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2019 Vol. 40, No. 3
Published: 2019-05-22
 
353 Thermal Analysis of Permanent-Magnet System in the Joule Balance
REN Fei-an,XU Jin-xin,YOU Qiang,LI Zheng-kun,CHEN Le
DOI: 10.3969/j.issn.1000-1158.2019.03.01
The temperature field of permanent-magnet system is analyzed based on COMSOL finite element simulation.Through the thermal analysis of permanent-magnet system, the temperature rise curves of permanent-magnet in different working modes are obtained. It is found that the permanent-magnet-disk has a temperature difference of 10-4 between the two working modes. Because of the temperature coefficient of -3×10-4 K-1 for samarium cobalt permanent magnet disk,the impact on the measurement of flux difference in 10-8 orders of magnitude. Three schemes are proposed to solve the coil heating problem, reduce the interference of the temperature to the the measurement of Planck constant. The three options are to adjust the induction coil current, increase the radiation coefficient and change the balance support structure.
2019 Vol. 40 (3): 353-360 [Abstract] ( 437 ) HTML (1 KB)  PDF (1263 KB)  ( 447 )
361 Water Level Detection Based On U-net
CHENG Shu-hong,ZHAO Kao-peng,ZHANG Shi-jun,ZHANG Dian-fan
DOI: 10.3969/j.issn.1000-1158.2019.03.02
Based on U-net, a new method of automatic segmentation water level line is proposed and validated through a variety of scenarios. Firstly, the water and background in the original image are marked and grayscale. Then, the processed image and the original image are used to make the data set. The data set is used as the input to segment the image. Finally, all the segmented images are extracted to obtain the water level line. As the experimental results show that the automatic segmentation of U-net can accurately mark the water level and solve the influence of image background in the process of water level measurement. The recognition rate of U-net water level automatic segmentation method is above 96%, and the segmentation effect is better than other segmentation methods.
2019 Vol. 40 (3): 361-366 [Abstract] ( 416 ) HTML (1 KB)  PDF (1640 KB)  ( 488 )
367 Human Motion Measurement System Based on Monocular Videos
ZHANG Ye,ZHOU Xiao-jing,YANG Xiao-tong
DOI: 10.3969/j.issn.1000-1158.2019.03.03
In order to solve the problem of low efficiency caused by camera calibration in video-based human motion measurement process, a design scheme of human motion measurement system is proposed for uncalibrated monocular videos. The vanishing points and the vanishing lines of the scene are computed by Maximum Likelihood Estimation,and real-time stature is measured according to the cross ratio theorem. On the basis of height measurement, a method for extracting the feature points of the left and right feet is proposed to measure the pedestrian′s stride. The trajectory, real-time speed and stride frequency of the pedestrian are estimated by tracking the motion of centroid, and the speed measurements are fitted by sinusoidal function to prove the conformity with the objective law of walking. The experimental results show that the relative errors of height and average velocity measurements are no more than 0.84% and 3.72% respectively, which prove that the system is accurate and robust.
2019 Vol. 40 (3): 367-372 [Abstract] ( 416 ) HTML (1 KB)  PDF (1531 KB)  ( 876 )
373 Analysis of Calibration Factor of Superconducting Gravimeter iGrav-012
MOU Li-shuang,FENG Jin-yang,WANG Qi-yu,LI Chun-jian,WU Shu-qing,SUN Bin
DOI: 10.3969/j.issn.1000-1158.2019.03.04
FG5X-249 absolute gravimeter and iGrav-012 superconducting gravimeter were observed in the same period and site in Changping campus of National Institute of Metrology, China. The calibration factor of iGrav-012 superconducting gravimeter is calculated by the method of least squares regression analysis. The calculation results from observations during the year of 2014 to 2017 showed that the relative calibration factor accuracy of each year is better than 0.1%. When the drop numbers of FG5X-249 absolute gravimeter is more than 6000, the calibration factor can be stable. According to the analysis result the annual maximum variation is less than 0.6nm·s-2·V-1, so that calibration once a year can meet the requirements of accuracy. The iGrav-012 can be used as part of national metrologia reference standard of gravity measurement, provide the gravity variation with time link during the international key comparison of absolute gravimeters CCM.G-K2.2017 and be used for the traceability of absolute gravimeters after comparison.
2019 Vol. 40 (3): 373-377 [Abstract] ( 388 ) HTML (1 KB)  PDF (375 KB)  ( 355 )
378 Optimization of Parameters of Vibration Absorber of Rolling Mill System under the Nonlinear Spring Force of Hydraulic Cylinder
LIU Bin,JIANG Jia-lei,PAN Gui-xiang,LIU Zhao-lun
DOI: 10.3969/j.issn.1000-1158.2019.03.05
Considering the factors that restrict the force of the nonlinear spring of the hydraulic cylinder of the four-high mill, the vibration absorber control device is introduced to establish the dynamic model of the rolling mill system with the vibration absorber of the mill. The optimum damping coefficient and stiffness coefficient of the absorber are obtained, through optimizating the basic parameters of the vibration absorber of rolling mill. Simulation analysis of the influence of different mass, spring force and friction force on the amplitude frequency characteristic curve of roll system, the optimal quality of the vibration absorber of rolling mill can effectively improve the stability of the system, the optimal spring force of the vibration absorber of rolling mill can reduce the unstable region of the system, the optimum friction force of the vibration absorber of a rolling mill can effectively reduce the height of the amplitude frequency characteristic curve, the theoretical support is provided for the effective suppression of vertical vibration of rolling mill roll system.
2019 Vol. 40 (3): 378-384 [Abstract] ( 398 ) HTML (1 KB)  PDF (462 KB)  ( 343 )
385 Rolling Bearing Fault Diagnosis Based on Improved Coupling-enhanced Stochastic Resonance
ZHANG Jin-feng,LI Ji-meng,YANG Ying,LI Xue,LIU De-yu
DOI: 10.3969/j.issn.1000-1158.2019.03.06
In view of the problem that the extraction effect of the traditional stochastic resonance (SR) method for rolling bearing fault feature is unsatisfactory under strong background noise, a fault diagnosis method of rolling bearing based on improved coupling-enhanced SR is proposed. First, the coupled SR system is constructed by using a fixed-parameter bistable system forced by an external input signal and a variable-parameter bistable system. Second, the SR control of coupled system is realized by adjusting the system parameter and coupling coefficient. And the genetic algorithm is used to realize the adaptive selection of the control parameters. Finally, experiments and engineering application are performed to verify the effectiveness and superiority of the proposed method in the rolling bearing fault diagnosis.
2019 Vol. 40 (3): 385-391 [Abstract] ( 401 ) HTML (1 KB)  PDF (2046 KB)  ( 436 )
392 Research on Automatic Calibrating System for Pipette Capacity
ZHAO Yu-xiao,XIE Xuan-da,SUN Bin,ZHANG Jing-yue,WEN Ying-jie
DOI: 10.3969/j.issn.1000-1158.2019.03.07
Aim at the shortcomings of manual calibration such as instability of the press, temperature deviation and data that can not been processed in batches, an automatic calibration method for pipette capacity based on simulated manual press was proposed. By measuring the pressure at the two stop points of the button of the pipette, the approximate pressing distance can be obtained; comparing and analyzing data with manual operation, the optimum press distance of simulated manual press was obtained. An automatic device for simultaneous calibration of 4 pipettes was developed. Those works were intelligently controlled including extraction, discharge, weighing, and data processing adopting manipulator and LabVIEW software, fully-automatic calibrating were realized. Research results show that comparing to manual operation, the repeatability reduces 0.0%~0.9%, and the relative error decreases by 0.1%~0.7%.
2019 Vol. 40 (3): 392-396 [Abstract] ( 384 ) HTML (1 KB)  PDF (725 KB)  ( 437 )
397 A Method for Calculating the Error Control Weight of Key Measurement Feature Points in Position and Pose Adjustment of Large Parts of Aircraft Components
ZHANG Li,HUA Qiang
DOI: 10.3969/j.issn.1000-1158.2019.03.08
To achieve the best assembly pose of large aircraft parts, a method of the analytic hierarchy process (AHP) combined with error evaluation is proposed, which can comprehensively evaluate the weights of key points in digital assembly and solve the problems of position and posture adjustments of large parts using the least square method with weight values to improve the assembly accuracy. The AHP and error assessment method determine the subjective and objective weights of key measurement feature points, respectively. The combination of these two methods is used to evaluate the weights comprehensively, with the minimum assembly error as the optimization goal. Weight allocation is applied to optimize the allocation of errors of several key points. In the case analysis, the error of the overdraft intersection point is reduced from 1.23 mm to 0.72 mm, which satisfies the tolerance requirement for each measurement point. The singular value decomposition algorithm is then used to calculate the initial value of the result and the Newton method is employed iteratively to obtain the optimal pose of the parts. The rationality of the weight distribution is verified through the measured data of mid-back fuselage docking.
2019 Vol. 40 (3): 397-402 [Abstract] ( 354 ) HTML (1 KB)  PDF (377 KB)  ( 325 )
403 Research on 3D Measurement of Sand Pile Based on Multi View Stereo Vision
CHEN Hui,YANG Jian,HUANG Xiao-ming,PEI Qin,HUANG Mei-li
DOI: 10.3969/j.issn.1000-1158.2019.03.09
Based on the structure from motion (SFM), a 3D reconstruction and measurement method based on multi view stereo vision is proposed. Firstly, according to the unstable characteristics of the SFM method, the SFM solution process is analyzed and optimized by the bundle adjustment method. Secondly, the SFM reconstruction result is sparse point cloud, and the patch-based dense reconstruction algorithm is used to regenerate the dense 3D points. The cloud is then reconstructed by a Poisson algorithm for a 3D surface of a dense point cloud. Finally, the 3D size information of the model is obtained. The 3D measurement experiment of the sand pile at a construction site is carried out. The experimental results verify the effectiveness and feasibility of the method, improve the reconstruction ability and accuracy, and consider the actual measurement error and reconstruction error of the target, which can meet the requirements of actual intelligent measurement applications.
2019 Vol. 40 (3): 403-408 [Abstract] ( 408 ) HTML (1 KB)  PDF (1316 KB)  ( 953 )
409 Application of Accurate Measurement Technology of Barcode Scale in Doffing Vehicle Based on Machine Vision
MA Dan-dan,WANG Peng-cheng,LIU Ji-hong
DOI: 10.3969/j.issn.1000-1158.2019.03.10
Aiming at the self-development requirement of the automatic doffer, a bar code scale measurement technique based on machine vision is designed to detect the position of the doffing vehicle in the track. The measurement method is based on the barcode scale which consists of a scale and barcode. In the experiment, the camera and the barcode scale are calibrated at the initial position of the camera. In the process of camera movement, the current corresponding barcode scale image is obtained, and the current barcode coordinates are calculated to get the displacement of the camera relating to the barcode scale. The results show that the measurement method has no error accumulation, and realizes the real-time monitoring of the vehicle during the walking process. When the frame frequency is 30 Hz, the object distance is 15 cm, the output image resolution is 640×480 pixels, and the running speed of the vehicle is less than 2 cm/s, the barcode coordinate measurement accuracy is less than 1 mm. When the speed of the vehicle is 2~6 cm/s, the coordinate measurement accuracy is 1~2 mm, when the speed of the vehicle is 6~10 cm/s, the coordinate measurement accuracy is 2~3.5 mm. The method can meet the requirement of positioning precision of a doffing cart under low-speed running conditions.
2019 Vol. 40 (3): 409-415 [Abstract] ( 356 ) HTML (1 KB)  PDF (1572 KB)  ( 936 )
416 Nonlinear Correction of Optoelectronic Array Sensor
TONG Jian-ping,YANG Jian-wu,ZHENG Wen-qiang,WANG Fei,YANG Hao
DOI: 10.3969/j.issn.1000-1158.2019.03.11
Optoelectronic array sensors exhibit nonlinearity near saturation, but can be corrected by extrapolating the coefficients in the linear region of the array sensors. The response curve between exposure and A/D conversion can be extended to any wavelength position as long as the exposure curveis measured at one wavelength position. For this reason, the least square method is used through polynomial fitting and software nonlinearity correction. Under the same hardware configuration, the linear region of linear array sensor is added, and the dynamic range of sensor is extended. In the whole dynamic range, the measurement error of the system can be reduced to ±2%. This non-linear correction method is also very suitable for intensity calibration correction in spectrometer production factories using photoelectric array sensors.
2019 Vol. 40 (3): 416-420 [Abstract] ( 337 ) HTML (1 KB)  PDF (560 KB)  ( 872 )
421 Study on Phase Transition Characteristic of Mini Ga-In-Sn Eutectic Fixed Point
DIAO Fu-guang,CAI Jin-hui,SUN Jian-ping,WANG Ying-wen,GAO Kai,YE Meng
DOI: 10.3969/j.issn.1000-1158.2019.03.12
Taking Ga-In-Sn ternary alloy as the research object, a mini Ga-In-Sn eutectic cell which can be used for on-site and on-line calibration was developed, and the effect of three-ratio for the Ga-In-Sn on phase transition temperature and temperature plateau were investigated. The results show that the plateaus of three-ratio Ga-In-Sn realization last about 1.2 h to 2 h, the reproducibility is less than 4.5 mK and combined expanded uncertainty is 9.3 mK(k=2). The average value of the phase transition temperature is 10.748 ℃ and is not affected by the ratio of Ga-In-Sn ternary alloy. Changing the melt cooling rate can change the supercooling of the mini eutectic fixed point.
2019 Vol. 40 (3): 421-426 [Abstract] ( 447 ) HTML (1 KB)  PDF (1165 KB)  ( 1419 )
427 Research on Integrated Blackbody Emissivity Measurement Based on Laser Integral Sphere Reflectometry
SHAO Chun-teng,HUAN Ke-wei,LI Zhi-bin,DONG Wei,WANG Jing-hui,SONG Xu-yao
DOI: 10.3969/j.issn.1000-1158.2019.03.13
Integrated blackbody emissivity is one of the key uncertainty components of its effective spectral radiance. The measurement principle and experimental system of the laser integral sphere reflectometry were established. The normal spectral emissivity of the integrated cavity blackbodys were experimentally studied at 633nm, the experimental results showed that the effective emissivity of the integrated blackbody was higher than 0.998, and the deviation from the model Carlo simulation result was within 0.04%. The agreement was good within the measurement uncertainty, which validated that the laser integral sphere reflectometry is feasible to estimate the normal spectral emissivity of the integrated cavity blackbody.
2019 Vol. 40 (3): 427-431 [Abstract] ( 390 ) HTML (1 KB)  PDF (1005 KB)  ( 540 )
432 Seepage Heat Transfer Model with Thermal Non-equilibrium of High Temperature Clinker
WANG Mei-qi,CHEN En-li,GUO Wen-wu,LIU Peng-fei,QI Zhuang,HOU Shuang
DOI: 10.3969/j.issn.1000-1158.2019.03.14
The high temperature cement clinker can be regarded as glowing red and translucent porous media when it is discharged from rotary kiln to grate cooler. It brings greater difficulty to technology improvement of grate cooler since the gas-solid heat transfer mechanism is complex. According to the problem, the glowing red particle can be equivalent to optically thick medium, then an integrated heat transfer coefficient is derived for high temperature clinker particle when heat conducting and thermal radiating. Based on the seepage mechanics and heat transfer theory, an unsteady seepage heat transfer model with thermal non-equilibrium of cement clinker is built which considering the heat radiation effect between the high temperature clinker particle. By solving the model, the distribution of clinker temperature and gas temperature inside the material layer are obtained, at the same time, the difference of cooling rates in different regions are compared to gain the impact of radiation heat transfer factor on the material layer temperature distribution.
2019 Vol. 40 (3): 432-439 [Abstract] ( 358 ) HTML (1 KB)  PDF (1522 KB)  ( 375 )
440 Development of a Water Profile Temperature Measuring Instrument
Lü Biao, HAO Xiao-peng, SUN Jian-ping, CHANG Jia-qiang,
DOI: 10.3969/j.issn.1000-1158.2019.03.15
An instrument to measure the profile temperature of water surface and water body is developed. The design principle, structure, testing process and final experimental result of the instrument are expounded. The water body temperature thermometer integrates the radiation temperature measurement and the contact temperature measurement, and can measure the temperature of the water body at different positions between the depth 1200mm below the surface of the water. The temperature range is 0～40℃ which the uncertainty of the radiation thermometers and the contact thermometers are 0.24K and 0.12K, respectively. The instrument has the function of automatically storing data, and also can be floated on the water surface continuous automatic measurement in two weeks.
2019 Vol. 40 (3): 440-446 [Abstract] ( 391 ) HTML (1 KB)  PDF (1993 KB)  ( 460 )
447 Optimization on Inital Pressure of a Steam Turbine Based on Symbiotic Organisms Search Algorithm
NIU Pei-feng,WANG Xiao-fei,LIU Nan,CHANG Ling-fang,ZHANG Xian-cheng
DOI: 10.3969/j.issn.1000-1158.2019.03.16
To obtain the optimal initial pressure of a steam turbine under loads,a heat rate forecasting model was established using fast symbiotic organisms search (FSOS) algorithm and extreme learning machine (ELM). The model was compared with BP neural network, symbiotic organisms search (SOS) algorithm’s optimizing extreme learning machine (ELM) and fast symbiotic organisms search (FSOS) algorithm’s optimizing support vector machine (SVM). Then, FSOS was employed to seek the optimal initial pressure and the main steam flow based on the forecasting model to make the heat rate under each load the lowest. Finally, an optimal initial pressure curve was fitted by the optimized main steam pressure and compared with the factory designed sliding pressure curve. The results showed that the average heat rate decreases about 58.51 kJ·(kW· h)-1 according to the optimal initial pressure curve, which improved the energy conversion efficiency of the unit and had a significant effect on the economic operation of the steam turbine.
2019 Vol. 40 (3): 447-454 [Abstract] ( 359 ) HTML (1 KB)  PDF (1415 KB)  ( 404 )
455 Electrical Resistance Tomography and the Application in the Simulation Experiment of Hydrate Mining
SUN Hai-liang,LI Yan-long,LIU Chang-ling,XING Lan-chang,MENG Qing-guo
DOI: 10.3969/j.issn.1000-1158.2019.03.17
As a visual nondestructive measurement method, electrical resistance tomography can provide an effective monitoring method for the simulation experiment of natural gas hydrate. Firstly the working principle, development history and application status of electrical resistance tomography are introduced, the main application and existing problems of the electrical resistance tomography used in the natural gas hydrate simulation experiment are summarized and analyzed. On the basis, the problems of the application of electrical resistance technology in the simulation experiment of hydrate mining are pointed out, and the suggestions for solving the problems are given, the thoughts for the next phase of the electrical resistance tomography experiment of hydrate are provided.
2019 Vol. 40 (3): 455-461 [Abstract] ( 313 ) HTML (1 KB)  PDF (1389 KB)  ( 407 )
462 Study of Three-dimensional Image Reconstruction for Electrical Capacitance Tomography
ZHANG Li-feng,JIANG Yu-hu
DOI: 10.3969/j.issn.1000-1158.2019.03.18
Simulation research of three-dimensional image reconstruction for electrical capacitance tomography (ECT) was carried out. First, the three-dimensional sensor model of ECT was built using COMSOL software. After that, based on the high accurate solution of finite element method by COMSOL, the sensitivity matrix of ECT was calculated. Secondly, image reconstruction based on linear back-projection (LBP) and Landweber iterative algorithm was realized with MATLAB programming and then the three-dimensional images were obtained by image display program. Finally, image reconstruction was carried out for the sphere and cylinder models and the satisfying results can be obtained.
2019 Vol. 40 (3): 462-465 [Abstract] ( 434 ) HTML (1 KB)  PDF (1063 KB)  ( 950 )
466 Characterization of Particle Size Distribution Based on Ultrasonic Spectra Analysis
JIA Nan,GU Jian-fei,SU Ming-xu
DOI: 10.3969/j.issn.1000-1158.2019.03.19
To verify the effect of different ultrasonic spectra and analysis methods on particle size distribution, the experimental setup was established to provide a non-invasive way in synchronously acquiring ultrasonic reflection and transmission signals. Then the experiments were carried out on four polystyrene-water solutions at volume fractions from 1% to 4% to extract the ultrasonic spectra based on pulse-echo method, reference reflection method and through-transmission method, respectively. Based on the ECAH model, the ORT algorithm was used to solve the particle size distribution by means of various experimental spectra, which were also compared with the optical microscope method. It showed that the different spectra analysis yielded a relatively consistent result and the volume median diameters within a deviation of 15%, which further verified the reliability in measuring the particle size distribution of the suspension.
2019 Vol. 40 (3): 466-471 [Abstract] ( 380 ) HTML (1 KB)  PDF (1385 KB)  ( 948 )
472 Study on Using Intermittent Chaos to Detect Unknown Frequency Signal in Noise
LIU Jian-ming,FENG Song-he,REN Li-na,LIU Fu-cai
DOI: 10.3969/j.issn.1000-1158.2019.03.20
It is found that changes both of the frequency of measured signal and interference noise could cause the change of interval of intermittent chaos.The correlation between the frequency of the measured signal and the interference noise on the intermittent chaotic characteristics is analyzed through simulation experiments.The effects on the intermittent chaotic characteristics by the frequency and the phase angle of the measured signal are analyzed theoretically.A method for measuring the signals of unknown frequency in noisy environment by using intermittent chaotic characteristic changes is proposed.Experiments are designed to detect the frequency of acoustic signals in both noisy and noiseless environments.The experiments show that the detection of the signals of unknown frequency by intermittent chaos in noise by the Liu-cos chaotic system is better than that by Duffing chaotic system.
2019 Vol. 40 (3): 472-476 [Abstract] ( 386 ) HTML (1 KB)  PDF (1422 KB)  ( 273 )
477 High-frequency Transducer Array Sound Field Measurement Method Based on Near-field Acoustic Holography
GUO Shi-xu,HAO Zhen-yu,ZHENG Hui-feng,ZHAO Peng,XIONG Jiu-peng
DOI: 10.3969/j.issn.1000-1158.2019.03.21
Based on the theory of two-dimensional plane acoustic pressure construction technology, combined with the spatial Fourier transform near-field acoustic holography technology, a sound field measurement method with high measurement efficiency was proposed. A rectangular piston transducer array composed of four piezoelectric elements was used as a measurement object, and the sound field simulation and experimental measurements were performed to verify the measurement accuracy and efficiency of the measurement method. The results showed that the method improves the measurement efficiency by 560 times compared with the surface scanning method. Compared with the integration method, the calculation speed increases by two times. This method can be effectively applied to the sound field measurement of high-frequency transducer arrays.
2019 Vol. 40 (3): 477-480 [Abstract] ( 368 ) HTML (1 KB)  PDF (810 KB)  ( 288 )
481 Precision Measurement of Non-sinusoidal Voltage Based on Staircase Waveform
LU Zu-liang,YANG Yan,HUANG Lu,WANG Lei
DOI: 10.3969/j.issn.1000-1158.2019.03.22
A novel method using the regular distributed partial data for the periodic signal analysis is proposed. Differential measurement of the non-sinusoidal voltage signal based on a staircase waveform is discussed, where the first and last parts of each step are discarded to overcome the transient effect and Gibbs phenomenon. In Fourier transformation of higher frequency components the significant deviations will be caused. When the base functions are divided with same mode, the relevant influence matrix will be derived; its inverse matrix can then recover the original Fourier coefficients. The key point here is to simplify calculation of the inverse matrix. The condition of this simplification is proposed in which the influence matrix becomes sparse. The limiting amplitude condition required in the differential sampling based on the staircase waveform is investigated. Simulations and demonstration experiments show an acceptable workload and a very high accuracy. This method can be applied to spectrum analysis when partial samples are regularly lost.
2019 Vol. 40 (3): 481-490 [Abstract] ( 403 ) HTML (1 KB)  PDF (1033 KB)  ( 353 )
491 The Method for Single-frequency Cycle-slip Detection and Reparation Based on Modified EEMD and LSSVM
ZHU Jiang-miao,YAN Di,GAO Yuan,CHEN Ye,WANG Xing
DOI: 10.3969/j.issn.1000-1158.2019.03.23
To solve the problem that it is difficult to detect and repair the small cycle-slip, a method which uses modified EEMD to detect the cycle-slip and uses LSSVM to repair the cycle-slip is proposed. First, pseudorange and carrier-phase measurements are used to construct the cycle-slip detectable quantity; Second, the quantity is decomposed by MEEMD; as a result, it can obtain some intrinsic mode functions (IMF). Choose the IMFs which possessed relatively high correlativity with the detectable quantity to do the analysis use Hilbert. And the Hilbert modulus maximum is applied to judge if the cycle-slip appeared and its epoch. Finally, the value at these epochs for every IMFs whose correlation is high is predicted by the LSSVM. Compare the predictive value with the real value and the cycle-slip can be repaired. The experiments show that this method can successfully detect and repair the cycle-slip as small as one cycle.
2019 Vol. 40 (3): 491-497 [Abstract] ( 354 ) HTML (1 KB)  PDF (1740 KB)  ( 285 )
498 Study on an Improved Extended PSO Algorithm Based on Geese Flight
LIU Hao-ran,CUI Jing-chuang,LU Ze-dan,GUO Chang-jiang,DING Pan
DOI: 10.3969/j.issn.1000-1158.2019.03.24
To solve the local minimum problem of PSO, a new algorithm called GeEPSO is proposed, which hybrids the PSO based on the flight of geese and the extended PSO algorithm. The GeEPSO take the advantage of the various directions of geese and make full use of the position of each particle to assure the diversity of particle swarm. And to further improve the convergence performance, the simplified PSO is introduced to obtain another new algorithm GeESPSO. The simulation results of some benchmarks demonstrate the GeEPSO algorithm can deal well with the conflict between the convergence rate and the local minimum problem, which is better on the whole. And to further investigate the effect of the proposed algorithms in practical application, the new algorithms were used to optimize the BP neural network. Finally the prediction of PM2.5 is made with the improved BP neural network, using the meteorological data.
2019 Vol. 40 (3): 498-504 [Abstract] ( 376 ) HTML (1 KB)  PDF (1883 KB)  ( 720 )
505 Robot Path Optimization Research Based on Improved Immune Genetic Optimization Ant Colony Algorithm
ZHAO Chun-fang,LI Jiang-hao,ZHANG Da-wei
DOI: 10.3969/j.issn.1000-1158.2019.03.25
Aiming at the problem that the ant colony algorithm(ACO) is easy to fall into the local optimum and the convergence speed is slow in the path planning of mobile robots, an improved algorithm is proposed for the static path optimization of robots, which is called as improved immune genetic algorithm (IMGAC). The algorithm can automatically adjust the mutation probability and mutation mode according to the actual situation and automatically adjust the length of individual immunization bits. The improved mutation operator and immune operator are embedded in ant colony algorithm to improve the global optimization ability and convergence speed. Simulation and experiment show that compared with the classical ACO algorithm and the maximum and minimum ant system, the IMGAC algorithm can converge faster and have better global search ability. The IMGAC algorithm also improves to the result and efficiency of robot path optimization.
2019 Vol. 40 (3): 505-510 [Abstract] ( 358 ) HTML (1 KB)  PDF (1245 KB)  ( 530 )
511 Study on Measurement System for Bacteriophage ΦX174 Reference Material
LIU Si-zhang,SUI Zhi-wei,ZHANG Tao,WANG Jing,LIU Xiao-xia,
DOI: 10.3969/j.issn.1000-1158.2019.03.26
The double-layer agar counting method of phage ΦX174 in international standard (ISO 16604) was adopted as the calibration method of phage ΦX174 standard substance, and the method was validated by the method and verified by synergistic experiment and the uncertainty analysis. The results showed that the repeatability and reproducibility of the method were good, the relative standard deviation of indoor repeatability was 10.18%, and the relative standard deviation was 14.58%. According to the statistical analysis, the relative expansion uncertainty of the double agar counting method was 12.44%, which was suitable for the determination of the standard substance of phage ΦX174, which was very important for the evaluation of protective performance of personnel protective equipment.
2019 Vol. 40 (3): 511-516 [Abstract] ( 381 ) HTML (1 KB)  PDF (397 KB)  ( 408 )
517 Research on a FTIR System for Accurate Measurement of Low Concentration NO2
LI Jian,WANG De-fa,XIA Chun,MA Hao-miao,WANG Man,WANG Zhen,HUANG Peng
DOI: 10.3969/j.issn.1000-1158.2019.03.27
A FTIR system for the accurate measurement of low concentration NO2 was developed. By using the proposed syestem, the concentration of NO2 in the different standard gas were measured; the standard gas were obtained by dynamic dilution method. It was indicated that the system has a good linear response, thus the calibration equation of the system was established. The comparison test showed that the system is accurate and reliable. The stability study showed that the system has good long-term stability. By using dynamic dilution method based on mass flow controllers, the standard gases with different concentration were obtained. This system has a calibration curve with good linearity. The comparison test shows that the system is accurate and reliable. The stability study shows that the system has good long-term stability.
2019 Vol. 40 (3): 517-521 [Abstract] ( 338 ) HTML (1 KB)  PDF (627 KB)  ( 1039 )
522 Monte-Carlo Simulation about Wall Correction Factor for the Spherical Graphite Cavity Chamber
HAO Yan-mei,HUANG Jian-wei,LI De-hong,WANG Chen-yi,WU Qi
DOI: 10.3969/j.issn.1000-1158.2019.03.28
Calculate the wall correction factor Kwall of spherical graphite cavity chambers by MC (Monte Carlo) method, and study the influence of Kwall about photon energy, wall thickness and graphite density. And the result shows that for the same volume chambers Kwall sharply reduces with energy at the low energy side. As the wall thickness increases, Kwall approximates linearly increase. And when the calculation accuracy is greater than 0.2%, the effect of density can be neglected on the simulation of Kwall. The above results indicate that in order to calculate the wall correction factor of the graphite cavity chamber accurartely, photon energy, wall thickness and graphite density must be considered.The above results indicate that the calculation of wall correction factor needs to consider the influence of photon energy,wall thickness and graphite density.And the calculation of correction factor of the graphite chamber ionization chamber must be high accuracy.
2019 Vol. 40 (3): 522-525 [Abstract] ( 326 ) HTML (1 KB)  PDF (540 KB)  ( 385 )
526 Rapid Detection of Radioactive Content in Stone by Hand-held γ Radioisotope Identification Device
LU Xiao-jun,HE Lin-feng,XIN Zhi-wei
DOI: 10.3969/j.issn.1000-1158.2019.03.29
A rapid measurement method using a handheld gamma radionuclide recogniser to rapidly measure the content of natural radionuclides in stone was proposed. The reference values of the calibration coefficients of 226Ra, 232Th and 40K in the handheld radionuclide recogniser were determined by means of the energy spectrum analysis method of the low background HPGe γ spectrometer. Then the radionuclide gamma spectrum in the stone was measured by the handheld radioisotope identification device (RID). The specific activity of 226Ra, 232Th and 40K in stone was estimated according to the calibration coefficient. The results showed that the maximum deviations between the proposed method and the low background HPGe gamma spectrometer were 25.1%(CRa), -27.2%(CTh), -15.2%(CK) respectively. The proposed method can be applied to the rapid and nondestructive detection of specific activity of gamma radiation in stone samples and the rapid estimation of external radiation dose caused by decorative stone.
2019 Vol. 40 (3): 526-529 [Abstract] ( 323 ) HTML (1 KB)  PDF (709 KB)  ( 375 )
530 Analysis of Convergence Trend of Adaptive MCM Volatility Index
WEI Ming-ming
DOI: 10.3969/j.issn.1000-1158.2019.30
The rule of adaptive Monte Carlo method(MCM) for measurement uncertainty evaluation is analyzed and apply it to practise areas. Firstly, the basic principles of MCM, the detailed process, steps and program implementation on the evaluation of adaptive MCM are introduced. Secondly, combined with the characteristics that the stability of adaptive MCM needs to be analyzed, the concept of adaptive MCM volatility index is proposed. Finally, the general law of convergence trend of adaptive MCM volatility index is concluded by means of simulation experiments, which use representative linear model (relational model of measuring error value by using platinum resistance air temperature sensor) and non-linear model (resistance-temperature relationship model). Ultimately, a technical reference for the measurement uncertainty evaluation by adaptive MCM is provided.
2019 Vol. 40 (3): 530-537 [Abstract] ( 424 ) HTML (1 KB)  PDF (1035 KB)  ( 549 )
538 The Experience from Full Chain Implementation of NQI Technologies Based on Graphene Related Productions
REN Ling-ling
DOI: 10.3969/j.issn.1000-1158.2019.03.31
The study, integration and implementation of NQI technologies based on graphene related productions is one project of National Key R & D Program of China from Generic Technology and Application for National Quality Infrastructure (NQI) of China, which content is including the study of metrology, standardization and conformity assessment technologies, then integrating these technologies to supply application in factories as a full chain implementation of NQI. Some rules and experiences are abstracted and shared with researchers, producers and managers. The aim is to improve the application of the project fruits and to supply much better NQI supports to the high quality development of industry.
2019 Vol. 40 (3): 538-540 [Abstract] ( 431 ) HTML (1 KB)  PDF (369 KB)  ( 303 )
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