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Spherical robot: A novel robot for exploration in harsh unknown environments

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IET Cyber-Systems and Robotics 2023年第4期5卷 1-15页

作者： Wei Ren You Wang Haoxiang Liu Song Jin Yixu Wang Yifan Liu Ziang Zhang Tao Hu Guang Li State key laboratory of Industrial Control Technology Institute of Cyber Systems and ControlZhejiang UniversityHangzhouChina

The authors propose a complete software and hardware framework for a novel spherical robot to cope with exploration in harsh and unknown *** proposed robot is driven by a heavy pendulum covered by a fully enclosed spherical shell,which is strongly protected,amphibious,anti-overturn and has a *** for location and perception,planning and motion control are comprehensively *** the one hand,the authors fully consider the kinematic model of a spherical robot,propose a positioning algorithm that fuses data from inertial measurement units,motor encoder and Global navigation Satellite System,improve global path planning algorithm based on Hybrid A*and design an instruction planning controller based on model predictive control(MPC).On the other hand,the dynamic model is built,linear MPC and robust servo linear quadratic regulator algorithm is improved,and a speed controller and a direction controller are *** addition,based on the pose and motion charac-teristics of a spherical robot,a visual obstacle perception algorithm and an electronic image stabilisation algorithm are ***,the authors build physical systems to verify the effectiveness of the above algorithms through experiments.

关键词： mobile robots robot control robot perception robot planning

Modeling and performance evaluation of TomoSAR system based on reflected signal of Beidou navigation satellite

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Modeling and performance evaluation of TomoSAR system based ...

Single-/fused-band dual-mode mid-infrared imaging with colloidal quantum-dot triple-junctions

第十四届中国卫星导航年会

作者： Chenghao Wang Feifeng Liu Cheng Hu Zhanze Wang Zhixiang Xu Radar Research laboratory School of Information and Electronics Beijing Institute of Technology key laboratory of Electronic and Information Technology in Satellite navigation (Beijing Institute of Technology) Ministry of Education

TomoSAR improves the information dimension of radar image from2D to 3D, and is widely used in elevation modeling, deformation inversion of infrastructure such as high-rise buildings, dams and mining areas, and forest vegetation biomass estimation. However, the revisiting time of traditional spaceborne TomoSAR is more than 10 days, it is difficult to monitor and forecast the sudden deformation in real time. Furthermore, most of the loworbit satellites are deployed in the north-south direction, so the deformation measurement accuracy in the north-south direction is relatively poor. The orbit baselines in height direction of low orbit satellites are small, so the image quantity and cost of high resolution tomography processing are ***, low orbit TomoSAR is difficult to achieve high frequency, high precision and low-cost three-dimensional deformation measurement. Although GEO SAR and MEO SAR systems have the advantages of shorter revisit period, longer observation time and larger beam coverage area theoretically,there are no satellites in orbit at present. GNSS-TomoSAR, based on the reflected signals of navigation satellites, uses the in-orbit navigation satellite as the irradiation source, and a stationary receiver is placed on the ground to receive the echo signal reflected from the scene for synthetic aperture radar tomographic processing, which can achieve high frequency, high precision and low-cost three-dimensional deformation monitoring of the scene. GNSSTomoSAR is a relatively novel signal processing concept, which is rarely studied at home and abroad. In this paper, the signal processing model of GNSS-TomoSAR is established, the performance boundary of GNSSTomoSAR is discussed, and the actual track of Beidou IGSO satellite is used to conduct the simulation of height inversion of point target in GNSS-TomoSAR configuration. In above, the application prospect of GNSS-TomoSAR technology is preliminarily explored, lying a foundation for GNSS-TomoSAR real

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Photonics Research 2022年第8期10卷 1987-1995页

作者： SHUO ZHANG GE MU JIE CAO YUNING LUO QUN HAO MENGLU CHEN YIMEI TAN PENGFEI ZHAO XIN TANG School of Optics and Photonics Beijing Institute of TechnologyBeijing 100081China Beijing key laboratory for Precision Optoelectronic measurement Instrument and Technology Beijing 100081China Yangtze Delta Region Academy of Beijing Institute of Technology Jiaxing 314019China

image data acquired with fused multispectral information can be used for effective identification and navigation owing to additional information beyond human vision,including thermal distribution,night vision,and molecular ***,the construction of photodetectors with such capabilities is hindered by the structural complexity arising from the integration of multiple semiconductor junctions with distinct energy gaps and lattice *** this work,we develop a colloidal quantum-dot dual-mode detector capable of detecting,separating,and fusing photons from various wavelength *** three vertically stacked colloidal quantum-dot homojunctions with alternating polarity,single-band short-wave infrared imaging and fused-band imaging(short-wave and mid-wave infrared)can be achieved with the same detector by controlling bias polarity and *** dual-mode detectors show detectivity up to 8×10^(10)Jones at the fused-band mode and 3.1×10^(11)Jones at the single-band mode,*** image post-processing algorithms,the dual-mode detectors could provide both night vision and thermal information-enhanced night vision imaging *** the best of our knowledge,this is the first colloidal quantum-dot detector that can achieve such *** operation mode can be changed at a high frequency up to 1.7 MHz,making it possible to achieve simultaneously dual-mode imaging and remote temperature sensing.

关键词： fused quantum polarity

X-ray photon-counting detector based on a micro-channel plate for pulsar navigation

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Chinese Optics Letters 2011年第6期9卷 13-16页

作者：陈宝梅赵宝升胡慧君鄢秋荣盛立志 State key laboratory of Transient Optics and Photonics Xi'an Institute of Optics and Precision Mechanics Chinese Academy of Sciences Graduate University of Chinese Academy of Sciences

The pulse time of arrival （TOA） is a determining parameter for accurate timing and positioning in X-ray pulsar navigation. The pulse TOA can be calculated by comparing the measured arrival time with the predicted arrival time of the X-ray pulse for pulsar. In this study, in order to research the measurement of pulse arrival time, an experimental system is set up. The experimental system comprises a simulator of the X-ray pulsar, an X-ray detector, a time-measurement system, and a data-processing system. An X-ray detector base is proposed on the basis of the micro-channel plate （MCP）, which is sensitive to soft X-ray in the 1–10 keV band. The MCP-based detector, the structure and principle of the experimental system, and results of the pulse profile are described in detail. In addition, a discussion of the effects of different X-ray pulse periods and the quantum efficiency of the detector on pulse-profile signal-to-noise ratio （SNR） is presented. Experimental results reveal that the SNR of the measured pulse profile becomes enhanced as the quantum efficiency of the detector increases. The SNR of the pulse profile is higher when the period of the pulse is smaller at the same integral.

关键词： Data handling Detectors Electromagnetic wave emission image storage tubes navigation Plates (structural components) Quantum efficiency Signal to noise ratio X ray apparatus

Improved calibration method for displacement transformation coefficient in optical and visual measurements

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Nanotechnology and Precision Engineering 2023年第1期6卷 12-25页

作者： Haopeng Li Zurong Qiu State key laboratory of Precision Measuring Technology and Instruments School of Precision Instruments and Opto-electronics EngineeringTianjin UniversityTianjin 300072China

Optical and visual measurement technology is used widely in fields that involve geometric measurements,and among such technology are laser and vision-based displacement measuring modules(LVDMMs).The displacement transformation coefficient(DTC)of an LVDMM changes with the coordinates in the camera image coordinate system during the displacement measuring process,and these changes affect the displacement measurement accuracy of LVDMMs in the full field of view(FFOV).To give LVDMMs higher accuracy in the FFOV and make them adaptable to widely varying measurement demands,a new calibration method is proposed to improve the displacement measurement accuracy of LVDMMs in the ***,an image coordinate system,a pixel measurement coordinate system,and a displacement measurement coordinate system are established on the laser receiving screen of the *** addition,marker spots in the FFOV are selected,and the DTCs at the marker spots are obtained from calibration ***,a fitting method based on locally weighted scatterplot smoothing(LOWESS)is selected,and with this fitting method the distribution functions of the DTCs in the FFOV are obtained based on the DTCs at the marker ***,the calibrated distribution functions of the DTCs are applied to the LVDMM,and experiments conducted to verify the displacement measurement accuracies are *** results show that the FFOV measurement accuracies for horizontal and vertical displacements are better than±15μm and±19μm,respectively,and that for oblique displacement is better than±24μ*** with the traditional calibration method,the displacement measurement error in the FFOV is now 90%*** research on an improved calibration method has certain significance for improving the measurement accuracy of LVDMMs in the FFOV,and it provides a new method and idea for other vision-based fields in which camera parameters must be calibrated.

关键词： Displacement transformation coefficient(DTC) Laser and vision-based displacement measuring module(LVDMM) Displacement measurement Locally weighted scatterplot smoothing(LOWESS) Calibration method

Corn ear test using SIFT-based panoramic photography and machine vision technology

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Artificial Intelligence in Agriculture 2020年第1期4卷 162-171页

作者： Xinyi Zhang Jiexin Liu Huaibo Song College of Mechanical and Electronic Engineering Northwest A&F UniversityYangling 712100ShaanxiChina key laboratory of Agricultural Internet of Things Ministry of Agriculture and Rural AffairsYangling 712100ShaanxiChina Shaanxi key laboratory of Agricultural Information Perception and Intelligent Service YanglingShaanxi 712100China

Corn ear test is important to modern corn *** test indexesmainly include lengths,radiuses,rows and numbers of corn ears and the kernels they bear,which can benefit the study on breeding new and fine corn *** corn traits are often collected by traditional manual measurement,which is difficult to meet the needs of high throughput corn ear *** this study,image sequences of corn ear samples were captured by building a panoramic photography collecting *** then,to get the lengths and radiuses indexes,the corn area images were processed based on Lab color space and adaptive threshold *** sequence images were then matched and the panoramic image of a corn surface were extracted using Scale-invariant feature transform(SIFT).Finally,by using Exponential transformation(ETR)and Sobel-Hough algorithm,ears and rows indexes were *** results showed that the accuracy of the radiuses and lengths were 93.84%and 94.53%,***,the accuracy of kernels and rows indexes were 98.12%and 96.14%,whichwere 4.03%and 7.25%higher than that of common mosaiced panoramic *** the accuracy of kernel area and length-width ratio were 95.36%and 97.42%,*** the results showed that the proposed method can be used for corn ear test effectively.

关键词： Corn ear Panoramic photography image segmentation image stitching image rectification

Error evaluation of binocular vision method for reconstructing breaking wave surface

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Journal of Hydrodynamics 2022年第5期34卷 970-974页

作者： Qian Wang Hao-cheng Lu Chang-ze Zhao Hua Liu Department of Engineering Mechanics Shanghai Jiao Tong UniversityShanghai200240China key laboratory of Hydrodynamics(MOE) Shanghai Jiao Tong UniversityShanghai200240China

Quantization error and its source of the binocular stereo vision technique are evaluated by measuring breaking wave surface in wave *** verification test focuses on the run-up process of a breaking solitary wave on a *** three-dimensional topography of the free surface is reconstructed at three representative stages of wave *** two-dimensional profile from the side view and statistical data are used to evaluate the quantization *** breaking degree of wave surface has a mild influence on the performance of stereo reconstruction in the current *** mean error of detecting the surface elevation is about 2 mm,around 0.1%of the measurement *** percent of the error comes from the deficient match in image interrogation,and the remaining forty percent arises from the limited system *** precise stereo measurement of the breaking surface shows that the present binocular vision system provides a new technique in experiments in hydrodynamics with the breaking surface.

关键词： Binocular stereo reconstruction surface deformation breaking wave image processing

A wide-field and high-resolution lensless compound eye microsystem for real-time target motion perception

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Microsystems & Nanoengineering 2022年第4期8卷 199-207页

作者： Li Zhang Haiyang Zhan Xinyuan Liu Fei Xing Zheng You Department of Precision Instrument Tsinghua UniversityBeijing 100084China State key laboratory of Precision measurement Technology and Instrument Tsinghua UniversityBeijing 100084China Beijing Advanced Innovation Center for Integrated Circuits Beijing 100084China

Optical measurement systems suffer from a fundamental tradeoff between the field of view(FOV),the resolution and the update rate.A compound eye has the advantages of a wide FOV,high update rate and high sensitivity to motion,providing inspiration for breaking through the constraint and realizing high-performance optical ***,most existing studies on artificial compound eyes are limited by complex structure and low resolution,and they focus on imaging instead of precise ***,a high-performance lensless compound eye microsystem is developed to realize target motion perception through precise and fast orientation *** microsystem splices multiple sub-FOVs formed by long-focal subeyes,images targets distributed in a panoramic range into a single multiplexing image sensor,and codes the subeye aperture array for distinguishing the targets from different sub-FOVs.A wide-field and high resolution are simultaneously realized in a simple and easy-to-manufacture microelectromechanical system(MEMS)aperture ***,based on the electronic rolling shutter technique of the image sensor,a hyperframe update rate is achieved by the precise measurement of multiple time-shifted spots of one *** microsystem achieves an orientation measurement accuracy of 0.0023°(3σ)in the x direction and 0.0028°(3σ)in the y direction in a cone FOV of 120°with an update rate~20 times higher than the frame *** study provides a promising approach for achieving optical measurements with comprehensive high performance and may have great significance in various applications,such as vision-controlled directional navigation and high-dynamic target tracking,formation and obstacle avoidance of unmanned aerial vehicles.

关键词： precise resolution compound

A spawning particle filter for defocused moving target detection in GNSS-based passive radar

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Journal of Systems Engineering and Electronics 2023年第5期34卷 1085-1100页

作者： ZENG Hongcheng DENG Jiadong WANG Pengbo ZHOU Xinkai YANG Wei CHEN Jie School of Electronic and Information Engineering Beihang UniversityBeijing 100191China National key laboratory of Science and Technology on Space Microwave China Academy of Space TechnologyXi’an 710000China

Global navigation Satellite System(GNSS)-based passive radar(GBPR)has been widely used in remote sensing ***,for moving target detection(MTD),the quadratic phase error(QPE)introduced by the non-cooperative target motion is usually difficult to be compensated,as the low power level of the GBPR echo signal renders the estimation of the Doppler rate less ***,the moving target in GBPR image is usually defocused,which aggravates the difficulty of target detection even *** this paper,a spawning particle filter(SPF)is proposed for defocused ***,the measurement model and the likelihood ratio function(LRF)of the defocused point-like target image are ***,a spawning particle set is generated for subsequent target detection,with reference to traditional particles in particle filter(PF)as their *** that,based on the PF estimator,the SPF algorithm and its sequential Monte Carlo(SMC)implementation are proposed with a novel amplitude estimation method to decrease the target state ***,the effectiveness of the proposed SPF is demonstrated by numerical simulations and pre-liminary experimental results,showing that the target range and Doppler can be estimated accurately.

关键词： Global navigation Satellite System(GNSS)-based passive radar(GBPR) defocused target moving target detec-tion(MTD) likelihood ratio function(LRF) spawning particle fil-ter(SPF)