machine based on the radial basis kernel function was used to identify the electromagnetic directional valve pattern. The research results showed that compared with the support vector machine based on energy eigenvalues, the support vector machine based on multi-feature fusion can improve the recognition accuracy by 8.7% and the verification accuracy by 42.11%.
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表 1 不同SVM准确率对比
Table 1. Comporison of different SVM accuracy rates
SVM类型 训练准确率/% 测试准确率/% 五折交叉验证准确率/% C-SVC 100 91.30 50 υ-SVC 94.74 84.78 50 ε-SVR 100 86.96 υ-SVR 100 86.96 表 2 不同核函数SVM准确率对比
Table 2. Comporison of SVM accuracy rates of different kernel functions
核函数 训练准确率/% 测试准确率/% 五折交叉验证准确率/% Polynomial 97.74 89.13 50 RBF 100 91.30 50 Sigmoid 76.32 67.39 42.11 表 3 四种不同状况特征向量
Table 3. Four feature vectors under different situations
电磁换向阀状态 组号 E30 E31 E32 E33 E34 E35 E36 E37 阀芯正常 第1组 0.0871 0.1096 0.0829 0.1920 0.2944 0.6247 0.1529 0.6606 第2组 0.0769 0.1060 0.0997 0.2109 0.2433 0.6577 0.1945 0.6315 弹簧断裂 第1组 0.0121 0.0302 0.0969 0.0845 0.6050 0.5377 0.2156 0.5299 第2组 0.0013 0.0034 0.1421 0.1759 0.6216 0.7014 0.1777 0.1972 阀芯卡死 第1组 0.0219 0.0747 0.1492 0.1535 0.6368 0.4306 0.3047 0.5142 第2组 0.0226 0.0388 0.0892 0.0574 0.5849 0.4790 0.2479 0.5947 阀芯轻微卡滞 第1组 0.0326 0.1608 0.1768 0.1104 0.2458 0.4869 0.2196 0.7642 第2组 0.0400 0.0893 0.2242 0.1792 0.3224 0.7458 0.2200 0.4467 表 4 各主元贡献率
Table 4. Contribution rate of each principal
主元数 贡献率/% 1 60.0411 2 29.1488 3 9.0540 4 1.6772 5 0.0659 6 0.0071 7 0.0051 8 0.0005 9 0.0002 10 0.0001 11 1.21×10−5 表 5 前4主元系数
Table 5. First 4 pivot coefficients
时域信号 第1主元 第2主元 第3主元 第4主元 p1 −0.3333 0.2689 0.171 0.1703 p2 −0.2795 −0.330 −0.290 0.5124 p3 −0.2594 0.414 0.0356 0.1565 p4 0.2871 0.2245 0.5244 −0.3011 p5 −0.3333 0.2687 0.1719 0.1717 p6 0.2469 0.3678 −0.4031 −0.0773 p7 0.3537 0.0989 0.3041 0.520 p8 0.3529 0.2034 −0.0267 0.4869 p9 −0.350 0.1216 0.3778 0.0651 p10 0.3101 −0.3042 0.2449 0.2126 p11 0.1439 0.4806 −0.3499 0.0305 -
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