Office Online  
    Office Online
    Manuscript Tracking
    Editor Work
    Office Work
    Editor-in-chief
Journal Online
    Current Issue
    Advanced Search
    Archive
    Read Articles
    Download Articles
    Email Alert
Traffic
Quick Search  
  Adv Search
2024 Vol. 45, No. 10
Published: 2024-10-28
 
1425 Evaluation Method of Impulse Voltage Scale Factor Based on Multi Frequency Weighted Superposition
FAN Jiawei,ZHOU Feng,LEI Min,LONG Zhaozhi,DIAO Yinglong,LI Wenting,
DOI: 10.3969/j.issn.1000-1158.2024.10.01
To ensure the uniformity of the values of impulse voltage parameters in China, a method for synthesizing impulse voltage scale factors based on multi frequency component weighting is proposed.According to the Parseval’s theorem, a functional relationship between the impulse scale factor and the AC scale factor is established for the impulse voltage conversion device.The problem of tracing the transient and single waveform scale factor is transformed into the problem of obtaining the steady-state and periodic AC scale factor and calculating the frequency band weight.At the same time, the calculation error of the proposed evaluation method is better than 0.05% through analysis.Finally, an implementation method based on the mentioned synthesis method is proposed, and calculation validation based on the standard capacitor voltage divider is carried out, which expanded uncertainty is better than 0.02%.The results show that the proposed method for synthesizing the scale factor of impulse voltage based on multi frequency component weighting can accurately calculate the scale factor of impulse voltage.
2024 Vol. 45 (10): 1425-1434 [Abstract] ( 14 ) HTML (1 KB)  PDF  (0 KB)  ( 0 )
1435 A Harmonics Signal Extraction Method Based onImproved mSDFT Algorithm
LI Yan,LIN Xiaoming,ZHAO Yuming,ZHANG Fan,HE Shan,QIAN Bin
DOI: 10.3969/j.issn.1000-1158.2024.10.02
An improved mSDFT algorithm is proposed. For the improved algorithm, the structure of the comb filter contained in the transfer function generated from the traditional mSDFT algorithm is decomposed. That means retaining the specific zero points in the comb filter whose effect is to extract the specified harmonic in the power grid signal and making rest of zero points form a separate factor whose effect is amplitude correction and phase correction. The number of zeros contained in the comb filter is decreased by decomposing the structure of the comb filter, therefore, the delay time of the transient response is reduced. Besides, the principle of improved mSDFT algorithm is expounded and the formula derivation is completed. The results of simulation show that the improved algorithm can quickly track and extract the changed harmonic when the harmonic signal changes suddenly which indicates that it reduces the transient response delay of the traditional mSDFT algorithm, and has the advantages of no cumulative error and stability.
2024 Vol. 45 (10): 1435-1443 [Abstract] ( 7 ) HTML (1 KB)  PDF  (0 KB)  ( 0 )
1444 Attack Detection of Microgrid Based on ARO-MKELM
WU Zhongqiang,ZHANG Weiyi
DOI: 10.3969/j.issn.1000-1158.2024.10.03
The complexity and openness of smart grids make them more vulnerable to the threat of cyber attacks when exchanging information. Most of the current detection methods only focus on detecting the existence of the attack and cannot determine the specific location of the attacked distributed power supply, which results in the inability to quickly isolate the attacked distributed power supply and subsequently cause serious damage. To propose a false data injection attack detection method for AC microgrids based on the artificial rabbit swarm optimization algorithm optimizing a multi-core limit learning machine. A combined kernel function is introduced into the traditional extreme learning machine to improve the learning ability and generalization ability of the detection model, and the artificial rabbit pack optimization algorithm with strong global search ability is used to optimize the kernel function parameters and regularization coefficients of the multi-core extreme learning machine to further improve the detection accuracy of the detection model. Simulation verification is carried out using step attack signals with amplitudes of 55 and 95 within the non-training samples, and the detection accuracy ranges from (93.44~94.64)% and (98.11~99.23)%, respectively, and comparative analyses are carried out with other detection models to verify the superiority of the proposed method.
2024 Vol. 45 (10): 1444-1452 [Abstract] ( 12 ) HTML (1 KB)  PDF  (0 KB)  ( 1 )
1453 Characterization of the influence of bubbles on copper particle signal in electromagnetic abrasive detection
GUO Mingyuan,PANG Xinyu,WANG Shuo,CUI Shijie4,Lü Kaibo,LI Feng
DOI: 10.3969/j.issn.1000-1158.2024.10.04
Three-coil electromagnetic abrasive sensor is widely used in oil online monitoring, and the bubbles in the oil are easy to interfere with the detection of copper particles, and the quantitative analysis of the influence of bubbles in particle detection will help to improve the detection accuracy of electromagnetic abrasive sensors. Based on the magnetic coupling effect in the detection of electromagnetic abrasive particles, the influence characteristics of bubble gap, bubble size, bubble position and number of bubbles on the detection of copper particles were studied, and the electromagnetic abrasive sensor with large diameter channel (38mm) was simulated and tested. The results show that the larger the gap between the bubble and the copper particles, the smaller the signal amplitude of the copper particles, and the influence range is (0.52~10.31)%. The signal amplitude of copper particles also increased when the bubble size increased, and the influence of bubble diameter was 3.07% and 5.47% when the bubble diameter was 20mm and 25mm, respectively. The larger the angle between the center line of the bubble and the copper particle and the center axis of the sensor, the smaller the detection impact, and the influence range is (0.4~5.6)%; The greater the number of bubbles, the greater the disturbance, and the influence degree of single and double bubbles was 5.66% and 8.74%, respectively.
2024 Vol. 45 (10): 1453-1461 [Abstract] ( 6 ) HTML (1 KB)  PDF  (0 KB)  ( 0 )
1462 Research on the Key Technology and Standardization for Current Sensing Based on Diamond NV Color Center
CEN Wei,BAI Jingfen,MENG Jing,LI Qilin,Lü Yingjie,DUAN Yongxian
DOI: 10.3969/j.issn.1000-1158.2024.10.05
To promote the practical application of quantized current sensing technology, a current sensing technology based on diamond NV color centers was explored, and its standardization technology was preliminarily researched. Firstly, the structure and physical properties of diamond NV color centers were introduced, and the optical properties and spin quantum coherence based current sensing measurement principles of diamond NV color centers were analyzed. Practical technologies such as magnetic noise suppression, magnetic measurement sensitivity improvement, and miniaturization of measurement chips were studied. Then, the technical advantages and standardization requirements of current sensing measurement technology based on diamond NV color centers were analyzed, and suggestions for standard system construction were proposed to provide technical support for the research, equipment development, and sensing measurement system implementation of current sensing technology based on diamond NV color centers.
2024 Vol. 45 (10): 1462-1469 [Abstract] ( 6 ) HTML (1 KB)  PDF  (0 KB)  ( 0 )
1470 Kinematic Calibration of Industrial Robots Based on Binocular Vision Distance Error Measurement
JIANG Xiaohui,LI Xuxiang,SUN Yifei,ZHU Haojie
DOI: 10.3969/j.issn.1000-1158.2024.10.06
Aiming at the high cost and low end precision of robot calibration in the production process, a kinematic calibration method for industrial robots based on binocular vision distance error measurement is proposed. Firstly, we performed binocular camera calibration and distortion correction, then calculated the distance of matching feature points based on a binocular vision measurement model, and proposed a binocular disparity spatial position matching strategy in 3D spatial coordinates. Secondly, based on the robot kinematic model, the differential operator is introduced to establish the robot differential motion model and the robot kinematic error model, and then we obtained the relationship between the kinematic parameters of each joint of the robot and the end position error of the robot. Finally, by taking the IRB1200 robot as the research object, we compared and analyzed the distance error and position error obtained by using the high-precision laser tracker and binocular vision measurement method, and both errors are within the range of 10-1 mm, which meets the requirements, and after we performed the kinematics calibration on robot by using various optimization algorithms, the distance error has been reduced by an average of 61.5% compared with the pre-optimization level. The kinematic calibration method of industrial robot based on binocular vision distance error measurement can effectively improve the robot end precision and reduce the calibration cost.
2024 Vol. 45 (10): 1470-1479 [Abstract] ( 5 ) HTML (1 KB)  PDF  (0 KB)  ( 0 )
1480 Development of Spatial Resolution Standard for Metrological Micron X-ray Coordinate Measuring Machine
WANG Yunxiang,WANG Zhen,SHI Yushu,HU Jiacheng,TAN Haochen,FANG Dan1,FU Chen,HUANG Hongping,SUN Baojun,WANG Jun
DOI: 10.3969/j.issn.1000-1158.2024.10.07
Aiming at the problem that the spatial resolution standard of X-ray coordinate measuring machine cannot be traced, the development and calibration method of the spatial resolution standard of X-ray coordinate measuring machine are studied.Firstly, based on the wire-to-card method, a regularly traceable grid standard is developed by lithography and inductively coupled plasma (ICP) etching.Secondly, the measurement traceability of the standard is realized by scanning electron microscope. The grid period of standard are 4~40μm, and the uniformity is up to 0.1%, which can meet the current metrological X-ray coordinate measuring machine spatial resolution traceability requirements. Finally, the detachable package protection structure is designed and prepared by 3D printing technology, which is convenient for the popularization and use of the standard in the industry. The above method is helpful to improve the calibration work of X-ray coordinate measuring machine and improve the accuracy level at present.
2024 Vol. 45 (10): 1480-1486 [Abstract] ( 5 ) HTML (1 KB)  PDF  (0 KB)  ( 1 )
1487 Research on UAV Target Detection Algorithm Based on Improved YOLOv8n
ZHANG Liguo,YUAN Yulin,JIN Mei,ZHANG Qi,WU Wenzhe
DOI: 10.3969/j.issn.1000-1158.2024.10.08
To address the problems such as misdetection and omission of low-altitude UAV targets, the algorithmic model ASSM-YOLO for improving YOLOv8n is proposed. Firstly, a small target detection head is added and the original Neck structure is replaced using asymptotic feature pyramid network (AFPN), which asymptotically fuses low-level and high-level features. Second, the shuffle attention (SA) mechanism is introduced to enhance the perception of UAV targets. Again, the backbone network convolutional layer is replaced with space to depth convolution (SPD-Conv) to improve the feature loss problem in the convolution process. Finally, the loss function MPDIoU Loss is replaced to optimise the regression loss calculation. Experiments on the DUT-UAV dataset show that the ASSM-YOLO algorithm results in 92.5%, 72.2%, and 62.9% on the RmAP@0.5、RmAP@0.75 and RmAP@0.5:0.95 metrics, which are 5.9%, 8.3%, and 6.5% respectively compared to YOLOv8n, so significantly improves the detection accuracy of the UAV targets.
2024 Vol. 45 (10): 1487-1493 [Abstract] ( 5 ) HTML (1 KB)  PDF  (0 KB)  ( 2 )
1494 Construction of On-line Image Acquisition Device for Cylindrical Metal Pipe Fittings and Control Optimization of Key Parameters
TAO Guohao,LIU Zihao,XU Xiaomeng,LU Yebo,TAO Kai,HONG Zhe
DOI: 10.3969/j.issn.1000-1158.2024.10.09
The appearance of defects in cylindrical metal pipe fittings during the production process is random, and it is difficult for traditional mono- and binocular machine vision systems to acquire the full-surface information of the pipe fittings, an on-line image acquisition scheme for the full surface of the pipe fittings is proposed to realize high-quality and all-round imaging information collection. Firstly, by acquiring the two-dimensional image captured by a single camera, establishing the correspondence between the two-dimensional image and the surface covered by the column, calculating the actual pipe surface coverage angle corresponding to the two-dimensional image, and judging the number of cameras required to acquire the full-surface information of pipe fittings, we adopt multi-camera coordination with the real-time acquisition of the image in the clockwise direction of the disk. Secondly, a multi-factor experimental program is established based on the response surface design method to evaluate the effects of aperture value, exposure time and gain of the camera lens on image quality. The optimal camera parameters of cylindrical side camera and cylindrical ends camera are determined at the acceptable maximum speed to reduce the influence of motion blur and improve the efficiency of shooting. Finally, based on the optimal parameters, the images of metal pipe fittings are acquired and evaluated on-line in real-time to retain better quality images of pipe fittings. The experimental results meet the requirements of high-quality, fine defects clear metal surface defect detection data, and lay a foundation for the subsequent study of real-time defect detection of cylindrical metal pipe fittings.
2024 Vol. 45 (10): 1494-1501 [Abstract] ( 3 ) HTML (1 KB)  PDF  (0 KB)  ( 1 )
1502 Signal Preprocessing of Gas Ultrasonic Flowmeter Based on Wavelet Threshold Algorithm
GE Wenqi,ZHANG Kun,LIU Caizhi
DOI: 10.3969/j.issn.1000-1158.2024.10.10
When the ultrasonic signal of gas ultrasonic flowmeter propagates in the gas, it is easy to be interfered by various kinds of noises, with serious energy attenuation, weak echo signal amplitude and low signal-to-noise ratio, in order to accurately collect the ultrasonic signal of the gas ultrasonic flowmeter, Based on the traditional threshold filtering algorithm, an improved wavelet threshold algorithm is proposed to preprocess the gas ultrasonic flowmeter signal; Simulate and compare the improved wavelet threshold algorithm with the traditional threshold algorithm,The collected ultrasonic signal is processed by 6-layer Coif5 wavelet filter using FPGA. The comparison between simulation and experiment shows that the root mean square error of the improved threshold filtering algorithm is 0.0014, and the signal-to-noise ratio is 88.3290dB,it improves the acquisition quality of ultrasonic flowmeter, has good noise reduction effect.
2024 Vol. 45 (10): 1502-1511 [Abstract] ( 7 ) HTML (1 KB)  PDF  (0 KB)  ( 0 )
1512 Gas-Liquid Two-Phase Flow Characteristics Analysis Based on Time-Frequency Analysis and Complex Network
ZHANG Lifeng,WU Chuanbao
A method for analyzing the flow characteristics of gas-liquid two-phase flow in vertical pipelines based on time-frequency transformation and complex networks is proposed. This method is based on the measurement data collected by a digital electrical resistance tomography system. Three methods, Choi-Williams distribution (CWD), adaptive optimal kernel (AOK), and smooth pseudo Wigner-Ville distribution (SPWVD), are used to perform time frequency analysis on the pre-processed one-dimensional time series, and then extract energy sequences from the time frequency plane. The limited penetrable visibility graph method is used to construct complex networks for original time series and three types of energy series, respectively. Finally, three network indicators, namely, average clustering coefficient, average degree, and global efficiency, are used to characterize the evolution from bubbly flow to slug flow. The results show that the three network indicators of the complex network constructed from the original sequence are irregular; The average clustering coefficient and global efficiency corresponding to AOK and SPWVD are only regular under some operating conditions; The three network indicators corresponding to CWD all exhibit good regularity, which can more effectively reveal the complex flow behavior of gas-liquid two-phase flow.
2024 Vol. 45 (10): 1512-1519 [Abstract] ( 4 ) HTML (1 KB)  PDF  (0 KB)  ( 0 )
1520 Research on Characteristics of Collision Contact Force During Traceability Process of Spring Hammer
GAO Jianzhuo,CHEN Long,WANG Ningxi,LUO Xin
DOI: 10.3969/j.issn.1000-1158.2024.10.12
In order to improve the measurement accuracy of the spring hammer calibration device in the traceability work, and fully evaluate the energy loss in the impact end collision process of the traceability work, Newton restitution coefficient is introduced. And combined with the generalized contact force model, the dynamic modeling and numerical simulation analysis on the impact end collision process of the traceability device are carried out. The results show that the maximum contact force with Newton restitution coefficient is larger than that not considered, and the maximum contact force increases nonlinearly with the increase of Newton restitution coefficient, there is almost no effect on the relative deformation during the collision. Based on the experimental results, the simulation results are closest to the measured values when e=0.8, with a relative error of about 2%.
2024 Vol. 45 (10): 1520-1524 [Abstract] ( 8 ) HTML (1 KB)  PDF  (0 KB)  ( 1 )
1525 Theoretical Calculations for Distortion Coefficient of Piston Gauge Based on Finite Element Analysis
WANG Bowen,MA Kun,DONG Jia,HUANG Qian,YANG Ying,YANG Yuanchao,YUE Jin
DOI: 10.3969/j.issn.1000-1158.2024.10.13
Based on the finite element analysis(FEA)method,the distortion coefficients of the 600kPa gas piston gauge and 500MPa oil piston gauge are computed. According to the coupling relationship between the pressure distribution in the piston-cylinder gap and the gap distortion, the final pressure distribution and gap values under a certain measuring pressure are determined by iteration calculations.Based on this, the effective areas of piston gauge at various pressure points are calculated, and the pressure distortion coefficient is obtained by the least-square fit. A script for computation is developed using Python and ANSYS APDL. The influence of tuning parameters on the results is studied, and the uncertainty of the computed distortion coefficient is estimated. For the 600kPa gas piston gauge, the difference between the computed distortion coefficients by FEA and simple theory is only 0.8%. For the 500MPa oil piston gauge,the distortion coefficient computed by FEA is consistent with the value from experimental measurement within the uncertainty.
2024 Vol. 45 (10): 1525-1532 [Abstract] ( 8 ) HTML (1 KB)  PDF  (0 KB)  ( 0 )
1533 Bearing Fault Diagnosis Based on Optimized VMD and Envelope Kurtosis
LIU Feng,CHEN Xuejun,ZHANG Lei,YANG Kang
DOI: 10.3969/j.issn.1000-1158.2024.10.14
In view of the difficulty in selecting the decomposition layer K and penalty factor α of variational mode decomposition (VMD), a subtraction-average-based optimizer (SABO) is proposed to optimize the parameters. Firstly, the SABO is used to optimize K and α, output the optimal parameter combination, and substitute it into VMD to decompose the original vibration signal into K modal components. Then, the maximum envelope kurtosis is used as the index to extract the component with the largest kurtosis among the K modal components as the optimal component, and the eigenvector sample set is constructed by calculating the relevant time-domain and entropy theory characteristic parameters of the optimal component. Finally, the eigenvector sample set is input into the support vector machine (SVM) with mesh search and 5-fold cross-validation for fault diagnosis. To verify the effectiveness of this method, experiments were conducted using the bearing dataset from Case Western Reserve University. The experimental results show that the classification effect of the method is better, and the accuracy rate is 99.44%. Based on the bearing data set experiments of three different working conditions in Jiangnan University, the final fault diagnosis accuracy rate reaches more than 95%.
2024 Vol. 45 (10): 1533-1540 [Abstract] ( 10 ) HTML (1 KB)  PDF  (0 KB)  ( 1 )
1541 Calibration of Detecting Depth of LCR Wave of Ultrasonic Stress Transducer Based on Slotting Method
YI Chang,YAO Lei,ZHENG Huifeng,NIU Miao,WU Delin,GAO Shenping,YU Xingyan
DOI: 10.3969/j.issn.1000-1158.2024.10.15
In order to accurately characterize the detection depth (LCR wave penetration depth) of ultrasonic stress transducers at different frequencies and improve the spatial resolution of stress measurement, a study on LCR wave detection depth calibration of ultrasonic stress transducers based on slotting method is carried out. The slotting calibration method is based on the principle that when the slotting depth exceeds the penetration depth of LCR waves, the propagation of waves will be affected by the slotting. Firstly, a finite element research model for the penetration depth of LCR waves is established by using a physical field of elastic waves with time domain. The generation and propagation process of LCR waves are simulated, and the influence of groove shapes on LCR waves and detection depth are analyzed. By analyzing the two characteristic parameters of sound time difference and amplitude change, it is concluded that rectangular slot is more suitable for the detection depth calibration. Based on this, detection depth calibration experiments are conducted of transducers at frequencies of 2.5, 5, and 7.5MHz. The uncertainty of the experimental results at 2.5MHz is evaluated. The results show that the average value of ten measurements of LCR wave detection depth for a 2.5MHz transducer is 2.85mm, with an error of 0.15mm from the nominal value, and the combined standard uncertainty is 0.29mm. The research results are meaningful for calibrating the detection depth of transducers at different frequencies and improving the spatial resolution of stress measurement, and can provide experimental reference for the empirical formula of LCR wave penetration depth.
2024 Vol. 45 (10): 1541-1548 [Abstract] ( 9 ) HTML (1 KB)  PDF  (0 KB)  ( 0 )
1549 Adaptive Denoising of Magnetic Flux Leakage Signals of Steel Wire Ropes Based on Different Attenuation Functions
WU Dong,HUANG Shengping,ZHOU Lifeng,SUI Xianjun,SONG Hongzhi,YANG Jianhua
DOI: 10.3969/j.issn.1000-1158.2024.10.16
The effects of three different attenuation functions, namely, hyperbolic function, exponential function and linear function, on the noise reduction effect of wire rope magnetic flux leakage signal are discussed.Adaptive shift average denoising is applied to noisy signals with damage, and the denoising effect is compared and analyzed using signal-to-noise ratio and correlation number.The results show that for the two types of magnetic leakage signals used, the maximum SNR of the denoising signal using hyperbolic functions can reach 14.1041dB and 10.8349dB, which is greater than the corresponding SNR obtained from exponential and linear functions.The output curve obtained is smooth and has better denoising effect.Meanwhile, as the noise increases, the correlation number of denoised signals using hyperbolic functions approaches 1 faster, exhibiting better dynamic characteristics.
2024 Vol. 45 (10): 1549-1554 [Abstract] ( 6 ) HTML (1 KB)  PDF  (0 KB)  ( 0 )
1555 Analysis of the Quantized Step Distribution Mechanism ofSine Parameter Fitting Error
LIANG Zhiguo,LIANG Jiayi
DOI: 10.3969/j.issn.1000-1158.2024.10.17
The impact of quantization error on the error bound of sine wave curve fitting parameters follows a step like jump with equal intervals as the length of the sampling sequence increases, which is completely different from the previous experience of monotonic decrease in fitting error with increasing sequence length. In response to this phenomenon, this article conducted in-depth mechanism analysis and discussion, and provided a mathematical explanation for the phenomenon, including the step like jump mechanism of fitting parameter error bounds, the slow increase mechanism of error steps, the saddle shape mechanism of the first error step, and the reason for no jump in amplitude fitting error. It is of great significance and value to understand, master, and fully utilize this law to obtain higher accuracy of fitting parameters.
2024 Vol. 45 (10): 1555-1561 [Abstract] ( 9 ) HTML (1 KB)  PDF  (0 KB)  ( 0 )
1562 A Calibration Device for Video Analyzer Based on Virtual Instrument Technology
LIU Lei,XU Shuwen,HAN Zhengtao,CHEN Peng,HAN Dong
DOI: 10.3969/j.issn.1000-1158.2024.10.18
In response to the issues of the main standard devices being discontinued and the cumbersome calibration process in the calibration of video analyzers, based on virtual instrument technology and in the LabVIEW development environment, a video analyzer calibration device was developed using the M4i.6622-x8 arbitrary waveform generation card as the signal generation module.The basic parameters and distortion parameters of the video analyzer were calibrated.The calibration signal generation process for Lum level, Chrom level, Chrom phase video basic parameters and Tilt, 2T Pulse k-factor, C/L Gain and Delay, Lum NL video distortion parameters were provided.By experiment, the technical indicators can achieve: Lum level is ±0.2%, Chrom level is ±0.2%, Chrom phase is ±0.1°, Tilt is ±0.1%, 2T Pulse k-factor is±0.1%, C/L Gain is ±0.2%, C/L Delay is ±3ns, Lum NL is ±0.2%.The technical indicators are better than the TG2000 programmable video signal generator, meeting the calibration requirements of video analyzers.
2024 Vol. 45 (10): 1562-1569 [Abstract] ( 10 ) HTML (1 KB)  PDF  (0 KB)  ( 1 )
1570 Absolute Measurement of Radioactive Gas 85Kr Activity Concentration Using a Digitizer
TUO Fei,LU Tianxiang,ZHANG Ming,ZHOU Qianqian,GUO Guiyin,WANG Shuo
DOI: 10.3969/j.issn.1000-1158.2024.10.19
Based on the length compensation method absolute measurement system for gas-filled proportional counters established by the National Institute of Metrology, this study utilizes the DT5730 digital analyzer developed by CAEN to replace multiple traditional analog electronic modules. The digital analyzer is employed to collect, reconstruct, and analyze β signals offline to perform the absolute measurement of the activity concentration of 85Kr radioactive inert gas.The influence of various conditions is experimentally studied, and the absolute measurement results of 85Kr activity concentration are obtained by correcting the proportional counter end effect, the proportional counter wall effect, background, noise, dead time leakage counts, and sub-threshold counts.Under the same threshold, with a main magnification factor of 100 times, gas pressure of 50.5kPa, and operating voltages of 1675V and 1700V, the relative deviations of 85Kr radioactive activity concentration measurements between the digital analyzer and the electronic modules are 0.83% and 0.74%, respectively. The measurement results are consistent within the uncertainty range, proving that the digital analyzer can effectively replace traditional electronic modules for the absolute measurement of the 85Kr activity concentration.
2024 Vol. 45 (10): 1570-1575 [Abstract] ( 3 ) HTML (1 KB)  PDF  (0 KB)  ( 1 )
1576 Quantitative analysis of FES rehabilitation effects based on three-dimensional muscle synergy analysis
DU Yihao,WANG Xiaoran,YU Jinxu,CAO Tianfu,FAN Qiang
DOI: 10.3969/j.issn.1000-1158.2024.10.20
The muscle synergy theory can be used to analyze the intrinsic functional mode of the neuromuscular system, based on which a quantitative research method for FES rehabilitation effect based on muscle synergy analysis is proposed. First, on the basis of two-dimensional muscle synergy analysis, the myoelectric tensor was established by continuous wavelet decomposition, and the non-negative matrix decomposition of the myoelectric tensor was carried out by using the CP_ALS algorithm, so as to realize the three-dimensional muscle synergy analysis covering the null domain, frequency domain and time domain. Then, a patient wrist extension rehabilitation experiment was designed to compare and analyze the changes of wrist extension muscle synergism before and after FES physiotherapy lasting 10 days in patients with different degrees of hemiplegia, using healthy subjects as the control group. The experimental results showed that after FES physical therapy, the number of muscle synergies of patients increased (from 2 to 3), the muscle synergies in the null domain all reached the positive correlation level (mean value of 0.5402), the muscle synergies in the frequency domain had the largest increase (mean value of increase was 0.8271), and the muscle synergies in the temporal domain had the best effect (mean value of 0.7979), which indicated that FES in stroke rehabilitation was able to improve the patients muscle synergy effect.
2024 Vol. 45 (10): 1576-1584 [Abstract] ( 7 ) HTML (1 KB)  PDF  (0 KB)  ( 0 )
News
Download
Links
Copyright © Editorial Board of Acta Metrologica Sinica
Supported by:Beijing Magtech