{"title":"Prototype Recalibration-Driven Incremental Learning Framework for Bearing Fault Diagnosis Without Exemplars","authors":"Hao Yang;Xuyang Tao;Yan Zhang;Juanjuan Shi;Changqing Shen","doi":"10.1109/JSEN.2025.3596151","DOIUrl":"https://doi.org/10.1109/JSEN.2025.3596151","url":null,"abstract":"As key components of rotating machinery, bearings continually encounter new fault classes in industrial applications. However, the existing deep learning-based diagnosis methods are limited by the requirement that all fault classes must be known during training. This constraint affects the applicability of the intelligent fault diagnosis (IFD) models in real-world scenarios. Incremental fault diagnosis methods can effectively enable models to accumulate knowledge for fault classes, but most require retaining training examples of previously learned fault classes as exemplars for new training tasks. This article proposes a prototype recalibration-driven incremental learning (PRIL) framework to address the challenge of continuous fault diagnosis for bearings without exemplars. Specifically, a feature prototypes recalibration mechanism is employed to align feature prototypes with the feature spaces, allowing features generated from feature prototypes of old fault classes adaptable to the latest training tasks. Additionally, a contrastive learning-based pretrained feature extractor is utilized to enhance the generalization ability of model in continuous fault diagnosis tasks. A distance-based incremental prototype classifier is designed to enable the model balance knowledge between different fault classes. Finally, a case study on continuous fault diagnosis is conducted to assess the effectiveness of the proposed method. The results demonstrate that PRIL can continually accumulate fault diagnosis knowledge while effectively mitigating catastrophic forgetting without retaining historical training data.","PeriodicalId":447,"journal":{"name":"IEEE Sensors Journal","volume":"25 18","pages":"35112-35120"},"PeriodicalIF":4.3,"publicationDate":"2025-08-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145078658","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"High Sensitivity Strain MZI Based on Spiral Core Fiber","authors":"Yong Wei;Zhi Zhang;Taiping Xie;Wang Peng;Chunlan Liu;Haoyang Xiang;Chao Guo;Chenyu Xu;Songquan Li;Zhihai Liu","doi":"10.1109/JSEN.2025.3595276","DOIUrl":"https://doi.org/10.1109/JSEN.2025.3595276","url":null,"abstract":"Fiber optic Mach–Zehnder interferometer (MZI) strain sensors are widely used in many fields, but their sensitivity needs further improvement. This article proposes a new method of strain sensitization by simultaneously increasing the effective refractive index difference and the difference in sensing path length between the fiber core and cladding to increase the change in optical path difference. By replacing the single-mode fiber in the middle part of the multimode-single mode-multimode (MSM) structure with spiral core fiber fabricated by the eccentric fiber, the separation of the core sensing length and the cladding sensing length of the sensing fiber was achieved, and the length difference of the fiber core and cladding sensing path was increased. However, due to twisting processing of the eccentric fiber, the higher order cladding modes were excited, thereby increasing the effective refractive index difference of the fiber core and cladding. By experimental testing, the highest strain sensing sensitivity of −72.9 pm/<inline-formula> <tex-math>$mu varepsilon $ </tex-math></inline-formula> was achieved, providing a new idea for the further development of fiber optic integrated MZI strain sensing.","PeriodicalId":447,"journal":{"name":"IEEE Sensors Journal","volume":"25 18","pages":"34631-34635"},"PeriodicalIF":4.3,"publicationDate":"2025-08-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145089951","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Flex-PCB-Based Multilayered LED Quantum Sensor (FleQS) Utilizing NV Centers in Randomly Oriented Microdiamonds With Novel Orientation Determination","authors":"Jens Pogorzelski;Jonas Homrighausen;Ann-Sophie Bülter;Ludwig Horsthemke;Markus Gregor;Peter Glösekötter","doi":"10.1109/JSEN.2025.3594104","DOIUrl":"https://doi.org/10.1109/JSEN.2025.3594104","url":null,"abstract":"We present a quantum magnetometer based on a flexible printed circuit (FPC) board with a streamlined and automated assembly design. By employing a foldable design, the system achieves advanced miniaturization and integration, along with the capability to form a multilayered structure for direct optical path generation. The sensor head, measuring <inline-formula> <tex-math>$text {(}{3}.{4} times {2}.{9} times {2}text {)} ~text {mm}^{{3}}$ </tex-math></inline-formula>, is combined with sidearms and a FPC connector which can extend the length as required (here 32 mm). The device demonstrates a sensitivity of <inline-formula> <tex-math>$70~text {nT}/text {(}text {Hz}text {)}^{text {1/2}}$ </tex-math></inline-formula> and a theoretical shot-noise-limited sensitivity (SNLS) of <inline-formula> <tex-math>${11}.{73}~text {nT}/text {(}text {Hz}text {)}^{text {1/2}}$ </tex-math></inline-formula>. This design is fully compatible with automated production processes, facilitating efficient and cost-effective manufacturing. With a power consumption of approximately <inline-formula> <tex-math>${0}.{1}~text {W}$ </tex-math></inline-formula>, which is mainly caused by the light-emitting diode (LED), the foldable sensor is well-suited for a wide range of applications, from handheld devices to stationary systems. A novel approach for automated orientation determination facilitates the usage of randomly oriented, 150-<inline-formula> <tex-math>$mu $ </tex-math></inline-formula>m sized, low-cost microdiamonds, further streamlining the fabrication process. Therefore, the sensor presented here offers a step further from the laboratory into the concrete application of quantum sensors based on nitrogen-vacancy (NV) centers.","PeriodicalId":447,"journal":{"name":"IEEE Sensors Journal","volume":"25 18","pages":"34537-34548"},"PeriodicalIF":4.3,"publicationDate":"2025-08-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11122380","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145089969","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"A Markov Probability Model-Based Framework for Bearing Fault Detection Under Variable Speed Conditions","authors":"Jingyang Zheng;Yuna Wang;Xuemei Liu;Yaqiang Jin;Yuzhuo Zhang;Shuai Zhang;Liyou Xu;Yuejian Chen","doi":"10.1109/JSEN.2025.3595281","DOIUrl":"https://doi.org/10.1109/JSEN.2025.3595281","url":null,"abstract":"Bearing fault detection is important for the reliable and safe operation of rotating machinery. The operating speed of the bearing is usually variable, which makes fault detection more challenging. Existing works have not explored a structural framework that links angle resampling with Markov models, leaving room for improvement in fault detection under variable speed conditions. This article proposes a Markov probability model-based fault detection method for bearing operating under variable speed conditions. First, angle resampling is used to resample the data obtained under different rotational speeds to demodulate frequency modulation. Then, the resampled vibration signal is modeled using the explicit-duration hidden Markov model (EDHMM). Finally, the fault is detected through the likelihood ratio test. The fault detection results are visualized through the receiver operating characteristic (ROC) curve, its quantification metric area under the ROC curve (AUC) value, and the corresponding sequence plot. The performance is compared with the angle resampling-free Markov model likelihood ratio detection method. The results indicate that the AUC of the proposed method is 0.9110, much higher than that of the angle resampling-free Markov model, 0.6439.","PeriodicalId":447,"journal":{"name":"IEEE Sensors Journal","volume":"25 18","pages":"35066-35076"},"PeriodicalIF":4.3,"publicationDate":"2025-08-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145078592","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Remaining Useful Life Prediction of Power MOSFETs Based on Deep Reinforcement Learning","authors":"Yuxuan Xie;Yujie Zhang;Qiang Miao","doi":"10.1109/JSEN.2025.3596121","DOIUrl":"https://doi.org/10.1109/JSEN.2025.3596121","url":null,"abstract":"The power metal–oxide–semiconductor field-effect transistors (MOSFETs) are the critical components extensively utilized in various fields. To ensure the safety and reliability of MOSFET-based systems, the remaining useful life (RUL) prediction techniques can be applied to calculate the RUL during the early to middle stages of equipment degradation, thereby avoiding more severe failures. Over the past few years, the RUL prediction technology utilizing reinforcement learning (RL) has steadily matured, with the deep deterministic policy gradient (DDPG) algorithm demonstrating excellent predictive performance in time-series data prediction. However, the complicated degradation mechanisms of power MOSFETs and the limited historical degradation data make it challenging for the hyperparameters of DDPG model to effectively converge to the global optimum. Consequently, the DDPG-based prediction method suffers from poor generalization and adaptability, leading to larger prediction errors. To address the issue, we propose a novel prediction method, named GDDPG, which integrates Gaussian process regression (GPR) with DDPG. First, monitoring data of MOSFETs are used to construct state matrix and optimal action space. Second, during the iterative prediction phase, the GPR algorithm is introduced to correct each single-step prediction result from the DDPG model. Finally, the corrected prediction value is incorporated into the next iteration’s state variables for subsequent prediction. Validation on the publicly available NASA prognostics center of excellence (PCoE) dataset “MOSFET Thermal Overstress Aging” demonstrates that the proposed method consistently surpasses all comparison methods across multiple evaluation metrics. Thus, the GDDPG-based method significantly enhances the precision and dependability of RUL prediction for MOSFETs.","PeriodicalId":447,"journal":{"name":"IEEE Sensors Journal","volume":"25 18","pages":"35090-35100"},"PeriodicalIF":4.3,"publicationDate":"2025-08-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145078603","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"A Novel Causal Federated Transfer Learning Method for Power Transformer Fault Diagnosis Based on Voiceprint Recognition","authors":"Kai Zhang;Hongming Lu;Shuai Han;Xin Zhao","doi":"10.1109/JSEN.2025.3595427","DOIUrl":"https://doi.org/10.1109/JSEN.2025.3595427","url":null,"abstract":"Fault diagnosis of power transformers based on voiceprint analysis has developed rapidly due to its nonintrusive advantages in recent years. However, it faces challenges in generalization across different voltage levels and collaborative training difficulties under distributed data barriers. Existing federated transfer learning (FTL) methods rely on statistical correlations, which are easily affected by noise and hinder better fault diagnosis performance. Therefore, this article proposes a novel causal FTL method for power transformer fault diagnosis based on voiceprint signals. First, a causal FTL framework is proposed by integrating a causal graph autoencoder into FTL to capture nonlinear causal features between voiceprint features and faults. Second, a graph autoencoder with a wavelet convolutional encoder layer and a subpixel convolutional decoder layer is constructed to extract domain-invariant causal features from key fault-related frequency bands. Third, a strategy is designed to aggregate encoder layer information using adversarial-loss-sensitive weighting, which effectively evaluates the contribution of each client while reducing communication overhead. Experimental results show that the proposed method can quickly identify fault types in cross-voltage-level power transformer fault diagnosis scenarios and outperforms existing models in all three scenarios. Even under a high noise level of −5 dB in the third scenario, the accuracy still exceeds 94%.","PeriodicalId":447,"journal":{"name":"IEEE Sensors Journal","volume":"25 18","pages":"35573-35584"},"PeriodicalIF":4.3,"publicationDate":"2025-08-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145073275","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"IGBT Junction Temperature Monitoring and State Identification Based on AWG-NN","authors":"Tianqi Li;Songwei Pei;Jinlong Zhang","doi":"10.1109/JSEN.2025.3596186","DOIUrl":"https://doi.org/10.1109/JSEN.2025.3596186","url":null,"abstract":"Precise monitoring of insulated gate bipolar transistors (IGBTs) junction temperature, which impacts device lifespan, is crucial for assessing their health and operational status. However, traditional monitoring methods are limited, and effective IGBT state assessment methods are lacking. This article presents a novel IGBT junction temperature monitoring and state identification method leveraging the synergy between arrayed waveguide grating (AWG) demodulation and neural networks (NNs). We first develop a comprehensive thermal simulation model of the IGBT to investigate temperature distribution, thermal stress, and potential weak points under diverse operating conditions. The junction temperature is calculated from the reflected wavelength data obtained by waveguide Bragg grating (WBG) sensors, while AWG enables high-precision, multichannel temperature monitoring through wavelength demodulation. For state identification, an attention-enhanced Siamese network (Siam-MMSA) is proposed. By designing a spatial micro-macro spatial attention (MMSA), integrating microscopic and macroscopic perspectives, this model leverages the attention mechanism to extract relationships between temperature features and aging status. Experimental results demonstrate that this method accurately captures dynamic junction temperature variations with an error margin below <inline-formula> <tex-math>$0.6~^{circ }$ </tex-math></inline-formula>C and achieves a 99.5% accuracy rate in IGBT state identification under testing conditions. This approach supports intelligent control, performance assessment, and lifespan optimization for power electronic devices, offering valuable engineering insights for real-world applications.","PeriodicalId":447,"journal":{"name":"IEEE Sensors Journal","volume":"25 19","pages":"37486-37498"},"PeriodicalIF":4.3,"publicationDate":"2025-08-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145204549","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Design, Simulation, and Modeling of a Highly Sensitive Multicapacitor Piezoelectric MEMS Accelerometer","authors":"Rahul Kumar Gupta;Sanjeev Kumar Manhas","doi":"10.1109/JSEN.2025.3595984","DOIUrl":"https://doi.org/10.1109/JSEN.2025.3595984","url":null,"abstract":"Increasing the on-chip sensitivity of an accelerometer enhances the transduction efficiency at the sensor level, thereby improving the signal-to-noise ratio (SNR) without introducing additional electronic noise. To enhance the sensitivity of the piezoelectric accelerometer, we report a novel series-connected multicapacitor pickup MEMS design. Using well-calibrated COMSOL simulations, we show that the number of series-connected integrated capacitors in the construction directly correlates with the differential sensitivity of the multicapacitor piezoelectric accelerometer. In this technique, the voltage across all the series capacitors in the structure is equal to that across the single-capacitor structure. A multicapacitor pickup structure can be designed using two, four, six, or more capacitors. The design is demonstrated using aluminum nitride (AlN) as a piezoelectric material, but it can be extended to other materials such as lead zirconate titanate (PZT) and zinc oxide (ZnO). Furthermore, we have developed a mathematical model for the multicapacitor structure of the piezoelectric accelerometer, and the results are compared with the simulated data, showing excellent accuracy with an error of less than 4%. The proposed method demonstrates significant potential for improving the efficiency of various vibration-sensing/energy-harvesting MEMS structures. The device proposed in this work has a wide range of applications, including autonomous systems, machine/structure health monitoring, and navigation systems.","PeriodicalId":447,"journal":{"name":"IEEE Sensors Journal","volume":"25 18","pages":"35418-35425"},"PeriodicalIF":4.3,"publicationDate":"2025-08-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145073215","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Triaxial Micro Force Plate Array for Measuring Ground Reaction Force in Ant Locomotion","authors":"Toshihiro Shiratori;Hidetoshi Takahashi","doi":"10.1109/JSEN.2025.3595999","DOIUrl":"https://doi.org/10.1109/JSEN.2025.3595999","url":null,"abstract":"Terrestrial insects, such as ants, are known for their agile locomotion on six legs. However, the ground reaction force (GRF) of each leg has not been well characterized due to its difficulty in measurement. In this report, a micro force plate array is presented that uses the sampling Moiré (SM) method, a prism, and a single camera to simultaneously measure the triaxial GRFs of multiple legs of an ant during its locomotion. The SM method is a high-resolution measurement method that measures the amount of displacement based on the shift of a captured grid pattern. The proposed micro force plate array consists of a <inline-formula> <tex-math>$3 times 3$ </tex-math></inline-formula> array of <inline-formula> <tex-math>$2900 times 2900 times 70 ; mu $ </tex-math></inline-formula>m plate bases with a gap of <inline-formula> <tex-math>$100 ; mu $ </tex-math></inline-formula>m as the contact surface of the ant legs. The plate base is supported by a spring structure with a grid pattern. By capturing this grid pattern from the backside via a prism, a camera can capture images from two different directions, allowing the triaxial displacement to be measured. By dividing the plate surface into nine sections and evaluating the error based on the position of the force application in the z-direction force, a maximum measurement error of 6% was found. The average force resolution in the x-, y-, and z-directions for the nine plates was 3.34, 2.47, and <inline-formula> <tex-math>$1.20 ; mu $ </tex-math></inline-formula>N, respectively. With the developed force plate array, it was possible to measure the GRF of each leg simultaneously while the ant was walking.","PeriodicalId":447,"journal":{"name":"IEEE Sensors Journal","volume":"25 18","pages":"34480-34490"},"PeriodicalIF":4.3,"publicationDate":"2025-08-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145073274","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Chenxuan Wang;Min Wu;Yawu Wang;Chengda Lu;Sheng Du;Zhejiaqi Ma;Zeyi Wang
{"title":"Dynamics Modeling and Parameter Identification of a Double-Layer 6-DOF Stewart Platform for Simulating Marine Exploration Processes","authors":"Chenxuan Wang;Min Wu;Yawu Wang;Chengda Lu;Sheng Du;Zhejiaqi Ma;Zeyi Wang","doi":"10.1109/JSEN.2025.3596150","DOIUrl":"https://doi.org/10.1109/JSEN.2025.3596150","url":null,"abstract":"Effective stability control is essential for marine resource exploration platforms, but conducting experiments on actual platforms is costly and risky. To address these challenges, this article proposes a simulation system based on a double-layer 6-degree-of-freedom (DOF) Stewart platform, enabling realistic simulations of marine exploration processes and various control experiments. The lower platform simulates environmental disturbances (e.g., waves, wind, and currents), while the upper platform replicates the exploration platform’s movements. This double-layer structure effectively models the interactions between the platform’s movements and the environmental forces, providing a more accurate representation of real-world conditions. A comprehensive dynamics model is established using the Lagrangian method and the virtual work principle to account for both kinematic and dynamics interactions. A nonlinear gray system estimation (NGSE) method with a trust-region reflective algorithm is used for parameter identification, and model order reduction improves accuracy and feasibility. Comparisons with real marine platform models validate the system, confirming that it accurately simulates marine resource exploration dynamics. The experimental results show that the parameter estimation error of the proposed model remains below 8.08%. The active-compensation strategy reduces the root-mean-square (rms) horizontal displacement from 0.122 to 0.023 m, representing an 81% decrease, and lowers the rms attitude error from 0.139 to 0.012 rad, corresponding to a 91% reduction. These results confirm the reliability of the dynamics model and highlight the experimental system’s value for stability control research on marine exploration platforms.","PeriodicalId":447,"journal":{"name":"IEEE Sensors Journal","volume":"25 18","pages":"35289-35302"},"PeriodicalIF":4.3,"publicationDate":"2025-08-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145078674","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}