Review and Comment

Research progress of intelligent audio SoC analog front-end


Author:Chen Chengying

Author Affilications:School of Opto-Electronic and Communication Engineering,Xiamen University of Technology,Xiamen 361024,China

Abstract:In the application of AI speech interaction, the analog front-end(AFE) circuit in audio SoC is responsible for digitalization of microphone analog output, and it is a bridge between the analog signal and the digital processing unit. The AFE function and dynamic performance are greatly limited due to the influence of complex audio environment application, the device mismatch and other non-ideal factors. The audio SoC AFE is analyzed in this paper, and the circuit characteristics and current development is discussed in detail. Finally the research route for design challenge is presented and development trend is prospected.
Key word:
artificial intelligence
analog front-end
develop trend

Artificial Intelligence

Target searching and global path planning in UAV/UGV cooperative systems


Author:Xi A′xing,Zhao Jin,Zhou Tao,Hu Qiuxia

Author Affilications:Department of Mechanical Engineering,Guizhou University,Guiyang 550025,China

Abstract:It is difficult for a single robot to perform tasks in a complex environment, so Unmanned Air/Ground Vehicle(UAV/UGV) cooperative systems have been widely concerned. In order to improve the efficiency of UAV/UGV cooperative systems, a global path planning for UGV under the target recognized by UAV was proposed. Firstly, SURF algorithm was studied in identify targets and image segmentation was applied to build a map. Then, the optimized A* algorithm was proposed in global path planning for UGV based on the information acquired by UAV. Finally, simulations were performed in a typical rescue scenario. Experiments show that SURF algorithm can achieve the accuracy, real-time and robustness of target recognition. The optimized A* algorithm can achieve the feasibility and real-time of global path planning.
Key word:
UAV/UGV cooperation systems
target recognition
global path planning
SURF algorithm
optimized A* algorithm

Research on visual SLAM method of mobile robot based on improved ORB algorithm


Author:Cheng Yi1,2,Tong Xiaoyu1,2

Author Affilications:1.Electronic Engineering and Automation,Tianjin Polytechnic University,Tianjin 300387,China; 2.Key Laboratory of Advanced Electrical Engineering and Energy Technology,Tianjin Polytechnic University,Tianjin 300387,China

Abstract:Taking mobile robot visual navigation as the application background, an improved ORB algorithm is proposed to solve the problems of feature points unevenly distributing and too many redundant features in visual SLAM. Firstly, the scale-space pyramid of each image is meshed to increase the scale information. Secondly, feature points are detected, using improved FAST corner points adaptive extraction and setting region of interest. Thirdly, non-maximum suppression method is used to suppress the output low threshold feature points. Finally, feature points variance values based on region image is used to evaluate of distribution feature points in images. Experiments verify that the improved ORB algorithm has more uniform distribution, fewer output overlapping feature points and shorter run time.
Key word:
mobile robot
visual navigation
visual SLAM
improved ORB algorithm

Research of personalized recommendation system based on deep neural network


Author:Zi Yunfei,Li Yeli,Sun Huayan

Author Affilications:School of Information Engineering,Beijing Institute of Graphic Communication,Beijing 102600,China

Abstract:The deep neural network is similar to the biological neural network, so it has the ability of high efficiency and accurate extraction of the deep hidden features of information, can learn multiple layers of abstract features, and can learn more about cross-domain, multi-source and heterogeneous content information. This paper presents an extraction feature based on multi-user-project combined deep neural network, self-learning and other advantages to achieve the model of personalized information. This model does deep neural network self-learning and extraction based on the input multi-source heterogeneous data characteristics,fuses collaborative filtering wide personalization to generate candidate sets, and then through two times of model self-learning produces a sort set. Finally,it can achieve accurate, real-time, and personalized recommendations. The experimental results show that the model can self-learn and extract the user′s implicit feature well, and it can solve the problems of sparse and new items of traditional recommendation system to some extent, and realize more accurate, real-time and personalized recommendation.
Key word:
deep neural network
personalized recommendation
candidate set
sort set

Microelectronic Technology

Hardware modeling of GPU geometric pipeline rasterization based on UML & SystemC


Author:Chen Jia1,Tian Ze1,2,Wu Xiaocheng1,Lou Xiaoqiang1

Author Affilications:1.AVIC Computing Technique Research Institute,Xi′an 710068,China; 2.Aviation Key Laboratory of Science and Technology on Integrated Circuit and Micro-System Design,Xi′an 710068,China

Abstract:Architecture and algorithm determine the performance of GPU, and they need be verified as soon as possible. The paper brings forward a method of modeling based on UML(Unified Modeling Language), and describes the process of modeling GPU geometry engine unit architecture and line primitive rasterization algorithm in detail. Model and simulation are implemented in SystemC language. The model verifies the correctness of architecture and algorithm, and its own effectiveness and feasibility, provides reference to RTL design.
Key word:
model simulation

An unequal dual-band power divider with composite left/right-handed transmission lines


Author:Lin Jianxin,Yu Kai,Li Sizhen,Zhang Guohao

Author Affilications:School of Information,Guangdong University of Technology,Guangzhou 510000,China

Abstract:Aiming at overcoming the drawback that a conventional power divider can only operate at a fixed frequency and its odd harmonics, a miniaturized unequal power divider operating at 1 GHz and 2.2 GHz is presented. The miniaturization is achieved by realizing the power divider′s impedance transformer using composite right/left-handed(CRLH) transmission lines(TLs). According to the theoretical and simulated results, the input terminal of the divider has good return loss and output terminals have good isolation result. Simulation result agrees well with theoretical one, which verifies the feasibility of this method.
Key word:
dual-band component
unequal power divider

An improved method for piecewise linear compensation in gap reference source


Author:Li Hongjie,Li Li,Wang Dandan

Author Affilications:College of Electronic Information and Electrical Engineering,Anyang Institute of Technology,Anyang 455000,China

Abstract:In order to reduce the temperature coefficient of band-gap reference source and improve the flexibility of temperature compensation,an improved piecewise linear compensation method was designed. A compensation current of seven different slopes in the whole temperature region was generated with the temperature of the bipolar transistor. Finally, The high order temperature components of the reference voltage were superimposed by the current mode. Based on the 0.25 μm BCD process it designed gap reference source here. HSPICE simulation results indicate that under 5 V power supply voltage and within -40 ℃~125 ℃ temperature range, the temperature coefficient of the reference voltage is only 0.37×10-6/℃. The power rejection ratio of the low frequency circuit is -85 dB. Within the range of 2 V~5 V, the linear adjustment rate of the reference voltage is 0.09 mV/V.
Key word:
piecewise linear compensation
temperature coefficient
linear adjustment rate
power supply rejection ratio

Design of input stage amplifier circuit for power operational amplifiers


Author:Wang Yongyong1,Yang Fashun1,2,Wang Decheng3,Hu Rui3,Ma Kui1,2

Author Affilications:1.School of Big Data and Information Engineering,Guizhou University,Guiyang 550025,China; 2.Key Laboratory of Micro-Nano-Electronics of Guizhou Province,Guiyang 550025,China; 3.Guizhou Zhenhua Feng Guang Semiconductor Co.,Ltd.,Guiyang 550018,China

Abstract:An input stage amplifier is designed for a power operational amplifier based on 70 V high voltage bipolar technology. The amplifier circuit implements a differential telescopic cascode pair using p-type JFETs. It has figure of merits involving low bias current, low offset voltage and current, and high CMRR. The common-collector common-emitter(CC-CE) configuration is used as the load for the input stage circuit in order to reduce the impact resulting from the load and improve the voltage gain as well. Simulation results based on Spectre simulator indicate that the input stage amplifier circuit has achieved 20 pA input bias current,0.11 mV offset voltage and 0.57 fA offset current,while the voltage gain is 89 dB and the unit gain-bandwidth is 8.13 MHz, with the CC-CE load.
Key word:
differential telescopic cascode
low bias current
power operational amplifier

Area and power consumption optimization based on dynamic frequency


Author:Zhan Ruidian1,2,Yang Jiachang1,2

Author Affilications:1.Chipeye Microelectronics Foshan Ltd.,Foshan 528225,China; 2.School of Automation,Guangdong University of Technology,Guangzhou 510006,China

Abstract:Area and power consumption of an integrated circuit chip is strongly related to its operating frequency. Using the switching principle of the gate-level circuit under different frequencies and keeping the original design, a system level chip area and power consumption optimization method based on dynamic frequency adjustment is proposed in this paper. Firstly, the relationships of area vs. frequency and power consumption vs. frequency are established by choosing the multiple test sets which satisfy the restricting constraints. Secondly, the mathematical models of area vs. frequency and power consumption vs. frequency are derived. Then, the optimal operating frequency is obtained by resolving the models. With a tape out design, the proposed method achieved about 0.59% area shrink and about 9.01% reduction in power consumption.
Key word:
dynamic frequency
system level

Design of S band power amplifier based on the GaN HEMT


Author:Zhang Shuyuan,Zhong Shichang

Author Affilications:Nanjing Electronic Device Institute,Nanjing 210016,China

Abstract:This paper uses internal matching technology and the cell structure of a single cell to design and implement a design of 3.8~4.2 GHz power amplifier. The amplifier is based on a GaN HEMT independently developed by Nanjing Electronic Device Institute. By optimizing the design, the amplifier achieves a peak output power of Pout greater than 30 W and the PAE of the amplifier greater than 48%, at a relative bandwidth of 10%, a drain-source voltage of 28 V, and a continuous wave operating condition,which fully shows the GaN power device′s broadband, high-efficiency, and high-power performance,so the device has broad prospects for engineering applications.
Key word:
internal matching
high efficiency
power amplifier
S band

Measurement Control Technology and Instruments

Design and implementation of multi-node data transmission system based on MLVDS and USB3.0


Author:Wang Hongliang,Wang Liuming

Author Affilications:Key Laboratory of Instrumentation Science & Dynamic Measurement,North University of China,Taiyuan 030051,China

Abstract:Aiming at the problem that the host computer can not communicate with the multi-node acquisition device at high speed in the distributed data acquisition system,a data converter based on MLVDS interface and USB3.0 interface is designed. The converter uses CYUSB3014 interface chip to achieve high-speed data transmission between computer and FPGA, uses ADN4693E interface chip to complete multi-node data transmission, uses FPGA as the core controller, and resolves multi-node communication logic based on MLVDS custom protocol to implement data interaction between MLVDS interface and USB3.0 interfaces. The test results show that the data conversion result of the converter is accurate and reliable, and the high-speed communication between the host computer and the multi-node data acquisition equipment is realized.
Key word:
data transmission
high speed communication

Harmonic detection algorithm based on improved SVD and Prony


Author:Ying Jun1,2,Zhu Yunpeng1,2,He Chao2

Author Affilications:1.School of Optoelectronic Engineering,Chongqing University of Posts and Telecommunications,Chongqing 400065,China; 2.Key Laboratory of Optical Communication and Networks,Chongqing University of Posts and Telecommunications, Chongqing 400065,China

Abstract:An improved algorithm based on singular value decomposition(SVD) and Prony is proposed to solve the problem that the traditional Prony algorithm is not very accurate because it is sensitive to noise during harmonic and inter-harmonic detection. Based on SVD theory, a singular point auxiliary algorithm is proposed to select the effective order of singular value decomposition adaptively, so as to accurately filter out the noise signal. According to the exact effective order, the improved Prony algorithm is used to identify the parameters of the signal after noise elimination, and the parameters of each harmonic and its components can be estimated accurately. Through MATLAB simulation analysis, it is shown that the algorithm can accurately extract the parameter information of power signal and has certain application value.
Key word:
harmonic detection
singular value decomposition
singular point detection

Short-term power load forecasting based on EEMD-SE and RBF optimized by genetic algorithm


Author:Gao Qiang1,2,Li Yilong1,2,Li Dahua1,2,Bai Zixuan1,2

Author Affilications:1.Tianjin Key Laboratory for Control Theory & Applications in Complicated Systems,School of Electrical and Electronic, Tianjin University of Technology,Tianjin 300384,China; 2.Center for Experimental Mechanical and Electrical Engineering Education,Tianjin 300384,China

Abstract:In order to improve the forecasting accuracy of short-term power load,a power load forecasting approach based on ensemble empirical mode decomposition(EEMD)-sample entropy(SE) and genetic algorithm(GA) for RBF neural network optimization is proposed in the paper. The EEMD decomposition method is used to decompose the load sequence adaptively, and according to sample entropy to combine the subsequences with similar complexity, which effectively reduces the scale of operation. Based on the difference of sub-sequence complexity, the corresponding RBF neural network model is constructed. The genetic algorithm is used to avoid the neural network falling into the local optimal and convergence problem. Then the new sub-sequences are forecasted and superimposed to obtain the final forecasting result. The simulated results show that the prediction algorithm has a satisfactory prediction effect and meets the requirements of short-term power load forecasting.
Key word:
load forecasting
ensemble empirical mode decomposition
genetic algorithm
neural network
sample entropy

Communication and Network

A sparsity adaptive multi-user detection algorithm for SIMO-NOMA systerms


Author:Zhao Xiaojuan1,Yang Shouyi1,Zhang Aihua2,Li Xiaoyu1

Author Affilications:1.School of Information Engineering,Zhengzhou University,Zhengzhou 450001,China; 2.School of Electronic and Information Engineering,Zhongyuan University of Technology,Zhengzhou 450007,China

Abstract:Non-orthogonal multiple access(NOMA) can improve spectrum efficiency and support massive connectivity by the use of resources in non-orthogonal way, which is expected to become one of the key technologies of 5G. Considering the situation that the base station(BS) is equipped with multiple antennas,this paper proposes a compressive sensing(CS) based sparsity adaptive matching pursuit hard fusion algorithm(SAMP-HFA) to realize multi-user detection(MUD) for uplink grant-free single-input multiple-output non-orthogonal multiple access(SIMO-NOMA) systems where the number of active user is unknown. The proposed algorithm consists of three steps. Firstly, it detects the user activity information by conventional SAMP algorithm at each antenna, and then amalgamates the detected user activity information to obtain a common active user set. Finally, the users′ data can be detected by the obtained active user set. The results show that the proposed SAMP-HFA demonstrates significant performance gain in terms of bit error rate(BER) with the number of antennas increases.
Key word:
compressive sensing
multi-user detection
sparsity adaptive
hard fusion

Low complexity detection algorithm applied to spatial modulation system


Author:Wang Huahua,Chen Dongfeng,Ma Chang,Kang Cheng

Author Affilications:School of Communication and Information Engineering,Chongqing University of Posts and Telecommunications, Chongqing 400065,China

Abstract:The paper proposes a low-complexity detection algorithm for spatial modulation. The proposed algorithm reduces the total complexity by reordering the receiving antennas. The algorithm combines the existing A-Star algorithm to layer and sort the receiving antennas, change the tree search structure and eliminate the wrong nodes, so that the selected branches include the optimal path as much as possible, which greatly reduces the number of required access nodes. The algorithm has approximately optimal BER performance and lower computational complexity. Compared with the maximum likelihood detection algorithm, the complexity is reduced by about 80%.
Key word:
spatial modulation
low complexity
tree search

Efficient opportunistic network routing algorithm based on bargaining game


Author:Ren Zhi,Kang Jian,Xu Zhaokun

Author Affilications:School of Communication and Information Engineering,Chongqing University of Posts and Telecommunications, Chongqing 400065,China

Abstract:The existing opportunistic network routing algorithms based on bargaining game has excessive control overhead caused by the excessive interaction process of nodes, the additional overhead caused by requesting for useless messages,the additional cost and the delay caused by the low probability of the transaction between the two parties. Besides, when the number of remaining messages in the SV list drops to 1,this condition will result in overhead as well. In response to the above problems, this paper proposes an efficient opportunity network routing algorithm——EORB. The algorithm reduces redundant overhead by adopting adaptive streamlined packet digest,adaptively merging SVDP messages and purchase messages, and comprehensively considering the game strategy of buyers′ and sellers′ benefits. It accelerates the message forwarding rate and improves the arrival rate of messages. The simulation results show that the algorithm effectively improves the rate of message delivery,reduces system overhead and reduces average end-to-end delay of messages.
Key word:
bargaining game
transaction success
opportunity network

Beamforming and power allocation using statistical channel information in massive MIMO networks


Author:Li Bo1,2,Chen Haihua1,2,Jin Ziwei1,2

Author Affilications:1.College of Electronic Information and Optical Engineering,Nankai University,Tianjin 300350,China; 2.Tianjin Key Laboratory of Optoelectronic Sensor and Sensing Network Technology,Tianjin 300350,China

Abstract:In order to improve the capacity of massive multiple input multiple output(MIMO) systems, this paper proposes an optimization method of beamforming and power allocation based on the statistical channel state information. The proposed beamforming aims to optimize the signal-to-leakage-plus-noise ratio(SLNR) and the power allocation is optimized to maximize the system capacity. The former beamforming problem can be solved analytically and the later problem is reformulated to an equivalent problem with multiple variables, which can be iteratively solved. Each iteration of the problem has a closed-form solution. Simulation results show that the proposed algorithm can significantly improve the system capacity.
Key word:
massive MIMO
statistical channel state information
power allocation

Low energy consumption multicast scheme for D2D multicast in wireless cellular network


Author:Xu Xiaoyao1,Tang Zefeng2,Chi Kaikai2

Author Affilications:1.No.36 Research Institute of CETC,Jiaxing 314033,China; 2.School of Computer Science and Technology,Zhejiang University of Technology,Hangzhou 310023,China

Abstract:This work studies the effective multicast of data from base station to multiple devices in a small area, and proposes a fixed-relay based multicast scheme and a dynamic-relay based multicast scheme. Furthermore, aiming to minimize the total energy consumption of all devices, this work analyzes and obtains the optimum relay and its transmit power. Compared to the traditional multicast scheme, the proposed two schemes greatly reduce the total energy consumption in a multicast cluster.
Key word:
wireless cellular network
D2D communication
energy consumption

Computer Technology and Its Applications

System design for target recognition and position-pose measurement based on TOF camera


Author:Zhao Shulei,Liu Jingmeng,Zhang Hui,Lv Zhiyu

Author Affilications:School of Automation Science and Electrical Engineering,Beihang University,Beijing 100083,China

Abstract:An embedded system based on the TOF camera with laser as the driving light source is designed. The gray image and depth image are collected to detect and match the cooperative target in real time, and the pose information of the target object is obtained. The target used is circular, and the classical threshold algorithm is used to extract the centroid coordinate of the target and calculate the center-of-heart rate as the target recognition condition. The target matching is completed using the classical deterministic annealing algorithm, and two sets of three-dimensional coordinates are obtained. And the SVD method is used to solve the pose data. In the experiment, the position calculated by the TOF camera can achieve an accuracy of 0.13 degrees, and the position translation has an accuracy of 0.6%. It can accurately identify the target and calculate pose, which verifies the feasibility of the TOF camera for rendezvous and docking, SLAM and other fields.
Key word:
TOF camera
target recognition
deterministic annealing
pose solution

Research on defect segmentation algorithm of industrial CT image after Faster R-CNN positioning


Author:Wu Xiaoyuan1,Chang Haitao1,Gou Junnian1,2

Author Affilications:1.School of Automation and Electrical Engineering,Lanzhou Jiao-tong University,Lanzhou 730070,China; 2.Key Laboratory of Optoelectronic Technology and Intelligent Control Ministry of Education, Lanzhou Jiao-tong University,Lanzhou 730070,China

Abstract:The defect area located by Faster R-CNN has weak edges. The area would be over-segmented or under-segmented if conventional segmentation algorithm is adopted. This paper made an analysis on precise threshold segmentation algorithm for workpiece defects based on Faster R-CNN location, reconstructing the localization area by morphological opening and closing reconstruction algorithm, processing the reconstructed image by Otsu′s dual threshold method, segmenting transformed images by maximum entropy threshold segmentation method, and finally measuring the area, perimeter and other parameters of the segmented defects. The research shows that the algorithm in this paper has higher segmentation ability regarding workpiece defects(crack, bubble and slag), compared to conventional algorithms. It not only can accurately segment objects with weak edges, but also can effectively remove the interference from the contour background to the segmentation.
Key word:
Faster R-CNN
defect segmentation
morphological opening and closing reconstruction algorithm
Otsu′s dual threshold method
maximum entropy threshold segmentation method

Design of industrial control safety protection system based on adaptive depth detection


Author:Guo Xiaowang,Min Xiaoshuang,Han Qingmin

Author Affilications:The 6th Research Institute of China Electronics Corporation,Beijing 100083,China

Abstract:Industrial control firewall and other network protection devices are easy to become response bottleneck when the interface flow is too large and resources are too occupied. In order to solve the problem, this paper proposes a kind of industrial safety protection system based on adaptive depth detection. The system is installed in the upstream of protection equipment, it can realize the recognition of industrial control protocol and parse protocol data deeply, and realize the depth of the realization of industrial control network protocol and testing or filtration. According to the state of industrial control field network, the system can adjust the level of depth detection algorithm dynamically, it can be able to handle all kinds of industrial control protocols in the current environment and analyzes protocol in-depth,which protects the industrial control site network.
Key word:
depth detection
industrial control safety

Embedded Technology

Design of FPGA online loading based on Flash controller


Author:Lin Tianjing,Ruan Xiang,Liu Chun

Author Affilications:The 52th Research Institute of China Electronics Technology Group Corporation,Hangzhou 310000,China

Abstract:Traditional way of FPGA configuration file update is using development tools to write FPGA target code to storage devices such as Nor Flash through the JTAG way.However,when the system becomes complicated with multiple FPGA,it takes a long time to update all the FPGA due to the limitation that the JTAG way can only update FPGA once a time. Therefore this paper proposes a FPGA online updating method,which can update multiple FPGA programs at the same time, greatly shorten the update time and reduce the cost of the system.
Key word:
online update

Design and fault analysis of motor control unit in XBT automatic launch and measurement system


Author:Wang Xinpeng,Men Yabin,Zhang Dongliang,Dong Tao,Kong Youdi

Author Affilications:National Ocean Technology Center,Tianjin 300112,China

Abstract:The XBT automatic launch and measurement system can automatically launch probes in severe sea conditions, and the motor control unit is the control core of the launch mechanism. The unit consists of a power management module, communication and motor control interface module, main control chip and etc, the stepping motor, servo motor and DC motor in the launch system can be controlled in real time. After putting forward the design scheme of hardware and software, the various faults found in the test for motor control unit are analyzed from mechanism. The test result after improved shows that the motor control unit can respond to the control commands of the host computer in real time, ensuring the stable motion of each motor, and the automatic launch and measurement system has the characteristics of good practicability, high efficiency and automation.
Key word:
real time motor control
XBT automatic launch
program compilation mode
microchip serial communication

MIPI CSI-2 image acquisition and processing system design based on FPGA


Author:Li Xianyou1,Zhao Shuguang1,Duan Yongcheng1,Wang Jianqiang2

Author Affilications:1.School of Information Science and Technology,Donghua University,Shanghai 201620,China; 2.SAIC Volkswagen Automotive Co.,Ltd.,Shanghai 201805,China

Abstract:A real-time image acquisition and processing system based on Lattice FPGA is designed for MIPI CSI-2 interface which is widely used in mobile embedded field. This system implements high-definition image acquisition, Bayer format conversion, image scaling, image inversion and saturation adjustment and other functions. It is shown that the system can stably capture 1080p60 image data and complete related image processing functions, through functional verification and testing of the system. It proves that this system has a certain practical value. Compared with other platforms, FPGA-based system has the advantages of high real-time performance, low power consumption, low cost, and easy system upgrade.
Key word:
image acquisition and processing

Control system design for marine microorganism in-situ concentrated pressure-retaining sampling


Author:Li Xiaofeng1,Li Xinjuan1,Gao Jinlong1,Wen Jingya1,Song Wenjie1,Liu Qiaojun1,Wang Lei2

Author Affilications:1.Institute of Oceanographic Instrumentation,Qilu University of Technology(Shandong Academy of Sciences),Qingdao 266001,China; 2.Qingdao Vocational Education Public Training Base,Qingdao 266112,China

Abstract:An autonomous control system for marine microorganism in situ concentration pressure-retaining sampler based on STC microcontroller is designed in order to realize the automatic collection of a large number of marine planktonic samples. The control system uses the method of magnetic transmission to ensure the reliable sealing and safety operation for motor. The control system uses the single chip microcontroller as the main controller; by measuring the seawater pressure and system working status, it controls the motor and solenoid valves to achieve the automatic sampling of marine microorganism combining with accumulator and the sampling filter device. Reliability is improved by simplifying the design of the control system structure. Experiments show that the sampler control system designed in this paper has simple structure and complete function and has successfully achieved the purpose of automatic sampling control of marine plankton.
Key word:
marine microorganism
autonomous sampling
magnetic transmission
control system design

Design of professional audio interface available for electroacoustic testing system


Author:Zhou Jinglei,Li Tengfei,Feng Yuan

Author Affilications:School of Electronic Information,Xi′an Polytechnic University,Xi′an 710048,China

Abstract:Aiming at low cost and high performance for audio interface requirements used in the electroacoustic testing system, a special audio interface is designed, which is composed of the slave computer embedded system and the host computer software. The audio interface uses high-speed USB2.0 interface to transmit audio data, and carries out D/A and A/D conversion through audio codec to achieve the function of playing and recording. By the test, the total harmonic distortion of sinusoidal signal generated by audio interface is lower than that of professional sound card; the amplitude frequency characteristic of the signal acquisition channel is better than that of the professional sound card; synchronous recording function enables full synchronization of recording and playing.
Key word:
electroacoustic testing system
audio interface
audio codec

Power Supply Technology and Its Application

Research on buck converter based on digital PID switching control


Author:Wu Zhiqiang,Yu Lianzhi,Kong Mengjun

Author Affilications:School of Optical-Electrical and Computer Engineering,University of Shanghai for Science and Technology,Shanghai 200093,China

Abstract:In order to improve the steady-state performance of DC-DC converters, a digital PID switching control technology is proposed. Different from traditional digital PID control technology, it switches the PID control by comparing the voltage error value with the setting value. This thesis takes digital PID switching control buck converter as an example and analyzes its steady-state performance which is simulated by Simulink. The results show that the digital PID switching control can obtain good steady-state performance while maintaining a good transient response when the load or input voltage changes.
Key word:
steady state performance
PID switching control
buck converter
transient response

Grid-connected inverter fault diagnosis in closed loop


Author:Han Yan,Pazilai Mahemuti

Author Affilications:School of Electrical Engineering,Xinjiang University,Urumchi 830047,China

Abstract:At present, the fault diagnosis method for the grid-connected inverter is mainly applied to the open-loop system, and the actual grid-connected inverter is mostly a closed-loop control system. Therefore, for the grid-connected inverter in the closed-loop state, this paper proposes a fault diagnosis method based on phase current. By analyzing the phase current of the grid-connected inverter in the closed loop state under normal and open fault types, the fault characteristics of the average value of the phase current and the average absolute residual value under the open circuit fault are obtained. Firstly, the average value of the phase current generated by the Park transform in the closed loop control loop is compared with the measured phase current, and then averaged according to the normalized phase current. The value is combined with the average absolute residual to diagnose the fault. Finally, it is verified by experiments that the diagnostic method can quickly detect and identify single-tube and multi-tube open-circuit faults under closed-loop control.
Key word:
grid-connected inverters
closed-loop control system
phase current average
multiple open-circuit faults

Research on QPR and sliding-mode control strategy for three-phase Vienna rectifier


Author:Ma Hui1,Yan Shengyang1,Wang Shuzheng2,Wei Wei1

Author Affilications:1.Hubei Provincial Research Center on Microgrid Engineering Technology,Yichang 443002,China; 2.Jiangsu Collaborative Innovation Center for Smart Distribution Network,Nanjing 211167,China

Abstract:Aiming to slove the PI controller′s problem that it is difficult to achieve the fast and accuracy performances of Vienna rectifier, this paper proposed a novel composited nonlinear control strategy with sliding mode controller(SMC) and Quasi proportional resonant(QPR) controller, which can enhance the accuracy performance and the sinusoidal degree of the three-phase currents. In addition, the rapidity and robust performance of DC voltage have also been improved when starting up the rectifier or the load is disturbed. Finally, the MATLAB/Simulink model and experimental platform based on Vienna-type rectifier were built, the results show that the composited control strategy not only has the adventages of the sliding mode control strategy, but also has better robust and dynamic performance. Meanwhile the speed and accuracy of the system have also been greatly improved.
Key word:
Vienna-type rectifier
sliding mode control
Quasi proportional resonant control
PI control

Performance optimization of VIENNA rectifier based on SVM under unbalanced grid


Author:Wang Da,Shao Ruping,Dong Feiju

Author Affilications:College of Electrical Engineering and Control Science,Nanjing Tech University,Nanjing 211816,China

Abstract:On the basis of the steady state analysis of the VIENNA rectifier, an improved direct synchronous decoupling method is used to model the current inner loop, and a small amount of power compensation is added to expand the working area to adapt to different degrees of unbalanced voltage, which can reduce the DC voltage ripple and reactive power DC component under unbalanced input condition. In addition, this paper adds dead-beat control to track the reference current and selects the best duty cycle to drive the gate. The control strategy effectively realizes DC side voltage ripple elimination and power factor correction. Simulation and experiment verify the correctness of the theoretical analysis and the feasibility of the control strategy.
Key word:
VIENNA rectifier
direct synchronous decoupling method
unbalanced grid
dead-beat control