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2015 Vol. 36, No. 4
Published: 2015-07-22
 
337 Experimental System for the Measurement of the Speed of Sound in Liquids at High Pressure Using the Differential Time-of-flight Method
WU Si,FENG Xiao-juan,LIN Hong,ZHANG Jin-tao,WANG Song-lin
DOI: 10.3969/j.issn.1000-1158.2015.04.01
An experimental system based on the differential time-of-flight method was built for the measurement of the speed of sound in liquids at high pressure. The double ultrasonic cavities were designed and assembled, the acoustic precision measurement system, liquid filling system with high pressure, pressure and temperature measurement system, and the data acquisition system were established. The speed of sound in pure water was measured at temperature from 303K to 353K and at pressure up to 10 MPa with a standard relative uncertainty of 0.018% (k=1). The measured speed of sound data shows good agreement with the equation of state and published experimental data. This system can be used in the measurement of speed of sound in other liquid such as sea water and new fuels in the next future.
2015 Vol. 36 (4): 337-343 [Abstract] ( 658 ) HTML (1 KB)  PDF (12138 KB)  ( 590 )
344 Uncertainty Evaluation of Piezoelectric Constant Measurement Based on Dynamic Resonance Method
ZHANG Rui-wen,HE Long-biao,ZHU Hai-jiang,YANG Ping
DOI: 10.3969/j.issn.1000-1158.2015.04.02
A labview programming was written to achieve automatic measurements and data analysis. Based on the mathematical models established, the sweeping frequency step was optimized, and the characteristic parameters of piezoelectric ceramic NCE51 cylinders were tested and the uncertainty was evaluated. For 15mm thick sample, the relative expanded uncertainty of d33 measurement of piezoelectric ceramic is 0.96% (k=2), when the frequency step is selected as 50Hz. Thus the sample measured by dynamic resonance method can be used as reference material to calibrate the commercial d33 measurement apparatus, which uncertainty is about 2% to 5%.
2015 Vol. 36 (4): 344-347 [Abstract] ( 703 ) HTML (1 KB)  PDF (4296 KB)  ( 628 )
348 A Calibration Method of Flash Dynamic Parameters
DING Xiang,LIU Wen-li,LI Jiao,SUN Jie,SUN Xin
DOI: 10.3969/j.issn.1000-1158.2015.04.03
A theoretical model of flash measurement is established. A method to calibrate flash dynamic parameters by using luminance step signal is proposed. Error sources of flash duration, dynamic luminance and intensity are analyzed. The method to realize traceability of flash dynamic parameters by static luminance and time parameters is demonstrated. An LED source is used to generate the luminance step signal to test the step response of the flash measurement system. Error components of the flash parameters are calculated and the equations to calculate the uncertainty are derived. It is demonstrated by measuring the Xenon flash parameters and calculating their uncertainties. Results indicate that the proposed method provide a solution to calibration and traceability of the flash dynamic parameters.
2015 Vol. 36 (4): 348-351 [Abstract] ( 592 ) HTML (1 KB)  PDF (536 KB)  ( 607 )
352 Detection of Moving Object by Combining Block Features Matching and Local Differential
WANG Hong-bin,YU Fei,LI Yi-jun,WANG Yue-ling
DOI: 10.3969/j.issn.1000-1158.2015.04.04
To investigate the moving objects in the situation of camera moving, a method that combines the scale invariant feature transform block feature matching with the local differential algorithm is proposed. The method can not only reduce the cost time of image registration and compensate the global motion compensation, which effects on the integrity of the image, but also detect moving objects accurately. Finally, the experiment results can provide its effectiveness.
2015 Vol. 36 (4): 352-355 [Abstract] ( 654 ) HTML (1 KB)  PDF (1074 KB)  ( 1019 )
356 An Extraction Method of Steel Plate Surface Depth Information Based on Image Pyramid
LIU Yuan-jiong,KONG Jian-yi,XU Fu-jun,HUANG Qian-de,WANG Xing-dong
DOI: 10.3969/j.issn.1000-1158.2015.04.05
To satisfy the requirement of both precision and real-time of traditional region matching algorithms, a region-based hierarchical matching algorithm based on the mean image pyramid was proposed combining with the normalized cross correlation method. The algorithm has been controlled efficiently through the parameters such as matching window size, the smallest eigenvalue, and the disparity search space, similarity measure threshold, etc. The extraction of steel plate surface depth information was realized by the ways of camera calibration of binocular stereo vision system and image correction based on equivalent standard epipolar structure. The experiment results showed that the algorithm yields better accuracy and higher efficiency.
2015 Vol. 36 (4): 356-359 [Abstract] ( 667 ) HTML (1 KB)  PDF (2460 KB)  ( 715 )
360 Research on Measurement Methods of Eccentricity of the Eccentric Shaft Part and Probe Error Analysis
WANG Xin,ZHAO Hong
DOI: 10.3969/j.issn.1000-1158.2015.04.06
To measure the eccentricity of the mechanical eccentric shaft parts, a method to measure the eccentricity is proposed.Based on reversal process and least square method,the main factors affecting the measurement accuracy are analyzed. The influence of the measurement position on the measurement accuracy is mainly discussed. Eccentricities and errors of different measurement locations are analyzed with the aid of digital simulation of robot joint reducer, and the error curve is given. It provides some technical supports for the actual measurement process, and therefore are beneficial for improving measurement accuracy.
2015 Vol. 36 (4): 360-364 [Abstract] ( 689 ) HTML (1 KB)  PDF (5834 KB)  ( 592 )
365 The Application of Ant Colony Loop Localization Algorithm in the WSNs Node Localization
ZHANG Li-guo,REN Li-bin,JIN Mei,LI Pan,ZHANG Zhi-fu
DOI: 10.3969/j.issn.1000-1158.2015.04.07
To overcome the problems of complex algorithm, less accurate in the wireless sensor networks (WSNs) ranging and locating, the loop localization algorithm is proposed based on ant colony algorithm. Firstly, the experimental data is measured by the received signal strength indication (RSSI) method, and the signal attenuation model is established to calculate the distance formula. Secondly, the cycle localization algorithm is used to locate the eight anchor nodes cyclically and the average of the eight results as the best position of the blind node. Finally, the algorithm proposed is compared with the weighted centroid localization algorithm and three sided measurement, and the experimental results show that the cycle localization algorithm has higher positioning accuracy and stability.
2015 Vol. 36 (4): 365-369 [Abstract] ( 684 ) HTML (1 KB)  PDF (2537 KB)  ( 507 )
370 Outline Extraction of Bundled Logs Cross Section Based on Multi-feature
JING Lin,LIN Yao-hai,HUANG Xi-pei
DOI: 10.3969/j.issn.1000-1158.2015.04.08
A model of outline extraction of bundled logs cross section based upon pixel feature and edge structure is developed to improve bundled logs image processing. A support vector machine (SVM) is used to extract the pixels of cross section of logs, and the least square method is applied to fit the circle of edge pixels. Finally, outlines of bundled logs are extracted. The obtained results of experiment demonstrate the validity of the proposed method in the case of the cross section of logs is not the ideal smooth and the background is complex.
2015 Vol. 36 (4): 370-374 [Abstract] ( 668 ) HTML (1 KB)  PDF (2069 KB)  ( 679 )
375 A Survey on Precise Coordinate Measurement Technology by Industrial X-ray Computed Tomography
DOI: 10.3969/j.issn.1000-1158.2015.04.09
A survey on precise measurement technology by industrial X-ray (XCT) computed tomography is presented, and comparison of the advantages and limits versus to the traditional CMMs.From published papers and information, the development nowadays in both sides is analyzed.This technology is not full-grown from globe, and there are many different issues to be focused on.And, it is obvious, that the technology of XCT in coordinate measurement has a great prospect in future development and utilization.
2015 Vol. 36 (4): 375-378 [Abstract] ( 867 ) HTML (1 KB)  PDF (1605 KB)  ( 703 )
379 2D Meshless De-noising Method of Images Based on the Thermal Infrared Image Temperature Measurement Technology
ZHANG Yu-cun,HOU Xin-yu,LIN Hong-bin
DOI: 10.3969/j.issn.1000-1158.2015.04.10
The temperature measurement process of infrared thermal image has a large amount of noise, which has seriously hampered the precision and accuracy of infrared thermal image. In order to accurately detect the correlative parameters of the measured object in the infrared thermal image, a 2D meshless denosing method based on infrared thermal images is proposed. Bilateral filtering, anisotropic denoising, meshless denoising are combined to create a 2D meshless denoising model. The model parameters are estimated by using robust regression algorithm, and realize infrared thermal images with meshless denoising. And it enhances the temperature measurement precision of infrared thermal image. Finally, the feasibility of the proposed method is verified by simulation experiments and the method lays the theoretical foundation for military, scientific research and other areas of temperature measurement of infrared thermal image.
2015 Vol. 36 (4): 379-383 [Abstract] ( 689 ) HTML (1 KB)  PDF (964 KB)  ( 466 )
384 Data Analysis for Thermal Conductivity Measurement Using Transient Hot-wire Method
PAN Jiang,LIN Na,WANG Yu-gang,XU Xu
DOI: 10.3969/j.issn.1000-1158.2015.04.11
A method for data analysis for thermal conductivity measurement using transient hot-wire method is present. Numerical simulation is introduced in data processing. Finite volume method is used to solve the control equations. The finial result is obtained by comparison of the simulated temperature curve with the experimental temperature curve. The presented method is very effective for experimental data analysis. The correct result could be gotten with much less data points, which is very helpful for the design of experimental system.
2015 Vol. 36 (4): 384-388 [Abstract] ( 1057 ) HTML (1 KB)  PDF (1366 KB)  ( 1592 )
389 Study on Measurement of Invalid Injection Time for Electronic Gasoline Injector
YE Chang,ZHANG Zhen-dong,CHENG Qiang
DOI: 10.3969/j.issn.1000-1158.2015.04.12
The electromagnetic structure model of electronic gasoline injector is established, then using the law of motionto the armature assembly and the changing course of the coil current within an injection pulse is analyzed combining with electromagnetic theory, and this confirms the consistency between the time of the armature assembly movement characteristic curve point appearing and the time of the coil current curve point mutating.By using this correspondence, anindirect measurement method of invalid injection time for an electronic gasoline injector is found, and a measurement system is developed.The result shows: the measurement results of this system for invalid injection time relative error of a variety of electronic gasoline injectors is less than 3%.
2015 Vol. 36 (4): 389-392 [Abstract] ( 619 ) HTML (1 KB)  PDF (505 KB)  ( 498 )
393 Design of Soft-elastic Sensor Array for Detecting Pressure-stretch
LI Lei-ming,HUANG Ying,MA Yang-yang,WANG Wei-hua,LIU Ping,ZHANG Yu-gang
DOI: 10.3969/j.issn.1000-1158.2015.04.13
Based on the pressure and tension characteristics of carbon black-silicone rubber composite, a new type of sensor array is designed for detecting pressure and tension of the robot skin. Flexible electrode overcomes the shortcomings of traditional sensors for it can not be stretched, makes the sensor array flexible. The array 9 pressure sensor units are designed to detect pressure and 2 tension sensor units are designed to detect tension, the interference problem of detecting pressure and tension simultaneously is solved by sensor structure design and compensating algorithm, and mathematical model is also built for solving pressure and tension. The experimental results demonstrate that the sensor array can detect pressure and tension simultaneously, and can be used in robot flexible skin on joints.
2015 Vol. 36 (4): 393-396 [Abstract] ( 675 ) HTML (1 KB)  PDF (688 KB)  ( 1017 )
397 Investigation of Shock Calibration Using Laser Interferometry
HU Hong-bo,YU Mei
DOI: 10.3969/j.issn.1000-1158.2015.04.14
The primary shock calibration method using laser interferometry is presented, the method is based on the standard of ISO 16063-13. The characteristics of two typical shock exciters are introduced, including generated shock waveform. After digitizing of the phase-modulated signals at the output of a homodyne or heterodyne interferometer, the time-dependent displacement is reconstructed on the basis of the principle coherent demodulation. The data processing steps can efficiently suppress deterministic and stochastic disturbing quantities. Computer simulations and experimental investigations proved that the peak value and the spectral components of shock pulse can be measured with expanded uncertainties of less than 1%(k=2).
2015 Vol. 36 (4): 397-402 [Abstract] ( 703 ) HTML (1 KB)  PDF (493 KB)  ( 492 )
403 Comparative Study on the Calibration Methods of the Indenter Area Function of the Instrumented Nanoindentation
LI Zheng-wei,TAO Xing-fu,SHU Xue-feng,REN Ling-ling
DOI: 10.3969/j.issn.1000-1158.2015.04.15
The indenter area function and the machine compliance of the instrumented nanoindentation are calibrated directly by atomic force microscope and indirectly by indentation of the standard fused silica, respectively. The calibration results of the two methods were applied to the indentations of the standard fused silica and the polycarbonate. The indentation results show, at low indentation depth, the hardness and the reduced modulus measured by the direct calibration method are more accurate than that of calibrated by the indirect method. However, the results of the two methods have small difference at high indentation depth.
2015 Vol. 36 (4): 403-407 [Abstract] ( 712 ) HTML (1 KB)  PDF (409 KB)  ( 1227 )
408 Feature Extraction Based on Double Inverse Limit Space in Hydraulic System
ZHU Dan-dan,LIAN Li-na,ZHANG Yu-cun
DOI: 10.3969/j.issn.1000-1158.2015.04.16
In order to extract leakage information of forging hydraulic press hydraulic system, a method of feature extraction based on double inverse limit space is proposed. The leakage information space of large forging hydraulic press hydraulic system is established, and double inverse limit space is established based on the leakage information space, and the two spaces are topological isomorphism. In a double inverse limit space, the large forging hydraulic press hydraulic system of leakage is reflected through the topological isomorphism. The feasibility of this theory is verified by simulation. The results show that ,the method of feature extraction based on double inverse limit space is more suitable for extracting the leakage coupling characteristics, the characteristics of information leakage extracted by this method has very good detection and location capability.
2015 Vol. 36 (4): 408-412 [Abstract] ( 440 ) HTML (1 KB)  PDF (2621 KB)  ( 422 )
413 Applying Genetic Algorithms in EMD False Component Identification
SONG Na,SHI Yu,ZHOU Ke-yin
DOI: 10.3969/j.issn.1000-1158.2015.04.17
As EMD (Empirical Mode Decomposition) produces false component, the false component was studied by combining genetic algorithm with Kullback-Leibler divergence. First, the original signal was decomposed into several intrinsic mode functions (IMF); the original signal and each IMF component were respectively selected the optimal bandwidth that the genetic algorithm and the optimization principles of bandwidth based on integral mean square error were combined;and then applied kernel density estimation methods to get their probability density function estimation;Finally, the Kullback-Leibler divergence between the original signal and each IMF was calculated, setting the threshold of K-L divergence,IMF component whose K-L divergence is greater than the threshold can be moved. The experiment shows that this method can obtain the bandwidth of experimental data quickly and accurately, the Kullback-Leibler divergence between the real components and the false ones has clearly difference, and the false component can be accurately identified according to the threshold.
2015 Vol. 36 (4): 413-417 [Abstract] ( 675 ) HTML (1 KB)  PDF (5483 KB)  ( 566 )
418 New Method for Identification of Hammerstein Model
LI Wen-jiang,LIN Si-jian,WANG Xuan
DOI: 10.3969/j.issn.1000-1158.2015.04.18
In order to improve the identification accuracy of nonlinear Hammerstein model, a new method of the hybrid optimization algorithm identifying the nonlinear model is put forward. The basic idea of the algorithm is to put the identification problem of parameters in the nonlinear system into a parameter space function optimization problem, and then using hybrid algorithm of the genetic algorithm and the improved particle swarm optimization algorithm to obtain the optimal solution of parameters problem. Finally, the simulation results show that the method for nonlinear identification has good effectiveness and robustness,get a good recognition effect, and is a feasible method to solve the problem of nonlinear recognition.
2015 Vol. 36 (4): 418-422 [Abstract] ( 547 ) HTML (1 KB)  PDF (2379 KB)  ( 498 )
423 Study on Stochastic Resonance Phenomenon in a Differential Circuit with Multiplicative Trichotomous Noise
ZHAO Xin,OU Jian
DOI: 10.3969/j.issn.1000-1158.2015.04.19
Based on the linear system theory, applying the statistical properties of the trichotomous noise, the analytical expression of the output amplitude gain (OAG) is derived.It is shown that, with the increase of the frequency of the input signal, the increase of the stable probability of the trichotomous noise, the increase of the switching rate between the noise states, as well as the increase of the parameter k (the reciprocal of capacitor C), the system OAG reaches a maximum value.For low signal frequency, with the increase of k, the OAG decreases monotonically, while for high signal frequency, the OAG increases monotonically with the increase of k.For low signal frequency, with the increase of the stable probability, the OAG increases monotonically, while for high signal frequency, the OAG decreases monotonically with the increase of the stable probability.The OAG decreases monotonically with the increase of the parameter G0 (the reciprocal of resistance).
2015 Vol. 36 (4): 423-427 [Abstract] ( 432 ) HTML (1 KB)  PDF (1406 KB)  ( 692 )
428 Method of the High-voltage Fast Edge Signal Generation for High-voltage Probe Calibration
ZHAN Guo-zhong,PAN Yang,SHI Bin,DAI Dan
DOI: 10.3969/j.issn.1000-1158.2015.04.20
In view of the fast pulse signal amplitude is too low to measure the rise-time parameter of high-voltage probe, a method of the high-voltage fast edge signal generation is proposed. The method is based on the pulse-forming principle with a single transmission line. A rectangular wave is generated on a matched impedance through the transmission of the high-voltage pulse signal in the line. The test results show that the rectangular wave amplitude can reach 2 kV and the front rise-time is less than 500 ps. By measuring the rise-time parameters of two high-voltage probes, the experimental results prove that the high-voltage pulse signal generated by this method is applicable for high-voltage probe calibration.
2015 Vol. 36 (4): 428-431 [Abstract] ( 520 ) HTML (1 KB)  PDF (1097 KB)  ( 840 )
432 Demodulation Technology Based on Phase-locked Loop
LUO Ying,ZHANG Zhi-wei,YANG Ning
DOI: 10.3969/j.issn.1000-1158.2015.04.21
The fundamentals of the PLL phase-modulated signal demodulation technique is described, and the integrated PLL NE564 is used to achieve lock demodulated for the signal. In order to demodulate the undistorted waveforms, the PM demodulation system using the integrated PLL NE564 and LM725CN chip is designed.The system can achieve the function of signal modulation demodulation directly and advantage of the characteristics of phase to the stability of the track to avoid the defect of the frequency lock loss, and improve the measurement accuracy.The system is simple, strong stability advantages, and has a strong practicability for heterodyne laser interferometer demodulation signal.
2015 Vol. 36 (4): 432-435 [Abstract] ( 576 ) HTML (1 KB)  PDF (1440 KB)  ( 1265 )
436 Design and Realization of a Frequency Lock Loop Circuit for a Miniaturized Rubidium Atomic Frequency Standard
SUN Bing-feng,YAN Shi-dong,WANG Peng-fei, HOU lin-shan,ZHONG-da,MEI Gang-hua
DOI: 10.3969/j.issn.1000-1158.2015.04.22
A frequency-locked loop (FLL) circuit was designed and realized for a miniaturized high performance rubidium atomic frequency standard (RAFS). The 10MHz signal from a VCXO was transformed into the microwave interrogation signal with frequency of 6834.6875MHz by a 45.5645833 multiplier and a consequent 15 one. The 455.645833 multiplier was designed by using the digital phase-locked technique. The frequency modulation of the interrogation signal was realized in the 455.645833MHz signal. The phase noise of the signal was measured and analyzed. Results showed that the fractional stability of the microwave signal is in a level of 3.2×10-12τ-1/2. The short-term frequency stability of a RAFS containing the FLL circuit was tested, and a result of 5×10-12τ-1/2（1 s≤τ≤100 s）was obtained. This result is obviously better than that of an average commercial RAFS.
2015 Vol. 36 (4): 436-440 [Abstract] ( 590 ) HTML (1 KB)  PDF (4501 KB)  ( 704 )
441 Study and Realization of Radiotherapy Quality Assurance Based on Image Analysis
LIU Ke,BIAN Xin,HOU Li-xin,ZHOUXin
DOI: 10.3969/j.issn.1000-1158.2015.04.23
To explore applications of image analysis in complex system’s performance evaluation and quantity traceability, the film dosimetry system for radiation therapy quality assurance (QA) is studied. Film dosimetry by dose-gray curve, plan data extraction by parsing certain DICOM files and parameters calculation such as Gamma by image analysis are realized, respectively. The algorithms of radiation therapy QA for intensity-modulated radiation therapy (IMRT) are developed. The proposed method can not only be suit for verification of IMRT, but also be used as reference to complex system’s performance evaluation based on image analysis.
2015 Vol. 36 (4): 441-444 [Abstract] ( 490 ) HTML (1 KB)  PDF (1120 KB)  ( 926 )
445 Experiment Investigation on Aging Performance of NBR in Town Gas
PAN Hai-ning,YAN Rong-song,ZHAO Zi-jun
DOI: 10.3969/j.issn.1000-1158.2015.04.24
Based on the hot air aging test methods,a device is created to test the aging performance of rubber, which has the ability to flush test samples in the circulation of atmosphere.The NBR is used as sample to test its aging performance under different temperature and atmosphere, and predict its use of time.The results show that when accelerated aging test under air atmosphere,the deviation of the predict results and actual use time is above 80%,the aging rate of NBR under gas environment is 1～2 times that of hot air, and when accelerated aging test undergas atmosphere, comparing the predict results and actual use time,the deviation is under 20%.
2015 Vol. 36 (4): 445-448 [Abstract] ( 422 ) HTML (1 KB)  PDF (1075 KB)  ( 476 )
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