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Chinese Control Conference (CCC)

作者： Jinhui Li Kai Ding Jianmei Sun Chi Wang Hongtao Zhao Huijie Zhu Science and Technology on Near-Surface Detection Laboratory Wuxi China Department of Precision Mechanical Engineering Shanghai University Shanghai China

ISBN: (数字)9789881563903

ISBN: (纸本)9781728165233

This paper addresses the active control for magnetic levitation system against two probes failures, which degrades the stability of the levitation control, decreases the ride comfort near the rail joint. Firstly, a minimum interaction model containing vertical dynamics of electromagnets, cabin and traditional control scheme is developed. The output characteristics of probes near or under the typical joint are obtained by fitting experimental data. It shows that the maximum of the deviation values is up to 11mm, which should be attenuated effectively. Inspired by the probes' output characteristics and limited response range in the process of crossing the joint, a practical joint recognition method is explored. It shows that the joint can be identified timely. Then a pair of complementary filters acting on acceleration and limited gap signal is developed to reconstruct the levitation gap signals. It shows that the deviations of the synthesized value are reduced substantially. After building the overall dynamic model with details, numerical simulations are carried out, and the results illustrating the improvement of stability and extended low speed range are provided.

关键词： Probes Levitation Electromagnets Rails Fluctuations Electromagnetic forces

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Acoustic Target Recognition Based on MFCC and SVM 22nd

Acoustic Target Recognition Based on MFCC and SVM

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22nd International Conference on Man-Machine-Environment System Engineering, MMESE 2022

作者： Ding, Kai Zheng, Shoujun Qi, Xiaogang Huang, Shan Liu, Haoting Science and Technology on Near-Surface Detection Laboratory Wuxi214035 China School of Mathematics and Statistics Xidian University Xi’an710071 China Nanjing ATE Electronic Tech Co. Ltd. Nanjing China Beijing Engineering Research Center of Industrial Spectrum Imaging University of Science and Technology Beijing100083 China

ISBN: (纸本)9789811947858

Feature extraction and classification are the main body of acoustic target recognition. Firstly, amplitude extraction based on harmonic set, MFCC and wavelet packet decomposition are selected as feature selection methods to extract the features of four kinds of measured sound signals respectively. Then, the feature vectors extracted by MFCC method with the best clustering effect are combined with GMM classifier, BP neural network, OVO-SVMs and multi-layer support vector machine as classifiers, and MATLAB is used for simulation recognition and classification. Finally, the recognition results are compared and analyzed. The results show that BP neural network has the best recognition effect, but its robustness is poor, the experimental results are unstable, and the selection of training and test data has a great impact on the recognition rate. The multi classification algorithm based on support vector machine has a better stable recognition rate. © 2023, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.

关键词： Support vector machines

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Angle of arrival (AOA)-based cross-localization algorithm using orientation angle for improved target estimation in far-field environments

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International Journal of Simulation: Systems, science and technology 2016年第31期17卷 20.1-20.8页

作者： Xu, Penghao Yan, Bing Hu, Shouwei Department of Weaponry Engineering Naval University of Engineering WuhanHubei430033 China Science and Technology on Near-Surface Detection Laboratory WuxiJiangsu214035 China

Passive positioning systems with a small aperture array exhibit poor accuracy of target estimation in far-field environments. To improve this accuracy, this paper presents a novel angle-of-arrival (AOA)-based cross-localization algorithm for direction finding using orientation angle. Improved geometric and numerical target-positioning models are constructed after analyzing the mechanism of the conventional AOA-based cross-positioning algorithm. The target predication equation is then derived using the constructed models, and the equation for nonlinear estimation is linearized using the Taylor series. An unbiased estimation of the target is obtained by optimizing the control of the iteration process, thus achieving an accurate positioning of the target. The performance of the proposed algorithm was evaluated in terms of its effectiveness and positioning accuracy under varying signal-to-noise conditions and orientation angle-measurement errors. Simulation results shows that the proposed algorithm is capable of positioning the target effectively, and offers better positioning accuracy than traditional algorithms under conditions of large AOA measurement errors or high-level background noise. © 2016, UK Simulation Society. All rights reserved.

关键词： Iterative methods

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The design of controller in permanent magnet linear synchronous motor

The design of controller in permanent magnet linear synchron...

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Chinese Automation Congress (CAC)

作者： Zhen Jia Jie Li Peichang Yu Jinhui Li Peng Leng Engineering Research Center of Maglev Technology National University of Defense Technology Changsha China Science and technology on near-surface detection laboratory Wuxi China

In this paper, the q-d axis currents in the vector control of permanent magnet synchronous linear motor are coupled with each other, which affects the control performance of the motor. By establishing a model of permanent magnet synchronous linear motor and analyzing the coupling reasons, a feedforward decoupling method is proposed to realize the current control of motor. On this basis, an anti-saturation integration algorithm is proposed to solve the saturation integral problem in motor speed-loop control. The system simulation results show that the decoupling current control performance is significantly improved, and the speed response performance is good.

关键词： Permanent magnet motors Synchronous motors Permanent magnets Steady-state Mathematical model Machine vector control Stators

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A resonant cavity based on birdcage coil for overhauser geomagnetic sensor

A resonant cavity based on birdcage coil for overhauser geom...

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2018 IEEE International Instrumentation and Measurement technology Conference, I2MTC 2018

作者： Bai, Bingjie Dong, Haobin Ge, Jian Liu, Huan Zhang, Cheng Wang, Luo Institute of Geophysics and Geomatics China University of Geosciences Hubei Wuhan China School of Automation China University of Geosciences Hubei Wuhan China Hubei Key Laboratory of Advanced Control and Intelligent Automation for Complex Systems Hubei Wuhan China Science and Technology on Near-Surface Detection Laboratory Jiangsu Wuxi China

ISBN: (纸本)9781538622223

The resonant cavity is an important component of Overhauser magnetometer sensor. Its function is to make the working substance generate dynamic nuclear polarization effect in the sensor. An alternative design of resonant cavity based on the birdcage coil structure was proposed to make the resonant frequency in accordance with the polarization frequency of the working substance. The structure and equivalent circuit of resonant cavity were analyzed. The model of resonant cavity was established and S-parameter is calculated to verify the frequency consistency of the resonant cavity and working substance. In addition, output signal experiment and simultaneous comparison testing of sensor prototype were conducted. Overall, this design has the advantages of high performance and strong anti-interference. © 2018 IEEE.

关键词： Equivalent circuits

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The formation of high-resolution FMCW SAR video

The formation of high-resolution FMCW SAR video

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Progress in Electromagnetic Research Symposium (PIERS)

作者： Chengfei Gu Wenge Chang Xiangyang Li Xinqun Luan College of Electronic Science and Engineering National University of Defense Technology Changsha Hunan China Science and Technology on Near-Surface Detection Laboratory Wuxi Jiangsu China

In this paper, the formation of high-resolution FMCW SAR video is introduced in detail. With the application of rational design and compact devices, a miniaturized FMCW SAR prototype is successfully realized. Based on this high-performance FMCW SAR system, the continuous real-time video is achieved after the preprocessing of raw data, the parallel realization of extended FSA and the reprocessing of imaged data. Moreover, the time consuming of each procedure is accurately tested on the processing board of FMCW SAR system. In the end, several airborne experiments have been performed, and beneficial FMCW SAR video results have been obtained.

关键词： Synthetic aperture radar Streaming media Digital signal processing Imaging Azimuth Real-time systems Electromagnetics

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A compact air-coupled SFCW ground penetrating radar and its application in the earthen sites 20

A compact air-coupled SFCW ground penetrating radar and its ...

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20th International Conference on Ground Penetrating Radar, GPR, 2024

作者： Ye, Shengbo Li, Xu Li, Xinhui Liu, Xiaojun Fang, Guangyou Jiang, Hejun Lyu, Rongqi Aerospace Information Research Institute Chinese Academy of Sciences Beijing100190 China Key Laboratory of Electromagnetic Radiation and Sensing Technology Chinese Academy of Sciences Beijing100190 China School of Electronic Electrical and Communication Engineering University of Chinese Academy of Sciences Beijing100049 China Science and Technology on Near-surface Detection Laboratory Wuxi214035 China

As a non-destructive testing technology, ground-penetrating radar (GPR) has been widely used in archaeological investigations of the earthen sites. Traditionally, a GPR antenna is ground-couple. It is attached to the measured object and thus may cause damage to the earthen sites. This paper develops a lightweight and compact air-coupled stepped frequency continuous waveform (SFCW) GPR system with frequency range from 1GHz up to 6GHz. We suppress the nonlinear variables of the radar system by calibration. And we perform tests on different weathering samples from the earthen sites. Our system is verified that can discriminate layered structures in samples and the results of tests are consistent with the simulations of the gprMax model. In general, this radar system can assess the weathering degree and provide technical support for the preservation of the earthen sites. © Published under licence by IOP Publishing Ltd.

关键词： Antenna grounds

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Camouflaged target tracking based on a scaleadaptive correlation filter algorithm

Camouflaged target tracking based on a scaleadaptive correla...

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Chinese Automation Congress (CAC)

作者： Yang Liu Congqing Wang Yongjun Zhou College of Automation Engineering Nanjing University of Aeronautics and Astronautics Nanjing China Science and Technology on Near-Surface Detection Laboratory Wuxi China

ISBN: (数字)9781665426473

ISBN: (纸本)9781665426480

Considering the continuous development of intelligent technology and the wide application prospects of unmanned aerial vehicles (UAVs), the target tracking technology will be applied in future combat. In order to deal with the complex battlefield environment and the scale change of the target during tracking, an improved scale-adaptive correlation filter algorithm based on fusion features is proposed to realize the tracking of military personnel. First, the fast histogram of oriented gradient (FHOG) features and the local binary pattern (LBP) features are adaptively weighted and fused to achieve the target location. Then the translation filter of kernelized correlation filters(KCF) and the scale filter of discriminative scale space tracking(DSST) are combined to comprehensively improve the calculation speed and scale adaptation performance of the algorithm and track the target in time. The experimental results prove the robustness and practicability of the proposed method, which can accurately track military targets in real time.

关键词： Histograms Target tracking Correlation Automation Filtering algorithms Autonomous aerial vehicles Robustness

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Wide-beam Vivaldi Antenna

Wide-beam Vivaldi Antenna

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Progress in Electromagnetic Research Symposium (PIERS)

作者： Jinjing Ren Zhongyuan Yu Qi Tang Research Center for Electromagnetic Environmental Effects Southeast University Nanjing China Science and Technology on Near-surface Detection Laboratory Wuxi China

ISBN: (纸本)9781665409889

Vivaldi antenna has superior radiation performance and simple process, which can be used for common radar ranging. However, as a transmitting antenna, the Vivaldi antenna beam width is insufficient. In this paper, the traditional radiation structure of Vivaldi antenna is improved. A wide beam Vivaldi antenna based on elliptical slot structure is proposed, and the size is 150 mm×150 mm×1.6 mm, and FR4 is selected as the dielectric layer material. In the 2.5GHz-4GHz frequency range, the half-power beam width of the antenna reaches 90°, and the maximum reaches 128.3°. The gain is greater than 3.26 dBi and the directivity consistency is good. In the direction finding and ranging experiment, the antenna was used as the transmitting source of the transceiver system to measure the distance of metal objects. The ranging results are in high agreement with the actual results, indicating that the performance of the antenna is good.

关键词： Antenna measurements Simulation Vivaldi antennas Transmitting antennas Metals Directive antennas Transformers

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Full-polarimetric GPR for detecting ice fractures 17

Full-polarimetric GPR for detecting ice fractures

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17th International Conference on Ground Penetrating Radar, GPR 2018

作者： Luo, Chaopeng Feng, Xuan Liu, Cai Zhang, Yan Nilot, Enhedelihai Zhang, Minghe Dong, Zejun Zhou, Haoqiu Science and Technology Near-Surface Detection Laboratory China Key Laboratory of Geophysical Exploration Equipment Ministry of Education Jilin University No.938 Xi MinZhu Street Changchun130026 China College of Geo-exploration Science and Technology Jilin University No.938 Xi Minzhu Street Changchun130026 China College of Earth Sciences Jilin University Changchun130061 China

ISBN: (纸本)9781538657775

The real-time monitoring of ice fracture width and direction is of great significance for the safety of Antarctic scientific expedition and the understanding of the process of ice fracture induced by avalanches. Using full-polarimetric ground penetrating radar (GPR) system to detect ice cracks, the scattering matrix is obtained and processed by polarization decomposition. Compared with the traditional pulse radar, more comprehensive and more intuitive information of ice cracks can be obtained. By using the Pauli decomposition method in polarization decomposition, the forward data obtained by the three-dimensional finite difference time domain (FDTD) method is processed, and the applicability of the proposed decomposition method is proved. For testing the feasibility, we performed numerical and laboratory experiments and applied the Pauli decomposition to the GPR data for ice fracture characterization. On this basis, the method is used to imaging small scale ice cracks on the lake surface, and good results are achieved, which paves the way for further practical application. © 2018 IEEE.

关键词： Polarization

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