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2012 Vol. 33, No. 2
Published: 2012-03-22
 
97 Study of Automatic Measurement System for Line Space Measurement with Nanometer Accuracy in 2m Length Comparator
GAO Hong-tang,YE Xiao-you,ZOU Ling-ding,SUN Shuang-hua,SHEN Xue-ping, GAN Xiao-chuan,CHANG Hai-tao,WANG Jian
DOI: 10.3969/j.issn.1000-1158.2012.02.01
The components of 2m Length Comparator are described.The principle of line space dynamic measurement with photoelectric microscope and laser interferometer is analyzed.The methods for improving the accuracy of line positioning and line space measurement are studied,and the methods for automatically and synchronously processing of line signal and interference signal with high speed are studied also.The signal processing system is based on integrate circuit FPGA and computer techniques.The experiment,according to Verification Regulation JJG 331-1994 (China):the interference length comparator,was performed for measurement of standard metal line scale.The result shows that the best standard deviation of position for line with good quality is less than 10nm,and the measurement uncertainty analysis for the line space shows that,when measuring high quality line scale,the expanded measurement uncertainty U=（20+40L）nm,k=2.
2012 Vol. 33 (2): 97-103 [Abstract] ( 490 ) HTML (1 KB)  PDF (2705 KB)  ( 627 )
104 Research of Locating Gas Source Based on Distributed Adaptive Deflection Projected Subgradient Algorithm
ZHUANG Zhe-min,LIAO Hai-long,WEI Chu-liang,LI Fen-lan
DOI: 10.3969/j.issn.1000-1158.2012.02.02
In view of gas source localization in wireless sensor networks, an adaptive projected subgradient method（APSM）is firstly introduced to estimate the gas source position. However, the APSM for locating is difficult to converge and consumes much time because of the concentrations corrupted by noise. So a distributed adaptive deflection projected subgradient method（DADPSM）is proposed for modifying the iteration search direction and combing the characteristic of distributed calculation in WSN. Under the attenuation model of a gas source in the wind field, this algorithm could process the distributed information by DADPSM, the deflection subgradient direction is used in place of original gradient and the deflection subgradient projection hyperplanes is applied as the searching areas in the process of relaxed projection to achieve the gas source localization. Simulation proves that this algorithm can provide good convergence property, locate the gas source accurately, and save large amount of energy.
2012 Vol. 33 (2): 104-109 [Abstract] ( 491 ) HTML (1 KB)  PDF (1947 KB)  ( 632 )
110 Study on Technique of Adaptive Filter Based on Incremental Optical Electrical Encoder Subdivision
MU Yi-ning,YU Lin-tao,ZHU Yi-feng,ZHANG Guo-yu,JIANG Hui-lin
DOI: 10.3969/j.issn.1000-1158.2012.02.03
Based on the principle of grating pair modulation, a method of self-adaptive filtering in the light of incremental optical electrical encoder subdivision based on the models establishment of physical optics and geometrical optics is described.It also analyzed the reason why the photoelectric signals output for Moiré fringe are uncertain,remaining the original baseband signals by self-adaptive filtering high frequency signals.The result of self-adaptive filtering is equivalent to a narrowband band pass filter whose center frequency is original baseband and the pass band will change accordingly the original baseband with random variation.Experiments showed that application of this self-adaptive filtering technology can filter all the high frequency in the main count signal except original baseband so that the output waveform of Moiré fringe photoelectric signals are close to the standard sine wave and the signal distortion is reduced by a factor of 8.
2012 Vol. 33 (2): 110-114 [Abstract] ( 527 ) HTML (1 KB)  PDF (1010 KB)  ( 835 )
115 Design and Calibration of the Wireless NC Turntable in 3D Point Clouds Measurement
WANG Hong-tao,WANG Xing,WANG Shi-zhou,ZHANG Li-yan,FENG Hang
DOI: 10.3969/j.issn.1000-1158.2012.02.04
The complete 3D point cloud of an object can be obtained by the NC turntable and the measuring equipment based on binocular stereo vision principle.A four-axis NC turntable which can implement two-dimensional linear and rotational movement through any wire-connected or wireless control ways was designed.A novel method for accurate calibrating the two rotation axes of the NC turntable was presented.Firstly,more than three circular markers were pasted on the turntable board and the turntable was drove by the AC servo motors to rotate around the axis to be calibrated.Secondly,the position of the axis to be calibrated was calculated from the three-dimension coordinates of the center of the markers which are captured by a optical coordinate measuring system from the any different rotation angle position of the turntable.Finally,the optimization of the multiple positions was conducted to further improve the calibration accuracy and the final position of the axis in the CCD coordinate system was calibrated consequently.The result of the experiment shows that NC turntable has a flexible and convenient control way,the designed calibration approach has the features of briefness,low cost,high stability and reliability.
2012 Vol. 33 (2): 115-120 [Abstract] ( 725 ) HTML (1 KB)  PDF (1193 KB)  ( 583 )
121 A Novel Algorithm of Image Noise Variance Measurement
LI Hong-jun,ZHAO Zhi-min,WEI Ben-zheng,JI Lei
DOI: 10.3969/j.issn.1000-1158.2012.02.05
To estimate noise variance of Gaussian white noise, a new method by the character of wavelet coefficients distribution is proposed. The wavelet coefficients in each sub-band can be well modelized by a Generalized Gaussian Distribution (GGD) whose parameters (scale and shape parameters) can be used to estimate noise variance. The simulation results show that the noise variance estimate method is efficient. It can obtain approximately optimal value, and need less computing time.
2012 Vol. 33 (2): 121-125 [Abstract] ( 744 ) HTML (1 KB)  PDF (722 KB)  ( 1691 )
126 Relative Study for Calibration of Infrared Thermometer under 200 ℃
LI Wen-jun,SUN Jian,CHEN Jian,LIU Zhao-lei,ZHAO Quan-qin
DOI: 10.3969/j.issn.1000-1158.2012.02.06
A standard blackbody source is developed, which is used for calibration of infrared thermometer under 200 ℃.The effective emissivity of blackbody cavity is calculated in different ways, the results of which are higher than 0.997 each and all.Through a series of experiment, the results show that the working distance and ambient temperature are two importance influencing factors,and the optimal working distance in the calibration is obtained,the importance of keeping constance of ambient temperature around thermometer is indicated.
2012 Vol. 33 (2): 126-129 [Abstract] ( 543 ) HTML (1 KB)  PDF (734 KB)  ( 653 )
130 The Principle of Fluidic Oscillator Type Electronic Water Meter and Its Flow Measurement Characteristics
YAO Ling,XU Liang,ZUO Fu-qiang
DOI: 10.3969/j.issn.1000-1158.2012.02.07
A fluidic electronic water meter based on the permanent magnet excitation electromagnetism examination method is described. Its structure principle,the major technique characteristic,the flow measurement characteristic,as well as the sensing and the signal processing technology are studied.In view of the fluidic electronic water meter is for small flow measurement the improvement idea and the method in the theoretical analysis and the experiment foundation is proposed.After volume production of the fluidic electronic water meter, it proves that the small flow characteristic idea and the method are effective.
2012 Vol. 33 (2): 130-134 [Abstract] ( 563 ) HTML (1 KB)  PDF (548 KB)  ( 445 )
135 The Measurement of Nine Inertial Parameters of Rigid BodyBased on the Moment of Inertia
WANG Jin,SUN Ning
DOI: 10.3969/j.issn.1000-1158.2012.02.08
For three-dimensional space, a new method which can measure the nine inertial parameters of a rigid body simultaneously is proposed.With the law of motion that when aerostatic bearing move slowly its angular velocity is a single exponential function decayed with time, the moment of inertia of the rigid body rotating a axis in an arbitrary direction is obtained. through nine measurements, the inertial parameters of a rigid body can be got finally. A set of instrument used for measuring the rigid body inertial parameters is designed. This instrument can measure the nine inertial parameters of a rigid body in three-dimensional space simultaneously. There’s no need to re-assembly in the process of measurement, so intermediate testing quantity, error made by human and measuring time are all reduced.
2012 Vol. 33 (2): 135-139 [Abstract] ( 526 ) HTML (1 KB)  PDF (562 KB)  ( 1090 )
140 Study on Spectrum Recognition Technique Based on Genetic Algorithm in Fiber Grating Sensing System under Transverse Uniform Stress
TENG Feng-cheng,DONG Li-ke,YANG Gang,DONG Bo
DOI: 10.3969/j.issn.1000-1158.2012.02.09
Genetic Algorithm is applied to the study of spectrum recognition technique in fiber grating sensing system under transverse uniform stress. The mathematical model of the system is established and the objective function related with Genetic Algorithm is assured. The affection of parameter value such as population size, generations, crossover fraction and mutation rate to Genetic Algorithm is analyzed, and the optimal running parameters of Genetic Algorithm is choosed. The relevant experimental system is constructed, and the related simulation and experiment are completed. The results show that the accuracy of fiber grating sensing system under transverse uniform stress using Genetic Algorithm can achieve 0.86%.
2012 Vol. 33 (2): 140-143 [Abstract] ( 456 ) HTML (1 KB)  PDF (388 KB)  ( 759 )
144 Study of the Influencing Factors in the High-frequency Hydrophone Calibration Based on the Two-transducer Reciprocity Method
YANG Ping,FENG Yan-qiang,ZHU Hai-jiang
DOI: 10.3969/j.issn.1000-1158.2012.02.10
Two-transducer reciprocity method is one of the primary method for high-frequency hydrophone calibration because of its dependence only on electric quantities. Several factors are studied except the electric quantities, such as the effective radius of the auxiliary transducer, acoustic field symmetry, soaking time, oxygen content and attenuation correction. Experiment shows that, if the diffraction value G1 and averaging factor G2 is calculated precisely, the effective radius and attenuation correction will introduce rather large uncertainties, the influence of field symmetry, soaking time and oxygen content can be neglected. Experiment data show that, the calibration results between 0.5～15 MHz are very close to the results of NPL by laser methods.
2012 Vol. 33 (2): 144-148 [Abstract] ( 523 ) HTML (1 KB)  PDF (994 KB)  ( 508 )
149 Research and Realization on the Testing Method of Error Correction for Dual-frequency Induction Tool
LU Tao,SHI Yi-bing,ZHANG Wei,HUANG Bo
DOI: 10.3969/j.issn.1000-1158.2012.02.11
The error correction of Dual-Frequency Induction Tool (DFIT) is a key link in the design of subsequent data processing on signal amplitude and phase difference, and also it is great importance in the correct evaluation of underground reservoir. The theory of the DFIT is described and the error source is found by the analysis of magnetic dipole model on this instrument coils. A method for measuring the system error and also the circuit implementation are proposed based on the error analysis method. Finally in the field of environmental simulation, the error of measurement and the correction of the instrument are determined. It is showed that this method can obviously improve the accuracy of the measuring instruments to achieve the purpose of error correction in the experimental results.
2012 Vol. 33 (2): 149-153 [Abstract] ( 716 ) HTML (1 KB)  PDF (887 KB)  ( 388 )
154 Research of Josephson Arbitrary Waveform Synthesizer
WANG Zeng-min,GAO Yuan,LI Hong-hui
DOI: 10.3969/j.issn.1000-1158.2012.02.12
A Josephson arbitrary waveform synthesizer（JAWS）is developed for synthesizing the AC Josephson voltage with the amplitude up to 1.2 V and the frequency up to 200 Hz.The experimental results show that Josephson ac voltage up to 200 Hz can be synthesized successfully and the uncertainty of synthesized 60 Hz waveform is less than 5 parts in 10-6.This research is the first step for to the establishment of our national AC Josephson voltage standard.
2012 Vol. 33 (2): 154-157 [Abstract] ( 492 ) HTML (1 KB)  PDF (1284 KB)  ( 879 )
158 The Development of the Video Distortion Calibration
YANG Zhi-jun,WU Zhao-chun,MA Xiao-qing,XU Hui
DOI: 10.3969/j.issn.1000-1158.2012.02.13
In order to calibrate the quantity of video distortion, the process and philosophy of measuring distortions of differential gain dG and differential phase dP are analyzed. A video distortion standard is developed based on a series video distortion signals which are yielded by the method of digital signal synthesis. The calibration system of the video distortion standard and its evaluation of uncertainty in measurement are described in detail. The video distortion quantity is traced to the voltage standard and phase standard.
2012 Vol. 33 (2): 158-162 [Abstract] ( 465 ) HTML (1 KB)  PDF (1095 KB)  ( 643 )
163 Design of WR19(40~60)GHz Microcalorimeter
ZHU Da-cheng,CUI Xiao-hai,TAO Yi,LI Yong
DOI: 10.3969/j.issn.1000-1158.2012.02.14
The design and correction factor evaluation of a WR19 (40~60 GHz) rectangular waveguide microcalorimeter which is based on a kind of thermistance power sensor is presented.This new kind of microcalorimeter will be developed as a 40~60 GHz microwave power standard of NIM.It can measure the effective efficiency of a wider frequency range of transfer standards than that of the previous microcalorimeter.The evaluation of correction factor is also given.
2012 Vol. 33 (2): 163-165 [Abstract] ( 514 ) HTML (1 KB)  PDF (831 KB)  ( 636 )
166 Denoising Millimeter Wave Image with Contourlet and Sparse Coding Shrinkage
SHANG Li,SU Pin-gang,ZHOU Chang-xiong
DOI: 10.3969/j.issn.1000-1158.2012.02.15
Combined the high-order statistical property of the sparse coding, which is based on kurtosis measurement (KSC) and the property of the contourlet's composing orientation and the energy variation, a new denoising method of millimeter wave image, which is based on contourlet and KSC shrinkage technique, is proposed. Kurtosis based Sparse Coding algorithm is an efficient image feature extraction method, which can model the human primary visual system. According to the sparse prior distribution knowledge of feature coefficients extracted, the shrinkage threshold can be determinate. Using this shrinkage technique in the contourlet transform field, the unknown noise contained in millimeter wave image can be reduced efficiently. And utilizing the relative single noise ratio criterion to measure the quality of the image denoised, the simulation experimental results show that comparing with other denoising methods such as sparse coding shrinkage, contourlet denoising and wavelet soft threshold shrinkage, this method proposed here can obtain the better quality of image restoration.
2012 Vol. 33 (2): 166-171 [Abstract] ( 605 ) HTML (1 KB)  PDF (1227 KB)  ( 642 )
172 Progress of Pulsed Microwave Hydrogen Maser
CHEN Peng-fei,XIE Yong-hui,LIN Chuan-fu
DOI: 10.3969/j.issn.1000-1158.2012.02.16
The digital attenuator controlled by Complex Programmable Logic Device (CPLD) outputs two coherent pulsed microwave signals.They interact with hydrogen atoms and induce Ramsey interference.So the line width of hydrogen maser is reduced and the performance of frequency stability could be improved.Single Chip Micyoco(SCM) controls Direct Digital Synthesizer(DDS) to implement frequency sweep.So the Ramsey fringe is obtained.It’s all based on conventional passive hydrogen maser.So far,The Ramsey fringe was observed and its line width is about 1.2 Hz,which is only 40% of that of conventional passive hydrogen maser in the same condition.
2012 Vol. 33 (2): 172-177 [Abstract] ( 626 ) HTML (1 KB)  PDF (2351 KB)  ( 838 )
178 The Uncertainty Evaluation of Determining the Moisture in Gases by the Method of Cavity Ring Down Spectroscopy
ZHOU Xin,ZHOU Ze-yi
DOI: 10.3969/j.issn.1000-1158.2012.02.17
A new method for determining the moisture in gases by the cavity ring down spectroscopy is available to measure the concentration between 0.2×10-9 mol/mol and 20×10-6 mol/mol.A mathematical model is established for the uncertainty evaluation,and the results of the expanded uncertaunties are in the range of（8～20）×10-9 mol/mol （k=2, p=95%）.
2012 Vol. 33 (2): 178-180 [Abstract] ( 688 ) HTML (1 KB)  PDF (417 KB)  ( 849 )
181 Prophase Development of Reference Material for Measurement of Blood Viscosity
ZOU Mi-sha,CAI Shao-xi,GAO Wei,WU Xi,ZHAO Zheng-li
DOI: 10.3969/j.issn.1000-1158.2012.02.18
The feasibility of the polyethylene glycol 6000 as a reference material is discussed.Based on the principles of “New guidelines for hemorheological laboratory techniques” released by the International Committee for Standardization in Hematology in 2009, the necessary conditions as the standard material for blood viscosity measurement are analyzed, and two aqueous solutions with different concentrations of high-purity polyethylene glycol 6000 are prepared as a candidate for the reference material.Homogeneity, stability of the two solutions are tested with the British Malvern Instruments Gemini HR nano200 senior high precision rotary rheometer.The results of the certification value and uncertainty are 3.95 mPa·s±0.18 mPa·s（solution NO.1）and 10.03 mPa·s±0.56 mPa·s（solution NO.2）.Uniformity and stability test results show the material meets the needs of the blood viscosity measurement quality control and can be used as a candidate reference material.
2012 Vol. 33 (2): 181-186 [Abstract] ( 629 ) HTML (1 KB)  PDF (500 KB)  ( 522 )
187 An Improved Methord for the Measurement of Spatial Resolution in CT System
WANG Tian-tian,YU Xiao-e
DOI: 10.3969/j.issn.1000-1158.2012.02.19
MTF can be computed from PSF and ERF ,which represents spatial resolution in CT system.In PSF method, according to the point that the spread rigion should be rounded, the point spread rigion be segmented by image processing, and using mathematical transformation method to identify the center position, and then the MTF curve will be calculated.In ERF method, the goal line should be segmented by image processing, then fitting and using mathematical transformation method to make out, the offset angle can be rotated accordingly.By transform method proposed,the data of the ERF corresponding to each other, the average processing can be made directly.Experiment has proved that the proposed transformation method is accurate, effective, simplified clinical scanning conditions, and convenience for CT evaluation.
2012 Vol. 33 (2): 187-192 [Abstract] ( 664 ) HTML (1 KB)  PDF (1670 KB)  ( 1107 )
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