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SSRN 2024年

作者： Cheng, Yang Hao, Qun Liu, Lin Cao, Jie Liu, Mengyao Ou, Yangqi Key Laboratory of Biomimetic Robots and Systems Ministry of Education Beijing Institute of Technology Beijing100081 China Yangtze Delta Region Academy of Beijing Institute of Technology Jiaxing314003 China National Key Laboratory of Science and Technology on Near-Surface Detection Beijing100012 China

A thin wide range varifocal diffractive Alvarez lens actuated by dielectric elastomers (DEs) is designed and proposed. The diffractive Alvarez lens is manufactured by the laser direct writing technique with four etching depths. The diffractive Alvarez lens consists of two diffractive phase plates, which can move laterally by applying an actuation voltage to the DEs, and then the focal length of the diffractive Alvarez lens changes. The thickness and the optical aperture of the proposed diffractive Alvarez lens are 4 mm and 10 mm, respectively. The focal length ratio is up to 10×, where the maximum the minimum focal lengths are 300 mm and 30 mm, respectively. The rise time and fall time are 134 ms and 206 ms. The average diffraction efficiency is 82% at 532 nm. Such a thin wide range varifocal diffractive Alvarez lens promises a potential solution for many applications, such as endoscopes, consumer electronics, and microscopies. © 2024, The Authors. All rights reserved.

关键词： Lenses

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Anti-personnel Mine detection by Sparse Representation of GPR B-scan Radargram Image

Anti-personnel Mine Detection by Sparse Representation of GP...

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2019 IEEE International Conference on Signal, Information and Data Processing, ICSIDP 2019

作者： Sun, Tao Luo, Chaopeng Liu, Mengna Zhou, Liqing Tang, Xianxiu Meng, Riheng Tang, Xinjian Hao, Weifeng Science and Technology on Near-Surface Detection Laboratory Wuxi China Electronic Information School of Wuhan University Wuhan China Dept.of Architectural Engineering Hubei Water Resources Technical College Wuhan China State Key Lab. of Geomechanics and Geotechnical Engineering Institutude of Rock and Soil Mechanics Chinese Academy of Sciences Wuhan China Antarctic Center of Sureying and Mapping of Wuhan Univeristy Wuhan China

ISBN: (纸本)9781728123455

Ground penetrating radar is an efficient close-range remote sensing and non-destructive-testing technique, which probes ultra-wide-band electromagnetic pulses to detect underground targets. Then theirs geometric features and material property characters will been figured out. A major clutter interference coupling with the response of the subsurface-buried-landmine is direct air wave and direct ground reflected waves, which hinder shallow buried landmine precise detection and discrimination. As for shallow buried targets, in this paper, a clutter and target response echo decoupling method with Linear-Gain-Compensation-Robust-PCA algorithm is proposed based on low-rank prior of clutters and target distribution spatial sparse prior. Compared with Principal Component Analysis, mean subtract algorithm, the performance of LGC-RPCA method is tested with simulations and indoor sand-box experiments. These demonstrate that the LGC-RPCA method with inexact augmented Lagrangian function is an efficient algorithm for shallow buried landmine detection and discrimination. Then, it will reduce the false alarm rate for identification of shallow buried anti-personnel Mine. © 2019 IEEE.

关键词： Ground penetrating radar systems

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A 3d Non-Stationary Geometry-Based Stochastic Model for Uav Air-to-Ground Mimo Channels

SSRN

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SSRN 2022年

作者： Zhou, Tianxiang Yan, Feng Li, Hao Pang, Jingming Ding, Kai Xia, Weiwei Shen, Lianfeng National Mobile Communications Research Laboratory Southeast University Nanjing210096 China Science and Technology on Near-Surface Detection Laboratory Wuxi214035 China Jiangsu ZhongLi Electronic Information Sci-Tech Co. Ltd Changshu215542 China

In this paper, a three-dimensional geometry-based stochastic model is proposed for unmanned aerial vehicle (UAV) non-stationary air-to-ground multi-input multi-output (MIMO) channels. In the proposed model, the scatterers around the UAV and ground station are assumed to be distributed on the surface of two cylinders respectively. In order to describe the channel non-stationarity, the impact of rotations and accelerated motion of UAV are taken into account. The computation method of the corresponding time-variant parameters are theoretically deduced, including UAV antenna array angles, time delays and maximum Doppler frequencies. Based on the model, the channel statistical properties such as space-time correlation functions are further derived. Simulation results show that the increasing accelerations of the UAV and ground station can reduce the time correlation function and increase the channel non-stationarity in time domain. The UAV rotation has an important influence on the spatial correlation function, and the influence of rolling is more significant than that of pitching. © 2022, The Authors. All rights reserved.

关键词： Unmanned aerial vehicles (UAV)

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Design and implementation of real-time localization system (RTLS) based on UWB and TDoA algorithm

arXiv

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arXiv 2021年

作者： Zhang, Fengyun Yang, Li Liu, Yuhuan Ding, Yulong Yang, Shuang-Hua Li, Hao Department of Computer Science and Engineering Southern University of Science and Technology Shenzhen China Army Engineering University of PLA Nanjing China Academy for Advanced Interdisciplinary Studies Southern University of Science and Technology Shenzhen China PCL Research Center of Networks and Communications Peng Cheng Laboratory Shenzhen China Science and Technology on Near-surface Detection Laboratory Wuxi China

Nowadays, accurate localization plays an essential role in many fields, like target tracking and path planning. The challenges of indoor localization include inadequate localization accuracy, unreasonable anchor deployment in complex scenarios, lack of stability, and the high cost. So the universal positioning technologies cannot meet the real application requirements scarcely. To overcome these shortcomings, a comprehensive Ultra Wide-Band (UWB) based RTLS is presented in this paper. We first introduce the architecture of real-time localization system, then propose a new wireless clock synchronization (WCS) scheme, finally discuss the time difference of arrival (TDoA) algorithm. We define the time-base selection strategy for TDoA algorithm, and analyze the relationship between anchor deployment and positioning accuracy. The Extended Kalman Filter (EKF) method is presented for non-linear dynamic localization estimation, and it performs well in terms of stability and accuracy in moving target. Copyright © 2021, The Authors. All rights reserved.

关键词： Extended Kalman filters

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Design and Implementation of Real-Time Localization System (Rtls) Based on Uwb and Tdoa Algorithm

SSRN

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SSRN 2022年

作者： Zhang, Fengyun Yang, Li Liu, Yuhuan Ding, Yulong Yang, Shuang-Hua Li, Hao Department of Computer Science and Engineering Southern University of Science and Technology Shenzhen China Army Engineering University PLA Nanjing China Academy for Advanced Interdisciplinary Studies Southern University of Science and Technology Shenzhen China PCL Research Center of Networks and Communications Peng Cheng Laboratory Shenzhen China Science and Technology on Near-surface Detection Laboratory Wuxi China

Nowadays, accurate localization plays an essential role in many fields, like target tracking and path planning. The challenges of indoor localization include inadequate localization accuracy, unreasonable anchor deployment in complex scenarios, lack of stability, and the high cost. So the universal positioning technologies cannot meet the real application requirements scarcely. To overcome these shortcomings, a comprehensive Ultra Wide-Band (UWB) based RTLS is presented in this paper. We introduce the architecture of real-time localization system, then propose a new wireless clock synchronization (WCS) scheme, finally discuss the time difference of arrival (TDoA) algorithm. We define the time-base selection strategy for the TDoA algorithm, and analyze the relationship between anchor deployment and positioning accuracy. The Extended Kalman Filter (EKF) method is presented for non-linear dynamic localization estimation, and it performs well in terms of stability and accuracy in moving target. © 2022, The Authors. All rights reserved.

关键词： Extended Kalman filters

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High-space-bandwidth product characterization of metalenses with Fourier ptychographic microscopy

arXiv

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arXiv 2024年

作者： Zheng, Chuanjian Wang, Wenli Ji, Yanfang Hu, Yao Zhang, Shaohui Hao, Qun School of Optics and Photonics Beijing Institute of Technology Beijing100081 China National Key Laboratory on Near-Surface Detection Beijing10012 China Tianjin H-Chip Technology Group Corporation Tianjin300480 China

Large numerical aperture (NA) and large aperture metalenses have shown significant performance and abundant applications in biomedical and astronomical imaging fields. However, the high space-bandwidth product (SBP) requirements for measuring the phase of these metalenses, characterized by small phase periods and large apertures, have resulted in no effective techniques for sufficient characterization. In this paper, we propose a high SBP phase characterization technique using Fourier ptychographic microscopy (FPM), enabling a high spatial resolution and wide field of view simultaneously. To demonstrate the feasibility and effectiveness of this technique, we achieve a high SBP (4.91 megapixels) measurement and characterization for focusing and focusing vortex metalenses, quantitatively displaying the effect of fabrication error on their typical optical performance. Furthermore, we characterize the aberration type and amount of wavefront deviations caused by fabrication. We also analyze compensation methods for different aberrations based on the wavefront characterization results, providing a targeted alignment strategy for optimizing overall optical system performance. We believe that our high SBP characterization technique cannot only help to improve metalens design but also optimize its fabrication processing, which will pave the way for the diversified applications of metalenses. Copyright © 2024, The Authors. All rights reserved.

关键词： Aberrations

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MEMS Accelerometer Stability and Temperature Compensation for Long Term Structure Surveillance System

MEMS Accelerometer Stability and Temperature Compensation fo...

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IEEE International Conference on Robotics and Biomimetics

作者： Yingjiao Rong Zengshuai Qiu Guang Luo Congcong Ma Guangyi Shi Juanhui Zheng The Science and Technology on Near-Surface Detection Laboratory Wuxi China DFH Satellite Co. Ltd. Beijing China Peking University Beijing China BEWIS Sensing Technology LCC Wuxi China School of Software and Microelectronics Peking University Beijing China

ISBN: (纸本)9781665405362

This paper describes the compensation strategy for MEMS accelerometer which needs long time stability and good temperature drift parameter for long time surveillance system. A noise filter for static monitoring environment is designed. The static stability algorithm is designed by studying railway monitoring data. Temperature compensate system is designed, temperature compensation model fitted with a polynomial equation is proposed. Experimental result shows the difference between the heating curve and the cooling curve, a method for judging the heating and cooling according to the readings of the temperature sensor is proposed. Accelerometer array with redundant structure is designed and temperature compensation model is designed to compensate the heating and cooling separately. Through experiments, the errors of the new method and the traditional method are compared. The temperature drift can be compensated less then 80 μg.

关键词： Temperature sensors Accelerometers Heating systems Micromechanical devices Wavelet transforms Cooling Surveillance

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Towards Automatic Operation Motion Tracking Algorithm Based on Inertial Sensors for Multi Joints Machinery

Towards Automatic Operation Motion Tracking Algorithm Based ...

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IEEE International Conference on Robotics and Biomimetics

作者： Yingjiao Rong Zengshuai Qiu Jiayi Liu Zhan Shu Chen Jiao Guangyi Shi Qiang Qin The Science and Technology on Near-Surface Detection Laboratory Wuxi China DFH Satellite Co. Ltd. Beijing China Peking University Beijing China BEWIS Sensing Technology LCC Wuxi China School of Software and Microelectronics Peking University Beijing China

ISBN: (纸本)9781665405362

This paper presents a novel method for multi joints machinery motion tracking, which is useful for automatic operation. Heavy machinery such as excavator bulldozer forklift and grader are with multiple arms for particular tasks. These arms with rotation motion will change the dimensional coordinates accordingly. Thus, the motion tracking will give the feedback for automatic control and realize the unmanned operation in the end. Inertial measurement units (IMUs) are designed with 6D MEMS sensors. Calibration method is studied and the installation error is corrected. Extend Kalman filter is designed for dynamic motion tracking. The acceleration chip structure is also studied for later on ASIC design. Experimental result shows that the dynamic angle error is better than 0.1 degree for every joint of a robot arm, which proves the dynamic tracking method.

关键词： Tracking Robot kinematics Heuristic algorithms Dynamics Arms Robot sensing systems Calibration

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Evaluation of Water Ecological Carrying Capacity Based on Natural Resource Endowment Characteristics: A Case Study of Yicheng City 12

Evaluation of Water Ecological Carrying Capacity Based on Na...

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12th Academic Conference of Geology Resource Management and Sustainable Development, GRMSD 2024

作者： Jiang, Xingzheng Liu, Xiaojing Li, Xuanhui Zeng, Guanzhong Center for Geophysical Survey China Geological Survey Lang Fang065000 China Technology Innovation Center for Earth Near Surface Detection China Geological Survey Lang Fang065000 China Key Laboratory of Coupling Process and Effect of Natural Resources Elements MNR Beijing100055 China Comprehensive Observation and Research Station for Hubei Xiangyang Natural Resource Elements Xiangyang441000 China

ISBN: (纸本)9798331314545

Water is the source of life, the foundation of ecology and the key to production. In Yicheng City, a typical county city in China's watersheds, the concept of water ecological carrying capacity and the assessment method are proposed by combining the general situation of the study area and the relevant research bases at home and abroad, taking into account the whole elements of natural resources. Determination of factor weights using a combined hierarchical analysis-entropy weighting approach. Deriving water ecological carrying capacity evaluation results suitable for adoption in rural China. Results and analysis of water ecological carrying capacity zoning and grading in Yicheng City. There are 223 village units in Yicheng City, and considering the spatial scarcity of the indicator factors, the study area is divided into four categories of village-level evaluation units, namely, the ideal carrying, preferable carrying, critical overloading and overloading. The proportion of the area is 9.56%, 25.24%, 46.65% and 18.55% respectively, providing scientific reference and data support for the construction of the "Thousand Villages Demonstration and Ten Thousand Villages Improvement" project and the realization of rural revitalization and sustainable development. © 2024 Proceedings of the 12th Academic Conference of Geology Resource Management and Sustainable Development, GRMSD 2024. All rights reserved.

关键词： Sustainable city

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Study on the Spatiotemporal Pattern of Land Use Change in Han River Basin 12

Study on the Spatiotemporal Pattern of Land Use Change in Ha...

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12th Academic Conference of Geology Resource Management and Sustainable Development, GRMSD 2024

作者： Yu, Peng Zeng, Guanzhong Liu, Xiaojing Li, Xuanhui Center for Geophysical Survey China Geological Survey Lang Fang065000 China Technology Innovation Center for Earth Near Surface Detection China Geological Survey Lang Fang065000 China Key Laboratory of Coupling Process and Effect of Natural Resources Elements MNR Beijing100055 China Comprehensive Observation and Research Station for Hubei Xiangyang Natural Resource Elements Xiangyang441000 China

ISBN: (纸本)9798331314545

In response to the frequent changes in land use and prominent conflicts between people and land in the Han River Basin, this study takes the Han River Basin as the research area, based on GIS technology, and uses the land use dataset from 2000 to 2022 to comprehensively utilize the land transfer matrix and standard deviation ellipse analysis to study the spatiotemporal characteristics of land use changes in the research area. The results show that from 2000 to 2022, the cropland area in the study area decreased the most, while the construction land area increased significantly;The spatial change of land use is inclined with the northwest to Dingnan direction as the main axis, concentrated in the southeast and central regions. The research results can provide scientific basis for the national spatial planning and sustainable development of central cities in the Han River Basin. © 2024 Proceedings of the 12th Academic Conference of Geology Resource Management and Sustainable Development, GRMSD 2024. All rights reserved.

关键词： Abiotic

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