Table of Content

15 July 2019 Volume 32 Issue 7

  

Research on Direct Torque Control of Permanent Magnet Synchronous Motor Based on Sliding Mode Control

JI Shengyang,WANG Xudong,XU Xiaozhuo,SUN Weixiang,SHI Kaining

Electronic Science and Technology. 2019, 32(7):  1-5.  doi:10.16180/j.cnki.issn1007-7820.2019.07.001

Abstract ( 691 )   HTML ( 27 )   PDF (1128KB) ( 117 )  

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For the direct torque control (DTC) of permanent magnet synchronous motor, there are large problems such as electromagnetic torque ripple, flux pulsation and low speed performance. To solve these problems, the sliding mode control strategy was introduced to control the permanent magnet synchronous motor. By establishing the vector mathematical model of PMSM, a direct torque controller based on sliding mode control was designed, and modeling and simulation analysis was carried out by using MATLAB/Simulink. The results showed that compared with the traditional DTC, the direct torque control system of the permanent magnet synchronous motor based on the sliding mode control strategy had lower amplitude of electromagnetic torque fluctuation, better dynamic performance and anti-disturbance capability, which could improve system characteristics more effectively to meet the needs of actual motor control.

Error Analysis of a Six-Point Method for Laser Positioned and Grasped

SUN Yuanyuan,SHAN Hongtao,LIU Fanghu

Electronic Science and Technology. 2019, 32(7):  6-10.  doi:10.16180/j.cnki.issn1007-7820.2019.07.002

Abstract ( 312 )   HTML ( 2 )   PDF (1080KB) ( 93 )  

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Aiming at the problems of poor positioning accuracy, low resolution and inconvenient operation in the traditional method, a six-point method combined with laser triangulation positioning and grabbing technique was proposed. The selection of relevant parameters and the error in the acquisition of laser spot on the measured object were the main factors determining the measurement accuracy. By analyzing the basic principles of the six-point method and the laser triangulation method, the relationship between the measurement error and the related parameters was obtained based on the Boolean model. MATLAB was utilized to simulate the relationship between parameters and sensor sensitivity and measurement error during laser triangulation measurement, and the influence of laser point specific coordinate acquisition process on the measured object. Through this method, the law that the error changed with the relevant parameters was obtained, indicating the practical significance of avoided coarse errors in the measurement.

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Real-time Tracking Algorithm Based on Adaptive Model Update

TENG Shuo,WANG Runling

Electronic Science and Technology. 2019, 32(7):  11-16.  doi:10.16180/j.cnki.issn1007-7820.2019.07.003

Abstract ( 265 )   HTML ( 4 )   PDF (1645KB) ( 26 )  

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To improve the speed and accuracy of hierarchical convolutional features for visual tracking method, a real-time and robust object tracking algorithm based on adaptive model update and single-layer convolutional features was proposed. This method firstly extracted the multi-channel convolutional features of the Pool4 layer to adjust the label function of the training samples,which improved the speed of the algorithm while ensuring the tracking accuracy.Meanwhile, the average peak-to-correlation energy was introduced in the proposed algorithm, which feedbacked the tracking results. Combined with the sparse model update strategy, the tracker was adaptively updated to improve the robustness of the algorithm to occlusion and similar object interference. For the problem of rapid scale variation, the scale pyramid was adopted to evaluate the scale to further improve the generalization ability of our tracker. Finally, the algorithm was verified on OTB2013 and OTB2015 benchmark datasets. The experimental results showed that the average distance precision was 91.0% and 86.8%, and the average speed was 43 frames per second, showing outperforming robustness and real-time performances.

Research on Scheduling of Pumped Storage Cascade Reservoir Based on SEOA Algorithm

ZHANG Xueying,WU Xiaoting,Daniel Eiliote Mbanze,ZHOU Zhengwei

Electronic Science and Technology. 2019, 32(7):  17-21.  doi:10.16180/j.cnki.issn1007-7820.2019.07.004

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Aim ing at the curse of dimensionality of power generation dispatching in cascade reservoirs with hybrid pumped storage power stations,based on the randomness and nonlinear characteristics of historical runoff series,a longterm optimal dispatching model of cascade reservoirs with hybrid pumped storage power stations was established.In the scheduling period,the maximum generating capacity of the cascade pumped storage power station was selected as the objective function,and the improved social emotional optimization algorithm was introduced to solve the problem.Taking a mixed flow cascade power station as an example,the simulation results showed that the new method could reduce the redundant calculation of traditional algorithms,and effectively combined the decision-maker’s subjective preference as well as interest propensity in the optimal operation of cascade type reservoirs in hybrid pumped storage power stations. Compared with the dynamic programming algorithm,the new method used a high-quality solution with an annual power generation of 66.96×10⁸ kWh in a short period of time.

Study on the Extraction of Lamb Waves Single Modal Damage Scattering Wave Field and Imaging

YANG Guoying

Electronic Science and Technology. 2019, 32(7):  21-27.  doi:10.16180/j.cnki.issn1007-7820.2019.07.005

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A filtering method of self-reference wavenumber interval was put forward in this paper. The proposed method was proven to be able to distinctly distinguish the different mode of Lamb wave and acquire a single Lamb wave mode damage scattering wave field without knowing the dispersion relation, which was of high practical value to detect the damage of plate-like structure. Based on the difference of wave-number values in different Lamb wave modes under the same frequency and the mapping relationships between wave direction and the 3 dimensional Fourier transform coefficient matrix, the corresponding arc filter window was designed in Matlab to filter the collected space-time wave field data. This article imaged the through-hole damage in aluminum plates by making use of the time-delay superposition imaging algorithm and rectangular array imaging data. The simulation and experiment results showed that the self-reference wavenumber interval filtering method effectively obtained the weak scattering wave field of double damage, and the position of damage reflection combining with the time-delay superposition imaging algorithm was located better. The imaging precision was improved with the increase of the number of elements, realizing the precise location of damage.

Research on Design of Synchronous High Speed Acquisition System of Microphone Array Based on ZYNQ

JIN Hengkang,ZHANG Yiwen

Electronic Science and Technology. 2019, 32(7):  28-32.  doi:10.16180/j.cnki.issn1007-7820.2019.07.006

Abstract ( 488 )   HTML ( 10 )   PDF (1384KB) ( 130 )  

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High-speed simultaneous sampling processing is the basis of a microphone array system. Aiming at the low acquisition rate, high cost, large size and poor portability of the traditional audio acquisition system, the paper designed a microphone array synchronous high-speed acquisition system based on the Xilinx Zynq-7000 series scalable platform. Using FPGA+ARM software and hardware cooperative working mode, data intercommunication was realized through AXI bus. The system was controlled by the analog audio transmission interface protocol and system of the FPGA.The Linux operating system was transplanted on the ARM with the data being transmitted and was saved by the Gigabit Ethernet port and the high-speed SD card.The Xilinx-Vivado kit was used to design the manufacturing system. The experimental results showed that the system supported up to 16 channels of synchronous acquisition with a sampling rate of 96 kHz. The overall weight was 1.67 kg, and the battery life was about 5 hours, which filled the blank of 1000-level small audio array.

Deign of High-Stability DOCXO

NIU Zhanlu,SU Zhangzhan,CHEN Pingping

Electronic Science and Technology. 2019, 32(7):  33-37.  doi:10.16180/j.cnki.issn1007-7820.2019.07.007

Abstract ( 444 )   HTML ( 10 )   PDF (1277KB) ( 102 )  

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In order to improve the temperature-frequency characteristics of OCXO, high stability double oven control crystal oscillator was designed. The temperature control system used double oven structure and improved the design through multipoint inducting and heating, which greatly improved the temperature-frequency characteristics. At the same time, the circuit used SC-cut crystal resonator and Colpitts capacitor three-point oscillating circuit to improve the short-term frequency stability of the product. According to the test, the frequency temperature characteristic and short term stability reached <±2E ^-10(-30~+70℃)and <1E ^-12/s respectively, which were both improved by an order of magnitude compare to similar products. Meanwhile, the aging characteristic was up to <5E ^-11/day.

Research on Adaptive Energy Saving Algorithm of Pump Based on Automatic Feedback System

ZHANG Fan,LIU Jin,YANG Haima

Electronic Science and Technology. 2019, 32(7):  38-42.  doi:10.16180/j.cnki.issn1007-7820.2019.07.008

Abstract ( 332 )   HTML ( 5 )   PDF (1112KB) ( 88 )  

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In view of the current situation of low operating efficiency, high energy consumption and high operating cost of industrial water supply pumps, an adaptive control algorithm of converter was proposed. The algorithm realized the pump pressure-current self-feedback control process and gave full play to the actual water supply performance of the water supply pump under the pressure control mode.After the technical transformation of the 100% capacity 80CHTA/4 water supply pump, the power saving efficiency of the water supply pump reached 9.568% under the condition that the original water supply capacity was unchanged after the transformation. The proposed method significantly improved the electrical energy efficiency of the water supply system, and provided a reference scheme for energy-saving retrofit work of pumps.

Face Recognition Algorithm Based on Multiple Feature Fusion

SU Rao,LI Feifei,CHEN Qiu

Electronic Science and Technology. 2019, 32(7):  43-48.  doi:10.16180/j.cnki.issn1007-7820.2019.07.009

Abstract ( 319 )   HTML ( 4 )   PDF (1342KB) ( 115 )  

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The texture information extracted by the LBP descriptor and the edge feature extracted by the GMQ operator cannot effectively and comprehensively describe the facial feature. To solve the problems, a novel multiple feature fusion algorithm based on Markov Stationary Features model was proposed. Firstly, the edge features obtained by GMQ operator as well as the texture features by LBP descriptor were fused with the MSF model respectively. Then the two MSF-based features were fused by linear weighting. Finally, experiments on the ORL dataset showed that the proposed algorithm could achieve an accuracy of 95.83%. Compared with a single feature extraction algorithm and a common face recognition algorithm, the effectiveness of the proposed method was proved.

Research Progress on Modeling and Control of Two-wheeled Self-Balancing Vehicle

XIONG Yucong,ZHANG Meng,WEI Dazhong

Electronic Science and Technology. 2019, 32(7):  49-55.  doi:10.16180/j.cnki.issn1007-7820.2019.07.010

Abstract ( 653 )   HTML ( 20 )   PDF (1220KB) ( 154 )  

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The two-wheeled self-balancing vehicle is a sort of bike-like vehicle, which can keep balance under action of external torque. Compared with common vehicles, the two-wheeled self-balancing vehicle has been characterized by high safety, environmental friendliness, light shape and convenient driving and has become the major trend of intelligent vehicle development. The study of balance of the two-wheeled vehicle date from the end of 19th century. And now, great achievements have been made both in the theoretical research and modeling. In this paper, the development status of two-wheel self-balancing vehicle in lateral dynamics modeling, actuators and control algorithms were discussed and summarized, and the future research directions were further prospected.

Research and Application of Mold Cavity Segmentation Algorithm Based on STL Model

WU Zhanxiang,GAN Yi,SUN Fujia

Electronic Science and Technology. 2019, 32(7):  56-60.  doi:10.16180/j.cnki.issn1007-7820.2019.07.011

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In this paper, a large concrete casting was taken as the research object, and a STL model based cavity segmentation algorithm was proposed to solve the problem of low efficiency of artificial design of multiple parts. By changing the direction of the triangular patch of the STL model, this paper transformed the STL model of the large component into the STL model of the mold cavity. This algorithm classified the mold cavity STL model data, and uses the normal vector of the triangular face as the judging condition. Then this algorithm classified the face slices of the same type surface to a same STL model. Thus, the STL model of a mold cavity was divided into several surface STL models, and the mold cavity was segmented. Finally, it was proved that the algorithm shortens the design time and improves the efficiency, and proved that the algorithm is feasible, by comparing the design time of two typical algorithms and the time of artificial design.

An Image Recognition Algorithm for Traffic Sign Recognition System

ZHANG Changqing,YANG Nan

Electronic Science and Technology. 2019, 32(7):  60-64.  doi:10.16180/j.cnki.issn1007-7820.2019.07.012

Abstract ( 338 )   HTML ( 2 )   PDF (1038KB) ( 37 )  

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Most of the machine algorithms for the traffic sign recognition system have problems of high computational complexity and poor real-time performance. Hence, based on the ELM model and the improved PCA method, an image recognition algorithm called PCA-ELM for the traffic sign recognition system was proposed. With the help of the extraction of HOG features, dimensionality reduction of improved PCA method, and the feature training of ELM model, the algorithm could realize the recognition of traffic sign images. Being tested and compared, it was found that the PCA-ELM algorithm had high recognition rate with suitable or even lower computational complexity, which well meets the accuracy and real-time requirements of image recognition for the traffic sign recognition system and had certain practical value.

UAV Path Planning Obstacle Avoidance Algorithm Based on Artificial Potential Field Method

MAO Chenyue,WU Pengyong

Electronic Science and Technology. 2019, 32(7):  65-70.  doi:10.16180/j.cnki.issn1007-7820.2019.07.013

Abstract ( 573 )   HTML ( 9 )   PDF (1174KB) ( 130 )  

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With the widespread use of drones in all aspects of production and life, the study of the algorithms of obstacle avoidance of drones has become a hot issue.In order to improved the obstacle avoidance performance of UAV, this paper proposed an obstacle avoidance algorithm for UAV path-planning based on the artificial potential field method.The algorithm decreased the attraction of the target point to the drone by generating the pre-planning path, and extends the continuity of the path. The dynamic adjustment factor was added to the potential field function to reduce the unnecessary turning maneuvers of the drone trajectory thus reducing the consumption of Mobile energy;The algorithm considered the safety, smoothness and maneuvering energy consumption of UAVs in flight. A new cost function is proposed and the optimal path was selected by minimizing the cost function.The experimental results showed that the algorithm overcomes the shortcomings of the traditional artificial potential field, and can plan safe, smooth, and small mobile energy consumption paths in different flight environments, effectively avoiding the obstacles with better adaptability.

Underwater Sensor Node Design of Micro Underwater Acoustic Sensor Network

CHEN Yuan,CAI Wenyu,HU Biwei

Electronic Science and Technology. 2019, 32(7):  71-75.  doi:10.16180/j.cnki.issn1007-7820.2019.07.014

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For the high transmission rate, high reliability and long-term operation of the underwater acoustic sensor network in the marine environment monitoring system, a low-power miniature underwater sensor node was designed. A transducer T235 with a higher energy conversion rate and receiving sensitivity was designed, and a transformer was used to impedance matching at the transmitting unit to maximize signal power transmission.The receiving unit used an eighth-order Butterworth bandpass filter to better filter out noise.On the software, the MAC protocol was transplanted and optimized to reduce the probability of bump and resend. According to the test, when the transmission rate was 19 200 bit·s ^-1 in a small scale, the total power consumption of the system was less than 20 W,and the communication transmission success rate of more than 90% could be achieved.

Design of Voice Coil Motor Position Control System Based on PID Algorithm

WANG Yuesheng,LI Wei

Electronic Science and Technology. 2019, 32(7):  76-81.  doi:10.16180/j.cnki.issn1007-7820.2019.07.015

Abstract ( 863 )   HTML ( 27 )   PDF (1099KB) ( 197 )  

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The mathematical model of the voice coil linear motor was analyzed. The system used the micro-processor combined with the analog circuit to design the drive system. The PID control algorithm and its noise model were analyzed. For the noise interference problem of the voice coil motor in operation, a control algorithm based on PID and Luenberger Observer, which eliminates motor noise interference by adding a pair of feedback resistors to the motor load. Compared with the conventional PID algorithm, the controller algorithm could not only eliminate low frequency noise but also high frequency. There were also obvious advantages in noise processing. The voice coil motor simulation model was established in Matlab/Simulink. Compared with the PID algorithm, the simulation results showed that the algorithm had stronger denoising ability in high frequency noise.

An Efficient Face Recognition System Based on Linear and Nonlinear Algorithms

LIU Fen

Electronic Science and Technology. 2019, 32(7):  82-86.  doi:10.16180/j.cnki.issn1007-7820.2019.07.016

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This paper presented a linear and non-linear face recognition method based on appearance. The linear algorithms used include principal component analysis (PCA) and linear discriminant analysis (LDA). Two non-linear methods were kernel principal component analysis (KPCA) and nuclear fisher analysis (KFA).Linear dimensionality reduction projection method was based on second-order dependency coding mode information, and non-linear method was used to deal with the relationship between three or more pixels. In the last stage,the Mahcos measure was used to define the similarity measure of two images after the corresponding dimension reduction technology.Experiments show that when used together with Gabor wavelet,LDA and KFA had the highest performance, 93.33% of CMC and ROC results, respectively. Through the comprehensive analysis of 400 images in AT&T database, it was found that the performance of linear and non-linear algorithms was affected by the number of image classification, image preprocessing and the number of face images in recognition test set.