Table of Content

15 February 2023 Volume 36 Issue 2

  

Design of A Multi-Channel Radar Echo Playback System Based on FPGA

ZHAO Yingxiao,SU Yang

Electronic Science and Technology. 2023, 36(2):  1-7.  doi:10.16180/j.cnki.issn1007-7820.2023.02.001

Abstract ( 435 )   HTML ( 1088 )   PDF (1913KB) ( 159 )  

Figures and Tables | References | Related Articles | Metrics

In order to solve the problem of effective verification of radar real-time signal processing function and performance, a wideband and narrowband integrated radar echo playback system with multiple channels is designed and implemented. The system transfers the radar echo data to the real-time signal processing system according to the time sequence and data rate of the radar operation, so as to reproduce the target tracking scene and realize the effective verification of the real-time signal processing function and performance of the radar. The data playback system comprises a disk array server and two PCIe fiber boards. Based on the Xilinx series products, the PCIe DMA control process and response mechanism are further adjusted according to the system characteristics, and the high-speed batch transmission of radar echo data from the server to the fiber board is realized. According to the working mechanism of the radar and the echo data structure, the FPGA playback control state machine and related function modules are designed, and the radar echo data is transmitted from the optical fiber board to the real-time processing system in strict accordance with the working sequence and data rate of the radar. To ensure the synchronization between multiple boards when wideband and narrowband echo playback is carried out at the same time, the study proposes two methods based on software and hardware respectively. The test results show that the system realizes the synchronous playback of wide-band and narrow-band radar echo data between boards, each data type supports 6 parallel data channels, and the peak data playback rate can reach 1 920 MB·s^-1.The designed system can be directly integrated in the origin radar hardware platform, without adding extra circuit boards or cables, which has good generality and convenience. The system has been successfully applied in a multi-function phased array radar.

Distribution Network Dispatching Optimization Strategy Energy Storage Based on Time-of-Use Electricity Price and User-Side

WANG Yumei,WANG Lulu

Electronic Science and Technology. 2023, 36(2):  7-12.  doi:10.16180/j.cnki.issn1007-7820.2023.02.002

Abstract ( 551 )   HTML ( 525 )   PDF (906KB) ( 121 )  

Figures and Tables | References | Related Articles | Metrics

In view of the problem of loss increase of distribution network caused by the access of distributed power and the fluctuation of load, this study proposes an optimal operation model that integrates the time-of-use electricity price mechanism with user-side energy storage to participate in the distribution network. Based on the time-of-use electricity price, a user load response model is established, and a distribution network operation optimization model is constructed with the user's daily electricity cost and the minimum distribution network loss as the objective function. The evaluation function method is used to convert multiple objectives into single objectives, and the simulated annealing Metropolis criterion is introduced into the traditional genetic algorithm to optimize the charging and discharging strategy of the user-side energy storage. The simulation results prove that the proposed strategy can effectively reduce the power loss of the distribution network and the cost of user electricity, which verifies that proposed algorithm has a faster optimization speed and better convergence performance.

Research on Battery Grid Connection Based on Voltage and Current Double Loop Control

SUN Sinan,HAO Zhenghang

Electronic Science and Technology. 2023, 36(2):  13-21.  doi:10.16180/j.cnki.issn1007-7820.2023.02.003

Abstract ( 456 )   HTML ( 448 )   PDF (1087KB) ( 109 )  

Figures and Tables | References | Related Articles | Metrics

In view of problems such as low accuracy, poor reliability, and difficulty in operation caused by the performance test of conventional battery discharge using variable resistors, a battery performance test method for grid-connected charging and discharging is proposed in the present study. Through the analysis of the differential expressions of charge, temperature and current in lead-acid batteries, a third-order equivalent mathematical model composed of the main reaction branch and parasitic branch is established. The charging and discharging of the battery adopts the constant current mode in which the step signal triggers the on-off of the Buck-Boost bidirectional conversion circuit switch. The inverter circuit adopts double closed-loop control of voltage and current, and is merged into the analog power grid after being filtered by inductance. Simulation experiments on MATLAB/Simulink software show that the various performance indicators of the battery and the grid-connected current dynamic response are good, which proves the effectiveness and environmental protection of the proposed method.

An Effective Segmentation Method for COVID-19 CT Image Based on Attention Mechanism and Inf-Net

ZUO Bin,LI Feifei

Electronic Science and Technology. 2023, 36(2):  22-28.  doi:10.16180/j.cnki.issn1007-7820.2023.02.004

Abstract ( 429 )   HTML ( 511 )   PDF (2320KB) ( 95 )  

Figures and Tables | References | Related Articles | Metrics

COVID-19 pandemic has recently ravaged the world, seriously affecting the life and health of human society. CT imaging technology is an important diagnostic method for detecting COVID-19. Automatic and accurate segmentation of the lesion is of great significance for diagnosis, treatment and prognosis. In view of the segmentation of new coronary pneumonia lesions, an improved automatic segmentation method based on the Inf-Net algorithm is proposed, which introduces the channel attention module to improve feature representation and attention gate model to better fuse edge information. The experimental results on COVID-19 CT segmentation datasets show that the Dice similarity coefficient, sensitivity and specificity of the proposed method are 75.1%, 75.4% and 95.4%, respectively, and the algorithm performance is also better than some mainstream methods.

Improvement of Earliest Deadline First Algorithm in CAN FD Bus

GUAN Yinfeng,ZHANG Fengdeng,ZHANG Haitao,ZHANG Yuhui

Electronic Science and Technology. 2023, 36(2):  29-36.  doi:10.16180/j.cnki.issn1007-7820.2023.02.005

Abstract ( 139 )   HTML ( 594 )   PDF (1861KB) ( 27 )  

Figures and Tables | References | Related Articles | Metrics

For the scheduling algorithm applied in CAN FD network, when the earliest deadline algorithm of average partition coding method performs non-preemptively scheduling on messages, it will have the problems of limited encoding ability for a large range of deadlines, high probability of priority reversal of messages and high bus load. By analyzing various causes that cause of message transmission delay and combining with the shortcomings of previous partition scheduling algorithms, this study proposes an improved method of message scheduling based on the earliest deadline first algorithm based on exponential-power function partition, that is, on the basis of exponential partition of message deadline, power function partition subdivision is further adopted. In this study, the schedulability of the algorithm is analyzed and verified by simulation using CANoe. Experiments show that compared with the existing average partition scheduling algorithm, the improved algorithm expands the representation range of deadline, reduces bus load, optimizes priority inversion problem, and achieves better scheduling effect.

Flux Equivalence Based Magnetic Pole Fault Tolerant Operation in Active Magnetic Bearings

ZHU Fangfu,CHEN Liangliang,JIANG Kejian

Electronic Science and Technology. 2023, 36(2):  37-45.  doi:10.16180/j.cnki.issn1007-7820.2023.02.006

Abstract ( 184 )   HTML ( 579 )   PDF (3764KB) ( 31 )  

Figures and Tables | References | Related Articles | Metrics

In view of the problem of fault-tolerant control of 8-pole electromagnetic bearings, a fault-tolerant control method of electromagnetic bearings based on flux equivalence is proposed in the present study. The method first obtains the current-flux influence coefficient of magnetic flux by simulation, and uses linear algebra theory to calculate the current distribution matrix. When a fault occurs in one pole circuit, the current distribution matrix is used to calculate the reconfiguration current so that the flux at the end surfaces of the eight poles remains the same before and after the fault, that is, the flux is equivalent, thus achieving fault-tolerant operation. The simulation is carried out in ANSYS finite element simulation platform, and the flux equivalent method can restore the flux and magnetic force line distribution at the end face before the failure, and the flux error (the maximum does not exceed 3.2%, and most of them are less than 0.5%) and force error (the maximum is not more than 7%, and most of them are less than 1.5%) are calculated, which proves the effectiveness of the proposed flux equivalent fault tolerance control method.

Study on Compliance Control for Falling Prevention of Smart Walking-Aids

ZHANG Yuwen,WANG Yagang,DING Damin,LIN Yanzhao

Electronic Science and Technology. 2023, 36(2):  46-52.  doi:10.16180/j.cnki.issn1007-7820.2023.02.007

Abstract ( 257 )   HTML ( 516 )   PDF (1432KB) ( 44 )  

Figures and Tables | References | Related Articles | Metrics

When users tend to fall down during the process of using walking-aids, it is necessary to quickly restore the human body to a normal standing posture and buffer the inertial force of the emergency braking of walking-aids. However, the compliance control is widely used in the mechanical arms, and the anti-fall control strategy applied to the walker model is relatively insufficient. To solve this problem, a new falling prevention compliance control strategy based on adaptive sliding mode impedance control is proposed and used in the walking-aids model to improve the performance of the walker through the fusion of array film pressure sensors and ultrasonic sensors. This strategy can improve the trajectory tracking effect of the walker and realize the safety protection for the users. The simulation results of two different operating conditions and two different terrain simulation experiments show that the human body can recover to stand upright in about 4 s, which proves that the strategy can achieve the motion flexibility of the walker.

Total Variation and Sparsity Regularized Deep Nonnegative Matrix Factorization for Hyperspectral Unmixing

ZHAO Wenjun,ZHAI Han,ZHANG Hongyan

Electronic Science and Technology. 2023, 36(2):  53-60.  doi:10.16180/j.cnki.issn1007-7820.2023.02.008

Abstract ( 223 )   HTML ( 589 )   PDF (1930KB) ( 73 )  

Figures and Tables | References | Related Articles | Metrics

The traditional nonnegative matrix factorization methods are based on single-layer model. The deep nonnegative matrix factorization methods are based on the mathematical theory, ignoring the actual spectral mixing process of materials. In this regard, this study starts from the physical process of spectral mixing, integrates non-negative matrix decomposition and deep learning, and reversely models the spectral mixing process. In addition, considering the sparsity and spatial smoothness of abundance, a fully-variation sparse constrained deep non-negative matrix factorization model for endmember matrix-oriented unmixing of hyperspectral remote sensing images is established. Through simulation experiments and real experiments, the proposed method is compared with five unmixing methods. The results show that compared with the abundance-oriented deep nonnegative matrix factorization algorithm, the average spectral angular distance and root mean square error of the proposed method are reduced, the best unmixing results are obtained.

Research on Dispatching of Multi-Source Combined Power Generation System Containing Hydrogen Energy Storage

GUO Chengwei,TIAN Shu,LIU Minghang

Electronic Science and Technology. 2023, 36(2):  61-66.  doi:10.16180/j.cnki.issn1007-7820.2023.02.009

Abstract ( 210 )   HTML ( 601 )   PDF (1806KB) ( 50 )  

Figures and Tables | References | Related Articles | Metrics

Wind power and photovoltaic power generation are intermittent and random. In order to reduce the abandonment rate in the multi-source combined power generation system, the hydrogen-containing energy storage system and the thermal power unit are used to smooth the output of wind power and photovoltaic units. This study aims to minimize the operating cost of the system and the penalty cost of power abandonment. A day-ahead scheduling model of multi-source combined power generation system is constructed with the constraints of system power balance, thermal power unit output and ramping, hot backup, wind power and photovoltaic output, hydrogen storage tank capacity of energy storage system, electrolyzer and fuel cell power. The model is programmed through the YALMIP toolbox, and CPLEX is called to solve the programmed program. A case study of a multi-source combined power generation system containing wind power, photovoltaic, thermal power generation and energy storage systems is carried out. By comparing the amount of abandoned wind and light with or without an energy storage system and the total operating cost of the system, it is proved that the hydrogen-containing energy storage system can effectively reduce the rate of abandoned wind and light and improve the economy of the system.

Mixed Prediction of Mine Pressure Time and Space Based on LSTM Network

YU Qiongfang,NIU Dongyang

Electronic Science and Technology. 2023, 36(2):  67-72.  doi:10.16180/j.cnki.issn1007-7820.2023.02.010

Abstract ( 315 )   HTML ( 590 )   PDF (1023KB) ( 61 )  

Figures and Tables | References | Related Articles | Metrics

The roof accident caused by the unbalanced pressure of the mine is one of the major mine accidents, so it is of great significance to perceive the change of the mine pressure in the fully mechanized mining face in advance to ensure the safety and efficiency of the coal seam. To improve the accuracy of mine pressure prediction, a spatiotemporal hybrid prediction model based on LSTM network is proposed in this study. Two independent LSTM networks are used to extract the pressure characteristics on the goaf side and the support moving side respectively, and the obtained data are merged through the fully connected layer, so as to realize the common prediction of mine pressure. Two indicators, MSE and MAE, are used to evaluate the prediction effect of the spatio-temporal mixture model based on LSTM. The experimental results show that MSE and MAE are reduced by 24.49% and 35.24%, respectively. The spatio-temporal mixture prediction model based on LSTM is excellent when compared with the traditional LSTM prediction model, and the prediction method of the spatio-temporal hybrid model has higher reliability and accuracy than the traditional model, and can predict the changes in the mine pressure during the advancement of the working face.

YOLO-Improve Detection Method of Real-Time Mask Wearing

CHENG Changwen,CHEN Wei,CHEN Jinhong,YIN Zhong

Electronic Science and Technology. 2023, 36(2):  73-80.  doi:10.16180/j.cnki.issn1007-7820.2023.02.011

Abstract ( 440 )   HTML ( 594 )   PDF (2859KB) ( 130 )  

Figures and Tables | References | Related Articles | Metrics

The existing YOLO target detection model is based on the One-stage idea for multi-target detection. It is insufficient for dual-classification detection, and the performance consumption is large during detection. In order to improve the detection efficiency of dual-classification mask wearing during the period of the outbreak of COVID-19, this study proposes a real-time detection method based on YOLO for detecting the condition of bi-objective mask wearing. The feedforward input layer of the model is improved, the data enhancement part is optimized, and adaptive image scaling is added to improve the detection accuracy and detection efficiency of dual-classification and small targets. The adaptive anchoring frame is added to replace the activation function so as to reduce the computational complexity of the method and improves the detection efficiency of the method. The optimization of Neck and the addition of Focus structure improve the capability of feature fusion and reduce the amount of parameters to raise the efficiency. The experimental results showed that compared with the YOLOv4, the proposed method has a 0.33% increase in F1 and a 0.71% increase in mAp in the data set in the text, and the detection efficiency is also significantly improved under the same experimental environment.

A GAN-Based Lightweight Style Transfer Model for Ink Painting

ZHAO Jin,LI Feifei

Electronic Science and Technology. 2023, 36(2):  81-86.  doi:10.16180/j.cnki.issn1007-7820.2023.02.012

Abstract ( 521 )   HTML ( 441 )   PDF (2030KB) ( 85 )  

Figures and Tables | References | Related Articles | Metrics

Current style transfer methods are mainly suitable for photos or Western paintings. Due to the inherent differences between Chinese and Western paintings, existing algorithms cannot generate satisfactory results when applied to the style transfer task of Chinese ink paintings. Consequently, a novel style transfer method based on GAN for ink painting is proposed in the study. This method combines AdaIN, style-attention module and perceptual loss to learn the style features of ink painting more accurately, thereby solving the problem that the generated results of ink painting have poor quality. According to the qualitative analysis and quantitative evaluation, experimental results show that this method has better performance and the generated results have higher visual quality. Compared with the baseline, the method reduces the number of parameters by about 55% and the training time by about 60%.