Pub Date : 2023-12-21DOI: 10.1088/1361-6501/ad1809
Xiangling Chen, Zhongjun Qiu, Haipeng Fan
The factors influencing the accuracy of the line scan imaging system (LSIS) are highly complex, and their error propagation mechanisms are poorly clarified. To reasonably and effectively mitigate the impact of mechanical factors on imaging accuracy, a novel comprehensive error model for LSIS is proposed in this paper, revealing the relationship between imaging errors and various mechanical error sources from manufacturing, assembly, and movement. Based on the analysis of the generation and propagation relationship of mechanical errors in LSIS, the integration of the mechanical system and the imaging system is accomplished to form a comprehensive multibody system, thus establishing a complete linear transmission mechanism for mechanical errors in the imaging process within the model. The experiments demonstrate that this model can provide a reference for the localization of mechanical error sources by utilizing the changes in extrinsic parameters during the calibration process. Furthermore, when the sensitivities of error sources are not exceptionally low, and certain cases with systematic errors are excluded, the model can make accurate estimations of the sensitivities of imaging errors to those errors generated by various mechanical sources. The estimated relative errors do not exceed 6%. The results confirm the effectiveness of this model, which can be utilized to ascertain the range of error sources and assess the extent to which errors from various sources impact imaging accuracy. This model provides a basis for the precision optimization of LSIS.
{"title":"A Novel Error Model for the Line Scan Imaging System","authors":"Xiangling Chen, Zhongjun Qiu, Haipeng Fan","doi":"10.1088/1361-6501/ad1809","DOIUrl":"https://doi.org/10.1088/1361-6501/ad1809","url":null,"abstract":"\u0000 The factors influencing the accuracy of the line scan imaging system (LSIS) are highly complex, and their error propagation mechanisms are poorly clarified. To reasonably and effectively mitigate the impact of mechanical factors on imaging accuracy, a novel comprehensive error model for LSIS is proposed in this paper, revealing the relationship between imaging errors and various mechanical error sources from manufacturing, assembly, and movement. Based on the analysis of the generation and propagation relationship of mechanical errors in LSIS, the integration of the mechanical system and the imaging system is accomplished to form a comprehensive multibody system, thus establishing a complete linear transmission mechanism for mechanical errors in the imaging process within the model. The experiments demonstrate that this model can provide a reference for the localization of mechanical error sources by utilizing the changes in extrinsic parameters during the calibration process. Furthermore, when the sensitivities of error sources are not exceptionally low, and certain cases with systematic errors are excluded, the model can make accurate estimations of the sensitivities of imaging errors to those errors generated by various mechanical sources. The estimated relative errors do not exceed 6%. The results confirm the effectiveness of this model, which can be utilized to ascertain the range of error sources and assess the extent to which errors from various sources impact imaging accuracy. This model provides a basis for the precision optimization of LSIS.","PeriodicalId":18526,"journal":{"name":"Measurement Science and Technology","volume":"2 7","pages":""},"PeriodicalIF":2.4,"publicationDate":"2023-12-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138952052","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 : 2023-12-21DOI: 10.1088/1361-6501/ad180b
Wei Liu, Hua Huang, Yuan Hu, Bing Han, Shengzheng Wang
Unmanned surface vehicle (USV) can navigate autonomously via the Global Navigation Satellite System (GNSS). However, the traditional GNSS scalar tracking loop easily loses lock in low carrier-to-noise ratio (CNR) situations, such as signal occlusion and weak signals. Meanwhile, an increase in the carrier/code phase error leads to an increase in the measurement error of the navigation filter, which decreases the accuracy of the position estimation. To solve this problem, this paper proposes a carrier and code tracking structure based on a forward and backward Kalman filter to dynamically adjust the gain of the vector tracking loop. The carrier and code phase errors calculated by the loop discriminators were linearly transformed into pseudo-range rate and pseudo-range errors after filtering and smoothing, which were used as the measurements of the navigation filter. The signal CNR was used to adaptively adjust the measurement noise covariance matrix of the loop filters. The field tests used a commercial receiver's navigation solution as the reference. In the stationary test, the proposed structure reduced the localization error by 44.3% compared with the traditional methods. In kinematic experiments, the proposed structure reduced the carrier and code phase errors in a harsh signal environment and improved the positioning accuracy at the source. The test results demonstrate that the proposed GNSS tracking method can provide a possible solution for the development of navigation systems for USV.
{"title":"A Robust GNSS Sensors in Presence of Signal Blockage for USV Application","authors":"Wei Liu, Hua Huang, Yuan Hu, Bing Han, Shengzheng Wang","doi":"10.1088/1361-6501/ad180b","DOIUrl":"https://doi.org/10.1088/1361-6501/ad180b","url":null,"abstract":"\u0000 Unmanned surface vehicle (USV) can navigate autonomously via the Global Navigation Satellite System (GNSS). However, the traditional GNSS scalar tracking loop easily loses lock in low carrier-to-noise ratio (CNR) situations, such as signal occlusion and weak signals. Meanwhile, an increase in the carrier/code phase error leads to an increase in the measurement error of the navigation filter, which decreases the accuracy of the position estimation. To solve this problem, this paper proposes a carrier and code tracking structure based on a forward and backward Kalman filter to dynamically adjust the gain of the vector tracking loop. The carrier and code phase errors calculated by the loop discriminators were linearly transformed into pseudo-range rate and pseudo-range errors after filtering and smoothing, which were used as the measurements of the navigation filter. The signal CNR was used to adaptively adjust the measurement noise covariance matrix of the loop filters. The field tests used a commercial receiver's navigation solution as the reference. In the stationary test, the proposed structure reduced the localization error by 44.3% compared with the traditional methods. In kinematic experiments, the proposed structure reduced the carrier and code phase errors in a harsh signal environment and improved the positioning accuracy at the source. The test results demonstrate that the proposed GNSS tracking method can provide a possible solution for the development of navigation systems for USV.","PeriodicalId":18526,"journal":{"name":"Measurement Science and Technology","volume":"33 24","pages":""},"PeriodicalIF":2.4,"publicationDate":"2023-12-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138948985","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 : 2023-12-21DOI: 10.1088/1361-6501/ad1814
Tianyu Li, Zhigui Ren, Xiaoping Pang, Dingjun Chen, Shusheng Cao
The evaluation of excavator performance relies heavily on digging force, which serves as a crucial indicator. However, the accuracy of performance assessment is hindered by the absence of a suitable method to characterize the dynamic digging capacity of excavators. This study addresses this limitation by proposing an approach to establish a set of solution-limited inequalities for dynamic digging force. The approach incorporates D'Alembert's principle and composite digging, while considering the influence of inertia force. Furthermore, to mitigate the issue of bucket tooth tip trajectory shaking caused by discontinuous posture during excavation, an amount of measurement data from a 20-ton machine is utilized to construct a consistent theoretical digging trajectory. The theoretical trajectory is subjected to numerical verification to determine the dynamic digging force along the trajectory. A comparative analysis is then conducted, contrasting the obtained dynamic digging force with different theoretical digging forces and measured resistances. Additionally, the dynamic digging forces within the selected digging area of the machine are characterized, without accounting for attitude continuity. The findings demonstrate that the dynamic digging force effectively captures the excavator's performance along the trajectory, and it also provides an excellent characterization of the digging force at discrete digging spots.
{"title":"Dynamic digging force modeling and comparative analysis of backhoe hydraulic excavators","authors":"Tianyu Li, Zhigui Ren, Xiaoping Pang, Dingjun Chen, Shusheng Cao","doi":"10.1088/1361-6501/ad1814","DOIUrl":"https://doi.org/10.1088/1361-6501/ad1814","url":null,"abstract":"\u0000 The evaluation of excavator performance relies heavily on digging force, which serves as a crucial indicator. However, the accuracy of performance assessment is hindered by the absence of a suitable method to characterize the dynamic digging capacity of excavators. This study addresses this limitation by proposing an approach to establish a set of solution-limited inequalities for dynamic digging force. The approach incorporates D'Alembert's principle and composite digging, while considering the influence of inertia force. Furthermore, to mitigate the issue of bucket tooth tip trajectory shaking caused by discontinuous posture during excavation, an amount of measurement data from a 20-ton machine is utilized to construct a consistent theoretical digging trajectory. The theoretical trajectory is subjected to numerical verification to determine the dynamic digging force along the trajectory. A comparative analysis is then conducted, contrasting the obtained dynamic digging force with different theoretical digging forces and measured resistances. Additionally, the dynamic digging forces within the selected digging area of the machine are characterized, without accounting for attitude continuity. The findings demonstrate that the dynamic digging force effectively captures the excavator's performance along the trajectory, and it also provides an excellent characterization of the digging force at discrete digging spots.","PeriodicalId":18526,"journal":{"name":"Measurement Science and Technology","volume":"58 20","pages":""},"PeriodicalIF":2.4,"publicationDate":"2023-12-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138952140","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 : 2023-12-21DOI: 10.1088/1361-6501/ad1803
Enrique Covián Regales, V. Puente, Miguel Casero, Pablo Cienfuegos Suárez
Volume represents a measurand of great interest in civil engineering and construction works. The estimation of this measurand is a problem already solved by surveying engineering, but the quantification of its uncertainty has been overlooked. As a result, the inaccurate estimation of the volume can lead to significant deviations in the execution costs of earthworks. Moreover, it is not possible to comply with the internationally accepted requirements concerning the expression of measures with an indication of its uncertainty, i.e., the guidelines of the BIPM (Bureau International des Poids et Mesures). In this context, this paper presents a methodology for the quantification of uncertainty in the surveying measurement of volumes, which is generally carried out through digital terrain models processed by CAD or specific surveying software. Two methods for volume estimation are presented and the variance-covariance propagation laws are applied to each of them, leading to the computation of volume uncertainty from measures of position coordinates for which uncertainties are known. Then, the developed methods for uncertainty estimation are successfully tested in different scenarios. The conceptual and mathematical developments for the uncertainty quantification in the computation of volumes resulted in closed-form algorithms implemented in MATLAB that can be potentially incorporated into commercial surveying software.
{"title":"Uncertainties estimation in surveying measurands: application to volumes.","authors":"Enrique Covián Regales, V. Puente, Miguel Casero, Pablo Cienfuegos Suárez","doi":"10.1088/1361-6501/ad1803","DOIUrl":"https://doi.org/10.1088/1361-6501/ad1803","url":null,"abstract":"\u0000 Volume represents a measurand of great interest in civil engineering and construction works. The estimation of this measurand is a problem already solved by surveying engineering, but the quantification of its uncertainty has been overlooked. As a result, the inaccurate estimation of the volume can lead to significant deviations in the execution costs of earthworks. Moreover, it is not possible to comply with the internationally accepted requirements concerning the expression of measures with an indication of its uncertainty, i.e., the guidelines of the BIPM (Bureau International des Poids et Mesures). In this context, this paper presents a methodology for the quantification of uncertainty in the surveying measurement of volumes, which is generally carried out through digital terrain models processed by CAD or specific surveying software. Two methods for volume estimation are presented and the variance-covariance propagation laws are applied to each of them, leading to the computation of volume uncertainty from measures of position coordinates for which uncertainties are known. Then, the developed methods for uncertainty estimation are successfully tested in different scenarios. The conceptual and mathematical developments for the uncertainty quantification in the computation of volumes resulted in closed-form algorithms implemented in MATLAB that can be potentially incorporated into commercial surveying software.","PeriodicalId":18526,"journal":{"name":"Measurement Science and Technology","volume":"61 15","pages":""},"PeriodicalIF":2.4,"publicationDate":"2023-12-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138952316","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 : 2023-12-21DOI: 10.1088/1361-6501/ad1816
Weili Ding, Zhipeng Zhang, Guo Xinya, Liancheng Su, Changchun Hua
In this paper, we propose a two-stage algorithm, named watershed-constrained image segmentation, for exploring complete edge-closed regions from edges. In the first stage, the input image is pre-processed and the image gradient information is obtained using a gradient operator. Anchors are then obtained from the gradient information. Finally, initial edges are obtained by intelligently connecting the anchors. In the second stage, a marker-based watershed algorithm is adopted to obtain marker points from the gradient information obtained in the first stage. A Gaussian filtered image is then used as the input image to obtain a watershed hyper-segmented edge map. Finally, complete edge-closed regions are obtained by combining the initial edges and the hyper-segmented edge map and searching for weak edges. The image segmentation results are then obtained from the edge-closed regions, demonstrating the excellent performance of our proposed algorithm on various images and videos.
{"title":"EWSeg: A Fast Segmentation Algorithm for Images based on Edge Linking and Watershed Constraints","authors":"Weili Ding, Zhipeng Zhang, Guo Xinya, Liancheng Su, Changchun Hua","doi":"10.1088/1361-6501/ad1816","DOIUrl":"https://doi.org/10.1088/1361-6501/ad1816","url":null,"abstract":"\u0000 In this paper, we propose a two-stage algorithm, named watershed-constrained image segmentation, for exploring complete edge-closed regions from edges. In the first stage, the input image is pre-processed and the image gradient information is obtained using a gradient operator. Anchors are then obtained from the gradient information. Finally, initial edges are obtained by intelligently connecting the anchors. In the second stage, a marker-based watershed algorithm is adopted to obtain marker points from the gradient information obtained in the first stage. A Gaussian filtered image is then used as the input image to obtain a watershed hyper-segmented edge map. Finally, complete edge-closed regions are obtained by combining the initial edges and the hyper-segmented edge map and searching for weak edges. The image segmentation results are then obtained from the edge-closed regions, demonstrating the excellent performance of our proposed algorithm on various images and videos.","PeriodicalId":18526,"journal":{"name":"Measurement Science and Technology","volume":"38 4","pages":""},"PeriodicalIF":2.4,"publicationDate":"2023-12-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138949825","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 : 2023-12-21DOI: 10.1088/1361-6501/ad1805
Yi Liao, Weiguo Huang, Tianxu Qiu, Juntao Ma, Ziwei Zhang
Monitoring vibration signals from a fault rotatory bearing is a commonly used technique for bearing fault diagnosis. Owing to harsh working conditions, observed signals are generally contaminated by strong background noise, which is a great challenge in extracting fault bearing signal. Sparsity-assisted signal decomposition offers an effective solution by transforming measured signals into sparse coefficients within specified domains, and reconstructing fault signals by multiplying these coefficients and overcomplete dictionaries representing the abovementioned domains. During the process, observed vibration signals tend to be decomposed, and fault components are extracted while noise is diminished. In this paper, a nonseparable and nonconvex log (NSNCL) penalty is proposed as a regularizer for sparse-decomposition model in bearing fault diagnosis. A convexity guarantee to the sparse model is presented, so globally optimal solutions can be calculated. During the process, tunable Q-factor wavelet transform with easily setting parameters, is applie din signifying multi-objective signals with a sparse manner. Numerical examples demonstrate advantages of the proposed method over other competitors.
{"title":"Sparsity-assisted signal decomposition via nonseparable and nonconvex penalty for bearing fault diagnosis","authors":"Yi Liao, Weiguo Huang, Tianxu Qiu, Juntao Ma, Ziwei Zhang","doi":"10.1088/1361-6501/ad1805","DOIUrl":"https://doi.org/10.1088/1361-6501/ad1805","url":null,"abstract":"\u0000 Monitoring vibration signals from a fault rotatory bearing is a commonly used technique for bearing fault diagnosis. Owing to harsh working conditions, observed signals are generally contaminated by strong background noise, which is a great challenge in extracting fault bearing signal. Sparsity-assisted signal decomposition offers an effective solution by transforming measured signals into sparse coefficients within specified domains, and reconstructing fault signals by multiplying these coefficients and overcomplete dictionaries representing the abovementioned domains. During the process, observed vibration signals tend to be decomposed, and fault components are extracted while noise is diminished. In this paper, a nonseparable and nonconvex log (NSNCL) penalty is proposed as a regularizer for sparse-decomposition model in bearing fault diagnosis. A convexity guarantee to the sparse model is presented, so globally optimal solutions can be calculated. During the process, tunable Q-factor wavelet transform with easily setting parameters, is applie din signifying multi-objective signals with a sparse manner. Numerical examples demonstrate advantages of the proposed method over other competitors.","PeriodicalId":18526,"journal":{"name":"Measurement Science and Technology","volume":"44 21","pages":""},"PeriodicalIF":2.4,"publicationDate":"2023-12-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138952513","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 : 2023-12-21DOI: 10.1088/1361-6501/ad1815
Xiangyu Liu, Xuehui Gan, An Ping
As an intermediate material for carbon fiber composites, surface flaws inevitably occur during carbon fiber prepreg preparation, which will seriously affect the quality of carbon fiber composite products. The current approaches for identifying flaws on carbon fiber prepreg have the drawbacks of being labor-intensive and inefficient. This research puts forward a novel model for identifying surface flaws on carbon fiber prepregs using an improved single-shot multibox detector (SSD), called CFP-SSD model. A machine vision-based platform for surface flaws identification on carbon fiber prepreg is created. Additionally, the modified-Resnet50 backbone employed in the proposed CFP-SSD model can enhance the effectiveness of network feature extraction. Then, the multi-scale fusion remote context feature extraction module is designed to efficiently fuse the information from the shallow and deep layers. The findings of performance comparison experiments and ablation experiments indicate that the proposed CFP-SSD model achieves 86.63% mean average precision (mAP) and a detection speed of 47 frames per second (FPS), which is sufficient for real-time automatic identification of carbon fiber prepreg surface flaws.
{"title":"Automatic flaw detection of carbon fiber prepreg using a CFP-SSD model during preparation","authors":"Xiangyu Liu, Xuehui Gan, An Ping","doi":"10.1088/1361-6501/ad1815","DOIUrl":"https://doi.org/10.1088/1361-6501/ad1815","url":null,"abstract":"\u0000 As an intermediate material for carbon fiber composites, surface flaws inevitably occur during carbon fiber prepreg preparation, which will seriously affect the quality of carbon fiber composite products. The current approaches for identifying flaws on carbon fiber prepreg have the drawbacks of being labor-intensive and inefficient. This research puts forward a novel model for identifying surface flaws on carbon fiber prepregs using an improved single-shot multibox detector (SSD), called CFP-SSD model. A machine vision-based platform for surface flaws identification on carbon fiber prepreg is created. Additionally, the modified-Resnet50 backbone employed in the proposed CFP-SSD model can enhance the effectiveness of network feature extraction. Then, the multi-scale fusion remote context feature extraction module is designed to efficiently fuse the information from the shallow and deep layers. The findings of performance comparison experiments and ablation experiments indicate that the proposed CFP-SSD model achieves 86.63% mean average precision (mAP) and a detection speed of 47 frames per second (FPS), which is sufficient for real-time automatic identification of carbon fiber prepreg surface flaws.","PeriodicalId":18526,"journal":{"name":"Measurement Science and Technology","volume":"58 9","pages":""},"PeriodicalIF":2.4,"publicationDate":"2023-12-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138951724","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The measurement of critical dimensions in the field of integrated circuits has moved from 7nm to 5nm. The existing chromium atomic lithography grating has a pitch period of 4700 l/mm and uniformity of picometre, and the interferometric signal period based on the above grating is as small as 106.4 nm, which brings new problems and challenges to the accurate processing of the signal. This paper investigates the error characteristics of ultra-high precision grating interferometric signals, establishes a Heydemann correction mathematical model for high inscribed line density grating interferometric signals, corrects the grating interferometer signals based on the random sample consensus (RANSAC), and verifies the effectiveness of the algorithm through simulation. By comparing the repeatability and linearity of the original algorithm and the self-traceable grating interferometric displacement measurement data processed by RANSAC, the conclusion that the standard deviation of the self-traceable grating interferometer repeat measurement after RANSAC is 1.60 nm in a 10,000 nm travel is obtained, and the purpose of improving the stability and uniformity of the signal solution with the algorithm of this paper is achieved, which is important for the study of laser interferometer and grating interferometer The results show that the stability and uniformity of the signal solution can be improved by the algorithm of this paper, which is of great significance for the study of the displacement solution of laser and grating interferometers.
{"title":"Study of interferometric signal correction methods in ultra-precision displacement measurement","authors":"Zhangning Xie, Tao Jin, Lihua Lei, Zichao Lin, Yulin Yao, Dongbai Xue, Xiong Dun, Xiao Deng, Xinbin Cheng","doi":"10.1088/1361-6501/ad179b","DOIUrl":"https://doi.org/10.1088/1361-6501/ad179b","url":null,"abstract":"\u0000 The measurement of critical dimensions in the field of integrated circuits has moved from 7nm to 5nm. The existing chromium atomic lithography grating has a pitch period of 4700 l/mm and uniformity of picometre, and the interferometric signal period based on the above grating is as small as 106.4 nm, which brings new problems and challenges to the accurate processing of the signal. This paper investigates the error characteristics of ultra-high precision grating interferometric signals, establishes a Heydemann correction mathematical model for high inscribed line density grating interferometric signals, corrects the grating interferometer signals based on the random sample consensus (RANSAC), and verifies the effectiveness of the algorithm through simulation. By comparing the repeatability and linearity of the original algorithm and the self-traceable grating interferometric displacement measurement data processed by RANSAC, the conclusion that the standard deviation of the self-traceable grating interferometer repeat measurement after RANSAC is 1.60 nm in a 10,000 nm travel is obtained, and the purpose of improving the stability and uniformity of the signal solution with the algorithm of this paper is achieved, which is important for the study of laser interferometer and grating interferometer The results show that the stability and uniformity of the signal solution can be improved by the algorithm of this paper, which is of great significance for the study of the displacement solution of laser and grating interferometers.","PeriodicalId":18526,"journal":{"name":"Measurement Science and Technology","volume":"77 12","pages":""},"PeriodicalIF":2.4,"publicationDate":"2023-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138956763","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 : 2023-12-20DOI: 10.1088/1361-6501/ad179e
Bingnan Hou, Yanchun Wang
WiFi-based indoor positioning technology has gradually become a hot research topic in the field of indoor positioning, but the development of this technology has been facing the challenge of susceptibility to environmental interference. Therefore, in this paper, the kernel function method (KFM) with stronger interference resistance is used for positioning, and the adaptive σ algorithm is proposed for the time-consuming and laborious problem of manual parameter tuning, which incorporates the ideas of cross-validation and iteration. In addition, too many wireless access points (APs) mean higher computational cost and longer positioning time, so it is necessary to choose reasonable APs for positioning. In this paper, we use the random forest (RF) algorithm to assess the importance of APs and filter out a small number of APs with high importance. Considering the obvious differences in the WiFi signals received on different floors, a system framework for positioning by floors based on WiFi fingerprints is proposed. In the offline phase, the fingerprint library is first divided according to floors, and then perform separately AP selection and parameter tuning for each sub-fingerprint library. In the online phase, support vector machine (SVM) is used to discriminate the floors first, and then KFM is used for planar positioning. Experiments are conducted on the public dataset, and the results show that the proposed algorithm has higher positioning accuracy, more robustness, and less time-consuming compared to several common algorithms.
{"title":"Positioning by Floors Based on WiFi Fingerprint","authors":"Bingnan Hou, Yanchun Wang","doi":"10.1088/1361-6501/ad179e","DOIUrl":"https://doi.org/10.1088/1361-6501/ad179e","url":null,"abstract":"WiFi-based indoor positioning technology has gradually become a hot research topic in the field of indoor positioning, but the development of this technology has been facing the challenge of susceptibility to environmental interference. Therefore, in this paper, the kernel function method (KFM) with stronger interference resistance is used for positioning, and the adaptive σ algorithm is proposed for the time-consuming and laborious problem of manual parameter tuning, which incorporates the ideas of cross-validation and iteration. In addition, too many wireless access points (APs) mean higher computational cost and longer positioning time, so it is necessary to choose reasonable APs for positioning. In this paper, we use the random forest (RF) algorithm to assess the importance of APs and filter out a small number of APs with high importance. Considering the obvious differences in the WiFi signals received on different floors, a system framework for positioning by floors based on WiFi fingerprints is proposed. In the offline phase, the fingerprint library is first divided according to floors, and then perform separately AP selection and parameter tuning for each sub-fingerprint library. In the online phase, support vector machine (SVM) is used to discriminate the floors first, and then KFM is used for planar positioning. Experiments are conducted on the public dataset, and the results show that the proposed algorithm has higher positioning accuracy, more robustness, and less time-consuming compared to several common algorithms.","PeriodicalId":18526,"journal":{"name":"Measurement Science and Technology","volume":"259 1","pages":""},"PeriodicalIF":2.4,"publicationDate":"2023-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139170111","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 : 2023-12-20DOI: 10.1088/1361-6501/ad17a0
Xiaoxia Wang, Xiaoxuan Zhang
Domain adaptation (DA) approaches have received significant attention in industrial cross-domain fault diagnosis. However, the scarcity of sufficient labeled fault data, particularly under varying loading conditions and harsh operational environments, can give rise to distinct label spaces between two domains, thereby impeding the application of DA-based diagnosis methods. In this paper, we propose a novel dual-weight domain adversarial network (DWDAN) for diagnosing partial domain faults of feedwater heater system in a large-scale power unit, where the target label space is a subset of the source domain. Firstly, domain adversarial network with an instance-based feature learning strategy is constructed to capture domain-invariant and class-discriminative features hidden in raw process data, thereby enhancing feature extraction and generalization abilities of fault diagnosis. Furthermore, a dual-stage reweighted induction module is designed to quantify the contribution of samples from both class-level and sample-level for selective adaptation. This module can automatically eliminate outlier fault categories in the source domain and facilitates alignment of feature distributions for shared fault categories. Comprehensive experiments conducted on the feedwater heater system of a 600-MW coal-fired generating unit demonstrate the outstanding performance of DWDAN.
在工业跨领域故障诊断中，领域适应（DA）方法受到了极大关注。然而，由于缺乏足够的标注故障数据，特别是在不同的负载条件和恶劣的运行环境下，两个域之间会产生不同的标注空间，从而阻碍了基于 DA 的诊断方法的应用。本文提出了一种新型双权重域对抗网络（DWDAN），用于诊断大型机组给水加热器系统的部分域故障，其中目标标签空间是源域的子集。首先，构建了基于实例特征学习策略的域对抗网络，以捕获隐藏在原始过程数据中的域不变特征和类区分特征，从而增强故障诊断的特征提取和泛化能力。此外，还设计了一个双级加权归纳模块，以量化来自类级和样本级的样本贡献，从而进行选择性适应。该模块可自动消除源域中的异常故障类别，并促进共享故障类别的特征分布对齐。在 600-MW 燃煤发电机组给水加热器系统上进行的综合实验证明了 DWDAN 的出色性能。
{"title":"A dual-weight domain adversarial network for partial domain fault diagnosis of feedwater heater system","authors":"Xiaoxia Wang, Xiaoxuan Zhang","doi":"10.1088/1361-6501/ad17a0","DOIUrl":"https://doi.org/10.1088/1361-6501/ad17a0","url":null,"abstract":"\u0000 Domain adaptation (DA) approaches have received significant attention in industrial cross-domain fault diagnosis. However, the scarcity of sufficient labeled fault data, particularly under varying loading conditions and harsh operational environments, can give rise to distinct label spaces between two domains, thereby impeding the application of DA-based diagnosis methods. In this paper, we propose a novel dual-weight domain adversarial network (DWDAN) for diagnosing partial domain faults of feedwater heater system in a large-scale power unit, where the target label space is a subset of the source domain. Firstly, domain adversarial network with an instance-based feature learning strategy is constructed to capture domain-invariant and class-discriminative features hidden in raw process data, thereby enhancing feature extraction and generalization abilities of fault diagnosis. Furthermore, a dual-stage reweighted induction module is designed to quantify the contribution of samples from both class-level and sample-level for selective adaptation. This module can automatically eliminate outlier fault categories in the source domain and facilitates alignment of feature distributions for shared fault categories. Comprehensive experiments conducted on the feedwater heater system of a 600-MW coal-fired generating unit demonstrate the outstanding performance of DWDAN.","PeriodicalId":18526,"journal":{"name":"Measurement Science and Technology","volume":"29 3","pages":""},"PeriodicalIF":2.4,"publicationDate":"2023-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138955200","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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