Table of Content

15 October 2015 Volume 28 Issue 10

  

Articles

UV Image Fusion Based on Adaptive PCNN

MA Lixin,ZHOU Xiaobo,SHAN Yu

. 2015, 28(10):  1. 

Abstract ( 552 )   PDF (708KB) ( 630 )  

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The ultraviolet wavelength that corona discharge emits is 200~400 nm.In order to avoid the interference of sunlight and fluorescent lamp,ultraviolet discharge images are acquired by using the sun-blind band from 240 to 280 nm.A visible and UV image fusion algorithm is presented for locating corona discharge.The proposed method uses spatial frequency and information entropy as PCNN linking strength values.Experimental results show that this algorithm offers better fusion results than the weighted average method,the Laplacian-based method and the wavelet-based method.

Research on Parallelism of Image Algebraic Reconstruction Algorithm

SU Ziqin,XU Boqing,SU Dongqi

. 2015, 28(10):  4. 

Abstract ( 546 )   PDF (777KB) ( 535 )  

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The algebraic reconstruction technique (ART) is proposed to reconstruct image from incomplete projection data.Using the PC cluster system,we accelerate the ART reconstruction process based on dispatching projection angle evenly to each CPU and then average all the results.Experiments show that the speedup factor is roughly equal to the number of CPU's used appropriately and that the image quality is better than those by the classical serial algorithm.

An improved SURF Algorithm by Reconstructing Feature Descriptor

SHI Peihong,DONG Shufu,SHAN Yong

. 2015, 28(10):  8. 

Abstract ( 545 )   PDF (805KB) ( 522 )  

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SURF algorithm has been extensively applied in object recognition and computer vision for its speed and well-performed robustness.To keep rotation invariance in original algorithm,Bay got dominant orientation of keypoint to which gradients were computed relatively,and this part takes considerable time.In this essay,a couple of isotropic vectors are selected to reconstruct feature descriptor to keep rotation invariance as well as computing speed by using Integral Image thereby exempting algorithm from consuming time for above operations.The test has proved that the performance of proposed method is improved almost 30% allowing for error to a certain extent.

Face Recognition Based on Fisherfaces Algorithm

YANG Aqing,HUANG Huasheng

. 2015, 28(10):  11. 

Abstract ( 539 )   PDF (741KB) ( 514 )  

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As a supervised technique,the Fisher's linear discriminant is generally applied for its simple calculation and good performance in classification.The Fisherfaces algorithm is proposed for feature extraction and minimum distance classifier is for face recognition.Experiments on ORL and YALEA face database yield recognition rates of 94.00% and 89.33%,respectively.

An Estimation Algorithm Based on the Dichotomy of LFM Modulation Slope

CUI Gang,LI Tao

. 2015, 28(10):  15. 

Abstract ( 395 )   PDF (566KB) ( 475 )  

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This paper focuses on the problem of the time consuming and poor anti-interference performance of traditional demodulate of modulation slope,the author advance a new demodulate method by using dichotomy,we first analyze the errors of the self-correlation estimation,then we use dichotomy on reasonable interval near the result,Through experiment,this mothed proofs effective and the coasting time reduce five times then the traditional demodulate.

Digital Fingerprint Coding Algorithm Based on QR Codes and Chaotic Scrambling

ZHOU Xiongkui,ZHANG Dinghui,DING Shan

. 2015, 28(10):  18. 

Abstract ( 576 )   PDF (783KB) ( 513 )  

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For efficient and accurate tracking of users in collusion,this paper puts forward a digital fingerprint coding algorithm based on the uniqueness of QR codes and chaotic scrambling binary image which can reduce the similarity between the fingerprint information.Experiments show that by setting the initial value and the coefficient of Logistic mapping,the fingerprint information plays an important role in encryption so as to improve the security of the fingerprint information;the correlation between illegal users and complicity QR code fingerprint images is higher than 80% (and the correlation for the users not involved is 70%~80%).The correlation is used to determine whether the user involves in complicity,thus effectively improving the precision of the tracking users in collusion.

Mathematical Model and Simulation Analysis of Pendulum System of Rotary Crane

JIANG Yinfang,JI Shengjie,PAN Lingyun,LIU Qiaozhen,JIANG Junjun

. 2015, 28(10):  22. 

Abstract ( 614 )   PDF (849KB) ( 525 )  

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Aiming at the lower work efficiency and security problem from load swing during rotary crane operation,this paper constructs a mechanical model of the pendulum system of rotary crane based on the relevant knowledge of mechanical analysis.The characteristics of the crane pendulum model under three movements are also analyzed with the help of Matlab.

Communication Between STM32 and Host Computer Based on Modbus Protocol

LIU Yuchen,ZHANG Renjie,LIU Hu,LIU Zhen

. 2015, 28(10):  27. 

Abstract ( 749 )   PDF (717KB) ( 581 )  

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This article designs a method for communication between PC and the STM32 based on the Modbus protocol for stepper motor control systems.The STM32 peripherals and the implementation of the Modbus protocol are introduced.The RS-485 communication circuit and the software design of the STM32 and the host computer are presented.Experiments show that the stepper motor controller and PC can exchange data by this method successfully.

Optimization of Static Segment of In-Vehicle FlexRay Network Protocol

LIU Yani,ZHANG Fengdeng

. 2015, 28(10):  31. 

Abstract ( 533 )   PDF (589KB) ( 457 )  

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An optimization model for the static segment of FlexRay network filed bus is deduced to improve bandwidth utilization and real time performance of the static segment of FlexRay communication protocol.The optimal slot length of static segment is given,the load length of static frame is cut up,and the network bandwidth utilization of static segment is analyzed.An optimal scheme for static segment is put forward to minimize the total response time.Numerical experiments verify the feasibility of optimization.

Large Capacity Data Storage and Transmission Based on NORFLASH

SONG Jiwei,CHANG Wenge,LI Xiangyang

. 2015, 28(10):  34. 

Abstract ( 506 )   PDF (829KB) ( 483 )  

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Aiming at the generation of high-speed modulation waveform in data storage and transmission,a design of large capacity data storage and transmission between NORFLASH and USB based on Virtex-6 FPGA is presented.The control interface of SLAVE FIFO and the controller of erasing,writing and reading NORFLASH are designed by using Verilog HDL hardware description language.Storage and playback verification of large data of 6Gbits are implemented between NORFLASH and USB.Test results show that the controller is stable,reliable and of good portability.

Analog Circuit Fault Diagnosis Based on PSpice and LM Algorithm

XIA Minfang,LIU Jian

. 2015, 28(10):  38. 

Abstract ( 581 )   PDF (728KB) ( 520 )  

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Fault diagnosis of analog circuit is accomplished based on LM algorithm combined with wavelet neural network.After multi-scale decomposition and normalization of impulse response signal,feature information is extracted and categorized as the neural network.The fault diagnosis method achieves efficient identification of analog circuits by combing PSpice and Matlab with significantly improved convergence and fault accuracy.Simulation results show that the network trained with sample set by this method offers better accuracy than those by traditional methods in fault diagnosis of analog circuits,and is applicable to the neural network.

Perceptual Image Hashing Based on Zernike Moment and Entropy

ZHANG Daxing,CHEN Juanjuan,SHAO Bozhong

. 2015, 28(10):  41. 

Abstract ( 489 )   PDF (729KB) ( 440 )  

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A novel perceptual image hashing based on entropies features and Zernike moments has been proposed in this paper.This approach calculates the reference orientation by Zernike moments and the entropies of equal area ring and angle as perceptual features.Then the hash sequence is generated after quantization.The Euclidean distance is used to measure content similarity in the scheme.The experimental results show that the proposed algorithm has good robustness on additive noise,JPEG compression,geometric operations and good discrimination for different images.

Workflow Process Modeling Based on Petri Nets and Its Time Performance Analysis

XIAO Zuobin,SUN Peng,ZHANG Zhihui,LI Xiaochun

. 2015, 28(10):  44. 

Abstract ( 479 )   PDF (721KB) ( 469 )  

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Workflow modeling technique has been the basis for the entire business process implementation,so selecting efficient modeling techniques for achieving actual complex business processes is particularly important.The time performance evaluation is also an important aspect in the evaluation of workflow models.Firstly,the workflow modeling techniques based on Petri nets are introduced.And then a complex process of production and operation is combined to construct a simplified and flexible model.The average time performance is analyzed using the stochastic Petri net.The results show that a complex model can be analyzed effectively and simply by the proposed performance analysis method.

Design and Implementation of Emergency Communication System Based on Ad Hoc Network

ZHU Qing,ZHANG Hengyang,MAO Yuquan,XIAO Leilei

. 2015, 28(10):  49. 

Abstract ( 562 )   PDF (962KB) ( 504 )  

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In some special fields such as military,patrol,rescue and relief,fieldwork and other emergency situations without infrastructure support,a stable and effective communication system is needed.An emergency communication system supporting real-time voice and video is designed and completed based on the Ad Hoc network,embedded system,and QT multimedia development.The optimized link state routing protocol is selected with the use of RTP,Speex and Ffmpeg to control the noise,echo and jitter of voice transmission effectively and to ensure low delay video and audio transmission with variable bit rate support.Tests show that the system is capable of fast building with support for multi-hop,broadcast and multicast and with fluent and stable message,voice and video communication.

Design of Data Transmission Interface Based on JESD204B Protocol

ZHOU Dianmiao,XU Hui,CHEN Weihua,LI Nan,SUN Zhaolin,DIAO Jietao

. 2015, 28(10):  53. 

Abstract ( 569 )   PDF (967KB) ( 571 )  

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A data transmission interface based on JESD204B protocol is realized with Xilinx FPGA GTX transceivers to solve the problem of PCB routing complexity and inter symbol synchronization in AD acquisition project.The original data and the received data from the receiving interface are compared on the simulation platform to verify the logic function of JESD204B data transmission interface.Test results show that the original data are consistent with the received data.

Design of a Wireless Telecommunications System

TU Ning,SHI Zhan

. 2015, 28(10):  56. 

Abstract ( 943 )   PDF (852KB) ( 483 )  

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The paper presents a wireless telecommunications system design based on the STM32 MCU and RS485 bus network to address the low accuracy,poor real-time performance and unstable data transmission of traditional telecommunication systems.The low-power high-performance STM32 offers rich interfaces for portable communications.The standard communication interfaces of STM32 are used to achieve a wireless telecommunications system based on the RS485 bus and the MODBUS protocol NRF24L01 wireless receiver chip.Experiments show that the error rate is about 0.015 with greatly improved reliability and stability.

Position Detection of Container Spreader Based on MEMS Sensors

XIE Yuduan,SONG Yanan,XU Ronghua

. 2015, 28(10):  61. 

Abstract ( 492 )   PDF (932KB) ( 468 )  

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According to the existing problem in position detection system of container spreader,including low handling efficiency highly cost,this paper investigates a position detection system of container spreader based on MEMS sensors.The system consists of the sensor data acquisition modules,the micro-controller and real-time dynamic monitoring.Sensor data acquisition modules contain the LSM303DLHC sensor and the L3GD20 sensor;micro-controller is STM32F303;the real-time dynamic monitoring is the PC interface.The gesture fusion algorithm based on gradient descent is analyzed.Comparison of the experimental data and analysis of the tracking monitoring interface show that the proposed system has good real-time performance,high accuracy and friendly interface.The system has been fully validated in related subjects.

Design and Realization of 3D Platform for Digital Earth Based on osgEarth

CHEN Bo,REN Qinghua,YANG Huabin

. 2015, 28(10):  65. 

Abstract ( 714 )   PDF (872KB) ( 550 )  

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The mainstream 3D digital earth platforms nowdays have compatibility problems in both data support and data management.To meet the requirements of 3D platform for digital earth,the paper makes an in-depth study of the real time terrain rendering mechanism of osgEarth and lucubrates the technical difficulties of data loading and wave simulation in the decelopment process of the platform.For the,the LOD four binomial tree model is put forward for real-time dataload and an improved Higgins algorithm is proposed for more realistic ocean wave simulation.A 3D digital earth platform for practical engineering application is developed using software component engineering.

A Moving Objects Detection Method Based on Background Subtraction

ZHANG Chuanwei,WANG Jingmei,LIN Xiaoming,ZHAO Wenjun

. 2015, 28(10):  69. 

Abstract ( 572 )   PDF (786KB) ( 469 )  

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Aiming at the failure of traditional background subtraction in the moving detection when the moving object is similar in color with the background,a complete motion objects detection method is proposed.The method selects independent thresholds for the three channels of the YUV color space to do the first detection,making full use of the image color information in the video.A second detection is performed in the smallest rectangle area that contains the first detected moving object to improve the detection accuracy effectively.Experiments demonstrate that the detection results by this method are more clear and complete than those by the traditional method.

Character Image Feature Extraction Method Based on Secondary Grid

FANG Yuling,WEI Yun

. 2015, 28(10):  72. 

Abstract ( 612 )   PDF (1218KB) ( 606 )  

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Traditional character feature extraction methods have such shortcomings as complexity,large calculating and low degree of differentiation.In order to improve the rate of license plate character recognition and overcome the presented drawbacks,this paper introduces a grid-based secondary character feature extraction method.Firstly,the normalized character images of license plate are divided into four grids and the curvature feature is extracted;secondly,the normalized character images are divided into 32 grids,followed by the extraction of the duty ratio of character pixels,center of mass,divergence,three quantitative characteristics to describe each grid.This method combines the advantages of structural feature and statistical feature.It is easier to distinguish characters which are similar in structure of strokes.What's more,it has strong anti-interference ability and enough stability.Features from 1500 different types of normalized character binary images are extracted by different feature extraction methods.The results show that the recognition accuracy of letters and numbers can reach more than 97% by the proposed method,a significant improvement over that achieved by other methods.

Real-time Ranging System Based on Stereo Vision Technology

WANG Shuai,HAN Junfeng

. 2015, 28(10):  78. 

Abstract ( 600 )   PDF (1057KB) ( 675 )  

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Real-time distance measurement is often unavailable in a stereo vision measurement system because of large amount of calculation and hardware limitation.In this paper,the key technologies of binocular stereo vision are introduced.The method of pre-calibration is used along with a fast stereo matching algorithm and optimized parameters to achieve the target real time tracking and measurement by the dynamic disparity search combined with the target tracking algorithm.Experiments indicate the low cost system has high feasibility and achieves real-time tracking and measurement of object with precision in a certain range.

Design and Implementation of a Web-based Visualization and Editing Tool for Biological Pathways

ZHU Yongnan,FANG Jinglong

. 2015, 28(10):  83. 

Abstract ( 438 )   PDF (734KB) ( 509 )  

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The biological pathway graph is a visual representation of pathways.Although there are many biological databases which provide visual analysis tools for pathways,a web-based tool for visualizing and editing biological pathway is yet available.This paper develops a web-based visualization and editing tool for biological pathways and introduces its key design technologies and system structure.This system is developed to assist researchers browsing and retrieving information,to help them understand biological processes and explore the relationship among the pathways.

Attitude Detection System Based on MEMS Sensors

WANG Tiaoli,SUN Yuguo

. 2015, 28(10):  86. 

Abstract ( 762 )   PDF (812KB) ( 694 )  

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A set of attitude detection system based on MEMS sensor is designed to obtain the angular velocity,acceleration and other information.The collected data is hardware filtered to achieve the measurement of the attitude angle of moving targets.Complementary filtering of data fusion effectively eliminates the noise interference and improves the detection accuracy of the system.The wireless module realizes the synchronous of lower computer and upper computer with real-time display of the motion attitude of the target.Experiments show that the system has high precision and good performance of real-time display.

Evaluation and Analysis of Survivability of Aviation Network Based on Pajek

LIU Dianyong,ZUO Xiaowu,ZHANG Bingbing

. 2015, 28(10):  90. 

Abstract ( 546 )   PDF (698KB) ( 492 )  

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Aviation complex network has many objects and varies from scale,and how to select the performance index of the network is a key factor on the evaluation.The performance index and survival analysis is evaluated and studied based on the complex network theory using the analysis software Pajek.Studies have shown that China's aviation network is a small world network which lacks a stable and resisting ability compared with foreign networks.

An Intelligent Water Supply System Based on Sedona Platform

SHEN Jin,WANG Yagang,CAI Jiejie

. 2015, 28(10):  93. 

Abstract ( 480 )   PDF (865KB) ( 411 )  

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This paper introduces an automatic constant pressure frequency conversion water supply system based on the Sedona platform.The design is composed of the Sedona controller 30P,the frequency converter,the pressure sensor,the I/O device,the touch screen display and other major equipment.This system uses a new automatic control technology to obtain constant water pressure by controlling the pump speed through the inverter and by adjusting the outlet pressure according to the water allowance and consumption.The system can run automatically even in case of system failure,so the water supply is guaranteed.Experimental tests show that the system is stable and can reach the target pressure quickly and accurately.

Design and Implementation of Cloud Disk Based on Ceph Object Storage Cluster

YANG Fei,ZHU Zhixiang,LIANG Xiaojiang

. 2015, 28(10):  96. 

Abstract ( 504 )   PDF (710KB) ( 562 )  

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Traditional cloud disks based on NAS storage have the disadvantages of poor scalability,low response performance,unreliable data and low security.This paper presents a design and implementation scheme based on the distributed object storage system of Ceph.The scheme can build high performance,high reliability and scalable cloud disks.The pools of Ceph storage clusters are based on the X86 server,in order to the service of object storage is published through multi-object gateway with soft load balancing to enhance the capacity of request and response in cloud disk and achieve the functions of isolation and security in object data by integrating with token-based authentication systems.Experiments show that the design and implementation scheme meets the requirements of practical application.

Research on Enterprise Task Schedule

WANG Xiu,SUN Zhonglin,JIANG Li

. 2015, 28(10):  100. 

Abstract ( 662 )   PDF (709KB) ( 510 )  

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Presently most web applications have the function of task schedule.In this paper,we study several task schedule methods based on Java implementation,including the use of JDK Timer,the implements of ScheduledExecuter and the use of Quartz for different requirements.

Design of Cold Chain Logistics Monitoring System Based on GPS/GPRS

QIN Xu,XIE Yalian,CHEN Huan

. 2015, 28(10):  103. 

Abstract ( 572 )   PDF (839KB) ( 553 )  

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A monitoring system based on GPS and GPRS is designed to solve the lack of monitoring information or poor regulation in cold chain logistics.The system consists of a vehicle terminal and a remote monitoring terminal.The vehicle terminal collects the information of vehicle location,temperature and humidity and sends the data via the network of GPRS to the remote monitoring terminal which displays the location of vehicle according to the data of longitude and latitude.The tests show that the error of temperature and humidity is less than 5% and the error of location information from GPS is less than 50 m,which meets the design requirements.

Development of Paperless Recorder HIM Based on DGUS Software

HUANG Bo,ZHOU Meijiao,ZHOU Yang,LIU Jinli

. 2015, 28(10):  108. 

Abstract ( 471 )   PDF (712KB) ( 419 )  

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The paper presents the research on paperless recorder HIM based on DGUS software.The paperless recorder has a complex HIM for its powerful function which requires intensive programming,where DGUS software is used for rapid development.Unlike the conventional LCM control display through sequential or command,the DGUS screen adopts direct variable driving display mode,in which all the display and operation are based on the preset variable configuration file saving large amount of programming with the help of PC,thus realizing rapid development.

Image Preprocessing Technology for H.264 Codec System

LI Xiaofeng,ZHANG Lijun,HU Yongchun

. 2015, 28(10):  111. 

Abstract ( 536 )   PDF (897KB) ( 406 )  

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In image acquisition,it is inevitable to introduce noise,which has certain influence on video image quality.In order to avoid noise sent into the codec system,preprocessing of collected video image is performed using median filtering technology with FPGA as the core processor component and modelsim simulation tool for verification.Results show that the preprocessing reduces video image noise with satisfying filtering effect and avoids noise transmission level by level,thus ensuring the display effect of video image.

Study of Indoor Localization Technique Based on WSN

ZHANG Xiling,SHI Weibin

. 2015, 28(10):  115. 

Abstract ( 860 )   PDF (920KB) ( 403 )  

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An intelligent barcode identification system based on the wireless sensor network is designed for long distance communication of wireless barcode scanning equipment for modern large-scale warehousing,logistics and supermarkets.The system uses CC2430 chips as the main communication chip with the CTP protocol based on the wireless sensor network operating system TinyOS to increase the distance of communication.The intelligent interface is written in the C# language to realize such functions as the outbound goods,storage,query,and smart reminder.

Fuzzy Adaptive Control of Sensorless Brushless DC Motor

WU Pingting,WEI Guoliang,WANG Yongxiong

. 2015, 28(10):  119. 

Abstract ( 522 )   PDF (833KB) ( 492 )  

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In view of the low precision and poor interference ability of the traditional PID control method,a parameter adaptive fuzzy PID integrated control strategy based on sensorless brushless DC motor (SLBLDCM) control system using back EMF zero crossing detection is proposed for a simpler system structure and faster torque response speed.The fuzzy adaptive PID control is applied to SLBLDCM control system.We establish a mathematical model of the brushless DC motor,and use the Fuzzy Toolbox and Simulink of Matlab to design the fuzzy adaptive double closed loop control system.Simulation results show that the control system runs smoothly with quick and accurate speed tracking,high control accuracy and good robustness.

Island Judging and Processing Based on Matlab and Matpower

MENG Xiang,SHEN Shudong

. 2015, 28(10):  123. 

Abstract ( 1040 )   PDF (568KB) ( 488 )  

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Island judging and processing is of great significance in power system reliability assessment.In order to improve the island judging and processing speed and accuracy,an island judging and processing method based on Matlab and Matpower is proposed.The method uses Matlab to establish the island discriminant matrix according to the nature of the islands,and then modifies the parameters in the Matpower for the Matpower to perform directly dc power flow calculation of the island system.Compared with the conventional manual calculation,this method offers higher speed as well as better accuracy and operability.

Design of a High Resolution Low Power Sigma-Delta Modulator

WEI Rongshan,CHEN Lincheng

. 2015, 28(10):  126. 

Abstract ( 444 )   PDF (689KB) ( 501 )  

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A Sigma-Delta modulator applied in the audio and sensor is proposed in this paper.The proposed modulator is implemented in the single loop forth order one bit CRFF structure.A fully differential switch capacitor circuit is used to reduce the even order distortions and the noises from substrate and power,and chopping is applied to reduce the offset and the 1/f noise,to improved the precision and reduce the power consumption.The whole circuit is based on the Global foundries 0.18 μm CMOS technology with a supply voltage of 1.8 V,an OSR of 128,and a sampling frequency of 5.12 MHz.Simulation results show that SNR of the modulator can reach 100.2 dB,while the power dissipation is merely 380 μW.

Design and Implementation of Short Wave Receiver Portable Antomatic Test Platform

WANG Yibo,LI Man,LIU Yunjiang,LIU Yujun

. 2015, 28(10):  130. 

Abstract ( 409 )   PDF (819KB) ( 497 )  

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A portable automatic test platform for short wave receivers is developed to save the need for various test instruments and complicated operations.This modulation RF signals production and analysis audio signal on this test platform are described.The test results show that the error is less than 0.1%,which meets the needs of test indicators of short wave receivers.

Design of an IEEE 1500 Wrapper for ALTECC_DECODER IP Core

WANG Jianxi

. 2015, 28(10):  134. 

Abstract ( 556 )   PDF (687KB) ( 441 )  

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IP core improves the efficiency of the integrated circuits.But the different functions of IP core embedded in integrated circuits require sophisticated test for the reuse IP core technology.IEEE Std 1500 provides a implementation mechanism for IP core test.This paper discusses the Wrapper design based on IEEE 1500,then takes the Hamming code decoding IP core ALTECC_DECODER as the experimental subject to verify the IEEE 1500 Wrapper's efficiency.

Multiplexed Output Type Switching Power Supply Based on UC3842

WANG Yuanyue

. 2015, 28(10):  138. 

Abstract ( 575 )   PDF (609KB) ( 602 )  

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In order,a multi output switching power supply system based on UC3842 is designed for higher efficiency and stability.The reasons for choosing the chips and the requirements and principles of the main modules in power supply are analyzed.Simulation using specific software show that the switch is stable under various power outputs with an error <1% (+12 V) and an error of 2% (+5 V);the work efficiency is also significantly improved.

Design and Verification of Wideband High-dynamic Full Digital Radar Receiver Based on AD9680

XIAO Dandan,SU Shaoying,LI Tao

. 2015, 28(10):  141. 

Abstract ( 598 )   PDF (844KB) ( 502 )  

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A verifiable platform of wideband high-dynamic full digital radar receiver based on the new ADC AD9680 was designed for demands of bandwidth,dynamic,processing speed and multichannel.First,results of performance and analysis were acquired in full-bandwidth mode and DDC mode on the platform of AD9680.Solutions of AD9680 to improve dynamic performance were proposed based on the results.Then,dual-channel synchronization of AD9680 was verified and a method of optimizing dual-channel time deviation was proposed.All test results in this article showed that AD9680 would meet the requirements of certain wideband radar.

Cold Junction Compensation in Thermocouple Thermometers

HUANG Yi,ZHOU Hanyi,TAO Qingdong,LI Yun

. 2015, 28(10):  145. 

Abstract ( 460 )   PDF (707KB) ( 406 )  

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The thermocouple is one of the common temperature sensors used in thermometers.In the measurement of temperature,it is difficult to maintain stable temperature for the thermocouple cold junction,so the results need cold-junction compensation.In this paper,the cold junction temperature measured by PT1000 is sent to the MCU of the host computer after A/D conversion to convert the resistance value by software into a voltage value,which is added to the voltage applied to the thermocouple,and then the effects of the temperature change in the cold junction is eliminated by the compensation module.Tests show that the method is accuracy and stable.

Design of a Boost DC/DC Converter Based on Phase-shifted Full-bridge Technology

YANG Liang,ZHANG Qinglei,WANG Zhenzhen,WANG Chuangang

. 2015, 28(10):  148. 

Abstract ( 594 )   PDF (726KB) ( 475 )  

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This paper designs a DSP control ZVS phase shifted full bridge soft switching DC/DC boost converter.It can better achieve zero-voltage-off and increase in conversion efficiency due to the design of main converter circuit using f a phase-shifted full-bridge.The control unit adopts the DSP processor for effective real-time correction and stable output.The software control for adjusting the phase angle alpha realizes a wide range of DC output adjustment.

A New Constant-frequency Current Hysteresis Loop Control Strategy

CHEN Bin,YANG Wenhuan,WU Shuai,LIU Junfeng

. 2015, 28(10):  151. 

Abstract ( 457 )   PDF (788KB) ( 363 )  

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Hysteresis circle current control method with variable circle width of the shunt active power filter not only ensures the tracking accuracy of reference current,but controls the switching frequency of inverters effectively through adjusting hysteresis circle width in real-time according to current amplitude.Traditional hysteresis circle current control method with variable circle width is improved by adding an amplitude limiting element and a frequency feedback PI control method,which limits the abnormal current fluctuations and controls the frequency of the PWM series accurately.The Matlab simulation results show that the total harmonic distortion of the system when harmonic current is tracked and compensated by the improved method is less than the value by the traditional method.

Design of HD Camera Driver Based on DM6467T

ZHANG Lei,SHI Weibin

. 2015, 28(10):  155. 

Abstract ( 503 )   PDF (594KB) ( 432 )  

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An HD camera driver is designed based on the DM6467T chip hardware platform with VPIF interface for high definition video monitoring with support for raw format.This paper analyzes the V4L2 drive structure and designs the V4L2 core driver,VPIF interface driver and sensor driven.The program for testing driver is written,and the experimental result shows that the image data in raw format can be collected successfully.

Analysis of RMxprt in Three-phase Asynchronous Motor in the 2D Electromagnetic Field

YANG Kaichen,YANG Wenhuan,WANG Feng,JI Lili

. 2015, 28(10):  158. 

Abstract ( 477 )   PDF (812KB) ( 445 )  

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RMxprt is a design concept of simulation and calculation of various motor models based on motor equivalent circuit and magnetic circuit with the advantages of simple and fast modeling and easy parameter adjustment.The application of RMxprt module in the 2D field of three-phase asynchronous motor is discussed with a three-phase asynchronous motor as example to achieve better simulation of three-phase asynchronous motor and solution of 2D and 3D finite elements.The calculation results of experiment agree well with the FEM results with an error only of 0.366 2%,fully meeting the needs of engineering.

Nonlinear Control of Parallel BUCK Converter

LI Shaolong,JIN Aijuan,LIU Ankang,YE Fang,XU Xiangli

. 2015, 28(10):  161. 

Abstract ( 341 )   PDF (803KB) ( 347 )  

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For DC-DC converter working in the switch operating frequency,the system is prone to produce high frequency harmonics,bifurcation and chaos,reducing the stability of system.Under proper frequency and amplitude,the change of system parameters by the parametric resonance interference method can avoid chaos system bifurcation and suppress high frequency harmonics.Our study of the voltage control mode in parallel BUCK converter shows that the parameter resonance interference method can inhibit the bifurcation and chaos with improved system stability.

Design of a Constant Output Voltage DC-DC Boost Circuit

DONG Qingchen,FAN Ming

. 2015, 28(10):  166. 

Abstract ( 476 )   PDF (760KB) ( 379 )  

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A DC-DC boost converter with constant output voltage is designed to solve such drawbacks of common DC-DC boost converter as low efficiency,excessive ripple voltage and output voltage instability.The fluctuating input voltage is changed to constant DC voltage output by using the boosting circuit and the voltage feedback technique.Comparing the converter output voltage with the reference voltage,the differential of the compared value generates a PWM signal to control the switch time,thus achieving a constant voltage output.The simulation results show that the designed circuit could produce a constant output voltage of 24 V,an output power of 100 W,and a switching frequency of 20 kHz in continuous conduction mode.

Research on Brushless Motor Temperature of Power Steering System

CHEN Jin,QIAN Weikang

. 2015, 28(10):  169. 

Abstract ( 372 )   PDF (874KB) ( 385 )  

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The electric power steering system controls motor output torque by the controller ECU according to signal of the hand torque,vehicle speed senor etc.The thermal management for ECU and motor is the key to control cost and security of system.This article puts forward the distinction between fast and slow temperature rising by theoretic model to get the system's temperature increasing value in different heating conditions and the relationship between the motor current and the immediate temperature to calculate the motor temperature.Simulation and experiments show that the thermal management analysis and the design method can effectively solve the problem of the heating system and successfully realize the unification of the system cost and system safety.

Design of Monitoring Center System for Remote ECG Monitoring Based on LabVIEW

SUN Jinping

. 2015, 28(10):  173. 

Abstract ( 353 )   PDF (741KB) ( 450 )  

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Developed a software System for remote ECG monitoring,which include server and doctor client.The functions of server are receiving ECG data,storing ECG data,sending the ECG data to the doctor client,transmitting the doctor's diagnosis;The functions of the doctor client are receiving the ECG data from sever,displaying ECG data,giving the diagnosis,showing position.After the test,the software has user friendly interface and completely meets the design requirements.

Research on Polarization Modulation Effect of Optical Current Transformer Controlled by MCU

GAO Jun,ZHOU Lei,CHEN Lin,JIAO Xinbing

. 2015, 28(10):  176. 

Abstract ( 550 )   PDF (656KB) ( 410 )  

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The garnet with grooved films (Ta (50 nm)/Nd2Fe14B (500 nm)/Ta (50 nm),Ta (50 nm)/Nd2Fe14B (1 000 nm)/Ta (50 nm) grooved films) is the sensitive element of the optical current transformer.Degree of polarization (DOP) is the ratio of the light intensity of polarization section and the entire section of the light intensity.The rotating garnet controlled by MCU has no effect on degree of polarization of incident beam;however,rotating garnet with grooved films is capable of modulating the polarization of the laser beam.And DOP domain by this method is larger than that of light passing through disordered medium.The results provide a theoretical basis both for the measurement accuracy of the garnet-type photoelectric current transformer and structural improvements.

Photovoltaic Cell Model and MPPT Based on Matlab

ZHANG Yubin,ZHANG Wensheng

. 2015, 28(10):  179. 

Abstract ( 528 )   PDF (777KB) ( 345 )  

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A nonlinear variation of the output power of photovoltaic cells with the load is obvious as the ambient temperature and light intensity change.How to find the maximum power point rapidly and exactly is becoming a research hotspot.This article employs the disturbance observation method to study the maximum power point,and photovoltaic array model is established in the Matlab with an improved MPPT method.Comparison with the fixed step disturbance observation method by simulation shows that the improved MPPT method has significantly fewer iteration times with quicker determination of the maximum power point.

Assessment of Cyber-physical Systems

CHANG Min,CUI Yongjin,ZHANG Xuedian,QIN Min,CHEN Zheng

. 2015, 28(10):  182. 

Abstract ( 450 )   PDF (762KB) ( 441 )  

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Information system is introduced into traditional power system under the background of cyber physical system integration to build a new CPS system.However the introduction of information systems brings security risks while improving the reliability of the power system.A model of power system reliability assessment based on the CPS is proposed in comparison with the traditional power system evaluation model.The calculation method is also put forward according to the assessment model of the reliability.Finally the challenges in the assessment process are introduced and the whole assessment is summarized.

Research Based on Linear Regression and Realization of R Language

YANG Shanshan,WANG Songhui,SONG Dongdong

. 2015, 28(10):  186. 

Abstract ( 550 )   PDF (602KB) ( 396 )  

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Based on the actual situation of Pingdingshan Tianan distribution company,the coal density as a function of heat is analyzed by the mathematical method of regression and function approximation using the least squares method.The linear fitting model and method are given.