• Volume 40,Issue 9,2017 Table of Contents
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    • >Research&Design
    • Simulation study of capacitance imaging sensor based onCOMSOL software

      2017, 40(9):1-5.

      Abstract (1367) HTML (0) PDF 2.14 M (1792) Comment (0) Favorites

      Abstract:The difficulties in the simulation analysis of capacitance imaging sensor are discussed in this paper, using the eight electrode capacitance imaging sensor as an example, three dimensional finite element simulation mathematical model of capacitance sensor is established, this paper introduces how to use COMSOL software for three dimensional simulation of capacitance imaging sensor,postprocessing results show that the eight electrode capacitance imaging sensor can detect the defects in the inner surface of the glass with seven different depths, the feasibility of capacitance imaging detection technology is verified. In addition, COMSOL is used to extract and analyze the capacitance value of the eight electrode capacitance imaging sensor, and the results are compared with the experimental results. This method is convenient for the research on the problem of capacitance imaging detection technology, and provides the basis for the performance analysis and parameter optimization of the capacitance sensor using COMSOL software.

    • Energy harvesting surfaces in complex electromagnetic environments

      2017, 40(9):6-9.

      Abstract (1557) HTML (0) PDF 2.29 M (2067) Comment (0) Favorites

      Abstract:In order to harvesting electromagnetic(EM) energy effectively in the complex electromagnetic environment, a novel metasurface is proposed, whose unit consists of eight open resonant loops and is arranged in a regular octagon, with the addition of a parasitic patch of regular octagon. Eight resonant rings with the same opening are arranged in rotation, and the inner parasitic patch is used to form a central symmetrical structure. A novel electromagnetic energy collecting surface is designed, which has multifrequency and polarizationinsensitive working characteristics. The microstructures of the metamaterials are analyzed and optimized by the microwave simulation software CST. The electromagnetic energy collection efficiency, the energy distribution and the S parameters of the incident electromagnetic waves are studied. The simulation results show that the maximum collection efficiencies of 82%, 79%, 61%, 71%, 70% and 73% at five frequencies of 5.75, 6.5, 6.84, 7.56, 7.98 and 8.55 GHz when the electromagnetic waves are incident vertically ;In the 0° to 60° at 20° interval oblique incidence, the surface of the TE wave and TM wave can maintain an effective collection efficiency.

    • Design andimplementation of smart homelock’s gateway confi guration tool

      2017, 40(9):10-13.

      Abstract (1152) HTML (0) PDF 1.99 M (2168) Comment (0) Favorites

      Abstract:According to the development of the smart home market, intelligent locks have been applied to thousands of households. As a communication bridge between the mobile terminals and intelligent locks, thegateway’s progress of configuration is of great important. However, there isn’t a mature software in the market. And the process of traditional gateway configuration is not only complex, but also operated difficulty by nontechnical people.In order to solve this problem, the gateway configuration tool is designed for mobile terminalswhichis based on the intelligent lock’s gateway and the Android mobile platform. And it can not only simplify the process of gateway configuration, but also can be applied to the product testing of gateway produced by enterprises. The test results show that this softwarehas achieved the expected goals and is easy to install, easy to operate, easy to expand, and also has a good market promotion.

    • Evaluation of performance designs on EMAT

      2017, 40(9):14-19.

      Abstract (1251) HTML (0) PDF 2.69 M (2523) Comment (0) Favorites

      Abstract:It described the mechanism of ultrasonic wave excitation in EMAT (electromagnet acoustic transducer), mathematical expressions of oscillation amplitude solution of ultrasonic wave in polarisation process and transduction efficiency. EMAT physical prototypes were established and multiple comparative tests based on echo magnitude were designed to investigate influence factors including excitation coils with different geometry, electromagnetic induction intensity and liftoff distance. Then, based on the test results, the corresponding influences of core functional component design on EMAT test performance were analyzed, and the test efficiency and EMAT application range in different materials were compared. Test results show that the assembly of functional components and optimization of parameter factors can improve the test performance of EMAT, which provides the basic technical reference for EMAT optimal performance design and engineering test solution.

    • Image monitoring based on vehicle mobile platform

      2017, 40(9):20-25.

      Abstract (1086) HTML (0) PDF 2.49 M (1666) Comment (0) Favorites

      Abstract:At present, reverse image system and traveled recorder are the main functions in image monitoring of vehicle terminal, which can’t keep up the steps of development of internet of vehicles. This paper proposes a set of image monitoring project based on vehicle mobile platform. The vehicle mobile platform established implements data acquisition, data storage and remote communication, which combine image monitoring with mobile internet to realize cloud storage and remote monitoring. And data are fused from image monitoring system, vehicle CAN bus and GPS to achieve the intelligent emergency assistance. The actual result indicates that the system is stable and effective, and meet the needs of user in vehicle image monitoring.

    • Simulation and research on state feedback decoupling additional PI control strategy

      2017, 40(9):26-30.

      Abstract (975) HTML (0) PDF 1.81 M (1860) Comment (0) Favorites

      Abstract:In order to overcome the inherent shortcomings of traditional cascade speed control low power factor and high energy loss, a voltage type PWM cascade speed control system based on state feedback decoupling additional PI was proposed.The mathematical model of voltage type PWM inverter was deeply analyzed, and the mathematical expressions of the state feedback decoupling additional PI was derived in detail.In addition the chopper circuit IGBT selection of the speed current double closed loop PI control, the control chart of the system was obtained. Finally the simulation was proceeded by the MATLAB/Simulink software. The results proved that the control strategy not only had good dynamic and static characteristics, but also could achieve the purpose of improving power factor, reducing harmonic and saving energy.

    • Simulation of rolling aattitude measurement based on PLL

      2017, 40(9):31-35.

      Abstract (1390) HTML (0) PDF 3.04 M (1773) Comment (0) Favorites

      Abstract:To real time monitor the Rolling Rate and Phase of high spin projectile in flighting,general measurement method is difficult to meet the engineering requirements,this paper presents a geomagnetic sensor based phaselocked loop tracking loop measurement method. The rolling measurement model of PLL with different order is established by SIMULINK, determine the appropriate loop filter order and integraldump time, complete the realtime measurement of the rolling rate and phase. Simulation results show, 2nd order phase PLL in highspin roll measurement, there is a large tracking error and tracking more slowly in phase tracking; 3rd and 4th order phase PLL can tracking effectively to carry the frequency and phase of geomagnetic sensor signal, thereby calculating the high spin rolling speed and phase, it has a higher application value.

    • Multi channel master slave power supply system design and test

      2017, 40(9):36-40.

      Abstract (1507) HTML (0) PDF 3.30 M (1591) Comment (0) Favorites

      Abstract:Power supply system in high energy physics experiments is an important part of the electronics readout system. In addition to, the characteristics of high energy physics experimentsrequest the power supply system that not only has the fundamental capacity of output voltage and current but also has the capacity of multichannel output, flexible structure, resisting a dose of radiation and low output noise.In view of this, this paper aims to design a masterslave power supply system with 16 output channels.The power supply system is consisted by two identical power board cascaded by differential Ⅰ2C bus, master and slave board are automaticallydefined by way of controller and power supply board connection.Each positive output channel haslatchup during power up, the output voltage current threshold setting and monitoring, overcurrent protection, and other functions.Test results show that the power supply system can realize the automatic identification of masterslave board, output voltage, output current and low output noise can meet the requirements of design.The power supply system has good application and reference value in the high physics experiments.

    • Design of data intelligent remote transmission system based on mobile terminal

      2017, 40(9):41-44.

      Abstract (1186) HTML (0) PDF 1.74 M (1881) Comment (0) Favorites

      Abstract:According to the characteristics of industry information collection and transmission in the background of industry application, intelligent remote transmission system based on mobile terminal are studied. The management and transmission of industry data is researched and the application layer between the mobile terminal and the server is designed on the base of TCP/IP with the help of Socket communication. By developing the data exchange format, transmission format and transmission content, the effective interaction between the handheld terminaland the server is realized. Preliminary application shows thatthe system has a low packet loss rate and high speed during the data transmission and it is suitable for wireless transmission of industry data. It provides the framework for the industry of wireless transmission and meets the development requirements of the wisdom city. It has some versatility and scalability.

    • Optimization of axial flux permanent magnet synchronous generator

      2017, 40(9):45-52.

      Abstract (1134) HTML (0) PDF 3.27 M (2343) Comment (0) Favorites

      Abstract:In this paper, the method of Taguchi method is used to determine the polearc coefficient and width of coilside, which are the main parameters that affect the fundamental amplitude and the total harmonic distortion of the noload voltage of the axial flux permanent magnet generator. The winding factor with harmonic of electromotive force (EMF) of generators was deduced in the case of considering the flux density with harmonic. The winding factor with harmonic can be controlled by the optimization of the width of coilside and polearc coefficient. By the maximum amplitude of the fundamental harmonic of the EMF and the minimum total harmonic distortion (THD) as the optimizing goal, the optimization scheme of the match between polearc coefficient and width of coilside was found by the response surface methodology, and the optimization results was proved by finite element analysis (FEA) results. After optimization, the performance of the generator was improved obviously, the reliability of the optimization methodology applied in axial flux permanent magnet machine was proved.

    • Research on the traffic sign recognition based on Android terminal

      2017, 40(9):53-57.

      Abstract (941) HTML (0) PDF 3.43 M (1647) Comment (0) Favorites

      Abstract:Through the preliminary simulation and the Matlab simulation experiment based on the color and shape of the traffic sign detection method, the traffic mark detection method based on machine learning is proposed and realized. Because the traffic signs in the natural scene often have complex background, the traffic detection method based on machine learning can more accurately identify the traffic signs under the natural scene. Through the Android NDK technology, the C ++ language image processing program can be crosscompiled into the dynamic link library, which can be called in the Android side by the Java program to solve the problem that the commonly used computer vision library on the Android platform provides incomplete interfaces and incomplete data. The road traffic sign recognition algorithm is applied to the Android system platform, and the related function test is carried out.

    • Advanced data association algorithm based on FP-growth

      2017, 40(9):58-64.

      Abstract (1150) HTML (0) PDF 1.60 M (1739) Comment (0) Favorites

      Abstract:With the current data collection capacity and storage capacity greatly enhanced, the importance of largescale data mining analysis more and more important. However, the analysis of largescale data mining is not an easy thing. Therefore, in order to be able to more efficient analysis of these data, many new algorithms and data structures are gradually introduced to the data mining analysis. This paper is based on the correlation analysis, based on this article, proposed a called advanced frequent pattern mining (AFPM) algorithm. This algorithm is based on the prefrequent pattern tree (PFPtree) to improve the performance of association analysis and provide the corresponding algorithm to implement the association analysis based on this data structure. It is proved that this new data structure is superior to FPgrowth algorithm in association analysis problem through a large number of experimental data.

    • Construction for power meter condition inspection function

      2017, 40(9):65-70.

      Abstract (1022) HTML (0) PDF 3.50 M (1879) Comment (0) Favorites

      Abstract:With the popularization and application of both intelligent watthour meter and electricity information acquisition technology, their running monitoring means are greater substantial leap than the traditional watthour meters, in order to make remote monitoring for the running state of the watthour meter possible. With the help of information system platform, such as electricity information acquisition system, marketing business application system and measuring production scheduling (MDS), data collection can be successfully achieved, integrating effectively with data for I, II, III type metering device, and establishing a comprehensive evaluation based on measuring device database. By combining the evaluation results with the onsite inspection strategy, the state of watthour meter can be realized to judge, so as to guide the work inspection, and get the running state comprehensive evaluation in time. Identifying the fluctuation of metering device in advance, nipping in the bud is just around the corner.

    • Design and implementation for measuring operational monitoring in SGCC Anhui

      2017, 40(9):71-77.

      Abstract (1022) HTML (0) PDF 6.88 M (1980) Comment (0) Favorites

      Abstract:A new reformation of the electric power system is about to begin due to both sellingelectricity open policy and electricity market competition challenges. With the existence of government supervision, social regulation standards and users higher expectation, the requirement that the power supply of openness, fairness and justice is becoming more and more strict. With the largely promoting application of intelligent watthour meter, measuring business operations will be more and more frequent, risk gradually increases such as increasingly complex metering management work, work errors and anomalous index. Based on measuring operational monitoring construction need, combined with the measurement professional construction situation and the existing marketing information achievement, a comprehensive requirements of analysis metrological operations monitoring, measuring the whole business centralized supervision and management, providing strong technical support and guarantee to the company in order to improve big marketing system.

    • Load auto matching system for microgrid consisted of new energy

      2017, 40(9):78-81.

      Abstract (1395) HTML (0) PDF 1.87 M (1721) Comment (0) Favorites

      Abstract:With the development of distributed generation by new energy, it extended the type of using energy and eased the energy shortage. But the absorption problem of gridconnecting of new energy is still not solved effectively. Affected by weather, the fluctuation of the output of the new energy will be harmful to the stability of grid. This paper provides a method of load auto matching system which can adjust loads through opening or closing heaters, following the running condition of new energy system and loads. It is aimed to solve the absorption problem and increase the stability for the microgrid consisted of new energy in island or remote area.

    • Simulation and study of photovoltaic power system based on collecting and distributing type inverter

      2017, 40(9):82-87.

      Abstract (1563) HTML (0) PDF 3.03 M (2140) Comment (0) Favorites

      Abstract:In this paper, the photovoltaic grid power generation system is introduced in detail firstly, including the MATLABSIMULINK simulation of photovoltaic cells, and the analysis of its output characteristics. And then a scheme which is based on 1 MW photovoltaic grid power generation system, applies the collecting and distributing type inverter system to replace the traditional centralized inverter system and the set of string type inverter system is put forward. Multichannel MPPTs are adopting directly to track the maximum power point near the photovoltaic modules. And after direct current is boosted to 800 V, then is invertered centrakized into 520 V AC in the inverter rooms, and it is connected to the state grid finally. This system reduces the line loss during the DC/AC transmission and the inverters’loss, and improves the efficiency of the whole system.

    • >Theory and Algorithms
    • Research on the techniques for tracking algorithm of BD2 with high sensitivity based on Kalman filter

      2017, 40(9):88-94.

      Abstract (1412) HTML (0) PDF 3.78 M (2030) Comment (0) Favorites

      Abstract:In order to improve the ability of the tracking loop to filter out noise , a Kalman filter estimation algorithm is proposed to track the signal in high dynamic or weak signal environment steadily. Firstly, the influence of noise on the tracking loop is analyzed. The theoretical design basis of the Kalman filter estimation algorithm is discussed, and the adaptive Kalman filter tracking loop is designed from the aspects of loop structure, model establishment and optimization design. The experimental results show that the positioning performance and accuracy are improved greatly compared with the traditional tracking loop in both static and dynamic scenes.

    • Packetlength adaptation for improving the energy efficiency in public network

      2017, 40(9):95-98.

      Abstract (954) HTML (0) PDF 1.75 M (1914) Comment (0) Favorites

      Abstract:With the development of wireless mobile network, 3G and 4G technologies are more and more mature nowadays. In the case of public network, it has been a very important part to use RTU (remote terminal unit) for data exchange in our daily lives. Data communication is the main energy consumption part during the whole transmission process. As the main the communications parameter, packet size directly affects the RTU energy consumption. In order to save energy and extend battery life, this paper proposes a packet length adaptive algorithm ASPSA(adapted simultaneous perturbation stochastic approximation) based on SPSA, which can calculate the most effective payload length and obtain the most optimal packet length. The results of theoretical analysis, simulation and spot tests show that the algorithm aroused in this article can improve the energy efficiency of wireless data transmission terminals greatly.

    • Direction of arrival estimation method based on MIMO in automobile antiscratch radar

      2017, 40(9):99-103.

      Abstract (1093) HTML (0) PDF 2.23 M (1666) Comment (0) Favorites

      Abstract:Automobile antiscratch radar is designed to avoid scratches with the front car. The radar system estimates the cross range between two cars by estimating DOA of the wave reflected by front car. In our radar system, the front car is described by a distributed source model as algorithms based on the assumption of the point source model will seriously deteriorate. We propose an algorithm that estimates the central angle and angular extension of distributed sources in MIMO system unlike most existing algorithms which are on the assumption of point source model. Assuming that the car width is known, we are able to estimate the cross range between two cars. Theoretical analysis and computer simulation show that this method is not only effective but also has good estimation accuracy.

    • Controller design of power system with timedelay based on parameterization

      2017, 40(9):104-110.

      Abstract (1603) HTML (0) PDF 3.98 M (1629) Comment (0) Favorites

      Abstract:In order to eliminate the harm to the modern power system, in this paper, the design of the dynamic output feedback controller of the power system with time delay is researched. timedelay. Firstly, a specified transformation of the closedloop system with free matrices and correspondent construction of LyapunovKrasovskii functional are introduced, by which the stability criterion of power system with timedelay. Then, the parameterization of controller is used to establish the design condition in terms of LMI with respect to all parameters of controller and LyapunovKrasovskii function. The conservatism caused by nonconvexity in the existent results is relaxed by using the methods. Finally, the simulation results show that the dynamic output controller has a certain timedelay insensitive and improve the stability of power system.

    • Speed and rotor position estimation of sensorless PMSM based onMRAS

      2017, 40(9):111-115.

      Abstract (1561) HTML (0) PDF 3.29 M (1566) Comment (0) Favorites

      Abstract:In order to solve the problem of high cost,mounting volume increases,low reliability,being susceptible to interference and difficult to apply in a complex application environment caused by the traditional mechanical,there is find a new method based on the model reference adaptive (MRAS) control theory to estimate the rotor position and speed. Mathematical model of PMSM,speed closedloop control method and current sensorless control technology was studied. PMSM itself is considered as reference model and the stator current equations is considered as adjustable model containing variable speed. Adaptive law is designed based on Popov stability theory. As the result of the simulation proved that MRAS has a high estimation accuracy,good tracking performance,stable steadystate speed,good dynamic and static performance,and strong robustness towards speed variations and load disturbance of PMSM,this control is very simple and effective.

    • Coupling analysis of printed circuits based on nonuniform FDTD hybrid algorithm

      2017, 40(9):116-120.

      Abstract (1460) HTML (0) PDF 2.92 M (1461) Comment (0) Favorites

      Abstract:Printed circuit usually makes up of microstrip lines ,circuit elements and other parts of fine structures.using traditional FDTD method to simulate the electromagnetic interference of PCB board irradiated by Electromagnetic wave will lead to low computation efficiency due to a large amount of grids .In this paper,a novel hybrid algorithm in FDTD is proposed,in which the Nonuniform FDTD method and multi grid lumped element FDTD method are integrated together.As an example, the coupling problem of microstrip circuit with lumped elements excited by electromagnetic pulse is simulated and it is observed that the Transient voltage and current response of lumped elements can be rapidly obtained.Then the correctness of the hybrid method is verified with comparing with the simulation results of electromagnetic software based on the finite integral method.Finally the influences of types of electromagnetic pulses and the space between microstrip lines on the electromagnetic coupling of the printed circuit are analyzed.

    • >Information Technology & Image Processing
    • Error resilience algorithm for SAR image transmission based on SPIHT coding

      2017, 40(9):121-127.

      Abstract (1087) HTML (0) PDF 5.86 M (1543) Comment (0) Favorites

      Abstract:Synthetic aperture radar (SAR) systems produce large amounts of data which needs to be compressed and transferred. SPIHT compression algorithm performance superior, but the coded images have fragile visual quality when transmitted across the noisy channel. An errortolerance mechanism is necessary. An errorresilience algorithm called LL coefficients hiding (LLCH) for transmission of synthetic aperture radar (SAR) amplitude compression images in noisy channel is presented. The proposed method partitions data based on the coding process after the set partitioning in hierarchical tree (SPIHT’s) coding process, to ensure that the decoder can resynchronize after the error occurs. The most significant low frequency and sublow frequency coefficients are embedded into the end of high frequency data packets to achieve the purpose of protecting the important coefficients. For the high frequency coefficients of damage or loss, linear interpolation is used to recover the coefficients rely on the correlation between subbands. The experimental results show that the algorithm can effectively improve the quality of the restored image under the tiny redundancy cost.

    • Document image calibration recovery algorithm based on Hough line detection and two dimensional perspective transformation

      2017, 40(9):128-131.

      Abstract (1470) HTML (0) PDF 2.40 M (2495) Comment (0) Favorites

      Abstract:I In order to solve the current document image transform are random, document object edge detection and pattern transfer accuracy problem, leading to poor document image scanning, this paper from the perspective transformation of Hof line detection and two dimensional point of view, the author presents a document image and twodimensional scanning Hof line detection based on perspective transformation. First of all, according to the clustering segmentation and morphological processing, we get the two value image which contains the target of the document. Then, based on the linear detection of Hof, the linear coordinates of the document edges are calculated, and the contour of the two value image is coupled. Finally, the transformation matrix, the affine transformation and the rigid body transformation are used to construct the twodimensional perspective transformation matrix, and then the image coordinates are redistributed to achieve the purpose of image correction and conversion. The experimental results show that compared with the current scanning mechanism, this paper has a higher accuracy and antijamming performance. The proposed algorithm has good correction and recovery quality, and has important application value in the field of twodimensional code recognition

    • Research of mechanical metercharacter locating and segmenting algorithm based on image processing

      2017, 40(9):132-135.

      Abstract (998) HTML (0) PDF 1.89 M (1804) Comment (0) Favorites

      Abstract:Mechanical meter image recognition is a kind of new technology in meter reading field, it works by installing image acquisition device in front of meter. In order to solve the problem of low efficiency and high consumption of current technologies, we propose TMMSER (template matchingmaximized stable extremal regions) that based on template matching. TMMSER extends MSER(g) algorithm into twodimension algorithm, TMMSER (g, s), which using gray value and special template as parameters. TMMSER is more rapid by excluding the background noise interference.

    • Machine learning methods based on universal distance measurement for image classification and clustering

      2017, 40(9):136-140.

      Abstract (1157) HTML (0) PDF 1.98 M (1444) Comment (0) Favorites

      Abstract:In this paper, a new method for image feature extraction is proposed based on the image classification recognition problem. Firstly defining the complexity of the image string and the universal image distance (UID), and then proposing a UID distance measurement algorithm to measure the general image distance, a prototype selection algorithm for selecting the image prototype under the inherent difference between the maintenance feature categories, a feature vector generation algorithm to generate the eigenvector of the image to be classified by using the prototype selection algorithm to create the feature vector of the image to be classified, and finally an image classification learning algorithm to separate the region of interest of the image based on the aforesaid algorithms. The proposed method is applied to several supervised and unsupervised learning experiments of satellite image data. The results show the feasibility of the proposed method.

    • Adaptive rate switch algorithm based on HTTP streaming

      2017, 40(9):141-145.

      Abstract (1317) HTML (0) PDF 2.27 M (1574) Comment (0) Favorites

      Abstract:Dynamic adaptive streaming over HTTP (DASH) has been widely used in the video transmission. With the limited client buffer and varying network, this paper proposes a new adaptive bitrate switching algorithm based on the client buffer. The proposed algorithm divides the client buffer into several buffer levels and uses sliding window to analyze the download time of recent video segments in order to maintain the media buffer size in the balance interval. The algorithm uses a conservative strategy when switching to bit rates upwards, and when switching down, the logistic equation is used to determine the magnitude of the bit rate switching. In addition, this paper also proposed a fast start strategy, in which download rate could match the network bandwidth quickly after the system starts. Experiment results show that the proposed algorithm can make full use of bandwidth and buffer ,and reduce the number of rate switching in complex network environment.

    • Solving algorithm of sparse coefficient based on feature extraction matrix

      2017, 40(9):146-150.

      Abstract (688) HTML (0) PDF 1.56 M (1716) Comment (0) Favorites

      Abstract:On the basis of the compression sensing algorithm, this paper proposes to train a projection matrix in the process of dictionary learning algorithm, through which the method can obtain the sparse coefficient directly. The dictionary training process is based on the KSVD dictionary learning algorithm and is compared with the traditional L1 norm solving algorithm. It can be seen from the experiment that the method has more rapid and higher recognition rate than the traditional L1 algorithm using greedy method. The algorithm can solve the coefficient term directly through the matrix operation, while the latter is an NP problem, which needs to be solved by the iterative algorithm. For the large sample test, the proposed algorithm has better application space, and the time of saving will very noticeable.

    • >Communications Technology
    • Signal to noise ratio estimation algorithm at low signaltonoise

      2017, 40(9):151-154.

      Abstract (899) HTML (0) PDF 1.95 M (1946) Comment (0) Favorites

      Abstract:For problem that performance of classic SNR estimation algorithm is poor. Maximum likelihood amplitude estimation algorithm is improved in this paper. It used method of bisection and steepest descend iterative search method to improve the parameter estimation accuracy and reduces the SNR estimation bias. Simulation results show that within the scope of set SNR,two iterative search algorithm performance better than ML estimation algorithm, and steepest descend iterative search method with less number of iterations.

    • MQAM signal recognition based on diversity reception technology and ALRT algorithm

      2017, 40(9):155-158.

      Abstract (954) HTML (0) PDF 2.44 M (1490) Comment (0) Favorites

      Abstract:The high order MQAM (multiple quadrature amplitude modulation) signals are analyzed by the ALRT (average likelihood ratio test) algorithm in aeronautical communication. It proposes a ALRT algorithm based on the receive diversity technique, and progresses the recognition performance. The simulation results show that, the recognition performance of ALRT algorithm based on the receive diversity technique is better in taxi scenario. Susceptible to signal to noise than channel and the fading of the 16QAM signal modulation recognition performance is also greatly improved, in addition, when the signaltonoise ratio over 10 dB, based on the ALRT algorithm for multi antenna diversity reception MQAM signal the correct recognition rate basically reached 100%.

    • Research onlow power network protocolapplied to centralized meter reading

      2017, 40(9):159-162.

      Abstract (759) HTML (0) PDF 1.64 M (1768) Comment (0) Favorites

      Abstract:With therapid development of wireless communication technology, the threemeter (water, electric, gas) centralized meter readingbased on intelligent community networking technology is further mature.The current protocol does not consider the requirement of centralized meter reading whichneed lowerfrequency and power consumption. Based on AODV(Ad Hoc ondemand distance vector)routing protocol, a method named DEAODVwhich is based on the distance between nodes and the energy of node is proposed in this article. By combining the two factors, the transmission path of the message is reasonable selected as well as save the packet cost and improve the link lifetime.The theoretical analysis and experimental simulation show that the proposed DEAODV algorithm can effectively save the message overhead and improve the link life cycle in the application of threemeter centralized meter reading.

    • >Data Acquisition
    • Study on the acoustic insitu measurement techniques for determining temperature field around seafloor hydrothermal vents taking into account the refraction compensation of sound waves

      2017, 40(9):163-168.

      Abstract (756) HTML (0) PDF 6.96 M (1678) Comment (0) Favorites

      Abstract:This paper presents the basis of acoustic method used for temperature field measurement of seafloor hydrothermal vents. Study on the refracted propagation path of sonic waves in seafloor nonuniform temperature field with Fermat’s theory and by variational calculation, and is numerically calculated in the model’s temperature field. Experimental research is performed to exactly rebuild the temperature fields around hot springs on floor of Lake Qiezishan, Yunnan. The accuracy of time of flight estimation has been improved based on the technique of bending compensation of propagation paths of acoustic signal. At the same time, by comparison with two temperature fields, the max absolute error, the max relative error and the root mean square error are given. It shows that the bending compensation of propagation paths of acoustic signal technique can be applied to temperature field measurement detector around seafloor hydrothermal vents. It also has a good accuracy.

    • Helicopter transient electromagnetic occam inversion and software development

      2017, 40(9):169-173.

      Abstract (951) HTML (0) PDF 3.19 M (1683) Comment (0) Favorites

      Abstract:Helicopter transient electromagnetic system (HTEM) is an important tool for geophysical prospecting and detection in complex and harsh environment. The spatial sampling is dense and there is large amount of data to be interpreted. Taken the consideration of computing time, 1D inversion is mostly used in practical. This paper focuses on the HTEM system fixed with large circular transmitting loop, and develops Occam inversion for such system. In order to improve the computation accuracy, this paper derives Jacobian’s matrix in analytic way. A software for HTEM’s Occam inversion is developed to cater to the needs in field test. It can achieve data preprocessing and data inversion after selecting the receiver point. This software has a satisfying result when applied to the field data inversion.

    • Efficient and automatic communication experiment platform based on MATLAB

      2017, 40(9):174-179.

      Abstract (1048) HTML (0) PDF 2.67 M (1348) Comment (0) Favorites

      Abstract:As communication technology develops, the digital communication experiment platform is facing the challenge in operating efficiency and processing speed. Using MATLAB as the central control unit, this platform controls the signal transmitter, the signal receiver and the digital power source by exclusive communication interfaces written for the experimental instruments involved. Digital signal processing is completed in MATLAB. The programmable instruments and software are unified in this platform to complete the tasks of modulation, emission, reception, demodulation, data acquisition and process monitoring, which are key parts in digital communication. The experimental platform can improve the automation and efficiency of communication experiment system. The open software system allows users to develop new functions further according to the different conditions.

    • Study on the performance of reconstruction algorithm of compression acquisition for the mechanical vibration signals

      2017, 40(9):180-185.

      Abstract (1272) HTML (0) PDF 1.62 M (1641) Comment (0) Favorites

      Abstract:The compression acquisition of mechanical vibration signals can break through the limitation of ShannonNyquist sampling theorem, this method will turn sampling of the signal into the sampling of the information, which effectively solve the problem of traditional sampling methods to generate huge amounts of data as well as does not cause the loss of information. Reconstruction algorithm for vibration signal is a very important part of this technology, it directly affect the reconstruction accuracy of the vibration signal. However, some present typical reconstruction algorithms are universal, it is necessary to do a systematic research on the recovery effect of the mechanical vibration signal. The adaptability analysis of four typical reconstruction algorithm orthogonal matching pursuit(OMP), stagewise orthogonal matching pursuit(StOMP), basis pursuit(BP), gradient projection(GP) is systematically carried out for the reconstruction of the mechanical vibration signal, mainly in two aspects of the reconstruction precision and the reconstruction time. Simulation experiments show that OMP algorithm has low complexity but it is not suitable for the recovery of mechanical vibration signal; StOMP has a faster computing speed and is very suitable for solving large scale problems; Complexity of BP is high, solving speed is slow, but the reconstruction precision is very high; GP has very fast computing speed, but the reconstruction accuracy is poor.

    • SSVEP phase extraction based on HilbertHuang transform

      2017, 40(9):186-192.

      Abstract (1269) HTML (0) PDF 3.75 M (1292) Comment (0) Favorites

      Abstract:Steady state visual evoked potential (SSVEP) has been widely applied in brain computer interface (BCI) systems and brain’s cognitive research, phase feature is one of the important characteristics of SSVEP. Aiming at the uncertainty principle constraint of the fast Fourier transform (FFT) in SSVEP phase extraction, a phase extraction method based on HilbertHuang transform is proposed. In this method, the electroencephalogram signal is decomposed into a series of intrinsic mode functions (IMF) by empirical mode decomposition, and the mean value of the instantaneous frequency of each modal function is analyzed to determine whether the IMF component belongs to noise. Filtering the noise IMF components to get the electroencephalogram IMF components, on which is performed Hilbert transform to obtain the phase of SSVEP by operating with reference signal. Compared with FFT phase extraction, the experimental results show that the proposed mothed can extract the phase information of SSVEP while removing the noise components. It also has better accuracy, precision and adaptability.

    • Comparative study of DKSVD and SVM in magnetic flux leakage identification of rail cracks

      2017, 40(9):193-196.

      Abstract (1163) HTML (0) PDF 1.88 M (1427) Comment (0) Favorites

      Abstract:In order to solve the problem of defect identification in magnetic flux leakage testing, DKSVD dictionary learning method is introduced. By means of OMP algorithm and SVD algorithm to optimize the dictionary and the sparse coefficient, the optimal dictionary is constructed, and then the constructed dictionary atoms are combined to represent the data of the test set. The experimental results show the feasibility of the dictionary learning method in magnetic flux leakage signal recognition. And compared with the SVM algorithm, the DKSVD algorithm achieves better results.

    • UDP data transmission apply in space scientific experiments

      2017, 40(9):197-200.

      Abstract (717) HTML (0) PDF 1.82 M (1510) Comment (0) Favorites

      Abstract:As there are more and more space scientific experiments, the amount of experiments image data to be transferred have become increasingly large and the realtime transmission requirements are also increasing. Therefore, it is very necessary to design a new type of data transmission to meet realtime and highspeed transmission of data in space scientific experiments. This paper designs a system bases on UDP highspeed data transmission, the hardware platform bases on the spacegrade FPGA chip APA300 and industrialgrade Gigabit Ethernet chip 88E1111 as the core; The portability of the system is improved by using FPGA logic resources to design data receiving logic module and data sending logic module with packaging data in accordance with UDP protocol. The rate of the system is effectively improved by using UDP data transmission technology. The experiments show that the transmission speed can reach 864 Mbps, it can meet the space scientific experiments with a large amount of data transmission.

    • Hardware implementation of high efficiency video coding(HEVC)intra prediction

      2017, 40(9):201-205.

      Abstract (692) HTML (0) PDF 2.39 M (1417) Comment (0) Favorites

      Abstract:In order to meet the realtime requirements, an intraprediction parallel design architecture based on field programmable gate array (FPGA) is proposed. Through the parallel architecture to reduce the operation latency, through the lookup table to simplify the reference pixel selection process, through the prediction unit to reduce the computation and hardware implementation complexity. The experiment code is written in Verilog HDL, simulated with Modelsim SE 10.1a, and integrated on the Xilinx Virtex6 XC6VLX760 FPGA. The results show that the prediction of the 32×32 block requires 570 clock cycles. At 100 MHz clock frequency, the video frame sequence with 60 f/s (frame/s) and resolution of 1 920×1 080 can be encoded in real time.

    • >Embedded Technology
    • Method and implementation offixed MAC address in Android system

      2017, 40(9):206-209.

      Abstract (875) HTML (0) PDF 1.27 M (1319) Comment (0) Favorites

      Abstract:In recent years, Android system as a good open source system is widely used in various scenarios. But because of the diversity and nonnormality of hardware devices, many hardware devices will change MAC addresses every time they start. In view of the above problems, proposing a method to fix the MAC address with the software at the bottom of the Android system. This method saves a MAC address to a file through script at the first time of the system startup. The system obtains the saved MAC address every time it starts and configures it on the network card, so as to realize the purpose of fixing the MAC address. The experimental results show that the proposed method can realize the function of fixed MAC address, and it has the advantages of reduced production cost and simple realization method.

    • High speed counter in PLC based on FPGA

      2017, 40(9):210-215.

      Abstract (1308) HTML (0) PDF 3.44 M (1449) Comment (0) Favorites

      Abstract:This paper introduces the PLC highspeed counting module based on FPGA design. The core counting part of the module is finished by FPGA, and then the CPU reads the counting result throughinterface of the SPI. The response delay will only be affected by the FPGA internal clock delay and external configuration circuit. The highspeed counting module can implement frequency counting, pulse counting, coding count and other different scenarios of the counting function and achieve high accuracy of high frequency pulse count and improve the realtime responsiveness.In addition the module has 8 differential digital outputports which can be controlled by the count results.

    • Design of RSS main controller based on small RTOS51

      2017, 40(9):216-222.

      Abstract (916) HTML (0) PDF 3.93 M (1483) Comment (0) Favorites

      Abstract:A down hole main controller based on MCU is designed for RSS tools (rotary steerable system).The detailed functions of the main controller, the selection ofMCU, hardware design, and the software design based on RTOS (Realtime Operation System) are introduced. The module utilizes ADUC845 which has a C51 core, and an embedded RTOS,SMALL RTOS51, which is suitable for C51 MCU, is transplanted to implement all the functions needed with proper design of the thread tasks and semaphores. The realtime performance meets the requirement too. Experiments and field applications have proved that this main controller can guarantee steady and stable control of the RSS tool in harsh downhole environment,which proves it has brilliant application prospects.

    • >Sensor and Non-electricity Measurement
    • Development of tire semi finished extrusion parts on line detection system

      2017, 40(9):223-227.

      Abstract (729) HTML (0) PDF 2.99 M (1583) Comment (0) Favorites

      Abstract:The introduction of existing tire semifinished extrusion parts(TSEP) online detection methods and the analysis of advantages of point and line scanning method based on laser ranging technology are made. The system is mainly composed of twodimensional(2D) laser sensors, coordinated controller, industrial computer and the selfdeveloped software of data acquisition and process, analysis and recognition. Based on analysis of demand for TSEP and 2D laser sensor detection mechanism, a reasonable detection coordinate system is constructed, which can measure the TSEP contour size. At the maximum speed of 50 m/min and sampling frequency for 16 Hz, sampling distance can realize as low as 52 mm, width can be accurate to 0.5 mm and thickness can be accurate to 0.1 mm, which can meet the anticipation and thoroughly change the offline testing lag, preventing unqualified products from entering next procedure.

    • Design of hangar temperature and humidity monitoring system based on WSN

      2017, 40(9):228-233.

      Abstract (1049) HTML (0) PDF 2.94 M (1298) Comment (0) Favorites

      Abstract:High temperature, humidity and salt fog answer for most corrosion on airborne equipments deployed near coastline. Maintenance methods at present time are subjective and inefficient. Constructing distributed Realtime temperature and humidity monitoring system is important for scientific maintenance. After comparing several types of airport monitoring systems, considering distribution of air crafts and special restriction on sensor cable, new monitoring system based on WSN was brought forward. With the assistance of NIWSN products, the new system could merge wireless and wired network and was applicable to airports with various scale and form under various climatic conditions. It has the advantages of low energy consumption, less wire layout, strong software and hardware expandability. It can provides quantitative reference for accurate moistureproof maintenance work. It has an important significance to achieve the required maintenance and the airborne equipment intact rate.

    • Temperature monitoring for cubicle type substations equipment of photovoltaic power station based on FBG sensors

      2017, 40(9):234-237.

      Abstract (893) HTML (0) PDF 2.07 M (1706) Comment (0) Favorites

      Abstract:Aiming at the heat problem for cubicletype substations, based on FBG sensing technology, an online realtime temperature monitoring system is designed, and it realized the remote temperature monitoring at 11 positions inside cubicletype substation including the transformer, transmission cable connector and box shell. The temperature data all daylong well reflected the temperature variation of the monitored points; what is more, the results can be used for the development of early warning system for facilities protection. Compared with the traditional measurement methods, it has the advantages of insulation, high voltage resistance and antielectromagnetic interference, and it can be applied on temperature monitoring in different electrical environment.

    • Discuss of the method of linearly extending the calibrated value of cup anemometer

      2017, 40(9):238-240.

      Abstract (925) HTML (0) PDF 1.10 M (1504) Comment (0) Favorites

      Abstract:At this stage because most areas of the wind tunnel hardware and software conditions are limited , accuracy of 30, 40 and 70 m/s wind speeds for AWS wind speed sensors can not be verified, so that the accuracy and reliability of high wind speed data can not be guaranteed in these areas. In order to solve this problem, In this paper, the method of linearly extending the test data of low wind speed section to high wind speed section is proposed. Based on the physical principle of the threecup wind speed sensor, the feasibility of the method is proved by theoretical analysis and experimental verification, So as to solve this practical problems. The method provides a strong theoretical basis for making new test specification of the wind speed of Automatic meteorological station.

    • >Online Testing and Fault Diagnosis
    • Fault diagnosis of mine ventilator based on AGA optimized RBF neural network

      2017, 40(9):241-245.

      Abstract (861) HTML (0) PDF 1.58 M (1451) Comment (0) Favorites

      Abstract:Aimingat the problem that RBF neural network have a slow convergence speed and the diagnostic accuracy is low when applied to fault diagnosis, a fault diagnosis method of mine ventilator based on Adaptive genetic algorithm optimized RBF neural network is proposed.Using adaptive genetic algorithm to optimize the number of hidden layer nodes,the center and width of hidden layer function, and the generalization ability of network is improved.Through a large number of collection and finishing work to form a sample set,using the training sample set to train the network,make fault diagnosis of mine ventilator according to the network output results.The simulation reveals that compared with RBF neural network, the RBF neural network optimized by adaptive genetic algorithm has a faster convergence speed and less number of iterations. It can effectively identify the type of failure, and it has a higher accuracy of fault diagnosis.

    • Design of multi parameter monitoring and control system based on PLC

      2017, 40(9):246-251.

      Abstract (1287) HTML (0) PDF 3.14 M (1365) Comment (0) Favorites

      Abstract:In view of the current problems in the scale of chicken farms, such as the complex environment, the large number of monitoring parameters, the poor realtime monitoring capability and the low degree of automation of control equipment, A multiparameter monitoring and control system based on programmable logic controller (PLC) was designed to monitor the environment of the scale chicken farms in real time. The sensor transmitted the collected information to the PLC via the RS485 bus, After treatment and sent to the host computer, The host computer carried on the analysis, the processing, the storage to the data which transmitted, and carried on the comparison with the hypothesis value, The corresponding control instruction was sent to the PLC, Control the ventilation system and other related control equipment start and stop. Experimental results show that, The system operates stably, Rapid response, The temperature, humidity and ammonia concentration can be well detected and the related equipment can control these parameters in the appropriate range, To ensure the healthy growth of broilers, with a certain value of market promotion.

    • Design of cable insulation automatic test system used in spacecraft thermal test

      2017, 40(9):252-256.

      Abstract (1146) HTML (0) PDF 2.83 M (1508) Comment (0) Favorites

      Abstract:In order to detect the insulating property between the spacecraft thermal test external heat flux simulator and spacecraft, the heating cable insulation resistance automatic test technology is studied. a heating cable insulation resistance test system based on PXI bus is developed. The input channel switch device of heat cable is designed through relay matrix technology, the cable multiple core channel scanning and the insulation resistance measurement is reached through PXI bus technology,ant the control software is developed through VC++6.0. The test result shows that the system can detect the insulation fault of eight heating cables quickly and reliably, and greatly improve the automatic level of spacecraft thermal test.

    • Method of circuit power supply automatic

      2017, 40(9):257-261.

      Abstract (726) HTML (0) PDF 3.42 M (1255) Comment (0) Favorites

      Abstract:This article is aiming at complex test characteristics and working process of the circuit, make full use of the hardware and software of the computer and test equipment capability, using GPIB interface technology for device interconnection, implements a set of power supply automatic on electric power system. The computer can control many powers to realize circuit's poweron and off .Also the time interval of power can control by compute. Rely on the computer control of the equipment, reduce the complexity of the tester operation, improve efficiency, and effectively avoid the wrong operation to achieve the results of automatic measurement.This method has been used in several projects, and the results show that this method is more efficiency and reliability.

    • Application of CCD and auto focusing technology in the ship borne measurement and control antenna calibration telescope

      2017, 40(9):262-264.

      Abstract (776) HTML (0) PDF 1.74 M (1488) Comment (0) Favorites

      Abstract:This paper expounds the shortcomings and shortcomings of the traditional standard telescope by analyzing the principle and structure of the traditional standard telescope. The application of CCD and autofocusing technology in the telescope of the antenna is measured, and the CCD and autofocusing technology are analyzed and demonstrated. After the transformation is completed, the feasibility of the experiment is verified. Finally, the retrofit of the new telescope and the traditional standard telescope bin calibration methods and data for comparative analysis. The experimental results show that the improved new telescope has the characteristics of high calibration precision and convenient operation, and realizes the high precision focusing control function of the remote control telescope.

    • Field detection device for DC charging pile power metering module and its traceability

      2017, 40(9):265-270.

      Abstract (1215) HTML (0) PDF 1.79 M (1599) Comment (0) Favorites

      Abstract:In order to calibrate DC power metering modules in the electric vehicle charging pile in the field, developed a field detection device based on source and meter integration design. In the device, the power source module and the standard power metering module shared a set of transducer. In the device, voltage was measured by precise resistance voltage divider, current was measured by zero flux current transformer. In the zero flux current transformer, measuring sensitive parameter for feedback regulation was second harmonic component, which was extracted by secondorder filter and 2 stage amplifier. Designed a distributed synchronous traceability scheme. Evaluated uncertainty of calibration result. The results of calibration and evaluation indicate that the measurement accuracy is most high in the typical charging condition, and satisfy demand in the other charging condition.

    • HHT feature extraction of human pulse signal

      2017, 40(9):271-274.

      Abstract (1354) HTML (0) PDF 1.99 M (1802) Comment (0) Favorites

      Abstract:Characteristic parameters related to cardiovascular is contained pulse signal,certain reference information for the initial detection of cardiovascular is provided by extracting and analyzing the characteristic parameters of pulse signal. HilbertHuang transform is used to extract the timefrequency feature of the pulse signal in this thesis,including preprocessing and feature extraction in two aspects. Pulse signal is preprocessed by wavelet soft threshold denoising, the denoised signal is carried out by empirical mode decomposition and HilbertHuang transform to attain Hilbert spectrum and marginal spectrum. Physiological characteristic of pulse signal is analysed by Hilbert spectrum and marginal spectrum, which has guiding significance to the determinion of health status of the human pulse.

Editor in chief:Prof. Sun Shenghe

Inauguration:1980

ISSN:1002-7300

CN:11-2175/TN

Domestic postal code:2-369

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