Table of Content

15 September 2021 Volume 34 Issue 9

  

A Review: Radar Signal Processing Based on High Performance Computing

GENG Zhaoqian,ZHU Huming,LI Xuming,CHEN Meiqing,YANG Guipeng

Electronic Science and Technology. 2021, 34(9):  1-6.  doi:10.16180/j.cnki.issn1007-7820.2021.09.001

Abstract ( 639 )   HTML ( 35 )   PDF (899KB) ( 146 )  

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With the development of software defined radar technology and the ever-increasing complexity of signal processing algorithms, high performance computing hardware such as multi-core CPU and graphics processing unit has been widely used in radar system. This study focuses on recent technological progress of software and hardware for high performance computing, and briefly analyzes and reviews the technical characteristics of parallel computing models including CUDA, OpenCL, OpenMP, MPI and Pthread. A CPU-based parallel radar signal processing algorithm is designed using multi-threaded pipeline technology. The development trend for radar signal processing using high-performance computing in the future is prospected.

Optimizing the Real-Time Kernel Interrupt Management Mechanism of μC/OS-III

FENG Chong,WU Yaohui,WU Haozhen

Electronic Science and Technology. 2021, 34(9):  7-11.  doi:10.16180/j.cnki.issn1007-7820.2021.09.002

Abstract ( 217 )   HTML ( 18 )   PDF (835KB) ( 42 )  

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In the μC/OS-III real-time operating system, low priority interrupt task has greater interference with the deadline of urgent tasks. In view of this problem, an optimized interrupt management mechanism of μC/OS-III is proposed. Using the principle of priority deprivation based on μC/OS-III, the priority of interrupt task and common task is assigned uniformly. According to the urgency of the interrupt, the interrupt task is assigned an appropriate priority, and different processing methods are selected by comparing the priority of the interrupt task and the current executing task. If the priority of the interrupt task is lower than the currently executing task, it will be processed in task mode, otherwise it will be processed in the interrupt service routine. Theoretical analysis and μC/Probe software testing and experiments show that the optimized μC/OS-III real-time kernel interrupt management mechanism can shorten the deadline of emergency tasks, and the system can run reliably and stably with high real-time performance.

The Asymptotic Synchronization of Neutral Complex Networks with Adaptive Pinning Control

SHI Hui,TONG Dongbing

Electronic Science and Technology. 2021, 34(9):  12-16.  doi:10.16180/j.cnki.issn1007-7820.2021.09.003

Abstract ( 232 )   HTML ( 14 )   PDF (551KB) ( 47 )  

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For the asymptotic synchronization problem of neutral coupled complex networks with unknown control nodes, an adaptive pinning controller which is more suitable to engineering applications is designed, and the design basis of the adaptive update law is provided in the present study. According to the generalized Itö formula, linear matrix inequality and Lyapunov stability theory, the sufficient conditions for asymptotic synchronization of neutral coupled complex networks are given. Through a numerical simulation, the minimum number of pinned nodes required for synchronization is calculated, which further verifies the validity of the obtained results.

Optimization of Temperature Sensor Location Based on Genetic Algorithm

XIU Xiaobo,LI Boquan,ZHOU Feng

Electronic Science and Technology. 2021, 34(9):  17-23.  doi:10.16180/j.cnki.issn1007-7820.2021.09.004

Abstract ( 331 )   HTML ( 13 )   PDF (1474KB) ( 88 )  

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The temperature field distribution information reflects the internal operating state of industrial equipment in industrial applications, which helps to formulate control strategies and ensure the safety of industrial equipment operation. In view of the limitation of UDD section temperature field detection of chain grate in the iron and steel smelting equipment, a method is proposed to solve the problem of the optimal position and number of temperature sensor layout. A mathematical model of the UDD section is established using heat transfer theory, and the theoretical temperature field of the UDD section is obtained through computational fluid dynamics. An objective function for evaluating the location of sensor placement is designed and calculated using genetic algorithm to obtain the optimal solution for the number and location of temperature sensors. The effect of the scheme is verified by numerical simulation. The results show that when the radial basis function is used to convert the temperature field, the temperature field after optimization is increased by 30.90% when compared with the average before optimization, and the model hit rate is increased from 99.88% to 99.99 %.

Research on Optical Lens Reconstruction Algorithm Based on NURBS

HAN Shifan,FU Dongxiang

Electronic Science and Technology. 2021, 34(9):  24-29.  doi:10.16180/j.cnki.issn1007-7820.2021.09.005

Abstract ( 201 )   HTML ( 9 )   PDF (1234KB) ( 48 )  

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NURBS is suitable for mainstream and general surface design. In order to ensure the smoothness of optical progressive lens and keep its sphericity unchanged by partial modification, an optimization algorithm based on NURBS reconstruction technique is proposed. Because NURBS surface has good local modification and invariance under affine and perspective changes, the research method of using NURBS to reconstruct the optical lens and define the partial modification of the surface is selected. Through preprocessing, the shape value points on the lens are obtained, and a three-time NURBS surface reconstruction algorithm based on the reverse control points is designed. The basic concepts are defined, and the selection of shape value points is solved, the control points are solved by quadratic method, the surface re-fitting and the local modification are also defined. The effectiveness of the algorithm in this study is verified by experiments.

Design of a Sampling System Based on Four-Channel ADC Chip Time-Interleaved Sampling

LEI Wen,LI Jingyu

Electronic Science and Technology. 2021, 34(9):  30-35.  doi:10.16180/j.cnki.issn1007-7820.2021.09.006

Abstract ( 374 )   HTML ( 9 )   PDF (1411KB) ( 52 )  

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Signal sampling system with high speed, high precision and wideband is an important part of wideband imaging radar. For the problem that the sampling rate of single high-precision ADC chip cannot meet the direct intermediate frequency sampling of wideband imaging radar, the method of multiple ADC chips time-interleaved sampling is adopted in this study, which improves the sampling rate of the system under the condition of keeping the sampling accuracy unchanged. Four ADC12DJ3200 chips with a sampling rate of 3.4 GS·s^-1 are used to design a wideband TIADC system with a total sampling rate of 13.6 GS·s^-1, and the number of quantization bits is 12 bit. The test results show that in the frequency range of 440~6 140 MHz, the effective number of bits and spurious free dynamic range of the system are more than 7.2 bit and 51 dB, respectively.

Reconfigurable Radar System Enabled by Microwave Photonics Technology

CAO Jiming,CHONG Yuhua,MEI Li,ZHU Yupeng,DUAN Zongming

Electronic Science and Technology. 2021, 34(9):  36-40.  doi:10.16180/j.cnki.issn1007-7820.2021.09.007

Abstract ( 426 )   HTML ( 16 )   PDF (1262KB) ( 67 )  

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For the problem that operating band switching of traditional electrical radar system is hard with a single hardware platform, a reconfigurable microwave photonics radar based on de-chirp processing technology is proposed. Two cascaded Mach-Zehnder modulators are employed to implement a reconfigurable radar transmitter, and the operating band of the photonics radar are changed flexibly by adjusting the frequency of local signal. At the receiver end, radar echo signals are sent to a dual-parallel modulator to perform de-chirp processing. The performance of the proposed photon-assisted radar system is evaluated by inverse synthetic aperture radar imaging experiments. The photon radar system is validated at different bandwidths in the Ku band. The transmitted signal bandwidth is 1 GHz and 4 GHz, respectively. The sampling rate of the receiver’s analog-to-digital converter is 100 MSa·s^-1. The results show that the microwave photonics technology can provide solutions for implementing a reconfigurable radar structure.

Identification Method Based on Step Response and Genetic Algorithm to Optimize Higher-Order Plus Time-Delay Model

WANG Yang,WANG Yagang

Electronic Science and Technology. 2021, 34(9):  41-46.  doi:10.16180/j.cnki.issn1007-7820.2021.09.008

Abstract ( 240 )   HTML ( 8 )   PDF (753KB) ( 53 )  

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For high-order process objects with time-lag in industrial production, due to the complex structure of the controller, it is difficult to implement the method of directly designing the controller and reducing the order of the traditional model. In addition, noise will interfere with the controller. The above factors lead to unsatisfactory results using these methods. To solve these problems, the identification method based on step response is adopted in this study. By analyzing the input and output data of the step response of the object, a second-order plant with dead time model is established. The advantage of genetic algorithm to adapt the global search ability are used to optimize the static gain, time constant and pure hysteresis coefficient, so as to perform accurate model identification of high-order time-delay objects. MATLAB simulation results show that the proposed method has the advantages of high accuracy, strong robustness and wide applicability. Using this method to identify the model in the text under the unit step input signal, the ITAE indicators are 18.138 5, 6.271 5 and 167.889 2, respectively.

AC/AC Frequency Conversion Power Supply Based on Three-Phase Input

LI Yudong,LIAN Haishan,HU Xiaodan

Electronic Science and Technology. 2021, 34(9):  47-53.  doi:10.16180/j.cnki.issn1007-7820.2021.09.009

Abstract ( 226 )   HTML ( 8 )   PDF (2531KB) ( 33 )  

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In order to overcome the shortcomings of the traditional SCR phase-controlled AC-AC conversion method, such as complex control and more devices, on the basis of the single-phase blocking AC-AC conversion system, a three-phase input-type blocking AC-AC conversion system is proposed. In this system, the power frequency three-phase power supply is used as the input, and the traditional AC chopper voltage regulating circuit topology and high frequency PWM control are used. According to the area equivalent principle, the relationship between the duty cycle and the output voltage amplitude is deduced, which realizes the purpose of the system output voltage frequency and amplitude can be adjusted separately. Finally, the system mathematical model built in MATLAB 2016b/Simulink environment is simulated and analyzed, and a prototype of a three-phase input-type blocking-type cross-converter power supply based on the dSPACE semi-physical simulation platform is fabricated and tested. The simulation results and experimental results verify the correctness and feasibility of the system designed in the study.

Mobile Network Payment Secure Communication Protocol Model Based on Improved DNS Protocol

WEI Xing

Electronic Science and Technology. 2021, 34(9):  54-57.  doi:10.16180/j.cnki.issn1007-7820.2021.09.010

Abstract ( 233 )   HTML ( 8 )   PDF (961KB) ( 36 )  

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In view of the security problems in the process of mobile network payment, this study constructs a mobile network payment security communication protocol model based on the improved DNS protocol. The improved DNS protocol is adopted in the model. By introducing blockchain technology, each top-level domain name becomes an autonomous root, and then the autonomous root forms a root alliance, so as to participate in the publishing and management of each data node. Using this idea of decentralization, the security of mobile network payment is effectively improved. In particular, the PBFT consensus algorithm is improved by actively obtaining the views of all nodes in the node network and the latest block height and other information, so as to restore the backward execution of some nodes caused by the operation of the network, and further ensures the consistency and security of data.

Multi-Angle Virtual Glasses Trial Technology Based on Face Attitude Estimation

LIU Xuan,FU Dongxiang

Electronic Science and Technology. 2021, 34(9):  58-65.  doi:10.16180/j.cnki.issn1007-7820.2021.09.011

Abstract ( 290 )   HTML ( 20 )   PDF (2692KB) ( 69 )  

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In view of the problems that current high proportion of manual operations for virtual glasses try-on, single try-on angle, distorted try-on effect, and low commercial rate of try-on technology, a virtual try based on the combination of facial feature detection and head space pose estimation is proposed, and a virtual glasses try-on system is implemented. The real-time videos of the head are collected through the camera and analyzed by frame, and ERT cascade regression is used to locate facial feature points. According to the position information of the facial feature points and the head rotation information, the perspective-transformed eyeglass image is accurately integrated into the face image at the corresponding angle. The 3D real-time pose estimation is quantitatively evaluated on the AFLW face database, and the angle error within ±60° is about 8.8°. The results show that the algorithm has high precision and fast speed, and can quickly and accurately realize 3D multi-angle virtual try-on in complex situations with frequent angle changes, large changes in external light intensity, and many background interferences.The effect obtained by the algorithm is realistic and natural, and basically meets the requirements of virtual try-on technology.

Research on Motion Simulation and Visual Recognition Algorithm of Guide Dog Walking Mechanism

ZHAO Chong,CHI Mengmeng,CHU Cong,ZHANG Peng

Electronic Science and Technology. 2021, 34(9):  66-72.  doi:10.16180/j.cnki.issn1007-7820.2021.09.012

Abstract ( 361 )   HTML ( 14 )   PDF (3065KB) ( 67 )  

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In view of problems such as high training cost for guide dogs, this study proposes a walking mechanism with visual recognition function, which can realize a single stepper motor to drive a four-legged mechanism to walk. Through the simulation of the movement of the walking mechanism, the obtained data show that the four feet can alternately rise and fall relative to the ground, and can run smoothly in a more complex non-structural environment. Taking the recognition of the traffic lights on the crosswalk as an example, a visual recognition algorithm for mechanical guide dogs based on YOLO is proposed to determine whether the current signal status is passable. The mechanical guide dog recognizes 87.96% of the green light and 89.38% of the red light, and the detection speed is 23.5 frame·s^-1,indicating that the mechanical guide dog can detect and distinguish the traffic light information of pedestrian crossings in real time.

Siamese Network Binocular Stereo Matching Based on Super-Pixel Segmentation

LU Wei,LIU Xiang,XUE Mian

Electronic Science and Technology. 2021, 34(9):  73-78.  doi:10.16180/j.cnki.issn1007-7820.2021.09.013

Abstract ( 282 )   HTML ( 9 )   PDF (1567KB) ( 48 )  

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In view of the low accuracy problem in binocular stereo matching caused by image texture lacking, occlusion and depth discontinuous, this study proposes the matching cost calculation of local image features based on deep learning Siamese neural network model which takes mean filter preprocessing and SLIC super-pixel segmentation as input. The method effectively improves the accuracy of edge regional identification when disparity computation happens, and avoids the problems of edge expansion, blur and discontinuity, and thus improving the accuracy of stereo matching. The experiments are based on the Middlebury stereovision data set test platform, and compared with the disparity maps obtained by SGM, adaptive weight AD-Census and other possible methods. The results show that the algorithm has a significant improvement in the matching effect of the depth discontinuous area and the lack of texture area, and the average parallax error and average error rate are reduced, indicating that the proposed method has better robustness.