Editor in chief:Prof. Sun Shenghe
Inauguration:1980
ISSN:1002-7300
CN:11-2175/TN
Domestic postal code:2-369
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Tang Yongcong , Liu Tao , Zhang Fangfang
2017, 40(12):1-5.
Abstract:In the process of load disturbance, the traditional electronic virtual lineshafting control strategy had a great error in the speed and position of motors due to the time lag of the virtual elastic torque feedback, which leads to the decrease of the quality of the produce. Aiming at this problem, It proposes an improved ELS control strategy. In this strategy, the sliding mode observer is designed to load torque, the observed load torque feedback to the virtual machine and feedforward compensation in realtime; in order to reduce the position error of motors, the integral term is introduced in the virtual machine unit. Simulation results show that the improved ELS can improve the ability of paper transmission unit to deal with the load change, and effectively reduce the speed and position synchronization error of motors, and has a certain practical value.
Dai Xiaochen , Zhang Fengdeng , Zhang Yuhui
2017, 40(12):6-10.
Abstract:With the rapid development of the electrification of vehicles, Xbywire technology has been a major subject in the field of automotive electronics research. To build up an appropriate brakebywire system model, it has greatly significance to improve the system safe, reliability and strengthen the realtime and also push the progress on the research and design level of the brakebywire system. In the braking process of brakes, For hardware and software, there are five FlexRay communication nodes, including designation of PCB, hardware circuit debugging, designation of software and using of the experimental car’s platform to execute the order whether the car can brake smoothly. Experiments show that the brakebywire system can satisfy the national standard of braking performance requirements to ensure the system running safely and reliably.
Wu Yaohu , Zhang Jianqiang , Wu Haozhen
2017, 40(12):11-17.
Abstract:To solve the problem of calculating the transient temperature field of motor under steady load, taking the small enclosed structure of the asynchronous motor as the research object, the calculation of heat source in the motor electromagnetic field model is established by finite element methods, the corresponding temperature field model is established according to the characteristics of enclosed structure, the combined calculation of electromagnetic field and temperature field is realized by means of multifield coupling, attached to the model parameters related to the electromagnetic field and temperature field and the coupling parameters of the joint calculation, through doing combined calculation of electromagnetic field coupling temperature field properly, realizing the calculation of each transient temperature field under steady load. Through the actual system test, comparing between the global temperature field experiment of the motor under steady load and simulation results, multifield coupling calculation method can realize the calculation of the motor whole transient temperature field under steady load reliably.
Change Li , Zhi Qiuying , Liu Shuai
2017, 40(12):18-21.
Abstract:The quality of phase unwrapping is an important part of 3D reconstruction in grating projection. After the phase modulation of the deformed fringes, The folded phase needs to be unwrapped throughout the region ,which affects the result of 3D reconstruction of the measured object. Aiming at the problem that the phase unwrapping method based on discrete least square cannot get the correct expansion results in the case of interference, so put forward using ranks expansion method to improve the discrete cosine least square method, reducing the error in the process of phase unwrapping. The result of simulation and experimental show that the method improved can raise the quality of phase unwrapping, which is of practical significance to improve the accuracy of 3D reconstruction.
2017, 40(12):22-28.
Abstract:According to the business requirements for the meteorological satellites data acquisition and automatic batch preprocessing, a new scheduling mechanism on acquisition and preprocessing of meteorological satellite data based on observer pattern is proposed and implemented, and the overall architecture of the system is designed. The results of application test prove that the design is simplified and the degree of coupling is reduced, the robustness of the system is enhanced, and can meet the performance requirements (flexibility, reliability and timeliness). It realizes the automation of acquisition, transmission, preprocessing and dissemination of meteorological satellite data, and the monitoring interface is in good visualize and can be manipulated easily, providing effective and continuous meteorological observation data for scientific research.
Ji Hui , Li Zhijian , Chen Xiaogang
2017, 40(12):29-32.
Abstract:According to the existing defect parameters of traditional PID, such as: the difficulty of controlling the parameters and poor dynamic performance, the radar servo system based on FuzzyPID controller is proposed. According to the requirement, FuzzyPID controller is designed to combine traditional PID control with Fuzzy control. Through MATLAB software for radar servo system based on FuzzyPID controller in simulation experiment, compared with the traditional PID control method, FuzzyPID control significantly increase the rapidity and stability of the radar servo system, effectively improve the dynamic performance of servo system.
2017, 40(12):33-37.
Abstract:While the Android mobile platform is developing rapidly, a remote control system for small mobile robot based on Android is designed to solve the problem of the lack of flexibility of traditional robot control terminal. The system is composed of three parts: small mobile robot, wireless communication module and Android platform. The video transmission and data communication are realized through the LAN between the upper terminal and slave machine. The overall control architecture is given, and the realization of the system hardware and software is illustrated in two aspects. System tests show that the Android mobile terminal can control the state of the robot remotely, and successfully receive the realtime video returned from robot, which is displayed smoothly. The system has a good stability and reliability.
Tang Xi , Li Wenhai , Li Ruifeng , Wu Zhongde
2017, 40(12):38-42.
Abstract:In order to test and repair a kind of airborne radio compass, a design method of universal radio compass signal simulator based on DDS IP core is proposed. Firstly, the format and characteristics of the radio compass signal are discussed. Then, the DDS IP core in the FPGA is used to synthesize the conformal radio compass simulation signal. The host computer software is developed on the Lab Windows / CVI platform to realize the humancomputer interaction function. User can set easily and flexibly on the output signal frequency, azimuth and modulation coefficients and other parameters. Finally, the design of the radio compass antenna signal simulator was tested with the oscilloscope. The test results show that the parameters can meet the design requirements, the hardware structure is compact, the FPGA logic resources are saved, and the control is more flexible.
Zhang Suli , Li Yiyan , Yang Wenjuan , Huang Kai , Tian Xuelong
2017, 40(12):43-48.
Abstract:This paper reports a protable microfluid device with Bluetooth controller, which is conventi and lowcost. The theory of droplet actuation is electrowettingondielectric actuation. The device is made up of controller subsystem, highvoltage driver subsystem,bluetooth subsystem, software. The performance of our system is proved by testing the velocitory of droplet. The speed can reach 50 mm/s, when the droplet volume is 3 μL. This paper can help microfluidic chip used easily and widly.
2017, 40(12):49-53.
Abstract:Recent trend in the power distribution system is showing that the use of nonlinear loads and devices will take a rising profile in days to come. This introduces harmonics in source side currents which improves the power quality. In this paper, the use of a non harmonic detection method, so as to improve the accuracy of the compensation is no longer affected by the load current detection accuracy, control of output current waveforms using an optimized quasi proportional resonant controller. On the bases of shunt active power filter main circuit structure, the optimal control strategy of the quasi proportional resonant voltage current loop control and current ratio of negative feedback. Finally, through MATLAB/Simulink simulation results of the proposed control strategy, the proposed control strategy is feasible through the simulation experiment are fully verified.
Zhang Tong , Zhou Zhimei , Zhao Dongyan , Zhang Haifeng
2017, 40(12):54-58.
Abstract:We propose the design of DMA controller for 32bits low power SOC system, which expedites transfer of unaligned data through onthefly reassembling bytes by hardware circuit, requiring fewer resources, power and no extra software overhead. Although user configures the transfer of unaligned data in byte format, the DMA controller can automatically reorganize bytes in proper way, so as to transfer data in word format correctly and faster. Verification shows the design can evidently improve transfer efficiency of unaligned data. The design method has been applied to a MCU chip for electricity information acquisition system, and assists software to deal with encryption and decryption, to form communication frames, etc. The results show that the DMA controller works with high efficiency while easy to use, so the design meets the requirements.
Yang Kang , Shen Wenhui , Lin Jiahong , Ren Fang , Fan Di
2017, 40(12):59-63.
Abstract:A hetpa-band antenna design for the mobile phone of metal casing has been proposed. The antenna can operate at 800~960 MHz, 1 710~3 000 MHz, for 2G, 3G, and LTE bands. To guarantee the performance of the antenna, Ushaped slot is etched on the metal casing. By taking a feed matching capacitor and a switch circuit, the proposed antenna is capable of covering GSM850/900 (824~960 MHz), DCS/PCS/UMTS2100(1 710~2 170 MHz), LTE2300/2500(2 300~2 700 MHz), hetpaband. The outside dimension of the phone is 152 mm (length)×72 mm(width)×6.8 mm (height), a 7 m×67 mm area is excised at the top edge of the system board. The antenna prototype is fabricated and measured, and it has good radiation performance. For the 824~960 MHz, the radiation efficiency from 38% to 46%. For 1 710~2 700 MHz, the radiation efficiency is from 38% to 64%. It is appropriate for the application of mobile phone with metal casing.
Zhang Guozhong , Liu Feng , Li Wei
2017, 40(12):64-67.
Abstract:In this paper a waveguide to stripline transition structure for Kaband is proposed. In this designs, waveguide to stripline transition are realized in multilayer circuit board, which are coupled and matched through elliptical slots and two elliptical metal patches . The proposed structure is designed by software and the backtoback transition is simulated, fabricated and tested. The measurements of the designs exhibit that the input and output return loss less than -10 dB and the insert loss less than 1.2 dB between 32.3 and 38.3 GHz. The results show that this proposed structure has a good performance , the structure is simple and the processing is convenient and so on. All this indicates the structure has a good applicable worthiness in microwave circuit designs.
Jian Duanduan , Chen Dawei , Yuan Xiuhua
2017, 40(12):68-74.
Abstract:The purpose of this paper is to standardize steps, conditions, influence factors and matters need attention in UHF passive RFID chip testing, which help to make a decision in standard drafting. By investigation into the need and present research situation of domestic UHF RFID chip, we summarized the experimental requirements of RFID chip’s performance evaluation. “UHF passive RFID chip testing methods (draft)” is formed by working with several RFID design teams, which the first domestic UHF RFID chip test for comparison is based on. The results show that the read sensitivity performance of domestic chip can be less than -13 dBm in high and low temperature conditions, write sensitivity less than -11 dBm, and maximum power larger than 20 dBm, which still need to be improved to compare with international mainstream technology. Based on further analysis on test results, the standard test methods summarized in this paper can be used to evaluate the performance of the chip, and can be used in design, manufacture and application effectively.
Liu Zhen , Chen Wanmi , Xiong Qi
2017, 40(12):75-81.
Abstract:The installation error of odometer, accidented and smooth ground environment are the main reason which influence the positioning accuracy of odometry of robot. In order to solve this problem, the system error model was defined by UMBmark check algorithm first; Then an identification algorithm based on the measured data from gyroscope which inside in the robot was put forward, which can identify the nonsystematic error that caused by the robots when they move in a straight line. The fuzzy neural network(FNN) model was established by the input of given control and data of odometer, which can correct the serious positioning and direction error that resulted from nonsystematic error. The effective of this approach was proved by the strive robot of Shanghai University finally.
Yan Feng , Du Tengfei , Mao Jianhua , Liu Xuefeng
2017, 40(12):82-87.
Abstract:This paper improvesan analysis model ofstock text sentiment orientation based on stock emotion dictionary and LDA. For the problem of the incomplete stock dictionary and the unilateral analysing of sentence, this paper constructs a relatively complete stock emotional dictionary, and analyses the emotional tendency of stock text from the three aspects of the tendency, the degree and the correlation of sentence. This paper builds a more complete emotional dictionary by introducing the stock words,the degree words and the turning words. Then it extracts the sentiment words from stock text sentences after the processing. It educes the sentence tendency and degree vector from the emotional words in the sentence by the sentence algorithm, and uses SVM and K mean algorithm to classify sentence vector. The paper gets the words distribution of the topic and the topic distribution of document from the sentiment words by LDA model, and obtains the correlation of the sentence by this probability distribution. Finally it synthesizes sentence tendency, degree, correlation to obtain the sentence emotion, and acquires the emotional tendency of stock text through the sentence emotion. At last, This paper collects the text of Baidu news in the sector of the economy as the experimental material, and does experiment and compares with other algorithms. Experimental results show that the accuracy of sentence and article classification are 82.78% and 84.14%.
Nie Yong , Ye Xiang , Zhai Xuping
2017, 40(12):88-92.
Abstract:Spectrum sensing technology is one of the core technologies of cognitive radio. As the future development of wireless communication technology requires highspeed data communication, wideband spectrum sensing technology has become the focus of the current research. Wideband can’t be directly divided into occupied or idle, so it needs to be subdivided. The signal is divided into multiple subbands, and the problem of multivariate classification is transformed into binary classification problem by pretreatment. In order to reduce the complexity of the spectral sensing algorithm, a spectrum sensing algorithm based on estimation of noise(EN) and support vector machine(SVM) is proposed. The algorithm uses a slow sensing algorithm as estimation of noise and then combines it with low fast sensing algorithm for spectrum sensing. The experimental results show that the proposed algorithm has a significant improvement in the detection performance under the low SNR and can fully recognize the usage of each subchannel under SNR of -10 dB.
2017, 40(12):93-97.
Abstract:Traditional robot visual servoing control system to realize the calculation of the Jacobian matrix and the solution of the inverse Jacobian matrix, a large amount of calculation, the complex structure of the system, and realize the difficult calculation. In this paper, a six joint robot visual servoing system based on genetic neural network is designed, and genetic algorithm is used to optimize the neural network. This method not only solves the system of solving the Jacobian matrix and its inverse computation problem, and does not require the camera internal parameters and robot parameters are determined at the same time due to the addition of the genetic algorithm, to improve the performance of neural network, not only greatly simplifies the control system, improve the system speed, but also to ensure the control system precision.
Zhang Kui , Wang Jiannan , Wang Xiaofeng
2017, 40(12):98-101.
Abstract:In order to ensure the safe and efficient operation of the transformer in the power system, this paper proposes a method to fault the transformer by combining the RBF neural network with the fuzzy control algorithm.The neural network learning system with 6 layers is designed, and the fuzzy membership function is introduced into the second layer, which accelerates the learning speed of the neural network. Data Based on Transformer Faults This paper analyzes the types of faults by analyzing the internal gas content. The fuzzy RBF neural network designed by this paper is used to diagnose fault diagnosis. The diagnostic results show that the diagnostic model has better effect on the fault diagnosis of the transformer.
2017, 40(12):102-105.
Abstract:In this paper, the finite time stability for a class of discretetime switched systems with uncertainty is considered. Firstly, under the arbitrary switching signals, a sufficient condition of the finitetime stability which makes the discretetime switched system with uncertainty stability is given by constructed the Lyapunovlike function and utilized the linear matrix inequalities methods. Second, based on the given theorem,the finitetime control problem is considered, and the method of designing the switching state feedback controllers is given. Finally, a numerical example proves the effectiveness and feasibility of the proposed method.
2017, 40(12):106-109.
Abstract:Interharmonics are an important parameter of reflecting the power quality, and there are many measuring algorithms.This paper puts forward a detection method of interharmonics based on the S transform, it is a timefrequency analysis method combined STFT with CWT. Compared with STFT, the window height and width of S transform can be adjusted with frequency. Compared with CWT, phase correction is achieved and the measurement accuracy of Interharmonics is improved. The steady state signal, non steady state signal and different signal to noise ratio (SNR) signal are simulated and analyzed on the MATLAB platform. The frequency and amplitude measurement accuracy of Interharmonics is given in this paper.
2017, 40(12):110-116.
Abstract:To solve the problem of imaging ambiguity when there is random sway of ship target in inverse synthetic aperture radar (ISAR) application, a method for selecting optimal imaging time based on estimation of the Doppler centroid frequencies (DCF) and image contrast is proposed. This method calculates Doppler center from real echoes of ship target, then chooses optimal imaging time according to the change of Doppler center. After that, a definition of image contrast is given to help dealing with selecting optimal imaging time. In comparison with existing methods, the proposed one can select better period for ISAR imaging which leads to an imaging result with higher quality. The method is easy to implement and computational complexity is lower, which is suitable for realtime applications. The effectiveness of the proposed method is verified by the simulation data processing result.
2017, 40(12):117-120.
Abstract:The traditional intersection positioning formula is from the ideal model that assuming the flight target is a point. But when two thedolites observing on the same target, their principal optical axis always can not intersection in the same point, and this will cause the model system error. Therefore, in this paper, the photoelectric theodolite intersection positioning method based on fusion dynamic weighting is proposed; the model of this method and the determination principles of the fusion dynamic weighting coefficients is introduced in detail; then, using the simulation data, the positioning precision of this method and the traditional method is compared; finally, analysis of the experiments showed that, the method proposed in this paper is better than the traditional method in positioning accuracy. So this new intersection positioning method has a high value of engineering practice.
Ye Xiang , Nie Yong , Zhai Xuping
2017, 40(12):121-125.
Abstract:Cognitive radio is a new technology, which aims to achieve the user’s dynamic spectrum access and improve the efficiency of the spectrum. Spectrum sensing is the basic of cognitive radio, and spectrum sensing is used to discover the spectral holes in cognitive radio networks, which allows secondary users(SU) to communicate without causing harmful interference to primary users(PU). It requires good perceiving performance even at very low signaltonoise ratios to ensure that the perceived user communicates without affecting the primary user′s communication in spectrum sensing. This paper presents an efficient sensing algorithm based on stochastic resonance (SR) and support vector machine(SVM). Firstly, the detecting signal through the Stochastic resonance system to improve signaltonoise rate and strength the feature of signal. Secondly the FAM algorithm is used to extract the cyclostationary feature of signal. Finally, we use support vector machine to classify the feature to get the detection results. The experimental results show that the method proposed in this paper has higher detection reliability than the traditional detection method at low SNR.
2017, 40(12):126-131.
Abstract:A scheme of steppedfrequency radar that is uesd for building detection has been proposed,which solve the problem that the pulse throughthewall radar in the building layout inversion application of low resolution, the distance. The hardware platform of the scheme includes vector network analyzer, microwave RF control module, ultrawideband horn antenna and personal computer. Six ultrawideband horn antennas are arrayed by nonuniform interval, that the microwave RF control module was used to expand the channel and to achieve channel selection. LabVIEW is used to develop system software control platforms which achieves parameter configuration, data acquisition and online imaging processing. The experiments show that the system can be applied to different scenes of building wall imaging.
Li Zhiwei , Chen Xin , Xin Shangzhi , Song Xiaolan , Chen Jianbing
2017, 40(12):132-136.
Abstract:More than 5000 A circuit breaker is usually each phase by multipole structure of parallel double terminal derivation, for above 5000A universal circuit breaker normal work shows the current is significantly greater than the measured current situation, the display difference is usually more than the accuracy of the manufacture gived. In this paper, through the theoretical analysis and the actual test, Through the theoretical analysis of the circuit breaker inside and the connection between the mutual sense and selfinductance phenomenon, it is found that the impedance of each pole of the circuit breaker is not exactly the same, the value of the load current between them is not equal, there is a significant phase angle between the load currents at different poles at the same phase, the phase angle is about 32 °. Because of the mutual inductance and selfinductance between the internal and external loads of the circuit breaker, the display is larger than actual current and the difference is about 5%.
Zhao Liang , Zhu Mingming , Liu Qiming , Qu Shaocheng
2017, 40(12):137-141.
Abstract:By considering the problems of single function, a universal smart home monitoring system with multiclient, was designed and implemented based on Linux and ZigBee technology. An ARM CortexA8 microprocessor and Linux were applied as the hardware and software platform, respectively. And a ZigBee network was built by using lowpower CC2530 to collect various information of general home environment and to control them. In addition, several common remote clients compiled by Qt were designed to remotely monitor and control various appliances through TCP Socket, which can be compatible with some popular operating systems (such as Windows, MacOS, Android and iOS). The experimental results showed that the proposed system can accurately monitor and control various home appliances with short time delay.
2017, 40(12):142-147.
Abstract:In recent years, with the continuous updating of Internet technology, medical resources have also accelerated the information. Hospital information as a way to solve the shortcomings of traditional medical problems, but also received a lot of attention. This article based on modelviewcontroller design of the open hospital information management system of medical counseling website, the use of java language, mysql as a background database. Completed the system front desk design and database design, and finally tested by a certain reliability and stability.
Yin Xianhua , Chen Jingxi , Wang Qiang , Jiang Yan
2017, 40(12):148-151.
Abstract:When using terahertz timedomain spectroscopy(THzTDS) technology to perform quantitative analysis of nitrile rubber additives, the paper extending the partial least squares(PLS) to multidimensional partial least squares method(NPLS), which can solve the problem of high dimensional data modeling effectively and improve the model accuracy. To verify the effectiveness of the proposed algorithm above, PLS method and NPLS method are used respectively on sample modeling and analysis. Which obtained the root mean square error and the correlation coefficient of NPLS model is 2.04% and 0.98. While The root mean square error and the correlation coefficient ofPLS model is 2.71% and 0.97. The results show that both methods can forecast the content of some components in the mixture, but the prediction effect of NPLS model is better.
2017, 40(12):152-155.
Abstract:The temperature change has a great influence on the error of the strain measurement. Especially, the quarter bridge is widely used for large scale strain measurement, because the bridge temperature compensation can not be carried out, and the influence of temperature change is more significant. If the use of halfbridge temperature compensation for each channel, the operation is complex, high cost, low efficiency, it is necessary to analyze the error of quarter bridge when temperature changes. In this paper, by analyzing the heat output principle of ordinary strain gauges and temperature selfcompensating strain gauges for strain measurement, the influence of wires and strain gauges on temperature, then given the error of the whole measurement system under the influence of temperature when using the application of BE series ordinary strain gauges and temperature selfcompensation on multichannel acquisition system. The research solves the problem of error assessment of measurement system caused by temperature change in structural strength test, and determines the minimum value of the measured strain required to meet the 1% measurement error in different temperature range.
Zhang Meng , Li Jun , Wang Xingang , Wei Jianwei , Zhang Jingtao , Wang Shitao
2017, 40(12):156-159.
Abstract:Fiber optic current transformer (FOCT) can overcomes the disadvantage of traditional electromagnetic current transformer in transient current response, sensitivity and reliability of protective action can be remarkably improved by optimization of dynamic characteristics. The closedloop control algorithm is a main limitation to the detection bandwidth of the FOCT based on the closedloop signaldetecting scheme. The theory analysis and experiment show that the bandwidth of closedloop FOCT is greatly improved by introducing the PID control algorithm. It is of great significance for the promotion and application of fiber current transformer in smart grid protection.
Wu Qiong , Wang Nan , Qu Chaojie , Shi Keshuai , Sun Weiqing
2017, 40(12):160-164.
Abstract:Aiming at a problem of low availability of traditional photovoltaic system, taking STM32F103 whose core is CortexM3 as the system′s main chip, and taking GPS as well as4quadrant photoelectric sensor as the solar tracing device, and designed a new solar automatic tracing system. Firstly, take use of sun movement method to track roughly, then send the signal of photoelectric sensor to micro control unit after dealt with by adjust circuit, the MCU generate PWM waves to control biaxial stepper motor to adjust in the horizontal and vertical separately, so that the photovoltaic array could track the sun automatically. The experimental results show that, the control system has high tracing accuracy and operate stably and cost a litter, etc.
Jin Yanliang , Zhang Xiaoshuai , Qi Qi , Xie Qiuyun , Zhou Huyang
2017, 40(12):165-170.
Abstract:With increasing demand for indoor positioning, a lowcost inertial sensor positioning method based on PDR algorithm is favored. This paper proposed a sf relationship model on the basis of PDR algorithm . This model means step size may vary adaptively with step frequency changes. Because of PDR algorithm will inevitably produce accumulative error, this paper uses the absolute locations of WiFi signal access point to eliminate the accumulative error, while taking advantage of two adjacent WiFi signal access points to dynamically adjust the step size avoiding the influence of pedometer cumulative error. Experimental results show that this method can effectively improve indoor location accuracy.
Wei Jianhua , Qi Pan , Liu Qi , Jing Xiaoxiao , Wang Yafeng
2017, 40(12):171-175.
Abstract:In order to quickly detect the oil quantity sensor and improve the detection efficiency, a scheme about handheld oil quantity sensor of reed switch based on DSP is designed. The device adopts two wire resistance measuring method to measure the position resistance of the oil quantity sensor. By powering by dry batteries, taking the TMS320F28335 of TI as the core controller, collecting the sampling of the voltage of the sensor through the high speed ADC module in the chip of the core controller, and analyzing the sampling data, the test results are finally displayed through the 12864LCD screen. After many tests, the device can quickly and accurately detect the fault of the reed switch oil quantity sensor and can be made of the handheld. The device is stable, easy to use and easy to carry.
Mu Rimin , Li Peng , Qin Xiaonan
2017, 40(12):176-181.
Abstract:With the characteristics of high sensitivity, high repeatability, high reliability, rotary variable differential transformer(RVDT)is also extensively used in the field of aviation electrical control, and the function is more and more powerful. In this paper. According to the working principle of RVDT and the finite element analysis software Maxwell, various structural factors affecting the differential output voltage of RVDT are analyzed and the simulation verification is completed. The analysis and simulation results show that the structure parameters such as the width of the primary coil, the width of the stator slot, the outer diameter of the rotor and the outer diameter of the rotor yoke have important influence on the output characteristics of the sensor. In order to study the changes of sensitivity of output voltage on the structure parameters, the weight analysis method of orthogonal experiment is adopted and the influence of stator slot width, rotor outer diameter and rotor yoke outer diameter is relatively large.
2017, 40(12):182-186.
Abstract:For a long time,Lack of effective methods to detecting nonmetal pipeline, all kinds of conventional pipeline detection instrument which effect is not ideal.Now,a new method which based on the principle of magnetic of detection nonmetal underground pipeline is being used。In this paper,the author used the detection equipment which based on the principle of magnetic to detect some big diameters underground water pipelines of nonmetal in kunming as an example, Through rational analysis of the data processing,Good detection methods were obtained,and the paper summarizes the magnetic imaging characteristics of the nonmetal underground pipeline in this region and provides guidance method of detection for the similar underground pipeline detection.
Lin Dingjun , Zang Yuanzhang , Liu Sufang , Wang Rui
2017, 40(12):187-191.
Abstract:This paper introduced a circuit system based on USB and is designed for TDS(timedomain spectroscopy system). We can realize the measurement of time domain spectra of samples by controlling the optical delay line using this circuit system to provide bias control for terahertz transmitter, and acquire the data of terahertz detectors which then will be transformed by USB to the PC and finallywe will get the signal time domain and frequency domain signal THz through data processing.By comparison of spectrum pattern recognition algorithm and sample library, identification of objects to be measured component. The terahertz timedomain spectroscopy system can achieve the bandwidth of 3 THz, the spectral resolution is better than 10 GHz, and it can well satisfy the spectral measurement of the samples.
Dong Tan , Dang Youyun , Li Jingxuan , Zhang Cui , Luo Hui
2017, 40(12):192-195.
Abstract:Analysis the reasons for transient voltage of aviation generator, Based on the AC brushless generator principle, the structure diagram and the related mathematical model, the transient voltage signal is obtained by simulation of generator under MATLAB/Simulink environment. According to the relevant requirements of "GJB 1812003" aircraft power supply characteristics, The transient parameters such as voltage transients and frequency transients under the AC mode of an aircraft generator are determined, and the signals are analyzed and processed by using MATLAB, and to reduce the output delay further by zero phase filter of wave signal, and finally get the corresponding signal the AC voltage and frequency, compared to its envelope, to determine whether to comply with the relevant requirements.
2017, 40(12):196-202.
Abstract:Among the dimensionality reduction methods of 2D image, they often use L2 norm and L1 norm to construct the dimension reduction model, to a some extent, they realize the goal of dimension reduction. However, these methods only apply to the single norm, which is very limited. In this paper, we propose a new method, which uses Lp norm (1≤p≤2) instead of a single one. This method can construct a more generalized dimension reduction model and is suitable for all similar models. p=1 and p=2 can be regarded as a special case of this model. The proposed method is more flexible than a L1 or L2 norm and can adapt to different problems. In this paper, the objective function adopts the Lp norm of the twodimensional maximum margin criterion, and the intraclass discrete factor is defined to reduce the original data. The experiments on ORL and Yale and noise reduction databases show better robustness and efficiency.
Wang Qichao , Zhang Weiguang , Ren Yongping
2017, 40(12):203-208.
Abstract:A panoramic camera is a large field of view fast image acquisition device which uses the once imaging technique to obtain a 360 degree scene around it. In this paper, the single fisheye lens imaging model, the double fisheye panoramic camera model and the image transformation principle are studied respectively .The method of calibration of the parameters of fisheye lens imaging distortion is studied, and the correction of fish image distortion is realized. We stdudy the method of obtaining threedimensional space points by the double fisheye panoramic camera. Moreover, the mathematical model of the equivalent fisheye lens imaging data in either direction is proposed by the panoramic image data. Finally, the 3D coordinate data of the measured scenes are obtained by using the parallel axis binocular stereo vision technology. The results show that the accuracy of this method can reach 13 mm within the measurement range of 4 m×3 m×3 m.
Guo Ningbo , Chen Xiangning , He Yanhua
2017, 40(12):209-213.
Abstract:According to the data of space target surface reconstruction of TOF depth camera point cloud based on source vulnerable to the instrument itself, scanning the environment, the effect of external disturbances, invalid points and noise points and large amount, increases the computational burden and the impact of the reconstruction quality problems, this paper proposes a denoising method of random sample consensus background segmentation of point cloud based on knearest neighbor, to eliminate outliers and invalid target data. Firstly, the improved RANSAC (random sample consensus,RANSAC) algorithm, by setting different threshold of the original point cloud background segmentation, to Ensure the accuracy of extracting the main features of the reconstructed object. Then, through the Knearest neighbor point cloud average algorithm and bilateral filtering algorithm to remove outliers, finally using voxel grid method to achieve point cloud data sampling, simplified target point cloud, retains the local characteristics, to speed up the reconstruction speed. The experimental results show that the the algorithm can effectively eliminate noise, high accuracy, good realtime performance, meet the application requirements.
2017, 40(12):214-219.
Abstract:In order to solve the current moving object tracking algorithm in complex background model and target characteristics is not obvious, lead to the problem of insufficient algorithm tracking ability, this paper respectively from the feature point detection and the perspective of optical flow method, is proposed based on feature point detection and optical flow method of moving object tracking algorithm. First of all, according to the minimum image gradient matrix eigenvalue, by affine transformation, accurate feature points matching between frames, eliminate the false feature points and achieve the purpose of accurately detecting moving target feature points. Then, based on image pixel conservation principle, the deformation between two image assessments, establish image constraint equations, further precise tracking moving targets. Finally, based on the software development environment QTCreator algorithm, and system integration. Test results show that compared with the current motion target tracking technology, the algorithm has higher accuracy and stability.
Xu Yifan , Liu Aifang , Xu Hui , Huang Long , Wang Fan
2017, 40(12):220-227.
Abstract:A polarimetric SAR image classification method based on the improved threecomponent scattering model[1] is proposed. First, the method performs a deorientation operation on the polarization coherent matrix, and the orientation angle of each pixel is rotated to 0 degrees. Then, the improved threecomponent scattering model is used to decompose the target into surface scattering, doublebounce scattering, and volume scattering. Then the power scatter entropy is calculated by using the three scattering powers. According to the scattering entropy and the power of the three scattering components, an initial classification is made. Then, using Wishart iterative clustering to optimize the classification results. Finally, the results of Wishart clustering are reassessed to achieve unsupervised classification of polarimetric SAR images. The results show that the algorithm has a clear physical meaning and the classification result is easy to be combined with the actual features. The overall classification accuracy is 98.6% and the Kappa coefficient is 0.973.
2017, 40(12):228-232.
Abstract:his paper propose a new algorithm to hide information in part vertices of a 3D triangle mesh to improve the security. The algorithm first use the PCA method to analysis the 3D model and establish a unique vertex sequence. After that, to compute a seed from the mesh for the pseudorandom number generator called Mersenne twister. With the same seed, pseudorandom number generator will produce the same pseudorandom list. Than,to pick part vertices for hiding by using the pseudorandom list to index the vertex sequence. This steganography method effective reduce the accuracy of the steganalysis algorithm.
2017, 40(12):233-237.
Abstract:Considering the problem of existed pedestrians tracking method based on head detection often made mistakes during tracking in complex backgrounds, this paper proposes an improved pedestriantracking method based on head detection to adapt to a variety of complex scenarios. This method firstlyuses the foreground segmentation technology to extract the target people, and add human body negative samples in adaboost classifier which combined with the feature of haarlike to detect head, then establish headtracking chains to fulfill the tracking of pedestrians by using the gotten head. Expriments show that the improved method reduces the error rate of head dectetion and improve the correction rate of humantracking in complex backgrounds.
Gong Xue , Shen Tianfei , Wang Haonan
2017, 40(12):238-240.
Abstract:Endpoint detection based on LPC distance will first frame the signal processing, and then according to the LPC distance set threshold to determine whether each frame is the endpoint of the voice. However, it will have the following questions in the signal frame: if a larger window length is used, the total number of frames will be reduced, but the error in the endpoint detection will also increase, especially for the detection of the origin of the speech. If the frame length selection is too small, the calculation amount and the recognition speed are increased. Aiming at this problem, this paper proposes an improved endpoint detection algorithm combining the variable window length idea with the LPC distance endpoint detection algorithm. The method does not use the uniform window length in the frame, but in the quiet section uses a large window length quickly approaching the transition section. Then after the transition ,the small window length is used slowly to look for the starting point of the voice signal, the other stage is the use of conventional windows long. Simulation results show that the improved endpoint detection method proposed in this paper is superior to the other two endpoint detection methods.
Wang Peng , Rui Guosheng , Zhang Yang , Liu Linfang
2017, 40(12):241-245.
Abstract:Aiming at the problem of increasingly scarce spectrum resources in the modern digital communication system, the spectrum characteristics and error performance of continuous phase modulation signals were discuss in this paper. First of all, the general form of CPM signal with three kinds of phase pulses is presented respectively, and the power spectrum density distribution of the modulated signal is obtained. And then, based on the minimum Euclidean distance, error performance of three kinds of CPM signals is studied. Simulation results show that: the CPM signal with Gauss′s minimum frequency shift keying pulse has more prominence both on spectral characteristics and the error performance compared with the other types. In practical engineering, choose applicable phase pulse modulation method according to the objective requirement. Finally, the system can get a reasonable compromise between validity and reliability.
Wang Rui , Rui Guosheng , Zhang Yang
2017, 40(12):246-250.
Abstract:In the existing MIMOOFDM relay system, most channel estimation using the supervised channel estimation algorithm with training sequence has lower spectrum utilization. In this paper, based on the MIMOOFDM relay system and signal modeling, a channel estimation of MIMOOFDM relay system based on embedded PARAFAC model is proposed. Firstly, the KhatriRao decomposition algorithm is used to estimate the relaythe destinationend matrix, and then use the alternating least squares algorithm to estimate the sourcerelay channel matrix and the source matrix. Finally, the computational complexity and uniqueness of the algorithm are analyzed. The simulation results show that the algorithm has lower computational complexity and faster convergence rate than the trilinear least squares algorithm, and the performance is close to the traditional supervised channel estimation algorithm with training sequence.
Shang Helong , Li Hongquan , Zhou Kang , Zhang Shuyuan , Li Jun , Wang Xingang , Shi Guangyu , Wang Kang , Wang Guobin
2017, 40(12):251-256.
Abstract:The optical and electrical components of fiber optical current transformer (FOCT) are studied. The principle and structure of the system are described. By means of FMECA and FTA the reliability analysis of the system is made. Through the fault cases in practical application, the critical component failure modes of the system are determined. The fault tree of the optical unit is constructed. According to the risk priority number of failures the design weak points are determined and the improve measures are put forward. In this way the risks of critical components failure can be reduced. The fault cases of FOCT are analyzed and the validity of the system reliability analysis method is verified.
Zhang Chen , Zhang Zhihong , He Hong
2017, 40(12):257-261.
Abstract:Because the EMC characteristic of lowvoltage DC motor will affect the EMC characteristics of the vehicle, this paper will lead to the problem of reducing the safety of electric vehicle when the lowvoltage DC motor interference signal exceeds the upper limit, and study the electromagnetic emission characteristics of low voltage DC motor, including low voltage DC Motor impedance characteristics, radiation emission characteristics, transient conduction emission characteristics.The measures to suppress the electromagnetic interference are grounded, shielded, and so on. The paper studies the electromagnetic shielding technology in the background of the research on the electromagnetic compatibility of a new electric vehicle with the China Automotive Technology and Research Center.The test results show that the electromagnetic shielding can solve the problem that the electromagnetic radiation interference of the low voltage DC motor affects the EMC characteristics of the vehicle.
Liu Guangpu , Liang Ying , Ren Yong , Wu Changdao , Han Weizhong
2017, 40(12):262-265.
Abstract:The limit improvement factor of CINRAD/SA transmitter, which is the abbreviation of SA model of China New Generation Radar, is including two parts of transmitter input and output limit improvement factors. It can affect the spectrum estimation of radar echo signal and the filtering capabilities. In order to analyze and diagnose for abnormal limit improvement factor of CINRAD/SA transmitter, we introduce its principle firstly in this paper, elaborate mathematical model of minimum cut sets method, combining with the signal power and pulse envelope, then analyze the transmitter and receiver circuits which can impact the limit improvement factor, and last classify the disturbance causes of different frequency. We can find the causes for interring and provide relevant solutions in this way, give better advice and assist for radar technologists to complete test on site and the work of maintenance and service, ensure CINRAD/SA running smoothly.
Editor in chief:Prof. Sun Shenghe
Inauguration:1980
ISSN:1002-7300
CN:11-2175/TN
Domestic postal code:2-369