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2020 Vol. 41, No. 7
Published: 2020-07-28
 
769 Multi-DOF Laser Interferometry System for Metrological Standard Device for Nano-geometrical Characteristic Size in Millimeter Range
SHI Yu-shu,ZHANG Shu,LIAN Xiao-yi,LI Wei,LI Qi,HUANG Lu,GAO Si-tian
DOI: 10.3969/j.issn.1000-1158.2020.07.01
Accurate measurement of nano-geometric structure is the key technical support to improve the quality and performance of integrated circuits, micro-nano electromechanical systems and micro-nano technology products.In order to obtain accurate measurement results, it is necessary to realize the measurement value traceability and built the value transfer system.To meet the metrology requirements of nanometer geometry structure from small to large range, the metrological calibration device for nano-geometrical characteristic size in millimeter range is developed which integrated with multi-degree of freedom (multi-DOF) laser interferometry system, and the results can be traced to SI units.The results shows that the device can achieve the measurement accuracy in nanoscale in the measurement range in millimeter level, and the resolution is achieved sub-nanometer scale.
2020 Vol. 41 (7): 769-774 [Abstract] ( 374 ) HTML (1 KB)  PDF (1460 KB)  ( 651 )
775 Design and Establishment of the Machine VisionMeasuring System for Film Cooling Holes
BI Chao,HAO Xue,LIU Meng-chen,FANG Jian-guo
DOI: 10.3969/j.issn.1000-1158.2020.07.02
In order to reconstruct the 3D shape characters of the film cooling holes of the high-pressure turbine blade, a non-contact machine vision measuring system with four motion axes is designed and then established. Composed of the frame of a coordinate measuring machine (CMM), a high precision turntable, special fixture of blades and image acquisition device etc, the system could combine the advanced vision detection and traditional coordinate measurement together to cope with the inspecting difficulties of the film cooling holes. To derive the 3D shape data of the film cooling holes, the method of depth from focus (DFF) is applied to realize the 3D reconstruction of the shape of the hole wall, which is verified by the follow-up experiment. In the experimental procedure, a film cooling hole of a high-pressure turbine blade is selected and inspected by the machine vision measuring system. With the focus image stack derived within the depth of the film cooling hole, the 3D shape characteristics of the hole is reconstructed by the method of DFF and then converted to the depth information, which could be employed to display the morphology of the hole wall and converted to the 3D data cloud. Therefore, the experimental results show the effectiveness of the vision measuring system for film cooling holes established.
2020 Vol. 41 (7): 775-780 [Abstract] ( 381 ) HTML (1 KB)  PDF (1671 KB)  ( 785 )
781 Research on Ratiometric Linearization Based High Adaptive Grating Signal Subdivision Method
ZHAO Guo-bo,YE Guo-yong,SHI Yong-sheng,YIN Lei,LIU Hong-zhong
DOI: 10.3969/j.issn.1000-1158.2020.07.03
Electronic subdivision is the key technology to achieving the nanometer resolution for the grating displacement sensors.And the error is caused by the subdivision method and the grating signal quality.Aiming at the limitations of real-time signal correction method in small-step measurement and some complicated working conditions, based on signal amplitude ratiometric, a new electronic subdivision linearization method is proposed from the perspective of improving the adaptability of subdivision method to non-ideal grating signals.In this way, two kinds of real-time signal compensation algorithms are constructed to further improve the linearity of the signal.Then, the principle of the proposed method is described, the error under the input of non-ideal grating signal is analyzed.And a theoretical accuracy of up to 0.003 μm and an actual accuracy of 0.08 μm are achieved.The numerical simulation and comparison experiments show that the proposed method has better adaptability to the non-ideal grating signals than the commonly used arctangent algorithm and linearization method based on the difference between the absolute values of the sine and cosine signals.
2020 Vol. 41 (7): 781-788 [Abstract] ( 267 ) HTML (1 KB)  PDF (2924 KB)  ( 346 )
789 Research on the Influence of Scanning Parameters on Imaging Quality in AFM Tapping Mode
CHEN Jian-chao,AN Xiao-guang,FENG Shi-xu,WANG Jia-chun
DOI: 10.3969/j.issn.1000-1158.2020.07.04
The influence of scanning parameters on the atomic force microscopy(AFM) imaging quality is reviewed and analyzed. A novel amplitude error indicator that is employed to evaluate the AFM imaging quality is proposed. The coupling effect of scanning parameters on imaging quality is investigated with experiments. The result reveals the interaction effect between the three scanning parameters like scanning frequency(fs), integral gain(I), and amplitude set point(S), i.e. the larger I and fs can be set at low S, which implies that the optimal balance between imaging quality and measurement efficiency is achievable. The result also provides practical guidelines for the reasonable setting of scanning parameters in AFM imaging.
2020 Vol. 41 (7): 789-795 [Abstract] ( 326 ) HTML (1 KB)  PDF (1850 KB)  ( 789 )
796 Image Dehazing Based on Mixed Dark Channel Prior
SHAO Ming-sheng
DOI: 10.3969/j.issn.1000-1158.2020.07.05
The image dehazing is researched based on mixed dark channel prior. Firstly, threshold was divided mixed dark channel, mixed dark channel prior was combined with near and far scene, and evaluation function of maximum similarity was obtained fine-tuning coefficient of mixed dark channel prior. Secondly, near scene was used light intensity difference of dark channel of pixel point and region center, and far scene was used expansion and corrosion of pixel. Finally, the algorithm process was given. Experimental simulation shows that the mixed dark channel prior has better visual effect and quantitative analysis indexes than other algorithms.
2020 Vol. 41 (7): 796-800 [Abstract] ( 288 ) HTML (1 KB)  PDF (1000 KB)  ( 299 )
801 Study on Evaluation Method for Dynamic Uncertainty ofExplosion Temperature in Confined Space
ZHANG Long,ZHANG Ji-jun,ZHAO Jian-wei,ZHANG Bao-guo,ZHANG Dong-liang
DOI: 10.3969/j.issn.1000-1158.2020.07.06
Combining the grey model GM (1,1) with the bootstrap method and the uncertainty evaluation theory, a grey bootstrap evaluation model GBM (1,1) for dynamic measurement uncertainty of the explosion temperature in confined space was constructed by. A 300s temperature data in an explosion test were selected as the analysis data. Parameters such as the estimated true value, the estimated interval, and the mean uncertainty were used to characterize the estimation results. The results of this study indicate that the GBM (1,1) model, which combines the strengths of the GM (1,1) grey model and bootstrap method, can accurately model the probability distribution of the dynamic measurement data and track the variation trends of the measured instantaneous values in real time. Compared with the grey model GM (1,1) and bootstrap method, the grey bootstrap model has higher truth estimation accuracy and interval estimation reliability. The estimated error distribution range is ［-12.62, 13.58］, the standard deviation is 8.69℃, and the maximum relative error is 1.2%. Its interval estimation reliability exceeded 90%, and the estimated intervals fully enveloped the dynamic fluctuation range of the measured quantity. It proves that the GBM (1,1) model can evaluate the dynamic measurement uncertainty of the explosion temperature in confined space.
2020 Vol. 41 (7): 801-807 [Abstract] ( 326 ) HTML (1 KB)  PDF  (0 KB)  ( 119 )
808 Realization of Quadrature Demodulation Method for Coriolis Mass Flowmeter under Batch Flow Measurement
HANG Lun,XU Ke-jun,XU Hao-ran,YUE Jing,LIU Wen,LIU Chen-ci,HUANG Ya
DOI: 10.3969/j.issn.1000-1158.2020.07.07
In order to improve the measurement accuracy of the Coriolis mass flowmeter under batch flow conditions,the quadrature demodulation algorithm is selected as the signal processing method according to the characteristics of rapid response,it solves the difficulties in the implementation process. the demodulation signal with single period finite point data is realized by using the periodic characteristics of the sinusoidal signal;besides the demodulated signals are filtered by cascading the FIR notch filter and the IIR low-pass filter while guarantee accuracy and reduce algorithmic computation;a secondary average is added in the post-processing in order to reduce the steady-state fluctuations and remove the singular points in the calculation results,in addition,the resource configuration during algorithm implementation is optimized. On this basis,the Coriolis mass flow transmitter was developed,and the single-phase flow and batch flow calibration experiments were carried out. The measurement error was less than 0.1% and the repeatability was less than 0.05%. The experimental results show that the quadrature demodulation algorithm has better measurement accuracy under the batch flow,and the developed transmitter has better performance.
2020 Vol. 41 (7): 808-815 [Abstract] ( 288 ) HTML (1 KB)  PDF (1001 KB)  ( 292 )
816 Load Cell Loading Pad of Surface to Surface Contact Form with Bearing Ball
LIANG Wei,YANG Xiao-xiang,YAO Jin-hui,XU Hang
DOI: 10.3969/j.issn.1000-1158.2020.07.08
To eliminate the contact stress of the traditional loading pad of load cell and enhance the accuracy and longtime stability of the load cell, a loading pad of surface to surface contact form with bearing ball was designed. The contrast experiment was carried out to verify its performance. The testing results of a 20MN force transducer with the loading pad showed that the repeatability error and position error was less than 0.005% and 0.04%, respectively. The loading pad of surface to surface contact form with bearing ball was confirmed with better specification compared with the loading pad of surface to surface contact form without bearing ball. With smaller frictional resistance, the ball could rotate itself around the cup to compensate the angular misalignment between the upper and bottom contact platen of the load cell. It would uniform the outputs of the load cell loaded in different positions and get better position error. Besides that, the contact stress of this style loading pad was much low, which made the loading pad strong enough to bear large load.
2020 Vol. 41 (7): 816-822 [Abstract] ( 348 ) HTML (1 KB)  PDF (572 KB)  ( 436 )
823 Development the Primary Standard Machine of the Ball Indentation Hardness
LIU Ji-ping,WANG Jing-tao,CUI Yuan-yuan,ZENG Li-min
DOI: 10.3969/j.issn.1000-1158.2020.07.09
Derived precision requirements of relative quantities according to the value definition of Boll Indentation hardness, the new primary standard machine is developed. The machine structure and control system design are introduced. The experiment results that the machine is with characters of convenient traceability and great stability,uncertainty of the primary machine is 1.0% (k=2), better than the requirements of JJG2019-1995 Verification Scheme of Measuring Instruments for Plastic Ball Indentation Hardness, can carry out the value transmission in 8.45～467.2HB.
2020 Vol. 41 (7): 823-829 [Abstract] ( 270 ) HTML (1 KB)  PDF (1885 KB)  ( 241 )
830 Precisely Measure the Distance between the Falling Body's Mass Center and Its Optical Center for Absolute Gravimeters
YU Ye,HU Xiang,WANG Qi-yu,WU Shu-qing,FENG Jin-yang
DOI: 10.3969/j.issn.1000-1158.2020.07.10
To reduce the influence of falling body rotation on the measurement result for absolute gravity measurement based on optical interferometry,a novel method used to collocate the falling bodys center of mass(Ocm) with its optical center by torsion pendulum was proposed. Analyzing the eigenfrequency of falling body by standard mode,the measurement equation of the center of optical and the center of mass deviation along the plumb line was deduced. In addition,analyzing the influence of the corner-cube retroreflectors refractive index and the gas damping for the measured results,respectively. Numerical analysis shows that when the incidence angle is between 0 and 0.1 degree, and the quality factor Q=1000, the disturbance of gravity acceleration caused by rotation can be optimal controlled at the level of 1.4μGal.
2020 Vol. 41 (7): 830-834 [Abstract] ( 255 ) HTML (1 KB)  PDF (570 KB)  ( 234 )
835 Intelligent Diagnosis for Rolling Bearing Fault Based on Quotient Space and Support Vector Machine
ZHANG Jin-feng,LI Xue,YANG Rui,LI Ji-meng
DOI: 10.3969/j.issn.1000-1158.2020.07.11
Aiming at the problems in rolling bearing fault diagnosis that the types of faults are various, and effective features are difficult to select, an intelligent diagnosis model is proposed based on quotient space and support vector machine (SVM). Firstly, based on the stratification idea of quotient space, the model granulates input samples into different granular layers according to different equivalence relations, then time domain and frequency domain features are reduced to obtain the sensitive feature set of each granular layer. Secondly, the sensitive feature set of each layer is inputted into SVM for fault identification. Finally, the final diagnosis result is obtained by weighted fusion of the fault recognition results of each granularity layer. The model is applied to process the bearing run-to-failure test data, and the recognition accuracy reaches 96.92%, indicating the validity and practicability of the model.
2020 Vol. 41 (7): 835-841 [Abstract] ( 235 ) HTML (1 KB)  PDF (592 KB)  ( 310 )
842 Research on Time Delay Feedback of Roll System Based on Vibration Absorber Control
LIU Bin,WANG Ying-hui,JIANG Jia-lei,LIU Shuang
DOI: 10.3969/j.issn.1000-1158.2020.07.12
Considering the nonlinear spring force constraint of the four-roll mill hydraulic cylinder, a two-degree-of-freedom rolling mill roll model with a vibration absorber was established. Time-delay feedback control function was introduced. Time-delay feedback control equation for vibration displacement and vibration velocity of rolling mill roller system with vibration absorber was designed. By analyzing the stability of the amplitude limit and amplitude-frequency characteristics of the rolling mills vibration limit loop, the influence of different feedback gain parameters and time-delay parameters on the main system of the rolling mill roll system is obtained. Appropriate increase of the feedback gain coefficient g1 and g2, reduce the delay coefficient τ1 and τ2 can improve the stability and convergence of the system, which provides theoretical support for suppressing mill vibration.
2020 Vol. 41 (7): 842-847 [Abstract] ( 248 ) HTML (1 KB)  PDF (735 KB)  ( 287 )
848 Echo Frequency Estimation of Surface Acoustic Wave Resonator Based on Phase Information in Frequency Domain
LI Ya-fei,CHEN Zhi-jun,ZHU Wei-jun,HUANG Hong-wei,XIONG Zhi-qiang
DOI: 10.3969/j.issn.1000-1158.2020.07.13
A frequency estimation algorithm based on the phase information in the frequency domain was proposed, which estimated the echo frequency of surface acoustic wave resonator (SAWR)by using the relationship between frequency and phase in the Fourier transform phase spectrum of sinusoidal signal, and the autocorrelation operation was performed for eliminating the influence of the initial phase of echo signal on the estimation results. The algorithm was verified by wireless test system and simulation echo signal. It was shown that the frequency estimation accuracy of the algorithm is not affected by the frequency change of the excitation signal, and has high accuracy and stability in the whole variation range of resonance frequency of SAWR.
2020 Vol. 41 (7): 848-851 [Abstract] ( 319 ) HTML (1 KB)  PDF (1292 KB)  ( 357 )
852 Research on 1000V Multi-decade Inductive Voltage Divider Standard
WANG Wei,LIU Xia,ZHANG Xin
DOI: 10.3969/j.issn.1000-1158.2020.07.14
A multi-decade 1000V inductive voltage divider (IVD) was established at the National Institute of Metrology (NIM) in China to function as the 1000V voltage ratio standard at the power frequency. It can provide a wide output ratio ranging from 1×10-8 to 1. An error compensation method, based on the transformer injection, was introduced to improve the output ratio accuracy. An improved bootstrap calibration method with triaxial shielding was presented, and a multi-ratio reference transformer was designed to calibrate the multi-decade IVD for combinational usage. The accuracy of the mentioned IVD is better than 1×10-7 and the calibration expanded uncertainty less than 2×10-8.
2020 Vol. 41 (7): 852-856 [Abstract] ( 268 ) HTML (1 KB)  PDF (1929 KB)  ( 1075 )
857 Research on Design and Performance Analysis by Using Electromagnetic Assisted Piezoelectric Actuator
WEI Xiao-hua,ZHENG Ling-chen
DOI: 10.3969/j.issn.1000-1158.2020.07.15
Conventional piezoelectric actuator suffers from the limitation of small controling scale, due to the short travelling range of piezoelectric actuation.An electromagnetic assisted piezoelectric actuator was developed, which has the advantages with both long traveling range in electromagnetic actuator and high-resolution in piezoelectric actuator.The actuator consists of movable part, guide groove, flexible member, electromagnet, piezoelectric element, and control circuits.First of all, adjusting the electromagnetic force between the maximum static friction force and kinetic friction force by setting the pre-load structure and the coil current.Then, the micro-vibration was generated by piezoelectric components to control transition between static friction and kinetic friction using contact situation of the movable part and the guide groove.Therefore, the actuator can perform reciprocating motion with long traveling range(10mm) and high resolution(1.5μm). The experiment results showed that the proposed actuator has excellent positioning ability.
2020 Vol. 41 (7): 857-863 [Abstract] ( 262 ) HTML (1 KB)  PDF (1978 KB)  ( 205 )
864 Research on Method of Selecting the Matched Filter in EVM Measurement
SHEN Xiao-qing,YU Qing-hua,YANG yang,QIU bin,XIA wei
DOI: 10.3969/j.issn.1000-1158.2020.07.16
Based on the relationship between matched filter and BER and EVM, using “traversal method”,an engineering approximation method is proposed to search the best measuring filter, which making the EVM measurement in better accuracy for cases of unawareness of filter configuration or specialized filter in equipment under testing. Experiments show that the method is practical and effective. When there is a matched filter in the measuring instrument, the probability of finding the matching filter is 100%. When there is no matching filter in the measuring instrument, the “traversal method” can find the best measurement filter under limited conditions.
2020 Vol. 41 (7): 864-867 [Abstract] ( 291 ) HTML (1 KB)  PDF (608 KB)  ( 258 )
868 Weak Signal Detection Method Based on Delay Feedback Multistable Stochastic Resonance
SHI Pei-ming,YUAN Dan-zhen,ZHANG Wen-yue,LI Meng-di,HAN Dong-ying
DOI: 10.3969/j.issn.1000-1158.2020.07.17
In order to detect weak signals in noisy background, a novel multistable stochastic resonance model based on one-time delay is proposed. The influence of each parameter on the model is analyzed and compared with the delay feedback stochastic resonance model. In this paper, a multistable stochastic resonance model based on one-time delay is proposed, which can enhance the amplitude at the characteristic frequency of weak signals and improve the signal-to-noise ratio and spectral power amplification factor of output signals. Examples show that the proposed method can effectively detect the characteristics of early weak signals.
2020 Vol. 41 (7): 868-872 [Abstract] ( 298 ) HTML (1 KB)  PDF (2234 KB)  ( 384 )
873 Comparative Analysis of Film Dosimeter and Diode Detector in Small Field Dosimetry
GAO Xiang,YU Yan-juan,SHI Li-wan
DOI: 10.3969/j.issn.1000-1158.2020.07.18
For precise radiotherapy, especially stereotactic radiotherapy and intensity-modulated radiotherapy, the small irradiation field modeling data is particularly important. The tissue maximum dose ratio, the profile, point dose and total scattering factor Scp were measured and calculated under the condition of the accelerator with 6MV photons, using the film and diode detector, with 0.01cm3 in IBA Blue Phantom 2 tank and solid water, measuring the irradiation field of 0.6cm×0.6cm～10.0cm×10.0cm. The results showed: For percentage depth dose (PDD) curves, the measured data of digital diode detector and film in built-up area were basically consistent in different exposure fields, and there was a small deviation in the measurement results in water depth of 2～10cm, with a significant difference after water depth of 10cm (almost 0.07). For the profile curve, there was no significant difference between the measured data of film and finger diode detector under different irradiation fields. Conclusions were drawn as follows: (1)For different measuring probe, the accuracy of the physical measurements may differ greatly.(2)Film dosimeter has superior spatial resolution, but film absorbed dose range is limited, energy and directional are dependenced.
2020 Vol. 41 (7): 873-878 [Abstract] ( 304 ) HTML (1 KB)  PDF (1214 KB)  ( 253 )
879 Prediction of NOx Emission of Boiler Based on Improved Optimal Foraging Algorithm
NIU Pei-feng,PENG Peng
DOI: 10.3969/j.issn.1000-1158.2020.07.19
An improved optimal foraging algorithm is proposed, the update direction of adaptive inertia weight and global optimal solution is introduced in the optimal foraging algorithm, at the same time, the mechanism of phase space search is introduced. The improved optimal foraging algorithm (POFA) optimized by extreme learning machine (ELM) constructs an improved extreme learning machine model (POFA-ELM) and uses the POFA-ELM model to model the boiler NOx emission characteristics.Compared with ELM and differential evolution algorithm, particle swarm optimization, artificial bee colony algorithm, and basic optimal foraging algorithm optimized ELM model, the results show that the POFA-ELM model has better prediction accuracy and stronger generalization ability, which can predict the NOx emission quality concentration more accurately.
2020 Vol. 41 (7): 879-885 [Abstract] ( 254 ) HTML (1 KB)  PDF (1486 KB)  ( 198 )
886 Uncertainty Evaluation for the Oil Content of Microcrystalline Wax
JIA Wei-ming,GAO Xu-feng,LING Feng-xiang,ZHANG Hui-cheng,GUO Shi-gang
DOI: 10.3969/j.issn.1000-1158.2020.07.20
The uncertain factors influencing the oil content of microcrystalline wax were analyzed and evaluated. The synthetic uncertainty was evaluated by calculating uncertainly factors include the repetitive detections, weight of oil residue, weight of wax sample, volume of solvent, volume of solvent evaporated. The experimental results showed that the sources of uncertainty were mainly derived from the repetitive detections, the second was the volume of solvent and weight of oil residue. Through the evaluation of the uncertainty, it can improve the reliability of the test results and provide theoretical basis for the accurate determination of the oil content of microcrystalline wax.
2020 Vol. 41 (7): 886-890 [Abstract] ( 284 ) HTML (1 KB)  PDF (443 KB)  ( 297 )
891 Evaluating the Sampling Contribution to the Measurement Uncertainty
CHEN Ling-feng
DOI: 10.3969/j.issn.1000-1158.2020.07.21
If the objective of the measurement is to estimate the value of the analyte concentration in a sampling target, then the uncertainty associated with the sampling process inevitably contributes to the uncertainty of the measurement result. Heterogeneity, ambiguity in the sampling protocols, loss of analyte and fine particles, or contamination from equipment or previous samples are among the most important factors contributing to uncertainty associated with sampling. The empirical approach by EURACHEM is introduced, the general error sources are quantified as the sampling precision, analytical precision, sampling bias and the analytical bias respectively. The uncertainties associated with sampling precision and analytical precision are evaluated through duplicate methods and analysis of variance. An example is given to demonstrate how to evaluate the uncertainty associated with the sampling and sample preparations.
2020 Vol. 41 (7): 891-896 [Abstract] ( 458 ) HTML (1 KB)  PDF (1033 KB)  ( 1045 )
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