Pub Date : 2025-11-27DOI: 10.1016/j.measurement.2025.119887
Junren Sun , Fanchen Meng , Ruiyang Zhou , Zhipeng Wang
The Ground-Based Navigation System (GBNS) utilizing pseudolites (PL) deployed on surface of the earth for positioning shows superior robustness and accuracy than the Global Navigation Satellite System (GNSS) in urban and canyon environments, which is attributed to stronger signal strength, ionospheric-free characteristic, better terrain adaptability, and greater layout flexibility. However, multipath interference is a major cause of degraded navigation accuracy of GBNS. In this paper, we propose a deeply integrated GBNS/INS navigation system that utilizes a newly designed variable-period pre-filter and an adaptive vector tracking loop (VTL) architecture to enhance positioning accuracy in multipath environments. A software platform named multipath environments software platform (MESP) is constructed for navigation simulation in multipath environments, and a hardware-in-the-loop simulation based on this platform is carried out to evaluate effectiveness of the proposed multipath mitigation techniques. Numerical results and comparisons validate the feasibility and superiority of the proposed system scheme, and the positioning accuracy of this scheme is less than 1.5 m under the simulated multipath scenario.
{"title":"A deeply integrated GBNS/INS system for navigation in multipath environments","authors":"Junren Sun , Fanchen Meng , Ruiyang Zhou , Zhipeng Wang","doi":"10.1016/j.measurement.2025.119887","DOIUrl":"10.1016/j.measurement.2025.119887","url":null,"abstract":"<div><div>The Ground-Based Navigation System (GBNS) utilizing pseudolites (PL) deployed on surface of the earth for positioning shows superior robustness and accuracy than the Global Navigation Satellite System (GNSS) in urban and canyon environments, which is attributed to stronger signal strength, ionospheric-free characteristic, better terrain adaptability, and greater layout flexibility. However, multipath interference is a major cause of degraded navigation accuracy of GBNS. In this paper, we propose a deeply integrated GBNS/INS navigation system that utilizes a newly designed variable-period pre-filter and an adaptive vector tracking loop (VTL) architecture to enhance positioning accuracy in multipath environments. A software platform named multipath environments software platform (MESP) is constructed for navigation simulation in multipath environments, and a hardware-in-the-loop simulation based on this platform is carried out to evaluate effectiveness of the proposed multipath mitigation techniques. Numerical results and comparisons validate the feasibility and superiority of the proposed system scheme, and the positioning accuracy of this scheme is less than 1.5 m under the simulated multipath scenario.</div></div>","PeriodicalId":18349,"journal":{"name":"Measurement","volume":"261 ","pages":"Article 119887"},"PeriodicalIF":5.6,"publicationDate":"2025-11-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145692585","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-27DOI: 10.1016/j.measurement.2025.119869
Binjie Lu , Xiaobing Zhang
To address the noise interference in ship shaft-rate magnetic field signals, we propose a multistage denoising algorithm integrating Successive Variational Mode Decomposition (SVMD), Wasserstein Distance (WD), Spectral Entropy (SE), Enhanced Spectral Subtraction (ESS), and Improved Wavelet Threshold Denoising (IWTD). First, a bandpass filter was applied to preprocess raw signals, isolating the primary frequency band of shaft-rate magnetic fields. The SVMD then decomposed signals into Intrinsic Mode Functions (IMFs). Power Spectral Density (PSD) analysis of all IMFs enabled classification into three categories—signal-dominant IMFs (Signal IMFs), hybrid IMFs (Noisy IMFs), and noise-dominant IMFs (Noise IMFs)—using WD-SE criteria. Signal-dominant IMFs underwent ESS-based denoising, while hybrid IMFs were processed via IWTD. Noise-dominant IMFs were discarded. Final reconstruction combined denoised signal-dominant and hybrid IMFs. Comparative simulations and field experiments demonstrated the algorithm’s superiority: Signal-to-Noise Ratio (SNR) increased by 26.3∼177.3 % compared to SGMD-WD-SE-ESS-IWTD, EWT-WD-SE-ESS-IWTD, VMD-WD-SE-ESS-IWTD, IWTD and ESS algorithms. This methodology provides a robust solution for extracting weak shaft-rate magnetic signatures in complex marine environments, with potential applications in ship detection and magnetic anomaly navigation.
{"title":"SVMD-WD-SE-ESS-IWTD algorithm for ship shaft-rate magnetic field signals","authors":"Binjie Lu , Xiaobing Zhang","doi":"10.1016/j.measurement.2025.119869","DOIUrl":"10.1016/j.measurement.2025.119869","url":null,"abstract":"<div><div>To address the noise interference in ship shaft-rate magnetic field signals, we propose a multistage denoising algorithm integrating Successive Variational Mode Decomposition (SVMD), Wasserstein Distance (WD), Spectral Entropy (SE), Enhanced Spectral Subtraction (ESS), and Improved Wavelet Threshold Denoising (IWTD). First, a bandpass filter was applied to preprocess raw signals, isolating the primary frequency band of shaft-rate magnetic fields. The SVMD then decomposed signals into Intrinsic Mode Functions (IMFs). Power Spectral Density (PSD) analysis of all IMFs enabled classification into three categories—signal-dominant IMFs (Signal IMFs), hybrid IMFs (Noisy IMFs), and noise-dominant IMFs (Noise IMFs)—using WD-SE criteria. Signal-dominant IMFs underwent ESS-based denoising, while hybrid IMFs were processed via IWTD. Noise-dominant IMFs were discarded. Final reconstruction combined denoised signal-dominant and hybrid IMFs. Comparative simulations and field experiments demonstrated the algorithm’s superiority: Signal-to-Noise Ratio (SNR) increased by 26.3∼177.3 % compared to SGMD-WD-SE-ESS-IWTD, EWT-WD-SE-ESS-IWTD, VMD-WD-SE-ESS-IWTD, IWTD and ESS algorithms. This methodology provides a robust solution for extracting weak shaft-rate magnetic signatures in complex marine environments, with potential applications in ship detection and magnetic anomaly navigation.</div></div>","PeriodicalId":18349,"journal":{"name":"Measurement","volume":"260 ","pages":"Article 119869"},"PeriodicalIF":5.6,"publicationDate":"2025-11-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145682240","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-27DOI: 10.1016/j.measurement.2025.119872
Arnaldo Leal-Junior , Stanislav Kepak , Jan Nedoma , Radek Martinek , Wilfried Blanc
This paper presents the development of optical fiber interferometers for acoustic detection using specialty optical fibers. The Michelson (MI) and Sagnac interferometers (SI) are developed using nanoparticle-doped fibers (NPFs) for the acoustic detection in a wide frequency range from 500 Hz to 15 kHz. To compare and demonstrate the performance enhancement of interferometers using NPFs, the same configurations of MI and SI are applied using the standard single mode fibers (SMFs). The comparison is made in terms of amplitude of signal detection, usable frequency range and signal-to-noise ratio (SNR). Results in the SI configuration show that the NPF presented a ten times higher amplitude than the SMF, whereas the SNR is 55% higher than that of SMF. Furthermore, the NPF also shows superior performance than the SMF in the MI configuration, where there is a 5 times and 4.1% higher amplitude and SNR, respectively. Comparing both approaches, the MI presented a 60 times higher amplitude than the SI for the analyzed frequencies. Therefore, the proposed acoustic detection system demonstrated the feasibility and superior performance of the NPF for acoustic detection in different interferometric configurations, resulting in compact and highly sensitive interferometer structures for acoustic detection in a wide range of frequencies.
{"title":"Nanoparticle-doped fibers for enhanced acoustic detection interferometry","authors":"Arnaldo Leal-Junior , Stanislav Kepak , Jan Nedoma , Radek Martinek , Wilfried Blanc","doi":"10.1016/j.measurement.2025.119872","DOIUrl":"10.1016/j.measurement.2025.119872","url":null,"abstract":"<div><div>This paper presents the development of optical fiber interferometers for acoustic detection using specialty optical fibers. The Michelson (MI) and Sagnac interferometers (SI) are developed using nanoparticle-doped fibers (NPFs) for the acoustic detection in a wide frequency range from 500 Hz to 15 kHz. To compare and demonstrate the performance enhancement of interferometers using NPFs, the same configurations of MI and SI are applied using the standard single mode fibers (SMFs). The comparison is made in terms of amplitude of signal detection, usable frequency range and signal-to-noise ratio (SNR). Results in the SI configuration show that the NPF presented a ten times higher amplitude than the SMF, whereas the SNR is 55% higher than that of SMF. Furthermore, the NPF also shows superior performance than the SMF in the MI configuration, where there is a 5 times and 4.1% higher amplitude and SNR, respectively. Comparing both approaches, the MI presented a 60 times higher amplitude than the SI for the analyzed frequencies. Therefore, the proposed acoustic detection system demonstrated the feasibility and superior performance of the NPF for acoustic detection in different interferometric configurations, resulting in compact and highly sensitive interferometer structures for acoustic detection in a wide range of frequencies.</div></div>","PeriodicalId":18349,"journal":{"name":"Measurement","volume":"260 ","pages":"Article 119872"},"PeriodicalIF":5.6,"publicationDate":"2025-11-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145682242","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-27DOI: 10.1016/j.measurement.2025.119890
Anna Li , Yongquan Su , Cheng Zhang , Jiachang Zhang , Hao Huang , Dalong Chen , Wenli Xue , Lihao Wang , Yichen Liu , Feng Tian , Yang Wang , Zhenyu Wu
AlScN piezoelectric MEMS accelerometers are promising for distributed vibration monitoring system, due to their compact size, CMOS compatibility, and reliability at elevated temperatures. However, their operation in bending mode makes them highly susceptible to cross-axis interference, which can severely compromise measurement accuracy in practical applications. To address this limitation, this paper synthetically proposes the definition of transverse sensitivity, stress-induced degradation mechanisms, and suppression strategies. Firstly, theoretical model and Finite Element Method (FEM) demonstrate asymmetric surface warpage, induced by residual stress, is a primary cause of transverse sensitivity. A perforated diaphragm-island is proposed, which effectively releases stress and mitigates warpage. Secondly, the mechanism of air cavity in diaphragm-island structure as the source of excessive surface warpage is demonstrated, and thereby implementing effective structural improvement to suppress warpage. Finally, the developed perforated diaphragm-island accelerometer achieves a 55 % reduction in transverse sensitivity without performance loss. It achieves transverse sensitivity (1.2 %), charge sensitivity (0.60 pC/g), upper-frequency range (approximately 6000 Hz), and range (±500 g). Meanwhile, tests based on a triaxial vibration system demonstrate that the proposed accelerometer exhibits superior immunity to cross-axis interference compared with commercial products, which is meaningful for high-precision and real-time monitoring of broadband and large-range vibration signals.
{"title":"Low transverse-sensitivity AlScN piezoelectric MEMS accelerometers with perforated diaphragm-island for high-precision vibration monitoring","authors":"Anna Li , Yongquan Su , Cheng Zhang , Jiachang Zhang , Hao Huang , Dalong Chen , Wenli Xue , Lihao Wang , Yichen Liu , Feng Tian , Yang Wang , Zhenyu Wu","doi":"10.1016/j.measurement.2025.119890","DOIUrl":"10.1016/j.measurement.2025.119890","url":null,"abstract":"<div><div>AlScN piezoelectric MEMS accelerometers are promising for distributed vibration monitoring system, due to their compact size, CMOS compatibility, and reliability at elevated temperatures. However, their operation in bending mode makes them highly susceptible to cross-axis interference, which can severely compromise measurement accuracy in practical applications. To address this limitation, this paper synthetically proposes the definition of transverse sensitivity, stress-induced degradation mechanisms, and suppression strategies. Firstly, theoretical model and Finite Element Method (FEM) demonstrate asymmetric surface warpage, induced by residual stress, is a primary cause of transverse sensitivity. A perforated diaphragm-island is proposed, which effectively releases stress and mitigates warpage. Secondly, the mechanism of air cavity in diaphragm-island structure as the source of excessive surface warpage is demonstrated, and thereby implementing effective structural improvement to suppress warpage. Finally, the developed perforated diaphragm-island accelerometer achieves a 55 % reduction in transverse sensitivity without performance loss. It achieves transverse sensitivity (1.2 %), charge sensitivity (0.60 pC/g), upper-frequency range (approximately 6000 Hz), and range (±500 g). Meanwhile, tests based on a triaxial vibration system demonstrate that the proposed accelerometer exhibits superior immunity to cross-axis interference compared with commercial products, which is meaningful for high-precision and real-time monitoring of broadband and large-range vibration signals.</div></div>","PeriodicalId":18349,"journal":{"name":"Measurement","volume":"261 ","pages":"Article 119890"},"PeriodicalIF":5.6,"publicationDate":"2025-11-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145645575","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-27DOI: 10.1016/j.measurement.2025.119639
Mingyan Nie , Wenzhong Shi , Daping Yang , Min Zhang , Yitao Wei
Indoor LiDAR SLAM is essential for autonomous navigation, robotic mapping, and virtual environment reconstruction. In this work, we propose a plane-assisted LiDAR SLAM framework that leverages planar features as auxiliary pose constraints rather than primary registration primitives. A robust planar feature extraction algorithm is introduced, specifically designed for multi-line LiDAR sensors, enabling reliable detection of dominant planar structures in indoor environments. Planar features are integrated into both odometry and global pose optimization by constructing residuals between plane observations, which serve as geometric constraints to suppress drift and improve mapping accuracy. In addition, we propose a registration failure detection and correction mechanism based on plane occlusion analysis, which effectively identifies and mitigates errors arising from misaligned point cloud registration. Extensive experiments conducted in challenging indoor environments (including stairwells, narrow corridors, and multi-room areas) demonstrate that the proposed approach significantly outperforms state-of-the-art approaches in terms of SLAM accuracy and reliability.
{"title":"Plane-assisted indoor Lidar SLAM","authors":"Mingyan Nie , Wenzhong Shi , Daping Yang , Min Zhang , Yitao Wei","doi":"10.1016/j.measurement.2025.119639","DOIUrl":"10.1016/j.measurement.2025.119639","url":null,"abstract":"<div><div>Indoor LiDAR SLAM is essential for autonomous navigation, robotic mapping, and virtual environment reconstruction. In this work, we propose a plane-assisted LiDAR SLAM framework that leverages planar features as auxiliary pose constraints rather than primary registration primitives. A robust planar feature extraction algorithm is introduced, specifically designed for multi-line LiDAR sensors, enabling reliable detection of dominant planar structures in indoor environments. Planar features are integrated into both odometry and global pose optimization by constructing residuals between plane observations, which serve as geometric constraints to suppress drift and improve mapping accuracy. In addition, we propose a registration failure detection and correction mechanism based on plane occlusion analysis, which effectively identifies and mitigates errors arising from misaligned point cloud registration. Extensive experiments conducted in challenging indoor environments (including stairwells, narrow corridors, and multi-room areas) demonstrate that the proposed approach significantly outperforms state-of-the-art approaches in terms of SLAM accuracy and reliability.</div></div>","PeriodicalId":18349,"journal":{"name":"Measurement","volume":"261 ","pages":"Article 119639"},"PeriodicalIF":5.6,"publicationDate":"2025-11-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145692549","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-26DOI: 10.1016/j.measurement.2025.119808
Martin Leonhard Kliemank , Bernhard Rupprecht , Majid Ahmadzadeh , Joseph Zimmer , Ralf Brederlow , Karsten Stahl , Robert Liebich , Birgit Vogel-Heuser , Clemens Gühmann
In this study, an instantaneous angular speed (IAS) estimation algorithm suitable for low-power embedded systems is demonstrated and evaluated using a gas foil bearing as a challenging test case. While many algorithms for IAS estimation exist, none have been validated as suitable for use in low-power embedded systems to date. Instead, their evaluation is typically done with high-performance computers and laboratory-grade sensors. In this work, the ViBES algorithm is demonstrated running online in a real embedded system comprising a Cortex-M33-based microcontroller and a MEMS accelerometer. The system is part of a prototype fluid bearing that determines operating parameters during operation, thereby providing a dynamic and challenging test case. This system is validated on a test rig with reference measurements, continuously estimating the IAS in real-time during the operation of the mechanical system. The estimation achieves a median accuracy of 0.18 Hz, validating that the algorithm can function within the limitations of low-power hardware. The implementation requires only 65 kB of RAM and 3.0 ms processing time for a window of 4096 samples, confirming the hardware requirements determined by the authors in earlier work. These hardware requirements also indicate that most modern low-power microcontrollers and MEMS accelerometers should be sufficient for the presented algorithm.
{"title":"Practical implementation and validation of instantaneous angular speed estimation on resource-constrained embedded systems","authors":"Martin Leonhard Kliemank , Bernhard Rupprecht , Majid Ahmadzadeh , Joseph Zimmer , Ralf Brederlow , Karsten Stahl , Robert Liebich , Birgit Vogel-Heuser , Clemens Gühmann","doi":"10.1016/j.measurement.2025.119808","DOIUrl":"10.1016/j.measurement.2025.119808","url":null,"abstract":"<div><div>In this study, an instantaneous angular speed (IAS) estimation algorithm suitable for low-power embedded systems is demonstrated and evaluated using a gas foil bearing as a challenging test case. While many algorithms for IAS estimation exist, none have been validated as suitable for use in low-power embedded systems to date. Instead, their evaluation is typically done with high-performance computers and laboratory-grade sensors. In this work, the ViBES algorithm is demonstrated running online in a real embedded system comprising a Cortex-M33-based microcontroller and a MEMS accelerometer. The system is part of a prototype fluid bearing that determines operating parameters during operation, thereby providing a dynamic and challenging test case. This system is validated on a test rig with reference measurements, continuously estimating the IAS in real-time during the operation of the mechanical system. The estimation achieves a median accuracy of 0.18<!--> <!-->Hz, validating that the algorithm can function within the limitations of low-power hardware. The implementation requires only 65<!--> <!-->kB of RAM and 3.0<!--> <!-->ms processing time for a window of 4096 samples, confirming the hardware requirements determined by the authors in earlier work. These hardware requirements also indicate that most modern low-power microcontrollers and MEMS accelerometers should be sufficient for the presented algorithm.</div></div>","PeriodicalId":18349,"journal":{"name":"Measurement","volume":"260 ","pages":"Article 119808"},"PeriodicalIF":5.6,"publicationDate":"2025-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145616697","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-26DOI: 10.1016/j.measurement.2025.119882
Haowen Yu , Na Fan , Xing Liu , Ximin Lyu
Accurate real-time wind vector estimation is essential for enhancing the safety, navigation accuracy, and energy efficiency of unmanned aerial vehicles (UAVs). Traditional approaches rely on external sensors or simplify vehicle dynamics, which limits their applicability during agile flight or in resource-constrained platforms. This paper proposes a real-time wind estimation method based solely on onboard sensors. The approach first estimates external aerodynamic forces using a disturbance observer (DOB), and then maps these forces to wind vectors using a thin-plate spline (TPS) model. A custom-designed wind barrel mounted on the UAV enhances aerodynamic sensitivity, further improving estimation accuracy. The system is validated through comprehensive experiments in wind tunnels, indoor and outdoor flights. Experimental results demonstrate that the proposed method achieves consistently high-accuracy wind estimation across controlled and real-world conditions, with speed RMSEs as low as 0.06 m/s in wind tunnel tests, 0.22 m/s during outdoor hover, and below 0.38 m/s in indoor and outdoor dynamic flights, and direction RMSEs under 7.3° across all scenarios, outperforming existing baselines. Moreover, the method provides vertical wind estimates – unavailable in baselines – with RMSEs below 0.17 m/s even during fast indoor translations.
{"title":"Design and implementation of a high-precision wind-estimation UAV with onboard sensors","authors":"Haowen Yu , Na Fan , Xing Liu , Ximin Lyu","doi":"10.1016/j.measurement.2025.119882","DOIUrl":"10.1016/j.measurement.2025.119882","url":null,"abstract":"<div><div>Accurate real-time wind vector estimation is essential for enhancing the safety, navigation accuracy, and energy efficiency of unmanned aerial vehicles (UAVs). Traditional approaches rely on external sensors or simplify vehicle dynamics, which limits their applicability during agile flight or in resource-constrained platforms. This paper proposes a real-time wind estimation method based solely on onboard sensors. The approach first estimates external aerodynamic forces using a disturbance observer (DOB), and then maps these forces to wind vectors using a thin-plate spline (TPS) model. A custom-designed wind barrel mounted on the UAV enhances aerodynamic sensitivity, further improving estimation accuracy. The system is validated through comprehensive experiments in wind tunnels, indoor and outdoor flights. Experimental results demonstrate that the proposed method achieves consistently high-accuracy wind estimation across controlled and real-world conditions, with speed RMSEs as low as 0.06<!--> <!-->m/s in wind tunnel tests, 0.22<!--> <!-->m/s during outdoor hover, and below 0.38<!--> <!-->m/s in indoor and outdoor dynamic flights, and direction RMSEs under 7.3° across all scenarios, outperforming existing baselines. Moreover, the method provides vertical wind estimates – unavailable in baselines – with RMSEs below 0.17<!--> <!-->m/s even during fast indoor translations.</div></div>","PeriodicalId":18349,"journal":{"name":"Measurement","volume":"260 ","pages":"Article 119882"},"PeriodicalIF":5.6,"publicationDate":"2025-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145616696","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-26DOI: 10.1016/j.measurement.2025.119875
Xuewen Wang , Jiangang Wang , Zeyu Qin , Ning Liu , Yu Huang , Wenjun Shao
Silicon carbide (SiC) wafers are critical for power electronics and energy systems because of their ability to handle high power densities and voltages. However, detecting subtle defects in non-transparent SiC wafers remains challenging, as conventional optical imaging often fails to distinguish weak defect signals from background noise. To address this issue, we propose an oblique line confocal imaging system with a programmable virtual confocal aperture. The system employs a time-delay integration (TDI) camera, enabling flexible adjustment of the aperture width by modifying detection stages, which optimizes confocal gating and enhances image contrast. Imaging experiments on stacking faults and scratches demonstrate significantly improved contrast compared with non-confocal methods. Furthermore, aperture width optimization yields additional performance gains, while the oblique line illumination scheme removes the need for an achromatic objective covering both UV and visible bands across a near-centimeter field of view. The system achieves a resolution of ∼2 µm, and the combination of high contrast and fine resolution highlights its potential for reliable defect inspection in semiconductor manufacturing.
{"title":"Oblique illumination line confocal imaging with adjustable aperture for wafer defect detection","authors":"Xuewen Wang , Jiangang Wang , Zeyu Qin , Ning Liu , Yu Huang , Wenjun Shao","doi":"10.1016/j.measurement.2025.119875","DOIUrl":"10.1016/j.measurement.2025.119875","url":null,"abstract":"<div><div>Silicon carbide (SiC) wafers are critical for power electronics and energy systems because of their ability to handle high power densities and voltages. However, detecting subtle defects in non-transparent SiC wafers remains challenging, as conventional optical imaging often fails to distinguish weak defect signals from background noise. To address this issue, we propose an oblique line confocal imaging system with a programmable virtual confocal aperture. The system employs a time-delay integration (TDI) camera, enabling flexible adjustment of the aperture width by modifying detection stages, which optimizes confocal gating and enhances image contrast. Imaging experiments on stacking faults and scratches demonstrate significantly improved contrast compared with non-confocal methods. Furthermore, aperture width optimization yields additional performance gains, while the oblique line illumination scheme removes the need for an achromatic objective covering both UV and visible bands across a near-centimeter field of view. The system achieves a resolution of ∼2 µm, and the combination of high contrast and fine resolution highlights its potential for reliable defect inspection in semiconductor manufacturing.</div></div>","PeriodicalId":18349,"journal":{"name":"Measurement","volume":"260 ","pages":"Article 119875"},"PeriodicalIF":5.6,"publicationDate":"2025-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145616493","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-26DOI: 10.1016/j.measurement.2025.119857
Ian A. Eliovich , Viktor A. Korzhov , Andrei I. Protsenko , Ilya V. Kubasov , Andrei V. Turutin , Alexander M. Kislyuk , Mikhail D. Malinkovich
Rapid adjustment of X-ray optics is crucial for time-resolved studies that track dynamic material processes in real time. Conventional servo- or stepper-driven goniometers are too slow, prompting interest in piezo-actuated adaptive X-ray optical elements (AXOEs). A piezoelectric bimorph in an AXOE can sweep the beam by hundreds to thousands of arcseconds at several-hundred-hertz rates. Although single-crystal AXOE monochromators outperform mechanical stages, only double-crystal geometries preserve beam direction during energy scans and suppress angular divergence. Synchronizing two crystals, however, is difficult with standard PbZrxTi1-xO3 (PZT) bimorphs, whose hysteresis and thermal drift degrade reproducibility. We report a double-crystal monochromator that employs two adaptive bending X-ray optical elements (ABXOs) based on bidomain LiNbO3 (BLN) single-crystal bimorph actuators. The monolithic structure of BLN eliminates intergrain interfaces, yielding hysteresis-free response and high thermal stability. Two mechanically matched actuators, each resonant at ≈102.5 Hz with mirrors attached, deliver angular sweeps exceeding 1200 arcsec. We describe calibration and phase-synchronization procedures that provide traceable control of beam energy and alignment. Performance was verified at the Kurchatov Synchrotron Source. Measurements confirmed the predicted angular and spectral tuning ranges and quantified beam displacement. Using the prototype, we recorded the Cu K-edge absorption spectrum (∼20 µm foil) with markedly higher spectral resolution than a comparable single-crystal ABXO system. These results demonstrate that BLN-based ABXOs enable fast, reproducible, and direction-stable energy scanning for synchrotron diffraction and spectroscopy, opening a path toward sub-10 ms time resolution without complex feedback hardware.
{"title":"Double-crystal monochromator with adaptive X-ray optical elements for synchrotron studies of materials with temporal resolution","authors":"Ian A. Eliovich , Viktor A. Korzhov , Andrei I. Protsenko , Ilya V. Kubasov , Andrei V. Turutin , Alexander M. Kislyuk , Mikhail D. Malinkovich","doi":"10.1016/j.measurement.2025.119857","DOIUrl":"10.1016/j.measurement.2025.119857","url":null,"abstract":"<div><div>Rapid adjustment of X-ray optics is crucial for time-resolved studies that track dynamic material processes in real time. Conventional servo- or stepper-driven goniometers are too slow, prompting interest in piezo-actuated adaptive X-ray optical elements (AXOEs). A piezoelectric bimorph in an AXOE can sweep the beam by hundreds to thousands of arcseconds at several-hundred-hertz rates. Although single-crystal AXOE monochromators outperform mechanical stages, only double-crystal geometries preserve beam direction during energy scans and suppress angular divergence. Synchronizing two crystals, however, is difficult with standard PbZr<sub>x</sub>Ti<sub>1-x</sub>O<sub>3</sub> (PZT) bimorphs, whose hysteresis and thermal drift degrade reproducibility. We report a double-crystal monochromator that employs two adaptive bending X-ray optical elements (ABXOs) based on bidomain LiNbO<sub>3</sub> (BLN) single-crystal bimorph actuators. The monolithic structure of BLN eliminates intergrain interfaces, yielding hysteresis-free response and high thermal stability. Two mechanically matched actuators, each resonant at ≈102.5 Hz with mirrors attached, deliver angular sweeps exceeding 1200 arcsec. We describe calibration and phase-synchronization procedures that provide traceable control of beam energy and alignment. Performance was verified at the Kurchatov Synchrotron Source. Measurements confirmed the predicted angular and spectral tuning ranges and quantified beam displacement. Using the prototype, we recorded the Cu K-edge absorption spectrum (∼20 µm foil) with markedly higher spectral resolution than a comparable single-crystal ABXO system. These results demonstrate that BLN-based ABXOs enable fast, reproducible, and direction-stable energy scanning for synchrotron diffraction and spectroscopy, opening a path toward sub-10 ms time resolution without complex feedback hardware.</div></div>","PeriodicalId":18349,"journal":{"name":"Measurement","volume":"260 ","pages":"Article 119857"},"PeriodicalIF":5.6,"publicationDate":"2025-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145616991","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-26DOI: 10.1016/j.measurement.2025.119865
Zheng Zuo , Maocheng Zhao , Liang Qi , Bin Wu , Hongyan Zou , Weijun Xie , Xiwei Wang , Chi Zhou , Kai Zhang
To enable efficient and non-destructive monitoring of chlorophyll content in Ginkgo biloba canopies, this study integrates UAV-based hyperspectral imaging with machine learning regression methods. Feature wavelengths were extracted using the CARS algorithm, and an XGB-RF hybrid model was constructed to estimate canopy chlorophyll content. The proposed MSC–CARS–(XGB-RF) model achieved superior performance with an of 0.9033 and an of 0.3652 on the prediction set, outperforming traditional regression approaches. The results demonstrate that combining UAV hyperspectral imagery with ensemble learning provides an accurate and scalable method for canopy-level chlorophyll assessment, offering strong potential for applications in smart agriculture and forestry management.
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