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2015 Vol. 36, No. 5
Published: 2015-09-22
 
449 Study on the Setup for Measurement of Temperature-dependent Elastic Properties of Solids
BAO Jing,FENG Xiao-juan,LIN Hong,ZHANG Jin-tao,QI Xiao-feng,LI Xiao-ting
DOI: 10.3969/j.issn.1000-1158.2015.05.01
Based on the principle of ultrasonic resonance spectrum, a setup is developed including the ultrasonic signaling and detecting system, the thermostat and the data analysis software.The elastic modulus of three samples in different quality factors are measured at room temperature, and the effects influencing the measurement are investigated. The resonant frequency matching error (RMS) of 0.04% has been reached with the measurements by the developed setup. The results agree well with those of the global advanced commercial instruments. In addition, bearing steel（9Cr18）are measured at temperature from 293 K to 353 K for isothermal compressibility. The system is capable to measure the elastic modulus of solids at temperature up to 500 K at anti-oxidation atmosphere. After redesigning the ultrasonic signaling and detection system, it is capable for measurements at higher temperature.
2015 Vol. 36 (5): 449-454 [Abstract] ( 985 ) HTML (1 KB)  PDF (1484 KB)  ( 825 )
455 Development of a High Precision Constant-temperature Chamber for Micro-nanometric CMM
FENG Jian,LI Rui-jun,HE Ya-xiong,FAN Kuang-chao
DOI: 10.3969/j.issn.1000-1158.2015.05.02
The spacious constant-temperature room and the separated constant-temperature chambers can’t meet the requirement of micro-nanometric CMM because of low precision and vibration seperately. A high precision constant-temperature chamber based on the natural convection principle is developed. The walls of the custom-designed chamber is made of hollow acrylic upon which a lightweight thin vacuum insulation plate with ultra-low thermal conductivity coefficient is adhered. The temperature value of the instrument measuring point is taken as the feedback signal. Nine thermoelectric coolers used to cool the air inside the chamber are arranged on the ceiling of the chamber uniformly. The down flowing cool air and the up flowing hot air forms natural convection. The program of the high accuracy temperature-controlled system is developed using LabVIEW and MATLAB software. The experimental results show that the system steady-state error is 0.0032 ℃ on average, and the variation range is less than 0.03 ℃ when the set temperature is 20 ℃. It is superior to a Class I standard room. The new type constant-temperature chamber has the advantages of low cost, low energy consumption and no vibration.
2015 Vol. 36 (5): 455-459 [Abstract] ( 687 ) HTML (1 KB)  PDF (5418 KB)  ( 748 )
460 The Interferometric Method for the Cylindrical Surface
YU Ying-jie,XU Hai-feng,PENG Jun-zheng
DOI: 10.3969/j.issn.1000-1158.2015.05.03
An interferometric method to measure the cylindrical surface is proposed. The computer generated hologram was used as wavefront converter, which can convert the plane wavefront into cylindrical wavefront. With it, a cylindrical interferometric system was built. To get the real surface figure of the tested cylindrical surface, a misalignment aberrations removal method is also proposed .Lastly, several experiments were carried out to validate the proposed method and system, where the glass cylinder was chosen as a target. The repeatability of single aperture measurement was investigated by measuring the target 20 times. The standard deviation (PV) is 20.2 nm that is 0.55% of the average value of PV.
2015 Vol. 36 (5): 460-463 [Abstract] ( 696 ) HTML (1 KB)  PDF (3012 KB)  ( 1079 )
464 Basketball Image Segmentation Research Based on Quantum Search Algorithm
YANG Yang,LIU Jia
DOI: 10.3969/j.issn.1000-1158.2015.05.04
In order to improve the effect of basketball image segmentation,quantum search algorithm (QSA) is proposed. Firstly,basketball segmentation model was established,including basketball center and radius based on three scales,and basketball target was segmented based on gray probability distribution. Secondly,quantum phase was transformed based on quantum phase Grover conversion in order to establish weighting factor and basketball target relation, and maximum quantum search success possibility and angle of quantum rotation phase was determined.Finally, quantum search algorithm process was given.Simulation indicated that quantum search algorithm can accomplish basketball object segmentation effectively, and segmentation success rate is higher.
2015 Vol. 36 (5): 464-468 [Abstract] ( 635 ) HTML (1 KB)  PDF (1452 KB)  ( 607 )
469 Industrial Measurement Fitting Algorithm for Space Line/Plane Based on Error Decomposition Weighting
PAN Guo-rong,GUO Wei,ZHOU Yue-yin
DOI: 10.3969/j.issn.1000-1158.2015.05.05
In industrial measurement fitting applications, because of the measuring characteristics of instruments, error components of measurement data in different directions are difference, aiming at this problem a fitting algorithm for space line and plane base on error decomposition weighting has been proposed.Spatial attitude of workpiece and relationship between instrument and measuring points are considered.Then, influence quantity of vertical error and horizontal error on space line fitting and plane fitting are analyzed to weight measuring points.Experiment results show that compare with equal-weighted fitting algorithm, this algorithm improved the fitting precision about 16%.
2015 Vol. 36 (5): 469-472 [Abstract] ( 596 ) HTML (1 KB)  PDF (640 KB)  ( 507 )
473 Resonance Suppression on Nanoscale Viscoelasticity Measurement
DU Yi-hao,XIE Ping,ZHANG Lei,ZOU Qing-ze
DOI: 10.3969/j.issn.1000-1158.2015.05.06
Aiming at the cantilever resonance leads to large measurement data errors in indentation measuring soft material, a method to suppress the cantilever resonance on the broadband viscoelasticity measurement is proposed. A notch filter type prefilter based on z-axis dynamics is designed, and used to filter the input drive voltage; An adaptive filter based on the least mean square (LMS) is designed, and referring to the Hertz contact model to filter the complex compliance of soft materials, furtherly eliminate the residual cantilever resonance effects in input link and output link. The validity of the cantilever resonance suppression method is verified by implementing the polydimethylsiloxane (PDMS) sample viscoelasticity measurement.
2015 Vol. 36 (5): 473-476 [Abstract] ( 579 ) HTML (1 KB)  PDF (740 KB)  ( 503 )
477 Near-field Airspeed Estimation Based on MUSIC Algorithm
YU Fei,TAO Jian-wu,ZENG Bin,QIAN Li-lin
DOI: 10.3969/j.issn.1000-1158.2015.05.07
The problem of near-field airspeed estimation is researched based on acoustic vector sensor array. According to the propagation principle of acoustic waves in a continuous, uniform and stable air flow, the acoustic particle velocity measurement model based on the near-field output model of acoustic vector sensor array is constructed. The airspeed knowledge of interest is included in the steering vector of the proposed measurement model. Then a multiple signal classification algorithm for airspeed estimation is presented. To evaluate the performance of the proposed algorithm, a compact expression for the Cramér-Rao bound on the estimation error of the airspeed is derived. Simulation results are shown to verify the efficiency of the proposed algorithm.
2015 Vol. 36 (5): 477-481 [Abstract] ( 494 ) HTML (1 KB)  PDF (3448 KB)  ( 564 )
482 Fault Diagnosis Method for Rolling Bearing Based on Differential-basedEmpirical Mode Decomposition and Hidden Markov Model
MENG Zong,YAN Xiao-li
DOI: 10.3969/j.issn.1000-1158.2015.05.08
Based on the differential-based empirical mode decomposition（DEMD）and hidden Markov model(HMM), a new method for rotating machinery fault diagnosis is proposed. The method is applied to rolling bearing fault diagnosis. First of all, fault signals are decomposed by DEMD, the instantaneous energy distribution of each signal is extracted to form the fault feature vectors, and then input the feature vectors into the HMM classifier for malfunction recognition, the maximum likelihood probability which is output by HMM classifier is in the fault state. Finally, different fault types are recognized. A practical fault signal of a rolling bearing with corrosive pitting is applied to test the method.Experimental result showed that the method of DEMD-HMM is superior to the method of EMD-HMM and can identify the rolling bearing fault accurately and effectively.
2015 Vol. 36 (5): 482-486 [Abstract] ( 494 ) HTML (1 KB)  PDF (2247 KB)  ( 603 )
487 Research on the Volume Measurement Method of the Vertical Metal Tank Bottom Based on Digital Terrain Model
WANG Long-long,HOU Song-liang,HUANG Zhao-hui,LIU Zi-yong,TONG Lin, BAO Xue-song
DOI: 10.3969/j.issn.1000-1158.2015.05.09
In order to accurately measure the irregular deformation for the bottom of the vertical metal tank, a method based on digital terrain model was proposed. The bottom was calculated by the capacity of the triangulated irregular network which was built by three dimensional coordinates. This method will provide useful guidelines for future studies of the bottom deformation under the contour line expressed the undulations of the bottom completely. With a standard of the volumetric method, there is a comparison between the geometric method and the digital terrain model method in this experiment. The experiment results showed that the method is applicable to the bottom measurement of the vertical metal tank. Compared with the geometric method, the relative error was reduced 2.5% averagely.
2015 Vol. 36 (5): 487-490 [Abstract] ( 557 ) HTML (1 KB)  PDF (390 KB)  ( 511 )
491 Analysis of Residual Life of Derrick Steel Structure Based on the Time-varying Reliability and Fatigue Effects
HAN Dong-ying,WANG Zhi-lei,ZHU Jin-li
DOI: 10.3969/j.issn.1000-1158.2015.05.10
In order to predict the remaining service life of derrick steel structure accurately, the theory of a residual life prediction based on time-varying reliability and fatigue effects is established. The function between the rods equivalent cross-sectional area, damage and defects with time is derived. The varying model of resistance is established. Prepared the oil derrick fatigue load spectrum, and the life prediction based on fatigue effects is established based on S-N curve and rain flow theory. The residual life of JJ220/42-K type of derrick steel structure is predicted, the results show the reliability life of the structure with corrosion and rods bent is much less than the fatigue life of the structure only with corrosion, and the reliability life was much less than the fatigue life.
2015 Vol. 36 (5): 491-495 [Abstract] ( 615 ) HTML (1 KB)  PDF (459 KB)  ( 452 )
496 Weak Signal Detection of Adaptive Stochastic Resonance Based on Shannon Entropy of Symbolic Series
PAN Zheng-rong,QIAO Zi-jian,ZHANG Ning
DOI: 10.3969/j.issn.1000-1158.2015.05.11
A method of weak features detection for mechanical fault data is proposed, which combined the stochastic resonance and the improved Shannon entropy of symbolic series. Firstly, the basic principles of SR and symbolic sequence analysis (SSA) is briefly introduced. Secondly, symbolic sequence Shannon entropy of output signal is the measure whether the state of this system of SR is the best one. Finally, according to adjust system parameters a and b adaptively, the system of SR achieves the best state and analyzes signal to noise ratio (SNR) and spectrum of output signal. Information of output signal show that Shannon entropy of symbolic series can reflect the state of SR , the best SNR of output signal can be achieved and it can be easily used in practical projects, which confirms the new method proposed is correct and useful.
2015 Vol. 36 (5): 496-500 [Abstract] ( 575 ) HTML (1 KB)  PDF (4475 KB)  ( 787 )
501 A Signal Feature Extraction Method and Its Application Based on EEMD Fuzzy Entropy and GK Clustering
JIN Mei,LI Pan,ZHANG Li-guo,JIN Ju,ZHANG Shu-qing
DOI: 10.3969/j.issn.1000-1158.2015.05.12
A method of feature extraction combining ensemble empirical mode decomposition with fuzzy entropy, and Gustafaon-Kessel clustering to the rolling bearing fault diagnosis . is introduced.Firstly, rolling bearing vibration signal is decomposed into a series of IMFs.Secondly, IMFs are chosen by the criteria of correlation, and the fuzzy entropies of the chosen IMF component compose eigenvectors. Finally, the constructed eigenvectors are put into GK classifier to recognize different fault types. Experiments show that fuzzy entropy can characterize the feature information of the fault signal better than sample entropy and approximate entropy do, and the result of GK clustering is superior to FCM’s. So, experimental results show that the rolling bearing fault diagnosis method based on EEMD fuzzy entropy and GK clustering is effective and superiority.
2015 Vol. 36 (5): 501-505 [Abstract] ( 671 ) HTML (1 KB)  PDF (4898 KB)  ( 642 )
506 Measurement Error Analysis and Software Correction of Guided Wave Radar Level Gauge
LIU Zheng,WEI Meng,XU Ke-Jun
DOI: 10.3969/j.issn.1000-1158.2015.05.13
The causes of the error of the guided wave radar level gauge (GWRLG) are analyzed, and a software correction method is proposed. The impacts of transmit pulse width and equivalent time sampling interval are studied in hardware. The gross error, the random error and the systematic error generated in the signal processing are researched in software. Based on the existing hardware platform, a set of signal processing method is put forward to reduce the measurement error, i.e., combining feature parameters to recognize the actual level echo, performing 9 point moving average to preprocess the signal, selecting the minimum slope point as the echo positing point, and conducting median average filtering for the calculated values. The experimental results of water level measurement show that the actual measurement error is reduced to within 1 cm when the theoretical error is 2～4 cm, which validates the effectiveness of the proposed software correction method.
2015 Vol. 36 (5): 506-512 [Abstract] ( 545 ) HTML (1 KB)  PDF (2271 KB)  ( 389 )
513 Hardware Technology of High Accuracy Measurement System for Ocean Tide Based on Image Processing
JIA Wei-guang,JI Jian-hua,MA Zhi-gang,SI Jian-wen,LI Xi-ling,LIU Xiao-feng
DOI: 10.3969/j.issn.1000-1158.2015.05.14
In order to further enhance the measurement and evaluation level of the ocean tide, an introduction of digital image processing and digital signal processor technology in the field is usel. Using DM642 as the core processor, this can have a design of video capture circuit, encoding and decoding circuit, external memory module circuit, hard simulation through JTAG simulation interface, to realize analog/digital conversion, and data transmission functions. At the same time, system software design can ensure that DM642 can achieve the purpose of real-time processing tide video by CCD, and the realization of real time display of tidal level video and high accuracy data. The system can meet the requirements of high precision, real-time tide detection and automation. The tide variation range of detection is 0~8 m, and the maximum error of indication is 1.2 mm, and the measurement maximum standard deviation can less than 0.42 mm.
2015 Vol. 36 (5): 513-516 [Abstract] ( 662 ) HTML (1 KB)  PDF (712 KB)  ( 513 )
517 Aluminum Strip Hot Rolling Schedule Optimization Design Based on the Gravitational Search Algorithm
ZHAO Xin-qiu,ZHAO Li-juan,YANG Jing-ming,WANG Chun-peng
DOI: 10.3969/j.issn.1000-1158.2015.05.15
A reasonable rolling schedule is a strong guarantee for the quality of aluminum strip and the low power consumption of mill. This procedure set put forward multi-objective function to prevent skidding and balanced four mill power, establish a rolling force model based on Support Vector Regression to replace the traditional mathematical model and improve the accuracy of the prediction of the rolling force effectively. At the same time, it uses Gravitational Search Algorithm to optimize the rolling schedule. The algorithm can not only be able to prevent falling into local extremum point, but also avoid a blind search. So it improved the speed of evolution greatly.This procedure used in the finishing part of“1+4”aluminum hot strip in Henan province, the rolling procedure effect is ideal and it has a guiding significance for the secondary setting calculation.
2015 Vol. 36 (5): 517-520 [Abstract] ( 515 ) HTML (1 KB)  PDF (441 KB)  ( 507 )
521 Study on the Impact of the Shearing Force Sensor with an Interference Fit on the Rail Weigher to the Measure Area
XU Jin-li,CHEN Zhi-lei,LUO Wen-xin
DOI: 10.3969/j.issn.1000-1158.2015.05.16
The weighing principle of the shearing force sensor is explained,and the way to stick the strain gage and the direction of the metal gate by theoretical computation are decided. The assembling stress can be calculated through the finite element analysis software,and then the strain area of the elastomer is known. The deformation of the elastomer with differdent interference and contact area is gotten so that the effect of preloading on the sensor can be sure.
2015 Vol. 36 (5): 521-525 [Abstract] ( 543 ) HTML (1 KB)  PDF (1211 KB)  ( 593 )
526 Uncertainty Evaluation of Open channel Discharges Measurement with the Velocity area Method
ZHAO Wei-guo,WANG Cheng-li,ZHU Wei,DAI Liang-chao
DOI: 10.3969/j.issn.1000-1158.2015.05.17
According to the ISO 748, when the uncertainty of open channel discharge measurement was evaluated, the sufficient measurements and verticals need be set in the crosssection, but velocity interpolation to the edge and in the top/bottom layers are not taken into account. In order to solve the problems, a new approach is introduced for evaluating the uncertainty. The vertical velocity and transversal mean velocity distribution model of crosssection were achieved with FLUENT. In the experiment, the uncertainty caused by limited number of velocity measurements points and measurement verticals were computed with the velocity distribution models respectively. The uncertainty components are analyzed to calculate the uncertainty of discharge measurements. The experiment results showed that the method improves the accuracy of the measurement uncertainty.
2015 Vol. 36 (5): 526-529 [Abstract] ( 677 ) HTML (1 KB)  PDF (296 KB)  ( 653 )
530 A Digital Compensator and Its Application in Current-comparator Bridge
WANG Yun-jing,WANG Yu-tian,QU Zheng-wei
DOI: 10.3969/j.issn.1000-1158.2015.05.18
A digital compensator is designed to output regulated signal in four-quadrant and its core component is two 16-bit serial input multiplying digital-to-analog converters. With sinusoidal reference signal, the in-phase and the quadrature component of the output can be adjusted in accordance with the given code. A computer controlled current-comparator bridge is developed and magnetic potential self-balance can be got by applying the digital compensator and Newton iteration algorithm. The AC/DC relative difference of bifilar helix resistors are measured below 1592 Hz through the proposed bridge using substitution method, and the standard measurement uncertainty is 2×10-7 that can meet the requirement for quantity value dissemination of AC resistance.
2015 Vol. 36 (5): 530-534 [Abstract] ( 613 ) HTML (1 KB)  PDF (1490 KB)  ( 524 )
535 A Research on the Method of Motor Imagery EEG Feature Extraction Based on Blind Source Separation
ZHANG Li-guo,ZHANG Yu-man,JIN Mei,YU Guo-hui
DOI: 10.3969/j.issn.1000-1158.2015.05.19
Motor imagery has been widely used in EEG based brain-computer interface systems. In order to extract feature of the motor imagery EEG accurately and efficiently, the feature of the motor imagery EEG in time, frequency and spatial domain is analysed. Then an approach is put forward that extract feature of the motor imagery EEG from time, frequency and spatial domain, with preprocessing of wavelet transforming and using spatial filter obtained from SOBI and ITFE. Experimental results verify that the proposed method has an obvious improvement in feature extraction compared with the other methods, and the spatial filter obtained from SOBI and ITFE can reflect veridical brains activity.
2015 Vol. 36 (5): 535-539 [Abstract] ( 873 ) HTML (1 KB)  PDF (13135 KB)  ( 3993 )
540 The Design and Research on Performance of Round-saddle Coils for Magnetic Shielding
ZHAO Wei-xia, DONG Quan-lin,SUN Mao-duo,DING Ying,YANG Ya-jiao,DANG Yu-jie
DOI: 10.3969/j.issn.1000-1158.2015.05.20
The magnetic field distribution expression of one pair of round-saddle coils at any point in space is theoretically inferred based on the Biot-Savart Law, and the structure of the coils is optimized. The fact that the round-saddle coils can produce uniform magnetic field of a certain region is proved, and the partial magnetic field distribution of round-saddle coils is given quantitatively. The designed coils can produce uniform magnetic field of a certain area which is 28% of the axis area which the uniformity can be 1%, 10% of the axis area which the uniformity can be 0.1%. The maximum value of the magnetic field compensation of coils of one single round can be 15 nT in the current of 1 mA,and the relative deviation is less than 0.14 nT. Therefore the correctness of the magnetic field distribution expression is verified, providing the theoretical basis and reference for the design and research of the dimensional magnetic field compensation system.
2015 Vol. 36 (5): 540-545 [Abstract] ( 731 ) HTML (1 KB)  PDF (3716 KB)  ( 587 )
546 Separation of Two-span Rotor Fault Signal Based on Second-order Statistics Blind Identification
MIAO Feng,ZHAO Rong-zhen
DOI: 10.3969/j.issn.1000-1158.2015.05.21
A algorithm of blind source separation is proposed based on the second-order statictics.The method focuses on noise separation rather than noise removal.So there are no harms to effective signals. This idea might provide a new way for noise reduction. The algorithm of blind source separation based on the second-order statistics blind identification is applied to seismic data.The results show that the algorithm is effect ,noises are separated and re-moved,and accurate is improved.
2015 Vol. 36 (5): 546-549 [Abstract] ( 594 ) HTML (1 KB)  PDF (5824 KB)  ( 563 )
550 Research on Tube Potential of Industrial X-rays Generator by Invasive Measurement
WU Jin-jie,GUO Bin,LI Bing,JIANG Wei,CHEN Fa-jun,DUAN Sheng-lin
DOI: 10.3969/j.issn.1000-1158.2015.05.22
An invasive measurement method is established to get the tube potential of industrial X-rays generator base on high voltage divider. The tube potential of X-rays machine MG165 is obtained. The results show the ripple of tube potential is less than 4%, when tube potential is more than 35 kV, the ripple is less than 1%. The relative deviation between average tube potential and nominal value is less than 1.8% in the range from 7.5 kV to 150 kV. The repeatability of average tube potential is better than 0.01%. It is less than 0.02% on the condition of re-open beam and re-open generator. All the testing results shows this X-rays generator is satisfy the requirement for realization, dissemination and international comparison of primary standard of air kerma in the range of low-energy X-rays.
2015 Vol. 36 (5): 550-554 [Abstract] ( 615 ) HTML (1 KB)  PDF (2122 KB)  ( 515 )
555 Murexide Spectrophotometric Determination of Magnesium Oxide in Dehydration Products of Bischofite from Hydrated Double Salt Method
HU Hu-sheng,YANG Ming-de,WU Yu-long
DOI: 10.3969/j.issn.1000-1158.2015.05.23
For determination of MgO in dehydration products of hydrated double salt (C6H5NH2·HCl·MgCl2·6H2O), that direct measurement of the MgO in the water-insolvable residue of dehydration product samples was substituted for the conventional indirect method yielded more accurate results. The water-insolvable residue was resolved by boiling diluted H2SO4 solution and the microgram amount magnesium in the solution was measured by spectrophotometry, using murexide as a color reagent. The effects such as pH of solution, complex ratios of magnesium to murexide, dosages of chromogenic reagent, reaction time on the absorbances of coloured solutions, and the tolerance limits of some interfering ions such as C6H5NH2·H+、Fe3+、Zn2+、Ba2+、Ca2+、Ni2+、Co2+ and their masking reagents are investigated. The calibration curve is established under completely deduction of the absorbance of remnant colour reagent according to the correction spectrophotometric theory. In the concentration range of 0~2 mmol/L of Mg2+, the calibration curve is linear and molar absorptivity 2.45×102 L/(mol·cm). The experimental results show that this method can give high precisions and accuracies (recoveries of standard addition were close to 100%), therefore it is suitable for analysis of the MgO in dehydration products.
2015 Vol. 36 (5): 555-560 [Abstract] ( 567 ) HTML (1 KB)  PDF (3024 KB)  ( 604 )
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