Motor Bearing Fault Diagnosis Research Articles

Early-Stage Fault Diagnosis of Motor Bearing Based on Kurtosis Weighting and Fusion of Current-Vibration Signals.

To solve the problem of a low signal-to-noise ratio of fault signals and the difficulty in effectively and accurately identifying the fault state in the early stage of motor bearing fault occurrence, this paper proposes an early fault diagnosis method for bearings based on the Differential Local Mean Decomposition (DLMD) and fusion of current-vibration signals. This method uses DLMD to decompose the current signal and vibration signal, respectively, and weights the decomposed product function (PF) according to the kurtosis value to reconstruct the signal, and then fuses the reconstructed signals to obtain the current-vibration fusion signal after normalization, and then analyzes the fusion signal spectrally through the Hilbert envelope spectrum. Finally, the fusion signal is analyzed by the Hilbert envelope spectrum, and a clear fault characteristic frequency is obtained. The experimental results demonstrate that compared to traditional bearing fault diagnosis methods, the proposed method significantly improves the signal-to-noise ratio of fault signals, effectively enhances the sensitivity of early-stage fault detection in motor bearings, and improves the accuracy of fault identification.

Towards multi-scene learning: A novel cross-domain adaptation model based on sparse filter for traction motor bearing fault diagnosis in high-speed EMU

Fault diagnosis of traction motor bearing is of great significance to improve the reliability and safety of high-speed electric multiple units (EMU). While the fault diagnosis method based on cross-domain adaptation has been successful in scenarios involving speed or load fluctuations, existing methods ignore the independence and diversity of features, resulting in unsatisfactory diagnostic results under multi-scene learning, thereby reducing the generalization ability. Moreover, the development of complex models is time-consuming, and their computational efficiency is low. To address these issues, this study proposes a novel cross-domain adaptation model based on sparse filtering (SFCDA), which consists of only two fully connected (FC) layers. Firstly, pre-training is conducted to utilize the soft reconstruction penalties to constrain the weights of sparse filtering and improve the independence of features. The weights of unsupervised training are used to initialize the parameters of the first FC layer of the SFCDA model. Secondly, a multiple sparse regularization (MSR) algorithm is proposed and used to constrain the SFCDA. Then, fine-tuning is conducted, in which the structural alignment function is used to measure the distribution distance between the source and target domain data. Minimizing the kernel norm can improve the diversity of features and enhance the robustness. Finally, the effectiveness of SFCDA in multi-scene learning is proved theoretically. It is validated in three fault diagnosis scenes in four different bearing datasets. The results show that the suggested approach is more straightforward and has a better fault diagnosis effect than the state-of-the-art domain adaptive approaches.

Imbalanced deep transfer network for fault diagnosis of high-speed train traction motor bearings

Transfer learning-based fault diagnosis methods have been increasingly utilized for major equipment, including high-speed trains, turbine machines, and aircraft engines. However, most traditional transfer methods based on implicitly balanced data only consider feature shift. When applied to high-speed train traction motor bearing fault diagnosis, the cross-domain generalization ability of these transfer methods is weakened by label shift. Due to the complex operating conditions of high-speed trains, these transfer methods often fail under multiple operating conditions, resulting in reduced cross-domain diagnostic accuracy when faced with feature shift and label shift simultaneously. Therefore, we propose the imbalanced deep transfer network (IDTN) to tackle the aforementioned problem in cross-domain fault diagnosis of high-speed train traction motor bearings. Firstly, IDTN overcomes the influence of imbalanced distributions in source domain samples through deep imbalanced learning. Then, batch nuclear-norm maximization is introduced to enhance the prediction discriminability and diversity of the target domain samples. Finally, case studies of the high-speed train traction motor bearing fault dataset and the Case Western Reserve University bearing fault dataset are conducted. Experimental results prove the effectiveness and superiority of IDTN in the cross-domain fault diagnosis field with both feature shift and label shift.

TRA-ACGAN: A motor bearing fault diagnosis model based on an auxiliary classifier generative adversarial network and transformer network

Motor bearing fault diagnosis is essential to guarantee production efficiency and avoid catastrophic accidents. Deep learning-based methods have been developed and widely used for fault diagnosis, and these methods have proven to be very effective in accurately diagnosing bearing faults. In this paper, study the application of generative adversarial networks (GANs) in motor bearing fault diagnosis to address the practical issue of insufficient fault data in industrial testing. Focus on the auxiliary classifier generative adversarial network (ACGAN), and the data expansion is carried out for small datasets. This paper present a novel transformer network and auxiliary classifier generative adversarial network (TRA-ACGAN) for motor bearing fault diagnosis, where the TRA-ACGAN combines an ACGAN with a transformer network to avoid the traditional iterative and convolutional structures. The attention mechanism is fully utilized to extract more effective features, and the dual-task coupling problem encountered in classical ACGANs is avoided. Experimental results with the CWRU dataset and the PU dataset in the field of motor bearing fault diagnosis demonstrate the suitability and superiority of the TRA-ACGAN.

Bearing fault diagnosis via fusing small samples and training multi-state Siamese neural networks

Recently, deep learning techniques have been widely applied to fault diagnosis due to their outstanding feature extraction abilities. The success of deep-learning-based fault diagnosis methods is highly dependent on the quantity and quality of the training data. In practical scenarios, it is challenging to obtain sufficient high-quality training data for fault diagnosis tasks due to complex environments, which would affect the effectiveness of the deep learning methods. In this paper, a new fault diagnosis method is proposed for motor bearing fault diagnosis under small samples. The Siamese neural networks (SNNs) are employed to extract the fault features. A multi-stage training strategy is proposed to train the SNNs with the aim to prevent the training stagnation problem and handle the small sample problem. A multi-source feature fusion network is developed to make full use of the multi-source sensor data by fusing the extracted fault features for further fault diagnosis. The proposed method is applied to motor bearing fault diagnosis on two real-world datasets. Experimental results demonstrate the effectiveness and feasibility of the introduced method for motor bearing fault diagnosis under small samples.

Motor Bearing Fault Diagnosis in an Industrial Robot Under Complex Variable Speed Conditions

Abstract Motor bearing is the key vulnerable part of the servomotor in an industrial robot, which is always arranged at the joint that is the main load area. In the movement process of the robot, motor bearing bears a great impact due to the frequent movement of joints, which is easily damaged. The fault characteristic information of a bearing in these complex conditions shows strong nonstationary characteristics. Early nonstationary fault signals are often weak and submerged in background noise. The nonstationary signal processing method using computed order analysis and the weak signal enhancement method using adaptive stochastic resonance both show good performances for the above problems. Inspired by these, a hybrid diagnosis strategy for motor bearing under these speed conditions is proposed. Firstly, the nonstationary fault signals of the motor bearing are transformed into stationary angular signals via computed order analysis. Then, the fault modes are identified via resonance demodulation and variational mode decomposition in the order spectrum. Finally, adaptive stochastic resonance is used to extract the fault features reflecting the bearing operation state. Two types of typical speed conditions are considered, which are representative of the joint. Numerical simulation analysis and experiments verify the effectiveness of the diagnosis method.

A novel framework for motor bearing fault diagnosis based on multi-transformation domain and multi-source data

Through the application of deep learning and multi-sensor data, fault features can be automatically extracted and valuable information can be integrated to tackle intricate challenges in motor bearing fault diagnosis. Most existing fusion models focus primarily on the original time series signal with information extraction largely restricted to the time domain (without extensions into multiple transformation domains). Also, in most fusion models, the sensor fusion level is kept relatively simple which could lead to the oversight of correlations and complementarities among the information. To enhance the recognition capability of diagnostic network features, in this paper, we propose a novel framework for motor bearing fault diagnosis from the perspectives of multi-transformation domain and multi-source data fusion. Within this framework, feature extraction and fusion from various source data are achieved in the time domain, frequency domain, and time–frequency domain. Distinct independent networks are set up within these domains: one network is designated for overseeing feature fusion, while the others are dedicated to extracting features from individual sensors. To support the extraction of pivotal features across multiple fusion layers in various transformation domains, several fusion nodes are inserted between the layers of the multiple feature extraction networks and the feature summarization network. Furthermore, a channel attention mechanism is introduced as a fusion strategy that serves to pinpoint the significance of different features, thus enhancing the efficiency of feature extraction. Experimental evaluation reveals the efficacy of the proposed model and highlights its noteworthy performance attributes such as scalability and universality.

Retracted: Research on Motor Bearing Fault Diagnosis Based on the AdaBoost Algorithm and the Ensemble Learning with Bayesian Optimization in the Industrial Internet of Things

Retracted: Research on Motor Bearing Fault Diagnosis Based on the AdaBoost Algorithm and the Ensemble Learning with Bayesian Optimization in the Industrial Internet of Things

An adaptive morphological filtering and feature enhancement method for spindle motor bearing fault diagnosis

The unbalanced electromagnetic force and unqualified assembly of the spindle motor lead to weak vibration energy and the difference in fault features in different life cycles and different bearing individuals. Compared with single fault diagnosis and the datasets that come from the test bench, compound faults diagnosis of the spindle motor is a challenging task. To solve it, an improved filtering and feature enhancement method combined with the merits of AMF and TEO is proposed. Firstly, the adaptive morphological filtering (AMF) method is developed by adaptively constructing the size of the structural element (SE) for remaining in corresponding SE with the component of interest, which can reduce interference from background noise. Still, the periodic fault impulse, especially the incipient fault signals, is easily modulated by other fault-unrelated harmonic components. Thus, the filtered signals are processed by the Teager energy operator (TEO) for enhancing the faint transient impact compositions. Finally, the effectiveness of the method is verified by simulation and fault motor matched with NTN ceramic bearing and FAG metal bearing respectively, where the motor matched with NTN ceramic bearing is an early failure case and the other is a late failure case. Besides, compared with some traditional methods, the result proves that the proposed method has better performance under the actual engineering scenarios for different degrees of fault feature identification.

Induction Motor Bearing Fault Diagnosis Based on Singular Value Decomposition of the Stator Current

Among the most widespread systems in industrial plants are automated drive systems, the key and most common element of which is the induction motor. In view of challenging operating conditions of equipment, the task of fault detection based on the analysis of electrical parameters is relevant. The authors propose the identification of patterns characterizing the occurrence and development of the bearing defect by the singular analysis method as applied to the stator current signature. As a result of the decomposition, the time series of the three-phase current are represented by singular triples ordered by decreasing contribution, which are reconstructed into the form of time series for subsequent analysis using a Hankelization of matrices. Experimental studies with bearing damage imitation made it possible to establish the relationship between the changes in the contribution of the reconstructed time series and the presence of different levels of bearing defects. By using the contribution level and tracking the movement of the specific time series, it became possible to observe both the appearance of new components in the current signal and the changes in the contribution of the components corresponding to the defect to the overall structure. The authors verified the clustering results based on a visual assessment of the component matrices’ structure similarity using scattergrams and hierarchical clustering. The reconstruction of the time series from the results of the component grouping allows the use of these components for the subsequent prediction of faults development in electric motors.

A novel motor bearing fault diagnosis method based on a deep sparse binary autoencoder and principal component analysis

Due to the complex and variable operating conditions of motor bearings, it is difficult for a deep autoencoder (DAE) to effectively extract valuable fault features from the raw vibration signal, which makes it difficult to identify faults. To enhance the extraction ability of the deep features of a network model and improve the accuracy of fault identification, this paper proposes a fault diagnosis method for motor bearings based on a deep sparse binary autoencoder and principal component analysis (PCA). Firstly, a deep sparse binary autoencoder is constructed by combining an autoencoder with a binary processor to improve the ability to extract deep features. Secondly, principal component analysis is used to fuse high-dimensional features to reduce dimensionality and eliminate redundant information existing in the deep features. Finally, fused deep features are input into a Softmax classifier to train the intelligent fault diagnosis model. The proposed method is validated on a rolling bearing dataset. Compared with existing methods, the experimental results show that this method can effectively extract robust features from the original vibration signals and improve the fault diagnosis results.

A Deep-Learning-Based Fault Diagnosis Method of Industrial Bearings Using Multi-Source Information

In recent years, the industrial motor bearing fault diagnosis method based on deep learning and multi-source information fusion has made some research progress, and research results show that the uncertainty of noise interference and signal measurement error has been improved to a certain extent. However, the multi-source heterogeneous information of industrial motor bearings not only improves the stability and fault tolerance of the bearing fault diagnosis model but also brings conflicts in information fusion. If the conflicts caused by multi-source information cannot be reasonably resolved, it will be difficult to make further judgments on the bearing faults of industrial motors. Therefore, solving the multi-source information conflict effectively while fully using the complementarity of bearing multi-source heterogeneous information is an urgent problem to be solved in developing industrial motor-bearing fault diagnosis technology. This paper proposes an industrial motor bearing fault diagnosis algorithm based on multi-local model decision conflict resolution (MLMF-CR) to fully integrate multi-source heterogeneous information and reasonably resolve multi-source information conflicts. After the initial characteristic signal selection and cleaning of the vibration and current signals of industrial motor bearings, the algorithm deeply excavates the characteristic information of the bearing signals in each fault state through the local fault diagnosis model based on the bidirectional long short-term memory network (Bi-LSTM) and forms a local diagnosis. After the decision is made, evidence theory is used for fusion. In addition, the high conflict situation that may occur in the process of decision-making fusion is also considered. To this end, the trust degree distribution is introduced to reduce information conflict. Specifically, according to the difference in the sensitivity and reliability of bearing faults under different operating environments or specific conditions, the degree of difference in faults is refined into balanced sensitivity and unbalanced sensitivity. When the fault sensitivity is balanced, the trust of different information sources is quantified by support and uncertainty. When the sensitivity is unbalanced, gray relational analysis is used to assign trust degrees to different information sources. The algorithm can effectively resolve the high degree of conflict in the decision-making fusion process while considering the complementarity of multi-source heterogeneous information. Experiments evaluate the effectiveness of the proposed method.

Fault Diagnosis of Motor Bearing Based on Current Bi-Spectrum and Convolutional Neural Network

Fault Diagnosis of Motor Bearing Based on Current Bi-Spectrum and Convolutional Neural Network

An Intelligent Method for Early Motor Bearing Fault Diagnosis Based on Wasserstein Distance Generative Adversarial Networks Meta Learning

The fault diagnosis method based on generative adversarial networks (GAN) has been successfully applied to the early fault detection of motor bearings, and has effectively solved the problems of small samples, unlabeled sample features and data imbalance in early faults. However, the existing methods ignore the weak features of bearing vibration signals when solving the problem of missing early fault samples, which seriously affects the accuracy of diagnosis results. In addition, a large amount of human parameter adjustment work is required during the network model training process. This makes the whole diagnosis process lack of objectivity and intelligence. To address these issues, this paper proposes an intelligent diagnosis algorithm for early faults of motor bearings based on Wasserstein generative adversarial network meta learning (WGANML). First, the method performs feature extraction on the collected bearing vibration signals. Then, the generation of missing samples and the enhancement of weak features are completed by using the game between the generative and discriminative models. Second, to get rid of manual intervention, meta learning (ML) is applied to Wasserstein Distance Generative Adversarial Networks (WGAN) parameter variation training for the first time. Finally, the feasibility and effectiveness of the proposed WGANML algorithm are proved by the open data set of Case Western Reserve University and the data of the motor bearing fault experimental platform. In addition, compared with the existing advanced methods, the superiority of the proposed method in motor bearing early fault diagnosis is further verified.

Comprehensive Learning Particle Swarm Optimized Fuzzy Petri Net for Motor-Bearing Fault Diagnosis

Petri net is a widely used fault-diagnosis algorithm. However, it presents poor fault-diagnosis effectiveness and accuracy caused by the parameter setting and adjustment, depending entirely on expert experience in a system with a single input signal type. To address this problem, a comprehensive learning particle swarm optimized fuzzy Petri net (CLPSO-FPN) algorithm is proposed for motor-bearing fault diagnosis. CLPSO is employed to obtain an adaptive system parameter set to reduce the fault-diagnosis error caused by human subjective factors. Moreover, a new proposed concept of the transition influence factor replaces the traditional transition confidence to improve the nonlinear expression ability of traditional Petri nets, which suppresses the space explosion problem of the fault-diagnosis model. Finally, experiments are implemented on a dataset of motor bearings. Compared with traditional faults diagnosis methods, the proposed method realized better performance in the fault location and prediction functions of motor bearings, which is beneficial for troubleshooting and motor maintenance.

Motor bearing fault diagnosis based on local characteristic-scale decomposition and support vector optimized by sine cosine algorithm

When the motor bearing fails, the nonlinear and unstable characteristics of the vibration signal will lead to a low fault identification accuracy. This paper proposes a fault diagnosis method for motor bearings based on local characteristic-scale decomposition (LCD) and sine-cosine algorithm to optimize support vector machine. In this paper, the LCD algorithm is used to decompose the vibration signal, and screened out the effective intrinsic scale components (ISC) component. Then, Sample Entropy and Permutation Entropy are extracted from the filtered components. For the selection of parameters c and g of SVM, this paper introduces the sine and cosine optimization algorithm (SCA) for position update optimization, and builds an SVM model to obtain a classification model for motor bearing faults after training on the data set. After importing the remaining test data set into the classification model for testing, the fault classification accuracy results of the motor bearing can be obtained. The results of the simulation experiments show that the recognition rate of motor bearing faults based on LCD and SCA-SVM is 98.75%.

A motor bearing fault diagnosis method based on multi-source data and one-dimensional lightweight convolution neural network

Deep learning is widely adopted in the field of fault diagnosis because of its powerful feature representation capabilities. The existing diagnosis methods are always proposed based on the data only from a single source and are susceptible to interference. Due to the need to convertthe data into two dimensions, data preprocessing also requires a lot of time. To address these problems, a new fault diagnosis algorithm based on multi-source data and one-dimensional lightweight convolutional neural network is presented. In particular, original data can be exploited directly without conversion to two dimensions. To enhance data fusion, attention module and channel shuffle module are added. Besides, to improve the utilization of data, a modified [Formula: see text] criterion is proposed to remove outliers in multi-source data. The performance of the proposed method in multi-source data fusion is verified in bearing failure experiments. Compared with the existing diagnosis methods (one-dimensional convolutional neural network, ResNet, ShuffleNet, MobileNet, EfficientNet and the two recurrence methods), multi-source data and one-dimensional lightweight convolutional neural network does a better job of balancing the efficiency and robustness.

Application of Convolutional Neural Network in Motor Bearing Fault Diagnosis.

In the field of mechanical and electrical equipment, the motor rolling bearing is a workpiece that is extremely prone to damage and failure. However, the traditional fault diagnosis methods cannot keep up with the development pace of the times because they need complex manual pretreatment or the support of specific expert experience and knowledge. As a rising star, the data-driven fault diagnosis methods are increasingly favored by scholars and experts at home and abroad. The convolutional neural network has been widely used because of its powerful feature extraction ability for all kinds of complex information and its outstanding research results in image processing, target tracking, target diagnosis, time-frequency analysis, and other scenes. Therefore, this paper introduces a convolutional neural network and applies it to motor-bearing fault diagnosis. Aiming at the shortcomings of fault signal and convolutional neural network, a large-scale maximum pooling strategy is proposed and optimized by wavelet transform to improve the fault diagnosis efficiency of motor bearing under high-voltage operation. Compared with other machine learning algorithms, the convolution neural network fault diagnosis model constructed in this paper not only has high accuracy (up to 0.9871) and low error (only 0.032) but also is simple to use. It provides a new way for motor bearing fault diagnosis and has very important economic and social value.

Research on Motor Bearing Fault Diagnosis Based on the AdaBoost Algorithm and the Ensemble Learning with Bayesian Optimization in the Industrial Internet of Things

In order to adapt to the development of the industrial Internet of Things, the relationship between the internal components of electromechanical equipment is getting closer and closer, such as motor bearings. Nowadays, timely diagnosis of motor bearing faults is urgently needed. Most traditional methods for motor bearing fault diagnosis use a single learner and emphasize the role of feature extraction, which usually requires a large amount of sample support and computer runtime to obtain satisfactory performance. In this article, the Bayesian optimized decision tree with ensemble classifiers after feature extraction of the original data is finally proposed which has good performance. We use multiple feature extraction to establish the feature matrix and construct a decision tree model with the ensemble method for AdaBoost and a Bayesian optimized decision tree model with ensemble classifiers to conduct experiments on the accuracy, prediction speed, etc., of the model. We derived four sets of experimental data. The results show that the optimal method is the Bayesian optimized decision tree with ensemble classifiers after feature extraction. The accuracy of this method is as high as 99.9%. At the same time, unlike previous studies, we found in our study that feature extraction does not improve the accuracy of diagnosis for the decision tree with ensemble method for AdaBoost and there is a precipitous decline. In the industrial Internet of Things, the conclusion can improve certain reference value for the future fault diagnosis of motor bearings.

Application of Machine Learning to a Medium Gaussian Support Vector Machine in the Diagnosis of Motor Bearing Faults

In recent years, artificial intelligence technology has been widely used in fault prediction and health management (PHM). The machine learning algorithm is widely used in the condition monitoring of rotating machines, and normal and fault data can be obtained through the data acquisition and monitoring system. After analyzing the data and establishing a model, the system can automatically learn the features from the input data to predict the failure of the maintenance and diagnosis equipment, which is important for motor maintenance. This research proposes a medium Gaussian support vector machine (SVM) method for the application of machine learning and constructs a feature space by extracting the characteristics of the vibration signal collected on the spot based on experience. Different methods were used to cluster and classify features to classify motor health. The influence of different Gaussian kernel functions, such as fine, medium, and coarse, on the performance of the SVM algorithm was analyzed. The experimental data verify the performance of various models through the data set released by the Case Western Reserve University Motor Bearing Data Center. As the motor often has noise interference in the actual application environment, a simulated Gaussian white noise was added to the original vibration data in order to verify the performance of the research method in a noisy environment. The results summarize the classification results of related motor data sets derived recently from the use of motor fault detection and diagnosis using different machine learning algorithms. The results show that the medium Gaussian SVM method improves the reliability and accuracy of motor bearing fault estimation, detection, and identification under variable crack-size and load conditions. This paper also provides a detailed discussion of the predictive analytical capabilities of machine learning algorithms, which can be used as a reference for the future motor predictive maintenance analysis of electric vehicles.