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2014 Vol. 35, No. 4
Published: 2014-07-22
 
305 The Progress of Joule Balance
ZHANG Zhong-hua, LI Chen, HE Qing, LI Zheng-kun, HAN Bing, LU Yun-feng,LAN Jiang, LI Shi-song, FU Ya-qiong, WANG Gang
DOI: 10.3969/j.issn.1000-1158.2014.04.01
The National Institute of Metrology (NIM) has been studying the Joule Balance method (which is used for the same purpose as the Watt Balance method but operated differently),  for several years to establish a kind of quantum mass standard by means of measuring the Planck constant.  Since 2010, some progress has been achieved.  A new standard square wave compensation method has been developed to measure the DC mutual inductance with an uncertainty of several parts in 10-7 (k=1) An eddy current sensor for positioning has been designed and implemented to obtain a more accurate position of the movable coil  The alignment technique for the coil system has also been placed under consideration Specifically, a newly developed oil damping device reduces the small swing of the coil set which occurs because of a combination of the weak vibration of the balance base and the hot ascending warm air from the current heating of coils. As a result, the measurement uncertainty of the coil position and mutual inductance is improved.The recent measurement result of the Planck constant  h is 6626104(59)×10-34J·s  with an uncertainty of  8.9×10-6 (k=1) Further improvements and difficulties are also discussed.
2014 Vol. 35 (4): 305-310 [Abstract] ( 744 ) HTML (1 KB)  PDF (1463 KB)  ( 550 )
311 Successive Approximation Division Algorithm in Laser Interference Signal Subdivision Based on FPGA
HUANG Xiao-qing, GAO Si-tian, MIAO Qi, LU Rong-sheng
DOI: 10.3969/j.issn.1000-1158.2014.04.02
In order to achieve the goal of the laser interference measurement signal being in high speed and high precision subdivision, the division of tangent subdivision algorithm is improved.  The successive approximation algorithm instead of using shift subtraction algorithm  is used more in the past. Experiments prove that successive approximation algorithm is faster than shift subtractionm, resource usage is less, and successive approximation algorithm is more suitable for FPGA based on high speed and high precision requirements.
2014 Vol. 35 (4): 311-314 [Abstract] ( 611 ) HTML (1 KB)  PDF (3975 KB)  ( 613 )
315 Grain Edge Detection of Diamond Grinding Wheel Based on a Fuzzy C-means Clustering Algorithm
GAO Qi, CUI Chang-cai, HU Jie, YE Rui-fang, HUANG Hui
DOI: 10.3969/j.issn.1000-1158.2014.04.03
Based on a fuzzy C-means (FCM) clustering algorithm, the height data set of a measured grinding wheel surface is classified into two fuzzy clusters, which are named as “grain” and “bond” respectively. The clusters centers are initialized with the centroids of the classified data first, and then the most optimal cluster centers and the membership matrix are obtained with an iterative strategy. By choosing appropriate thresholds of the membership degree and the Euclidean norm of the two cluster centers, the edge of grains is determined. The method is validated with experiment. For further analysis, an evaluation is carried out by applying this method to a simulated grinding wheel surface, the results of which show that the error of this method is less than 2.0%.
2014 Vol. 35 (4): 315-322 [Abstract] ( 481 ) HTML (1 KB)  PDF (15698 KB)  ( 500 )
323 The Aluminum Hot Strip Mill Plate Crown Soft Sensor Modeling Based on the ABC-LSSVM
ZHAO Xin-qiu,LIU Zheng-liang,YANG Jing-ming,CHE Hai-jun
DOI: 10.3969/j.issn.1000-1158.2014.04.04
The plate crown is an important indicator of the aluminum strip in Aluminum hot strip mill flatness control. In order to accurately predict the aluminum hot strip mill plate crown,a soft sensor model was established on the base of artificial bee colony (ABC) and least squares support vector machine (LSSVM) . ABC was applied to the process of the model parameters optimization because prediction accuracy and generalization ability of LSSVM model depends on the choice of the parameters. The prediction performance of the model was tested by sample data collected at the scene of a factory 1+4 aluminum hot rolling. The model was compared with Marquardt and the LSSVM model whose parameters were optimized by Genetic Algorithms(GA).The simulation result shows that the ABC-LSSVM soft sensor model parameters optimization fast, simple structure and high precision .
2014 Vol. 35 (4): 323-326 [Abstract] ( 459 ) HTML (1 KB)  PDF (3063 KB)  ( 522 )
327 Measurement Methods of Fresnel Lens Optical Landing System Based on Imaging Illumination Detection
TANG Cui-rong,WU Wen-bin,ZUO Yong,XU Yong
DOI: 10.3969/j.issn.1000-1158.2014.04.05
In order to resolve the problem of  measuring the Fresnel Lens optical landing system,a measurement method which is based on imaging illumination detection  is proposed. According to the analysis of the measurement requirement, an imaging illumination detector is designed. Experiment results show that such detector, has high measuring speed and eliminate background light interference characteristics, can measure the luminous intensity of fresnel lens optical system which has long-distance and large divergence angle and meet the requirement of the measurement   detector.
2014 Vol. 35 (4): 327-330 [Abstract] ( 751 ) HTML (1 KB)  PDF (1603 KB)  ( 834 )
331 Application Research on Adaptive Interpolation Algorithm in Image Restoration
MA Min, ZHAO Liang, WANG Hua-xiang
DOI: 10.3969/j.issn.1000-1158.2014.04.06
Since the BSCB model has an inherent slow rate, and the total variation model is subject to staircase effect, to overcome these disadvantages, an adaptive interpolation algorithm is proposed based on the diffusivity function. The proposed algorithm repairs the unknown pixels by using the gradient weight function and distance weight function of the neighboring pixels whose values are known. Experimental results show that compared to the traditional methods, the proposed algorithm can obtain relatively higher image quality in a shorter time for both gray and color image restoration, additionally, the quantitative evaluation indicator has also verified the effectiveness of the proposed method.
2014 Vol. 35 (4): 331-334 [Abstract] ( 689 ) HTML (1 KB)  PDF (736 KB)  ( 741 )
335 A New Design of Digital Correlator for Johnson Noise Thermometry
FU Yun-fengQU Ji-feng, ZHANG,Jian-qiang，ZHOU Kun-li
DOI: 10.3969/j. issn. 1000-1158.2014.04.07
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The basic principles and characteristics of cross-correlators used in Johnson noise thermometry are described. A new digital correlator is presented based on commercial analog-to-digital converters and Lab VIEW software for the measurement of the thermal noise. High-precision synchronous dual-channel-sampling has been achieved by adjusting the phases of the external reference clocks. Experiments are carried out to validate the proposed approach and the results show that the new correlator is able to detect extremely small signals buried in the noise of the measurement circuits.
2014 Vol. 35 (4): 335-338 [Abstract] ( 736 ) HTML (1 KB)  PDF (3858 KB)  ( 901 )
339 Study on Selection Method for the Testing-level Crusher Gauge of Circumflex Type
WANG Fang, LI Jing, KONG De-ren, GAO Lu-peng
DOI: 10.3969/j.issn.1000-1158.2014.04.08
The selection method using relative deviation to execute error processing is proposed to eliminate the fluctuation of stressors. With the crusher gauge of circumflex type with 1cm2 and the conical copper cylinders withΦ6mm×9.8mm as the research objects, the test selecting are made for the testing-level crusher gauge of circumflex type. And with the analysis and treatment of the experimental data,  the proposed assessment and  the feasibility of the method has been validated. The results showe that the election method is more scientific and rational.
2014 Vol. 35 (4): 339-343 [Abstract] ( 487 ) HTML (1 KB)  PDF (302 KB)  ( 387 )
344 Damage Detection of Truss Structure Based on Strain Mode Analysis
WEN Yin-tang, ZHANG Yu-yan, ZGANG Li-li, LUO Xiao-yuan, WANG Hong-rui
DOI: 10.3969/j.issn.1000-1158.2014.04.09
Taking the truss structure as the research object, the strain modal analysis is used to identify the damage of the truss structure. The strain modal can be deduced from displacement model shapes,then the difference of strain modal is used to be truss structural damage detection index,and the damage threshold based on the 3σ criteria is presented. Through the strain mode difference and damage threshold of contrast to determine whether there is damage and locate it,furthermore preliminary determine the extent of the truss structure with the size of the strain difference between before and after injury. The damage conditions of single damage and multiple damages in different degree of a practical truss structure,are numerically simulated with finite element software numerical simulations respectively.Furthermore further experiment research,by applying this method to actual truss damage detection,proves the effectiveness of the proposed method.
2014 Vol. 35 (4): 344-349 [Abstract] ( 557 ) HTML (1 KB)  PDF (684 KB)  ( 431 )
350 Application of Wireless Sensor System to Bearing Capacity Measurement of Oil Derrick
LIU Jin-mei, YAN Tian-hong, ZHOU Guo-qiang
DOI: 10.3969/j.issn.1000-1158.2014.04.10
For solving the shortcomings of traditional test technology of oil derrick, a bearing capacity evalution method is proposed based on wireless strain test. According to mechanical and electrical theory, the strain sensor principle is particularly analyzed. Wifi Network used in test system is discussed. In order to realize the comprehensive performance evaluation of the derrick in-service, the optimal updating function is established according to residual equation between test and theory stress. An analysis is carried out for the derrick in-service of an oilfield. The results indicate that a satisfying result can be acquired. It can provide an effective method and basis for the safety assessment and monitoring of oil derrick in-service with damage.
2014 Vol. 35 (4): 350-354 [Abstract] ( 531 ) HTML (1 KB)  PDF (398 KB)  ( 516 )
355 Design of an Adaptive Two-step Kalman Filter Based on Fuzzy Logic
JIN Mei, ZHANG Zhi-fu, JIN JU, YU Guo-hui, LI Wen-chao
DOI: 10.3969/j.issn.1000-1158.2014.04.11
To analyze the modeling of the inertial/magnetic tracking system, the centralized Kalman filter algorithm depending on PC is often used to process the data. Because this algorithm is complex and the data processing speed is slow, it is difficult to realize high-speed motion tracking in the embedded system.  An adaptive two-step Kalman filter method based on fuzzy logic for real-time motion tracking of human body  is proposed. The parameters of Kalman filter are self- adjusted according to the different motion states of human body. The method can not only improve the estimation accuracy and fault-tolerant performance of the system to a certain degree, but also reduce the matrix dimension.
2014 Vol. 35 (4): 355-359 [Abstract] ( 469 ) HTML (1 KB)  PDF (1458 KB)  ( 802 )
360 Analysis on Dynamic Force Correction of Axial Fatigue Testing Machines
NI Shou-zhong, ZENG Li-min
DOI: 10.3969/j.issn.1000-1158.2014.04.12
The dynamic force correction of the fatigue testing machine is related to the position of load cell,the mass,stiffness and their distribution of the vibration system. An approximate correction formula is given by the analysis of the dynamic forces to the fatigue testing machines of load cell mounted in two different positions.A view point is proposed, it is that the static calibration is more reasonable than dynamic calibration in fatigue testing machine test by analysis of the mass distribution of the dynamic forces part of the vibration system,combined with experimental force data using dynamic and static calibration method while frequencies below 1000Hz.
2014 Vol. 35 (4): 360-362 [Abstract] ( 505 ) HTML (1 KB)  PDF (352 KB)  ( 746 )
363 Measurement of Particle Vibration Velocity in Air-borne Sound Field with the Photon Correlation Method
LI Liang-jie, HE Long-biao, WANG Xue-jing
DOI: 10.3969/j.issn.1000-1158.2014.04.13
The particle vibration velocity is an important parameter to evaluate the characteristics of the sound field. Photoelectric signal of scatter light was obtained laser Doppler velocimetry at different sound pressure level in plane wave sound field. And the Doppler signal was processed by autocorrelation method, the velocity can be calculated based on the time of characteristic values ??of the correlation function and compared with that of microphone. Furthermore, on the basis of the autocorrelation algorithm, the difference which caused by the ratio of the original signal frequency offset and the Doppler frequency is not an integer multiple was reduced by the interpolation method. The results demonstrate that the photon correlation method is able to obtain particle vibration velocity of the sound field. and results show good agreement with that measured by microphone, interpolation method is conducive to decreasing the deviation when velocity is large relatively。The deviation of the two methods is less than 0.7dB at the sound pressure level from 96 dB to 110 dB.
2014 Vol. 35 (4): 363-367 [Abstract] ( 593 ) HTML (1 KB)  PDF (5250 KB)  ( 521 )
368 A No-blind Area Detection Method of Detuning in Continuously  Tuned AC Filter
DENG Ya-ping, TONG Xiang-qian, BAO Yang, FENG Ying
DOI: 10.3969/j.issn.1000-1158.2014.04.14
The measurement of detuning is a very crucial step in continuously tuned AC filter, and the detection precision can affect the filtering performance and operation stability. To solve the problem of detection dead zone in existing indirectly measurement of AC filter detuning, a new detection method based on the harmonic voltage crossed between the filter reactor and capacitor is proposed. The presented method not only overcomes the detection blind area, but also has advantages of simple implementation. A detuning detection experimental system is developed, and the results show the effectiveness and accuracy of the proposed method for filter detuning.
2014 Vol. 35 (4): 368-372 [Abstract] ( 763 ) HTML (1 KB)  PDF (941 KB)  ( 530 )
373 Experimental Investigation on the Tribological Performance of the Ferrofluids in Uniform Gradient Magnetic Field
CHEN Shan-fei, Gu Bang-ming, Gong Yan, Wang Zheng-liang
DOI: 10.3969/j.issn.1000-1158.2014.04.15
Uniform gradient magnetic field can, more accurately, reflects the friction performance of ferrofluids in the magnetic field. Based on this, two coils, which could produce uniform gradient magnetic field, were constructed and placed on the commercial UMT3 tribo-meter. Using the poly-α-olefin synthetic oil (PAO)-based magnetic fluids as the lubricant, the tribological properties were tested with different loads, different reciprocating frequency and various magnetic field. The results show that: when the load and reciprocating frequency are constant, the friction coefficient decreased with the increase of the magnetic field; when the load, a uniform gradient magnetic field, the friction coefficient also decreased with the increase of the reciprocating frequency. Comparing with no magnetic field, the ferrofluids has higher bearing capacity and a longer wear life in the uniform gradient magnetic field.
2014 Vol. 35 (4): 373-341 [Abstract] ( 604 ) HTML (1 KB)  PDF (5195 KB)  ( 545 )
378 Design and Development of the WR-15 (50~75) GHz Millimeter-wave Power National Primary Standard
CUI Xiao-hai, LI Yong, ZHANG Shu-yi, SUN Wei-jie
DOI: 10.3969/j.issn.1000-1158.2014.04.16
The design and development technique of a WR-15 microcalorimeter based on a thermistor mount is presented. The microcalorimeter is designed as twn-line structure which can lower the influnece from the laboratory temperature floating. The basic principle of the measurement is presented too. The microcalorimeter will be national primary standard of WR-15 (50~75 GHz) millimeter-wave power. It enhanced China RF power measurement capability up to 75 GHz.
2014 Vol. 35 (4): 378-381 [Abstract] ( 646 ) HTML (1 KB)  PDF (4317 KB)  ( 632 )
382 Impact of Frequency Domain Window-adding for the Ramp Filter on Image Reconstruction
QIAO Zhi-wei
DOI: 10.3969/j.issn.1000-1158.2014.04.17
The performance of the ramp filter has an important influence on image reconstruction. The design method of frequency domain window-adding is the main method. Four classical window-adding filters were designed, which are RL filter, SL filter, Hamming window filter and exponent window filter. The four filters characteristics were analyzed using the unit impulse response and frequency response. The four filters were compared from the frequency response side and the sidelobe attenuation rate side. Theoretical analysis and simulation results show that the vibration noise of the exponent window filter is minimum and the SL filter is optimal as a whole.
2014 Vol. 35 (4): 382-386 [Abstract] ( 725 ) HTML (1 KB)  PDF (1596 KB)  ( 708 )
387 Visualization of Measurement Data Based on Virtual Reality
ZHOU Xin, FANG Hong, HOU Li-xin, LIU Ke, ZHAO Hai-ning,AN Ying, YANG Li, Bian Xin
DOI: 10.3969/j.issn.1000-1158.2014.04.18
Based on the classification of measurement data from the perspective of visualization, a method of 3D modeling for two types of measurement data is presented. Then by integrating the CAVE and 3D technologies into the basic procedure of data visualization, a new technical solution for measurement data visualization is proposed. The solution which has a 3-D effect and an immersion effect to enhance the perception of observers, is based on 3D modeling, assisted by scene setup, and uses view control as the essential part.
2014 Vol. 35 (4): 387-392 [Abstract] ( 593 ) HTML (1 KB)  PDF (3168 KB)  ( 726 )
393 Study on Online Fluorescence Measurement Technology for Petroleum Pollutants in Water with Optical Fiber Technique
YANG Li-li, WANG Yu-tian, LU Xin-qiong
DOI: 10.3969/j.issn.1000-1158.2014.04.19
According to the fluorescence spectral characteristic of the petroleum pollutants in water, using the fluorescence spectral technology, optical fiber sensor technology and CCD detection technology, a fluorescence spectral measurement instrument used to online measure petroleum pollutants in water is developed. In consideration of the particular environment, the automatic sampling and pretreatment system is designed. The real-time analysis is realized and the measuring is conducted conveniently. By experimental research and performance test of the instrument in situ, the feasibility is verified. The instrument is used to measure the petroleum pollutants in water, and then qualitative identification and quantitative analysis are conducted. The research provides a novel technical means for the petroleum pollutants monitoring in water.
2014 Vol. 35 (4): 393-397 [Abstract] ( 608 ) HTML (1 KB)  PDF (2329 KB)  ( 817 )
398 Magnesium Phosphate Cement with Rietveld Whole Pattern Fitting
LAI Zhen-yu, ZOU Qiu-lin, LU Zhong-yuan, Li Qian
DOI: 10.3969/j.issn.1000-1158.2014.04.20
Based on the qualitative analysis of X-ray diffraction, combined with the Rietveld whole pattern fitting method, the quantitative research for content of hydration products crystalline phase in magnesium phosphate cement at different hydration time was achieved. The results showed that the relative content of hydration products MgKPO4·6H2O in magnesium phosphate cement at hydration time 10 min, 1 h and 1 d were 12.39%, 15.77% and 18.38%, respectively. The Rwp factor changed from 9.73% to 12.8%, which indicated that the method could confirm the crystalline phase composition and relative content in magnesium phosphate cement accurately, intuitively and rapidly. It could obtain the crystallography parameters of every crystalline phase. Also in combination with the related theory, the hydration and performance of magnesium phosphate cement could be analysised objectively, thus provided a feasible method to deepen the understanding of cement materials.
2014 Vol. 35 (4): 398-402 [Abstract] ( 715 ) HTML (1 KB)  PDF (1017 KB)  ( 1232 )
403 New Method for Blood Type Detection Based on Bioelectrical Impedance Analysis Technology and its System Implementation
CHEN Li-li, LIAO Qiang, HU Xue, ZHANG Guo-zheng
DOI: 10.3969/j.issn.1000-1158.2014.04.21
A new method for blood type detection and a new automated blood typing system are developed. In the system, the combined use of the AD9850 chip and MCU are employed to realize the DDS technique and produce excitation signal. Then an elliptic filter is designed to eliminate the signal interference, and an amplitude stabilized circuit is designed to stabilize the amplitude of the signal output by using an AD8370 chip, which is a low-cost variable gain amplifier. The amplitude and phase measurement chip AD8302 is adopted to extract the impedance information. Based on neural network recognition model, a new method is designed to determine the degree of agglutination in red blood cell suspension. The use of this method combined with the discriminant rule could successfully identify the blood type. Contrastive test is carried out and the new system showed high measurement accuracy and good stability. This system could better distinguish the different intensity of agglutination in red blood cell, and identified ABO and Rh blood type correctly in normal samples. The self-developed new automated blood typing system is in better agreement with clinical requirements.
2014 Vol. 35 (4): 403-408 [Abstract] ( 543 ) HTML (1 KB)  PDF (2448 KB)  ( 928 )
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