There are multiple operating modes in the real industrial process, and the collected data follow the complex multimodal distribution, so most traditional process monitoring methods are no longer applicable because the...There are multiple operating modes in the real industrial process, and the collected data follow the complex multimodal distribution, so most traditional process monitoring methods are no longer applicable because their presumptions are that sampled-data should obey the single Gaussian distribution or non-Gaussian distribution. In order to solve these problems, a novel weighted local standardization(WLS) strategy is proposed to standardize the multimodal data, which can eliminate the multi-mode characteristics of the collected data, and normalize them into unimodal data distribution. After detailed analysis of the raised data preprocessing strategy, a new algorithm using WLS strategy with support vector data description(SVDD) is put forward to apply for multi-mode monitoring process. Unlike the strategy of building multiple local models, the developed method only contains a model without the prior knowledge of multi-mode process. To demonstrate the proposed method's validity, it is applied to a numerical example and a Tennessee Eastman(TE) process. Finally, the simulation results show that the WLS strategy is very effective to standardize multimodal data, and the WLS-SVDD monitoring method has great advantages over the traditional SVDD and PCA combined with a local standardization strategy(LNS-PCA) in multi-mode process monitoring.展开更多
Complex industry processes often need multiple operation modes to meet the change of production conditions. In the same mode,there are discrete samples belonging to this mode. Therefore,it is important to consider the...Complex industry processes often need multiple operation modes to meet the change of production conditions. In the same mode,there are discrete samples belonging to this mode. Therefore,it is important to consider the samples which are sparse in the mode.To solve this issue,a new approach called density-based support vector data description( DBSVDD) is proposed. In this article,an algorithm using Gaussian mixture model( GMM) with the DBSVDD technique is proposed for process monitoring. The GMM method is used to obtain the center of each mode and determine the number of the modes. Considering the complexity of the data distribution and discrete samples in monitoring process,the DBSVDD is utilized for process monitoring. Finally,the validity and effectiveness of the DBSVDD method are illustrated through the Tennessee Eastman( TE) process.展开更多
随着数据维度和规模的不断增加,基于深度学习的异常检测方法取得了优异的检测性能,其中深度支持向量数据描述(Deep SVDD)得到了广泛应用。然而,要缓解超球崩溃问题,就需要对Deep SVDD中映射网络的各种参数施加约束。为了进一步提高Deep ...随着数据维度和规模的不断增加,基于深度学习的异常检测方法取得了优异的检测性能,其中深度支持向量数据描述(Deep SVDD)得到了广泛应用。然而,要缓解超球崩溃问题,就需要对Deep SVDD中映射网络的各种参数施加约束。为了进一步提高Deep SVDD中映射网络的特征学习能力,同时解决超球崩溃问题,提出了基于混合高斯先验变分自编码器的深度多球支持向量数据描述(Deep Multiple-Sphere Support Vector Data Description Based on Variational Autoencoder with Mixture-of-Gaussians Prior,DMSVDD-VAE-MoG)。首先,通过预训练初始化网络参数和多个超球中心;其次,利用映射网络获得训练数据的潜在特征,对VAE损失、多个超球的平均半径和潜在特征到所对应超球中心的平均距离进行联合优化,以获得最优网络连接权重和多个最小超球。实验结果表明,所提DMSVDD-VAE-MoG在MNIST,Fashion-MNIST和CIFAR-10上均取得了优于其他8种相关方法的检测性能。展开更多
Predictive maintenance has emerged as an effective tool for curbing maintenance costs,yet prevailing research predominantly concentrates on the abnormal phases.Within the ostensibly stable healthy phase,the reliance o...Predictive maintenance has emerged as an effective tool for curbing maintenance costs,yet prevailing research predominantly concentrates on the abnormal phases.Within the ostensibly stable healthy phase,the reliance on anomaly detection to preempt equipment malfunctions faces the challenge of sudden anomaly discernment.To address this challenge,this paper proposes a dual-task learning approach for bearing anomaly detection and state evaluation of safe regions.The proposed method transforms the execution of the two tasks into an optimization issue of the hypersphere center.By leveraging the monotonicity and distinguishability pertinent to the tasks as the foundation for optimization,it reconstructs the SVDD model to ensure equilibrium in the model’s performance across the two tasks.Subsequent experiments verify the proposed method’s effectiveness,which is interpreted from the perspectives of parameter adjustment and enveloping trade-offs.In the meantime,experimental results also show two deficiencies in anomaly detection accuracy and state evaluation metrics.Their theoretical analysis inspires us to focus on feature extraction and data collection to achieve improvements.The proposed method lays the foundation for realizing predictive maintenance in a healthy stage by improving condition awareness in safe regions.展开更多
为解决传统航空发动机异常检测方法准确率和泛化性能较低的问题,提出一种混合核最大相关熵的深度支持向量数据描述(mixed kernel maximum correntropy criterion-deep support vector data description,MKMCC-DSVDD)方法。首先,采用合...为解决传统航空发动机异常检测方法准确率和泛化性能较低的问题,提出一种混合核最大相关熵的深度支持向量数据描述(mixed kernel maximum correntropy criterion-deep support vector data description,MKMCC-DSVDD)方法。首先,采用合成少数类过采样技术扩充异常样本规模,提高对非均衡样本的泛化性能;其次,建立基于混合核改进的最大相关熵损失函数,可以在无须数据分布假设的前提下提升准确率;最后,构建基于MKMCC-DSVDD的航空发动机异常检测方法。在航空发动机气路系统和滑油系统异常检测实验中,所提方法平均曲线下的面积(area under curve,AUC)达到98.53%,表明其具有较高的实用性和泛化性能。展开更多
针对风电机组叶片排水孔堵塞或被雷击穿孔等问题,提出一种非接触式的声学检测方法。该方法首先对采集到的信号转化为时频图,利用中值滤波和自适应阈值的方法将时频图二值化,根据二值化时频图中哨音轮廓特点,提取轮廓信号时域和频域等9...针对风电机组叶片排水孔堵塞或被雷击穿孔等问题,提出一种非接触式的声学检测方法。该方法首先对采集到的信号转化为时频图,利用中值滤波和自适应阈值的方法将时频图二值化,根据二值化时频图中哨音轮廓特点,提取轮廓信号时域和频域等9个参数作为特征向量,提出了动态半径的支持向量数据描述异常检测模型(dynamic radius support vector data description,DR-SVDD)。将DR-SVDD和SVDD的异常检测模型用于风机叶片哨声诊断,验证了该方法的有效性。展开更多
为了进一步提高电动汽车轮毂电机轴承状态识别技术的高效可靠性,提出一种基于双核支持向量数据描述(double kernel based support vector data description,简称DK-SVDD)的轮毂电机轴承状态识别方法。首先,针对轮毂电机轴承样本数据结...为了进一步提高电动汽车轮毂电机轴承状态识别技术的高效可靠性,提出一种基于双核支持向量数据描述(double kernel based support vector data description,简称DK-SVDD)的轮毂电机轴承状态识别方法。首先,针对轮毂电机轴承样本数据结构混杂致使SVDD识别率较低问题,通过一定的比例权重将径向基(radial basis function,简称RBF)核函数和高斯差分(difference of Gaussians,简称DOG)核函数结合构建DK核函数;其次,根据最优二叉树原理逐层设计状态识别分类器,并搭建DK-SVDD轮毂电机轴承状态识别模型,同时使用粒子群优化算法对模型参数寻优以提高DK-SVDD的学习能力和泛化能力;最后,基于轮毂电机轴承台架试验数据,验证所提方法的有效性和优越性。结果表明:针对轮毂电机轴承目标状态识别,DK-SVDD方法平均训练时间为0.0655 s,平均状态识别率为97.06%;与采用RBF或DOG核函数相比,DK-SVDD方法在多种工况下可以有效提高状态识别率并降低训练时间。展开更多
针对行星滚柱丝杠(planetary roller screw mechanism,PRSM)在实际应用中故障机理不明和故障种类少,难以有效进行故障决策这一现存问题,提出采用单分类模型——深度支持向量数据描述(deep support vector data description,deep SVDD)...针对行星滚柱丝杠(planetary roller screw mechanism,PRSM)在实际应用中故障机理不明和故障种类少,难以有效进行故障决策这一现存问题,提出采用单分类模型——深度支持向量数据描述(deep support vector data description,deep SVDD)进行故障检测,判断PRSM是否处于正常状态。首先,在PRSM试验台上采集正常状态、润滑失效和滚柱一侧断齿3种状态的振动信号;其次,对数据进行归一化并通过窗口裁剪的方式进行数据增强,以扩充样本数量;然后,通过小波包变换对信号进行分解,以初步提取数据的特征;最后,利用deep SVDD实现PRSM故障检测,同时与单分类支持向量机(one-class support vector machine,OCSVM)和支持向量数据描述(support vector data description,SVDD)方法进行对比,结果表明,deep SVDD具有更好的分类能力和较高的训练效率,较为适合实现PRSM故障检测。展开更多
基金Project(61374140)supported by the National Natural Science Foundation of China
文摘There are multiple operating modes in the real industrial process, and the collected data follow the complex multimodal distribution, so most traditional process monitoring methods are no longer applicable because their presumptions are that sampled-data should obey the single Gaussian distribution or non-Gaussian distribution. In order to solve these problems, a novel weighted local standardization(WLS) strategy is proposed to standardize the multimodal data, which can eliminate the multi-mode characteristics of the collected data, and normalize them into unimodal data distribution. After detailed analysis of the raised data preprocessing strategy, a new algorithm using WLS strategy with support vector data description(SVDD) is put forward to apply for multi-mode monitoring process. Unlike the strategy of building multiple local models, the developed method only contains a model without the prior knowledge of multi-mode process. To demonstrate the proposed method's validity, it is applied to a numerical example and a Tennessee Eastman(TE) process. Finally, the simulation results show that the WLS strategy is very effective to standardize multimodal data, and the WLS-SVDD monitoring method has great advantages over the traditional SVDD and PCA combined with a local standardization strategy(LNS-PCA) in multi-mode process monitoring.
基金National Natural Science Foundation of China(No.61374140)the Youth Foundation of National Natural Science Foundation of China(No.61403072)
文摘Complex industry processes often need multiple operation modes to meet the change of production conditions. In the same mode,there are discrete samples belonging to this mode. Therefore,it is important to consider the samples which are sparse in the mode.To solve this issue,a new approach called density-based support vector data description( DBSVDD) is proposed. In this article,an algorithm using Gaussian mixture model( GMM) with the DBSVDD technique is proposed for process monitoring. The GMM method is used to obtain the center of each mode and determine the number of the modes. Considering the complexity of the data distribution and discrete samples in monitoring process,the DBSVDD is utilized for process monitoring. Finally,the validity and effectiveness of the DBSVDD method are illustrated through the Tennessee Eastman( TE) process.
文摘随着数据维度和规模的不断增加,基于深度学习的异常检测方法取得了优异的检测性能,其中深度支持向量数据描述(Deep SVDD)得到了广泛应用。然而,要缓解超球崩溃问题,就需要对Deep SVDD中映射网络的各种参数施加约束。为了进一步提高Deep SVDD中映射网络的特征学习能力,同时解决超球崩溃问题,提出了基于混合高斯先验变分自编码器的深度多球支持向量数据描述(Deep Multiple-Sphere Support Vector Data Description Based on Variational Autoencoder with Mixture-of-Gaussians Prior,DMSVDD-VAE-MoG)。首先,通过预训练初始化网络参数和多个超球中心;其次,利用映射网络获得训练数据的潜在特征,对VAE损失、多个超球的平均半径和潜在特征到所对应超球中心的平均距离进行联合优化,以获得最优网络连接权重和多个最小超球。实验结果表明,所提DMSVDD-VAE-MoG在MNIST,Fashion-MNIST和CIFAR-10上均取得了优于其他8种相关方法的检测性能。
基金Supported by Sichuan Provincial Key Research and Development Program of China(Grant No.2023YFG0351)National Natural Science Foundation of China(Grant No.61833002).
文摘Predictive maintenance has emerged as an effective tool for curbing maintenance costs,yet prevailing research predominantly concentrates on the abnormal phases.Within the ostensibly stable healthy phase,the reliance on anomaly detection to preempt equipment malfunctions faces the challenge of sudden anomaly discernment.To address this challenge,this paper proposes a dual-task learning approach for bearing anomaly detection and state evaluation of safe regions.The proposed method transforms the execution of the two tasks into an optimization issue of the hypersphere center.By leveraging the monotonicity and distinguishability pertinent to the tasks as the foundation for optimization,it reconstructs the SVDD model to ensure equilibrium in the model’s performance across the two tasks.Subsequent experiments verify the proposed method’s effectiveness,which is interpreted from the perspectives of parameter adjustment and enveloping trade-offs.In the meantime,experimental results also show two deficiencies in anomaly detection accuracy and state evaluation metrics.Their theoretical analysis inspires us to focus on feature extraction and data collection to achieve improvements.The proposed method lays the foundation for realizing predictive maintenance in a healthy stage by improving condition awareness in safe regions.
文摘为解决传统航空发动机异常检测方法准确率和泛化性能较低的问题,提出一种混合核最大相关熵的深度支持向量数据描述(mixed kernel maximum correntropy criterion-deep support vector data description,MKMCC-DSVDD)方法。首先,采用合成少数类过采样技术扩充异常样本规模,提高对非均衡样本的泛化性能;其次,建立基于混合核改进的最大相关熵损失函数,可以在无须数据分布假设的前提下提升准确率;最后,构建基于MKMCC-DSVDD的航空发动机异常检测方法。在航空发动机气路系统和滑油系统异常检测实验中,所提方法平均曲线下的面积(area under curve,AUC)达到98.53%,表明其具有较高的实用性和泛化性能。
文摘由于电网企业不断加快数字化转型,利用北斗定位技术将自动获取区域内光伏计量装置经纬度这一关键技术参数。文章充分利用分布式光伏集群内光伏发电装机位置空间相关性,提出一种在弱监督下基于图滤波与支持向量数据描述(support vector data description,SVDD)的分布式光伏集群发电异常检测方法。首先建立分布式光伏集群发电图数据结构模型,通过加权邻接矩阵描述分布式光伏发电点空间耦合性,其次构造图高通滤波器将时域参数转化为频域参数,然后通过SVDD算法优化图滤波结果,进一步挖掘图高通滤波器阈值与输出功率数据之间的关系。结果表明,采用图滤波器和SVDD算法模型方法在分布式光伏发电异常检测精度上有显著提高。
文摘针对风电机组叶片排水孔堵塞或被雷击穿孔等问题,提出一种非接触式的声学检测方法。该方法首先对采集到的信号转化为时频图,利用中值滤波和自适应阈值的方法将时频图二值化,根据二值化时频图中哨音轮廓特点,提取轮廓信号时域和频域等9个参数作为特征向量,提出了动态半径的支持向量数据描述异常检测模型(dynamic radius support vector data description,DR-SVDD)。将DR-SVDD和SVDD的异常检测模型用于风机叶片哨声诊断,验证了该方法的有效性。
文摘为了进一步提高电动汽车轮毂电机轴承状态识别技术的高效可靠性,提出一种基于双核支持向量数据描述(double kernel based support vector data description,简称DK-SVDD)的轮毂电机轴承状态识别方法。首先,针对轮毂电机轴承样本数据结构混杂致使SVDD识别率较低问题,通过一定的比例权重将径向基(radial basis function,简称RBF)核函数和高斯差分(difference of Gaussians,简称DOG)核函数结合构建DK核函数;其次,根据最优二叉树原理逐层设计状态识别分类器,并搭建DK-SVDD轮毂电机轴承状态识别模型,同时使用粒子群优化算法对模型参数寻优以提高DK-SVDD的学习能力和泛化能力;最后,基于轮毂电机轴承台架试验数据,验证所提方法的有效性和优越性。结果表明:针对轮毂电机轴承目标状态识别,DK-SVDD方法平均训练时间为0.0655 s,平均状态识别率为97.06%;与采用RBF或DOG核函数相比,DK-SVDD方法在多种工况下可以有效提高状态识别率并降低训练时间。
文摘针对行星滚柱丝杠(planetary roller screw mechanism,PRSM)在实际应用中故障机理不明和故障种类少,难以有效进行故障决策这一现存问题,提出采用单分类模型——深度支持向量数据描述(deep support vector data description,deep SVDD)进行故障检测,判断PRSM是否处于正常状态。首先,在PRSM试验台上采集正常状态、润滑失效和滚柱一侧断齿3种状态的振动信号;其次,对数据进行归一化并通过窗口裁剪的方式进行数据增强,以扩充样本数量;然后,通过小波包变换对信号进行分解,以初步提取数据的特征;最后,利用deep SVDD实现PRSM故障检测,同时与单分类支持向量机(one-class support vector machine,OCSVM)和支持向量数据描述(support vector data description,SVDD)方法进行对比,结果表明,deep SVDD具有更好的分类能力和较高的训练效率,较为适合实现PRSM故障检测。