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(1) 边界强化混合分布建模优化少数样本生成策略以改善特征均衡 数控机床转轴组件在高强度加工环境中易发生轴承疲劳、轴弯曲或密封损坏等失效,这些问题往往因实验限制导致少数类数据稀缺,信号噪声高且类内分布不均,影响诊断模型的鲁棒性。本研究提出一种边界强化混合分布建模的少数样本生成方法,旨在提升生成数据的类内均衡和整体分离度。首先,开发结合谱分解技术和信息关联度的信号预处理框架,对原始振动信号进行噪声抑制和故障敏感成分提取,增强信号的表征能力。随后,利用混合分布模型对少数类样本进行内部结构模拟,通过密度引导的采样机制实现类内均衡分布,避免生成样本的聚集偏差。接着,引入最大间距最小内聚准则优化生成边界,确保新样本位于决策边界附近,提高信息价值和可辨识性。这种方法为下游智能模型提供高质量增强数据集,显著提升分类性能。在实验验证中,使用多组机床数据集对比显示,所提策略在少数类召回率和整体准确率上优于传统过采样技术。该框架还考虑了多模态信号融合,如加速度和温度数据的联合处理,进一步强化了在变负载工况下的适用性。通过迭代优化分布参数,该方法确保生成数据的统计一致性,减少过拟合风险。在实际工业应用中,这一策略可集成到在线监测系统中,实现实时数据平衡,降低因数据失衡引发的误诊率。扩展而言,它适用于其他机械系统如齿轮传动的故障诊断,提供了一个通用数据增强范式。研究为失衡数据下的特征均衡提供了创新路径,推动了从数据驱动向智能诊断的演进。
(2) 自激励生成对抗框架用于原始信号依赖的失效模式分类提升 传统生成对抗网络在处理一维机床信号时稳定性差,对原始数据依赖强,导致生成质量不佳影响诊断精度,本研究设计一种自激励生成对抗框架,以改善模型训练和数据生成效果。首先,借鉴树搜索算法引入自激励采样机制,对潜在空间进行奖励引导,缓解梯度消失并增强生成多样性。随后,构建新型损失函数,融合距离度量和惩罚项以稳定对抗过程,避免模式崩溃。采用序列记忆网络替换卷积层,捕捉时序依赖,并集成注意力组件提升对关键故障模式的关注。此外,开发基于滤波函数和注意力分类器的联合架构,与生成框架协同,实现端到端诊断。在对比实验中,该方法在失衡数据集上的生成保真度和诊断准确率显著高于标准对抗网络,特别是在噪声干扰下的表现突出。这一创新减少了对标注数据的依赖,适用于资源有限的工业场景。通过多轮训练验证,该框架的收敛速度更快,泛化能力更强。在机床应用中,集成转速监测可进一步适应变速条件,确保诊断的实时性。扩展到多传感器融合,该方法可处理振动与声学信号的联合生成,提供全面故障视图。总体,这一自激励策略解决了生成瓶颈,为失衡条件下的智能识别注入了新活力,推动了机床维护的智能化转型。
(3) 双辅助注意力增强生成模型应对变转速多态失效数据生成挑战 变转速工况下生成对抗网络对多模式故障样本生成效果差,本研究提出双辅助注意力增强生成模型,以提升复杂环境下的数据增强能力。首先,基于时频分析提出标准化熵映射图像作为故障表征,强化模型对动态信号的适应。随后,设计双辅助结构:噪声注入网络通过信息约束优化隐变量映射,提高对非平稳分布的拟合;独立判别网络解耦分类任务,改善多模式生成稳定性。接着,构建包含注意力模块的损失函数,增强全局特征提取和梯度流畅性。该模型在模拟变速数据集上的生成多样性和诊断性能优于基准方法,特别是在多故障共存场景中表现突出。通过实验迭代,该方法确保了在高变异工况下的鲁棒性。在机床实践中,可与转轴传感器集成,实现在线数据扩充,避免实验成本高企。
import numpy as np import pandas as pd from sklearn.mixture import GaussianMixture from sklearn.neighbors import NearestNeighbors from sklearn.metrics import mutual_info_score from sklearn.model_selection import train_test_split from sklearn.svm import SVC from sklearn.metrics import accuracy_score import torch import torch.nn as nn import torch.optim as optim from torch.utils.data import DataLoader, TensorDataset def signal_preprocess(data, window_size=50): u, s, vh = np.linalg.svd(data, full_matrices=False) reconstructed = np.dot(u[:, :window_size] * s[:window_size], vh[:window_size, :]) mi_scores = [mutual_info_score(reconstructed[:, i], reconstructed[:, j]) for i in range(reconstructed.shape[1]) for j in range(i+1, reconstructed.shape[1])] return reconstructed, np.mean(mi_scores) def boundary_enhanced_gmm_oversample(minority_data, n_components=3, n_samples=100): gmm = GaussianMixture(n_components=n_components) gmm.fit(minority_data) densities = gmm.score_samples(minority_data) sampled_indices = np.argsort(densities)[-n_samples:] neighbors = NearestNeighbors(n_neighbors=5).fit(minority_data) _, indices = neighbors.kneighbors(minority_data[sampled_indices]) synthetic = [] for i in range(n_samples): nn = minority_data[indices[i, 1:]] diff = nn - minority_data[sampled_indices[i]] synthetic.append(minority_data[sampled_indices[i]] + np.random.rand() * diff.mean(axis=0)) return np.array(synthetic) class SelfRewardGAN(nn.Module): def __init__(self, input_dim, hidden_dim): super().__init__() self.generator = nn.Sequential(nn.Linear(input_dim, hidden_dim), nn.ReLU(), nn.Linear(hidden_dim, input_dim)) self.discriminator = nn.Sequential(nn.Linear(input_dim, hidden_dim), nn.ReLU(), nn.Linear(hidden_dim, 1), nn.Sigmoid()) def forward_gen(self, z): return self.generator(z) def forward_disc(self, x): return self.discriminator(x) def train_gan(model, data_loader, epochs=10, lr=0.001): optimizer_g = optim.Adam(model.generator.parameters(), lr=lr) optimizer_d = optim.Adam(model.discriminator.parameters(), lr=lr) criterion = nn.BCELoss() for epoch in range(epochs): for real in data_loader: batch_size = real.size(0) real_labels = torch.ones(batch_size, 1) fake_labels = torch.zeros(batch_size, 1) z = torch.randn(batch_size, model.generator[0].in_features) fake = model.forward_gen(z) d_real = model.forward_disc(real) d_fake = model.forward_disc(fake.detach()) loss_d = criterion(d_real, real_labels) + criterion(d_fake, fake_labels) optimizer_d.zero_grad() loss_d.backward() optimizer_d.step() g_out = model.forward_disc(fake) loss_g = criterion(g_out, real_labels) optimizer_g.zero_grad() loss_g.backward() optimizer_g.step() def generate_dataset(n_samples=200, dim=10, classes=3): data = np.random.randn(n_samples, dim) labels = np.random.randint(0, classes, n_samples) return data, labels data, labels = generate_dataset() minority_idx = np.where(labels == 0)[0] minority_data = data[minority_idx] preprocessed, mi = signal_preprocess(minority_data) synthetic = boundary_enhanced_gmm_oversample(preprocessed, n_samples=100) augmented_data = np.vstack([data, synthetic]) augmented_labels = np.hstack([labels, np.zeros(100)]) X_train, X_test, y_train, y_test = train_test_split(augmented_data, augmented_labels, test_size=0.2) clf = SVC() clf.fit(X_train, y_train) preds = clf.predict(X_test) acc = accuracy_score(y_test, preds) class DualAuxGAN(nn.Module): def __init__(self, input_dim, hidden_dim): super().__init__() self.gen = nn.LSTM(input_dim, hidden_dim, batch_first=True) self.disc = nn.LSTM(hidden_dim, 1, batch_first=True) self.attn = nn.MultiheadAttention(hidden_dim, 1) def generate(self, z): out, _ = self.gen(z.unsqueeze(1)) attn_out, _ = self.attn(out, out, out) return attn_out.squeeze(1) def entropy_map(signal, bins=10): hist, _ = np.histogram(signal, bins=bins) probs = hist / np.sum(hist) entropy = -np.sum(probs * np.log(probs + 1e-10)) return entropy / np.log(bins) entropies = [entropy_map(d) for d in data] class ClusterGuidedTransfer(nn.Module): def __init__(self, input_dim, output_dim): super().__init__() self.fc = nn.Linear(input_dim, output_dim) self.gmm = GaussianMixture(n_components=2) def forward(self, x): return self.fc(x) def dynamic_weighting(scores, alpha=0.5): weights = np.exp(alpha * scores) / np.sum(np.exp(alpha * scores)) return weights source_data = np.random.randn(100, 10) target_data = np.random.randn(50, 10) model = ClusterGuidedTransfer(10, 3) optimizer = optim.Adam(model.parameters()) criterion = nn.CrossEntropyLoss() for epoch in range(5): source_out = model(torch.tensor(source_data, dtype=torch.float32)) target_out = model(torch.tensor(target_data, dtype=torch.float32)) source_loss = criterion(source_out, torch.randint(0, 3, (100,))) scores = torch.softmax(target_out, dim=1).max(dim=1)[0].detach().numpy() weights = dynamic_weighting(scores) target_loss = criterion(target_out, torch.randint(0, 3, (50,))) * torch.tensor(weights) loss = source_loss + target_loss.mean() optimizer.zero_grad() loss.backward() optimizer.step()如有问题,可以直接沟通
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