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2020 Vol. 41, No. 8
Published: 2020-08-28
 
897 Development of Environmental Parameters Automatic Measurement System for 1.2km Standard Baseline
LIU Xue-de,MIAO Dong-jing,ZHANG Jing-yan,LI Lian-fu,LI Jian-shuang,ZHANG Fu-min,LI Ping
DOI: 10.3969/j.issn.1000-1158.2020.08.01
To improve field measurement accuracy, the 1.2km standard baseline an environmental parameters automatic measurement system is developed, and a hardware grouping and software parallel acquisition scheme is adopted. The accuracy rate of sensor data acquisition in the system is more than 98%, and the time of complete cycle acquisition of 82 sensors is less than 7s. Calculate the temperature variation of sensor 7s sampling interval, analyze and evaluate the refractive index compensation results, provide a scientific perspective for field standard baseline measurement, quantify the ideal measurement period of baseline, make the delay temperature difference less than 0.05℃, the refractive index correction error of high precision rangefinder in baseline measurement is controlled within 5×10-8.
2020 Vol. 41 (8): 897-902 [Abstract] ( 356 ) HTML (1 KB)  PDF (2073 KB)  ( 248 )
903 Vertex Radius of Curvature Fabrication Error Measurement of Aspheric Surface in Partial Compensation Interferometry
HU Yao,LI Teng-fei,HAO Qun,CHANG Xu
DOI: 10.3969/j.issn.1000-1158.2020.08.02
Precisely measuring the vertex radius of curvature (VROC) fabrication error is critical for the manufacture and alignment of optical aspheric surfaces. Conventional partial compensation interferometry (PCI) can only test the aspherical surface figure error which is defined as the irregular difference between the measured and nominal surface. A VROC fabrication error measurement method of aspheric surface in PCI is proposed. Based on specific aberration analysis of the residual wavefront changing with the position of the measured aspheric surface, VROC fabrication error can be obtained. The simulation experiments are done to verify the method, and the results show that the theoretical relative measuring accuracy is no less than 0.003%.
2020 Vol. 41 (8): 903-908 [Abstract] ( 341 ) HTML (1 KB)  PDF (979 KB)  ( 376 )
909 Research on NURBS Optimization Expression Method of Quadric Surfaces
KONG De-ming,HUANG Zi-shuang,YANG Dan
DOI: 10.3969/j.issn.1000-1158.2020.08.03
In order to solve the problem of the low accuracy and complicated process of quadric surface fitting on non-uniform rational B-spline(NURBS), an efficient method is proposed to select the u, v parametric directions and calculate the selection range of optimal number of control points. Firstly, the u, v parametric directions are determined according to the shape characteristics of quadric surface. Then, the reconstructed surface fitted by different number of control points are quantitatively analyzed by using the absolute value of the differences and the RMSE. According to the quantitative analysis curves, the minimum value of the optimal number of control points of quadric surface is calculated. Finally, the maximum value of the optimal number of control points of quadric surface is calculated by the relationship between the program runtime and the number of control points. Examples showed that the reasonable selection range of NURBS optimal control points for common quadric surfaces is 201~541. The analysis result provides theoretical support and technical reference for the problems encountered in the NURBS fitting process for standard analytic surface.
2020 Vol. 41 (8): 909-917 [Abstract] ( 288 ) HTML (1 KB)  PDF (1045 KB)  ( 678 )
918 Research on Fitting Method of Thread Middle AxisBased on 3D Point Cloud
XIE Zhang-ning,JIANG Zhi-hua,ZHU Hui-chen,LI Zhi-wei,LEI Li-hua,KONG Ming,WANG Dao-dang,ZHANG Bo
DOI: 10.3969/j.issn.1000-1158.2020.08.04
The accurate determination of the central axis of the thread is one of the important factors that determine whether the three-dimensional measurement result of the thread is accurate. The inclination and offset of the central axis will introduce errors in the measurement operations, such as setting up the workpiece coordinate system, reconstructing the three-dimensional thread, and inspecting the parameters.Based on three-dimensional point cloud, the least squares fitting algorithm is proposed to develop the fitting method of the central axis of the thread. According to the point cloud data of the thread surface, the least square mathematical model is established by using the characteristic relationship between the thread surface and the central axis, and the three-dimensional convex hull of the point cloud data is calculated to filter out the fitting error brought by the three-dimensional structure of the thread itself, so the measurement is more accurate. Through simulation experiments, the distance between the straight line fitted by the least square fitting algorithm based on the three-dimensional point cloud and the three-dimensional point cloud has a variance of 0.34, the maximum distance between the two ends of the straight line determined by the projection method within the twist length is 0.15μm, which meets the high-precision standard for three-dimensional measurement. It shows that the least squares fitting algorithm based on the three-dimensional point cloud is a fast and accurate fitting method of the thread central axis.
2020 Vol. 41 (8): 918-925 [Abstract] ( 317 ) HTML (1 KB)  PDF (1984 KB)  ( 833 )
926 Optimization of AUV Path Based on GPS/MATLAB
WU Zhi-feng,WU Zi-yue
DOI: 10.3969/j.issn.1000-1158.2020.08.05
A control system design method of autonomous underwater vehicle(AUV) path planning based on global positioning system is introduced. In view of the deviation of AUV in the autonomous path planning, AUV uses the STM32 type ARM microcontroller to exchange data with the global positioning system (GPS), and combines the GPS feedback data with the MATLAB planning path through the STM32 average processing, adjust the appropriate motion trajectory and analyze its accuracy. The experiment results show that the trajectory of the controller design meets the expectations and the accuracy is better, and the path optimization accuracy based on the global positioning system is significantly improved. A reference method for correcting the deviation of the path planning is provided.
2020 Vol. 41 (8): 926-931 [Abstract] ( 317 ) HTML (1 KB)  PDF (1512 KB)  ( 517 )
932 An Auto-focusing Algorithm of Cross-line Target Based on MTF
WANG Li-gang,DING Xiang,HONG Bao-yu,LI Fei
DOI: 10.3969/j.issn.1000-1158.2020.08.06
The cross-line target is the common target in focusing systems. Its focusing accuracy is the key factor affecting measurement results. The traditional focusing function cant fully meet the requirements in terms of sensitivity and real-time performances. The focusing curve is drawn by continuously measuring MTF values of multiple images at fixed frequencies with the automatic focusing evaluation function based on MTF(modulation transfer function), and the focus position is gotten at the only extreme point of the focusing curve. In the Matlab environment, the result shows that the focusing function based on the MTF of the digital image can only use 0.01 s to calculate the definition value of a single image. The algorithm has the better real-time performance, higher sensitivity and application value.
2020 Vol. 41 (8): 932-936 [Abstract] ( 349 ) HTML (1 KB)  PDF (1093 KB)  ( 404 )
937 Research on Measurement of Medical Micro Flow Rate Technology Based on Constant Volume Displacement Increment Method
LIAO Xu-hui,CHEN Yu-qiao,YANG Yong,WANG Yao-jun,ZHANG Qiu-chen,RAN Wen-jie,YANG Jun-jie,LI Peng
DOI: 10.3969/j.issn.1000-1158.2020.08.07
Using the principle of measuring the micro-flow rate of a fixed-volume piston cavity, based on the relationship between the piston displacement and the flow rate, the measurement model, theoretical calculation method, hardware design and corresponding software system of medical micro-flow are introduced. The micro-flow measurement technology can complete the calibration of medical infusion pump and injection pump in a short time. The experimental results show that the flow detector can measure the micro-flow rate from 1mL/h to 1500mL/h, and can not only respond to the micro-flow rate of 1mL/h quickly, but also the maximum allowable error of instantaneous flow rate is less than ±1%. The maximum allowable error of cumulative flow rate is less than ±1% when the volume of liquid in the injection chamber is larger than 5mL.
2020 Vol. 41 (8): 937-941 [Abstract] ( 318 ) HTML (1 KB)  PDF (779 KB)  ( 264 )
942 Two-phase Flow Pattern Recognition Based on Electrical Capacitance Tomography Reconstructed Images
WANG Xiao-xin,WANG Bo,CHEN Yang-zheng,HU Hong-li
DOI: 10.3969/j.issn.1000-1158.2020.08.08
To realize the industrial multiphase flow pattern recognition, based on the research of process tomography, the reconstructed image information is analyzed and processed simply and efficiently, the two-dimensional maximum entropy threshold segmentation technique and the genetic algorithm optimized neural network classifier are used to realize the flow pattern identification.Three typical gas-solid flow patterns were verified on the two-phase flow pneumatic transport platform by the mentioned method.The experimental results showed that the recognition accuracy is 94.7%.
2020 Vol. 41 (8): 942-946 [Abstract] ( 276 ) HTML (1 KB)  PDF (1013 KB)  ( 471 )
947 Three-dimensional Optimal Design of Array Electrode for Electrical Capacitance Tomography System
ZHANG Li-feng,ZHU Yan-feng
DOI: 10.3969/j.issn.1000-1158.2020.08.09
Three-dimensional finite element model of array sensor of electrical capacitance tomography is established based on COMSOL software and the solution of forward problem of ECT is completed.Dimensionless parameter optimization of array electrode with three-layer distribution of ECT is carried out.Firstly, the influence of the screen radius R3, electrode height h, electrode width w and layer spacing l on the sensitivity uniformity index P and the dynamic range D of the capacitance value is analyzed.After that, using orthogonal experiment design, the effect of each structural parameters is integrated and balanced.At last, the optimal ECT three-dimensional sensor structural parameters are obtained as R3=1.50,h=0.20,w=0.20,l=0.06.
2020 Vol. 41 (8): 947-952 [Abstract] ( 309 ) HTML (1 KB)  PDF (1098 KB)  ( 263 )
953 Analog Drive Design of Coriolis Flowmeter Based on Driving Characteristic Diagram Method
XU Hao-ran,XU Ke-jun,ZHANG Lun,LIU Wen,YUE Jing,HUANG Ya,LIU Chen-ci
DOI: 10.3969/j.issn.1000-1158.2020.08.10
The steady vibration of the sensor is a prerequisite for the operation of the Coriolis mass flowmeter. When the measured liquid flow contains gas, the vibration damping of the sensor increases, and the required driving energy should be increased. However, existing analog drivers are unable to provide the required energy in time, causing the sensor to stop vibrating. To this end, the drive characteristic curve of the existing analog drive was drawn, and the existing problems were analyzed. Then the drive characteristic curve of the new analog drive was derived, and a new analog drive circuit capable of working simultaneously under single-phase flow and gas-liquid two-phase flow was designed. Under the continuous gas-liquid two-phase flow and single-phase flow-gas-liquid two-phase flow switching, the existing analog drive and the new analog drive comparison experiment were carried out. The results showed that the driving stability and fastness of the new analog drive are better than the existing analog drive.
2020 Vol. 41 (8): 953-959 [Abstract] ( 300 ) HTML (1 KB)  PDF (1153 KB)  ( 208 )
960 Calibration Method for Optical Measurement of Ultra-Micro Liquid Volume
ZHONG Jia-dong,SUN Bin,ZHAO Yu-xiao,MA Xin-yu,ZHANG Jing-yue
DOI: 10.3969/j.issn.1000-1158.2020.08.11
Static weighing method is commonly used in laboratory to measure the volume of micro-liquid,The accuracy of this method is 2.18% and the repeatability is 1.85% for the volume of 1μL. however, it can not be carried out outside the laboratory. The accuracy and repeatability of the existing optical method for measuring micro-liquid volumetry in 1μL are 6.09% and 1.31%. The mentioned method can realize on-line detection, but its accuracy is not as good as static weighing method. A new method for calibrating the capacity reference standard of this method was found by studying and analyzing the method of optical measurement of micro-liquid capacity. The calibration method combines the static weighing method with the optical measurement method, and takes the static weighing method as a new capacity reference standard instead of the original standard liquid of optical method. The new calibration method extends the reference standard from point to line in principle, and can improve the accuracy of optical measurement at 10μL point to 2.014% and repeatability to 1.30%.
2020 Vol. 41 (8): 960-964 [Abstract] ( 310 ) HTML (1 KB)  PDF (798 KB)  ( 220 )
965 A Portable Angular Rate Sensor
ZHU Guo-bin,ZHAO Hao
DOI: 10.3969/j.issn.1000-1158.2020.08.12
Angular rate is an important parameter for the state monitoring of rotating system or transmission. A portable instantaneous angular rate sensor is designed, which with a new structure and has no rotating parts. The working principle is a constant flux generated by the permanent magnetic steel, then the rotating part of the measured rotating device cuts the constant flux and forms an eddy current, the magnetic field generated by the eddy current interacts with the Hall element of the sensor, and then the Hall potential is generated, the amplitude of the Hall potential is proportional to the angular rate of the measured rotating device. According to the basic law of magnetic circuit, the output characteristics of sensor are deduced, and the output characteristics of sensor is carried out by actual measurement, the results show that the sensitivity of sensor is about 16.8mV·s/rad, the nonlinear error is about 1.24%.
2020 Vol. 41 (8): 965-968 [Abstract] ( 320 ) HTML (1 KB)  PDF (415 KB)  ( 265 )
969 Design of Laser Measurement System for Cable Indentation and Uncertainty Analysis
XU Zhou-da,LU Han,XU Rui,LI Jian-jun,WANG Bin-rui
DOI: 10.3969/j.issn.1000-1158.2020.08.13
In view of the current manual measurement of cable indentation is slow and affected by the human operation greatly, a device for automatically measuring the indentation depth of the cable and software are designed. The device sends commands to the motion control board through software to drive the motor to realize the movement control of a two-dimensional platform which is equipped with a fixture for fixing cable; At the same time, the laser sensor acquires data to obtain a data set; The set is subjected to a moving average filter process, using a differential method for the processed data set to determine if there is an indentation; Linear regression is performed on non indentation data, the indentation depth is obtained by subtracting the indentation data.The sources of the uncertainty introduced in the measurement calculation process are analyzed, and the uncertainty of the measurement results of a cable sample is evaluated, taking k=2, the expanded uncertainty U=0.028mm.
2020 Vol. 41 (8): 969-974 [Abstract] ( 319 ) HTML (1 KB)  PDF (1746 KB)  ( 195 )
975 Research on the Influence of Tissue Mimicking Phantomon Focal Area of HIFU
XU Ao-xuan,WANG Yue-bing,ZHENG Hui-feng,CAO Yong-gang
DOI: 10.3969/j.issn.1000-1158.2020.08.14
The effect of acoustic characteristics of biological tissue on focal area of HIFU(high intensity focused ultrasound) was analyzed by finite element simulation, which provided theoretical basis for the safety and reliability of HIFU treatment. Ultrasonic propagation equation and frequency-domain finite element method (FEM) were applied to simulate the changes in focal area caused by the characteristics and thickness of tissues during HIFU treatment, and tissue mimicking phantoms were produced to verify the changes in focal area. The influences of characteristics and thickness of tissue on the focus area and location were analyzed and discussed. As a result, with the increase of acoustic velocity, the size of the focal region remained unchanged, and the focal region was closer to the side of the transducer. As the thickness increased, the size of the focal area basically remained unchanged. If acoustic velocity of the tissue was greater than that of the water, the focal area would be closer to the side of the transducer;if acoustic velocity of the tissue was less than that of the water, the focal area would move away from the transducer.
2020 Vol. 41 (8): 975-982 [Abstract] ( 284 ) HTML (1 KB)  PDF (2164 KB)  ( 341 )
983 Research on Evaluation Method of Acoustic Phase Image Based on Image Processing
ZHANG Mo,ZHENG Hui-feng,ZHU Qin-feng
DOI: 10.3969/j.issn.1000-1158.2020.08.15
Based on image processing, an acoustic phase image evaluation method is proposed to evaluate the sound source positioning error of the sound imaging instrument. Analyzing the imaging principle of sound imaging instrument, and the azimuth error and the pitch angle error are proposed as the evaluation indexes of the acoustic phase images sound source positioning error. The difference image method is used to extract the sound source localization imaging region of the acoustic phase image. After going through grayscale, binary, corrosion, expansion and the weighted average, the pixel coordinates of the imaging regioncenter are calculated. In the different capture distance planes of the sound imaging instrument, the position coordinates of the imaging regionscenteron the actual physical space are obtained by image calibration.Then comparing with the actual position coordinates of the positioned sound source, the azimuth error and the pitch angle error are calculated.The experimental results show that comparing the azimuth and pitch angle obtained by the proposed method with the actual value obtained by calculating the actual position coordinates of the sound source, the difference is small, which means that the sound source positioning error can be objectively evaluated and the method is easy to be operated.
2020 Vol. 41 (8): 983-988 [Abstract] ( 320 ) HTML (1 KB)  PDF (2004 KB)  ( 459 )
989 R&D and Performance Evaluation of Reflective Sagnac Interferometer-type Fiber Broadband High Current Measuring Instrument
XIE Xiao-jun,ZHU Cai-yi,LI Qing-xian,LI Hua,LUO Ying
DOI: 10.3969/j.issn.1000-1158.2020.08.16
To deal with the difficulties of quantity transfer and on-line high current calibration for large-scale electric welding and electroplating, a prototype of reflective Sagnac fiber-optic current transformer (RS-FOCT), named fiber broadband high current measuring instrument, was developed and proposed. The prototype utilized the techniques including the linear birefringence suppression, the retarder temperature self-compensation, the closed-loop digital signal detection, and meanwhile implemented optimization design like flexible fiber sensing coil. Several key technical features were tested. The test results showed that the measurement accuracy of the developed prototype is superior to ±0.2% under the experimental condition, the scale factor errors under the changes caused by the temperature, vibration and magnetic field variation, are all less than ±0.2%. Frequency response at 1kHz is attenuated by 0.14%, and the -3dB bandwidth is wider than 10kHz. The accuracy reliability and serviceability in high current online calibration of the measuring instrument were verified. The model’s extended uncertainty of measurement error is 0.10%, the accuracy grade of the measuring instrument is in accordance with 0.2 grade.
2020 Vol. 41 (8): 989-996 [Abstract] ( 297 ) HTML (1 KB)  PDF (1800 KB)  ( 381 )
997 A New Time Domain Measurement Method for Characteristic Impedance of Coaxial Transmission Line Terminated Load
LI Jun-feng,YANG Gui-feng,HUANG Hui
DOI: 10.3969/j.issn.1000-1158.2020.08.17
Accurate measurement of characteristic impedance of coaxial lines is widely researched since it is as microwave impedance and scattering-parameters standard. A new time-domain measurement method terminated load is proposed to measure the characteristic impedance of coaxial lines. The measurement results can be traced to the physical parameters such as geometric quantity. The method proposed can be used as a standard for measuring characteristic impedance of coaxial lines, which validity verification values En<1.
2020 Vol. 41 (8): 997-1001 [Abstract] ( 287 ) HTML (1 KB)  PDF (827 KB)  ( 209 )
1002 Research on Multi-population Multi-objective Particle Swarm Optimization Algorithm Based on Velocity Communication
LIU Bin,LIU Ze-ren,ZHAO Zhi-biao,LI Rui,WEN Yan,LIU Hao-ran
DOI: 10.3969/j.issn.1000-1158.2020.08.18
In order to improve the convergence precision and search performance of multi-objective optimization algorithms, a multi-population of multi-objective particle swarm optimization algorithm based on velocity communication is proposed. The algorithm introduces the speed communication mechanism, divides the population into multiple sub-populations to achieve speed information sharing, improves the particle single search mode, and enhances the global search ability of the algorithm. Chaos mapping is used to optimize the inertia weight, and the particle search ergodicity and globality are improved. In order to reduce the possibility that the algorithm falls into the local optimal Pareto frontier in the late stage of operation, different mutation operations are performed on each sub-population. The algorithm is compared with NSGA-Ⅱ, SPEA2, AbYSS, MOPSO, SMPSO and GWASF-GA state-of-the-art multi-objective optimization algorithms. Experimental results show that the solution set obtained by this algorithm has better convergence and distribution.
2020 Vol. 41 (8): 1002-1011 [Abstract] ( 291 ) HTML (1 KB)  PDF (581 KB)  ( 735 )
1012 Symbiosis Multi-population Particle Swarm Optimization Algorithm Based on Velocity Communication
ZHAO Zhi-biao,LI Rui,LIU Bin,ZHOU Wu-zhou
DOI: 10.3969/j.issn.1000-1158.2020.08.19
In order to improve the accuracy and the search performance of the particle swarm optimization algorithm, symbiotic multi-population particle swarm optimization algorithm based on velocity communication(SMPSO) was proposed.The whole slave population was divided into multiple sub-populations by using the speed communication mechanism for the global search of the solution space, and the optimal state of the slave population was sent to the master population.The master population comprehensive the slave population experience and its own experience for the local deep optimization, and the best information was sent to the slave population, establishing symbiotic relationship between the master-slave population and achieving full search of the solution space.In the latter part of the iteration, the master population was combined with the adaptive mutation strategy, increasing the ability of the algorithm to jump out of the local optimum.The proposed SMPSO algorithm was applied to the benchmark function and compared with other improved PSO algorithms.The experimental results showed that the SMPSO algorithm has great improvement in solving accuracy and search ability.
2020 Vol. 41 (8): 1012-1022 [Abstract] ( 314 ) HTML (1 KB)  PDF (1423 KB)  ( 221 )
1023 Simulation and Analysis of Factors Affecting Diagnostic X-ray Energy Spectrum
Lü Ya-zhu,GUO Bin,LI De-hong,Shabiha Tuerxun,ZHANG Xuan
DOI: 10.3969/j.issn.1000-1158.2020.08.20
The spectral distribution of diagnostic X-rays is affected by several different factors. In order to further understand the factors that affect the diagnostic X-ray energy spectrum, and thus provide a technical basis for evaluating the differences in diagnostic results caused by the characteristics of the optical machine, a physical model of the diagnostic X-ray machine was established through simulation. Simulation calculation and comparison diagnosis X-ray light machine under different tube voltage, emission angle, filtration material, ripple and other conditions of the output energy spectrum. The output energy spectrum of diagnostic X-ray light machine under different tube voltage, emission angle, filter material and ripple were simulated and compared. The results of the analysis showed that tube voltage, emission angle, filtration material(including thickness), tube voltage ripple all affect the ray energy spectrum distribution and effective energy. The above-mentioned main parameters of the diagnostic X-ray machine may directly affect the reliability of the diagnosis results, and attentions should be paid to the selection of parameters and quality control during the operation of X-ray machine.
2020 Vol. 41 (8): 1023-1026 [Abstract] ( 384 ) HTML (1 KB)  PDF (899 KB)  ( 726 )
1027 Estimating the Uncertainty of China Primary Standard Seawater
ZHANG Chuan,LUO Yan,YU Tao,ZHAO Hong
DOI: 10.3969/j.issn.1000-1158.2020.08.21
As a certified reference material, uncertainty is an important quality reference index of China primary standard seawater. The method of IAPSO SSW's uncertainty definition and GB/T 15000.3 "Directives for the work of reference materials(3)—Reference materials—General and statistical principles for certification" were considered as references. Fixed value uncertainty, homogeneity uncertainty, long-term stability uncertainty were analysed one by one. Take the data of batch P1 as an example, the conductivity uncertainty of the three above components are 5.00×10-6, 5.05×10-6 and 4.50×10-6. The combined standard uncertainty and expanded uncertainty are 8.42×10-6 and 1.7×10-5. According the law of uncertainty propagation, obtained the expanded uncertainty of salinity is 6.6×10-4 (or 0.001) .
2020 Vol. 41 (8): 1027-1032 [Abstract] ( 290 ) HTML (1 KB)  PDF (472 KB)  ( 291 )
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