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14th International Conference on Information Optics and Photonics, CIOP 2023

作者： Zhang, Hengkang Liu, Kaige Wang, Li Chen, Mingce Guo, Shaogang Liu, Qiang Space Optoelectronic Measurement and Perception Lab. Beijing Institute of Control Engineering Beijing100190 China Ministry of Education Beijing100084 China Tsinghua University State Key Laboratory of Precision Measurement Technology and Instruments Department of Precision Instrument Beijing100084 China

ISBN: (纸本)9781510671744

Wavefront shaping technique has been applied to actively control the intensity profile of optical speckles, and a recent progress is to realize glare suppression with the low-transmittance eigenchannels of the transmission matrices (TMs). This makes it possible to custom-tailor the speckle fields. For the purpose of suppressing glare at will, research about the properties of low-transmittance eigenchannels in glare suppression is demanded. In this paper, we report the area expansion effect of glare suppression with low-transmittance eigenchannels. With numerical simulations, we found the actual darkened area was larger than the set target area due to the transverse correlation of the speckle field. Their difference is related to the measuring noise of the TM and gets smaller with the increase of the noise intensity. We believe our research could help to design structured speckle fields, and it will be of significant for advanced applications of optical speckles. © 2023 SPIE.

关键词： Glare

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Review of space Dim Target Detection Methods

Review of Space Dim Target Detection Methods

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Image Processing and Media Computing (ICIPMC), International Conference on

作者： Zhang Deyang Zheng Ran Cheng Huiyan Meng Xiaodi Li Lin Space Optoelectronic Measurement and Perception Lab Beijing Institute of Control Engineering Beijing China

At present, space dim target detection is easy to be disturbed by background noise and stars, difficult detection and long capture period. How to realize accurate detection of space dim target in low SNR condition, improve target sensitivity and obtain high-precision target position information, and meet the qualification of high detection rate and low false alarm rate is the key problem of space dim target detection technology. This paper introduces the current situation of image preprocessing, single-frame and multi-frame detection methods of space target, analyzes and evaluates its advantages and disadvantages, summarizes the development direction and trend of detection technology, and provides reference and suggestions for the research of space dim target detection technology.

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Accuracy Analysis and Verification Method on Vision Position-pose measurement System

Accuracy Analysis and Verification Method on Vision Position...

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optoelectronics Global Conference (OGC)

作者： Jie Bao Chenglong Zhang Xinpeng Wei Xingtan Liu Chunhui Zhao Space Optoelectronic Measurement and Perception Lab Beijing Institute of Control Engineering Beijing China

In order to realize position-pose measurement system of monocular camera, a measurement accuracy test system was established. First, we introduce the system principle, theoretical accuracy analysis, computational experiments and computational results. In order to solve the problem of obtaining the true value of high precision pose measurement and the poor accuracy evaluation results caused by accuracy of the simulated motion platform, we proposed single laser tracker with higher accuracy as the method to verify the system accuracy. By establishing the relevant coordinate system and coordinate system conversion, the absolute accuracy of the camera position-pose measurement can be accurately obtained. The result of the 16m measurement accuracy verification experiment shows that, the position measurement accuracy x and y can reach the sub millimeter level. Due to the weak distance perception of monocular camera, the orientation error of z-axis is large, on the order of tens of millimeters. The minimum accuracy of the angle measurement result is 0.2°. Using a single laser tracker for relative measurement to evaluate the accuracy of the measurement system can effectively evaluate the measurement accuracy of the high-precision relative position and attitude measurement system under the limited laboratory conditions.

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Gap Phase-Shifted Fiber Bragg Grating and Its Application

Gap Phase-Shifted Fiber Bragg Grating and Its Application

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International Conference on Optical Communications and Networks (ICOCN)

作者： Yuanhong Yang Liangya Du Lin Lu Yan Xiong Siyuan Liu Weichun Fu Qin Zhao Li Yuan Yanpeng Wu School of Instrumentation and Optoelectronic Engineering Beihang University Beijing China Space Optoelectronic Measurement and Perception Lab Beijing Institute of Control Engineering Beijing China

ISBN: (数字)9798350367652

ISBN: (纸本)9798350367669

A gap phase-shifted fiber Bragg grating (g-FBG) formed by cutting off a conventional FBG and re-coupling is proposed and demonstrated. Furthermore, a reflection g-FBG is put forward and investigated. The g- FBG can be implemented easily and used in optical spectrum filtering, tuning, and multiparameter sensing with better sensitivity and resolution.

关键词： Optical filters Optical fibers Optical fiber sensors Sensitivity Fiber gratings Reflection Optical fiber communication

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Reconstructing Three-Degree-of-Freedom Pose through Temporal Phase-Shifted Low-Coherence Spatial Interferograms 16

Reconstructing Three-Degree-of-Freedom Pose through Temporal...

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16th Pacific Rim Conference on Lasers and Electro-Optics, CLEO-PR 2024

作者： Shi, Liheng Zhang, Jinxu Gu, Yingying Gai, Fangqin Liu, Jing Wu, Guanhao Tsinghua University State Key Laboratory of Precision Measurement Technology and Instruments Department of Precision Instrument Beijing100084 China Yangtze Delta Region Institute of Tsinghua University Zhejiang Research Center of Opto-electronic Sensing Zhejiang 314006 China Beijing Institute of Control Engineering Space Optoelectronic Measurement and Perception Lab. Beijing100190 China China Academy of Space Technology National Key Laboratory of Space Intelligent Control Beijing100094 China

We introduce a method for measuring three degrees of freedom using low-coherence light and temporal phase-shifting to discern position and orientation from the coherence envelope shape, enabling direct measurement wit... 详细信息

ISBN: (纸本)9798350372076

关键词： Degrees of freedom (mechanics)

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Star Image Simulation for Starlight Refraction Sensor 6

Star Image Simulation for Starlight Refraction Sensor

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6th International Conference on Signal and Image Processing, ICSIP 2021

作者： Xu, Qing Zhao, Chunhui Li, Xiao Beijing Institute of Control Engineering Space Optoelectronic Measurement and Perception Lab Beijing China

ISBN: (纸本)9780738133737

The indirectly sensing horizon technique of starlight refraction utilizes star sensors to detect refracted starlight under the Earth's atmospheric limb background to achieve high precision attitude and position measurement of satellites. As star images usually can't be obtained in real time, software star image simulation is a quick and easy to implement approach for star identification algorithm validation. This paper firstly introduces the basic theory of starlight atmospheric refraction navigation. Then the atmospheric limb background radiation model and stellar radiation model of starlight refraction sensor are established. On this basis, the process of refraction star image simulation is discussed in detail. According to the given star sensor parameters and simulated radiation data, an example of refraction star image simulation is realized and the offset image coordinates of the refracted stars are analyzed for verification. © 2021 IEEE.

关键词： Refraction

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Star centroid extraction in stray light background for star sensor

Star centroid extraction in stray light background for star ...

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2021 International Conference on Signal Image Processing and Communication, ICSIPC 2021

作者： Xu, Qing Zhao, Chun-Hui Qiao, Chuan Yan, Si-Chang Yan, Peng-Bo Beijing Institute of Control Engineering Beijing100190 China Space Optoelectronic Measurement and Perception Lab Beijing100049 China

ISBN: (数字)9781510645417

ISBN: (纸本)9781510645400

The accuracy of star centroid extraction for star sensor is decreased in the stray light background due to the gray gradients of the star image, a star centroid extraction algorithm based on background removal by least square method is proposed. Firstly, the influence of stray light background on star centroid extraction is analyzed, and the result shows that the systematic error of star centroid extraction is proportion to the background gray gradients. In order to reduce the systematic error, the least square method is used to fit the window edge pixels to obtain the stray light background image, and then the star centroid is extracted through threshold centroid algorithm after removing the stray light background of the star image. The accuracy of star centroid extraction algorithm is simulated through the practical stray light background images. Compared with the traditional threshold centroid algorithm, the systematic error of star centroid extraction can be reduced from 0.021 pixels to 0.002 pixels. The validity of the algorithm is verified by field star observing experiments for star sensor at Xinglong observation station, and the angular distance of the navigation stars is measured and compared with the Hipparcos catalogue. The systematic error of angular distance is reduced from 0.307? to 0.013? after the stray light background has been removed by least square method while the operation time is only increased by 6.3%, which can meet the engineering requirements. © 2021 SPIE.

关键词： Stars

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A Neural Network-based Method for Fast Angle Calibration of MEMS LiDAR

A Neural Network-based Method for Fast Angle Calibration of ...

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2021 International Conference of Optical Imaging and measurement, ICOIM 2021

作者： Lin, Dayong Zhao, Chunhui Gu, Yingying Xu, Yunfei Hua, Baocheng Qu, Zonghua Beijing Institute of Control Engineering Space Optoelectronic Measurement and Perception Lab Beijing China Beijing Institute of Control Engineering Science and Technology on Space Intelligent Control Laboratory Beijing China

ISBN: (纸本)9780738112121

MEMS LiDAR has been drawing more and more attention as a representative achievement in low power consumption and miniaturization integration of LiDAR research. To address the problem that traditional angle calibration methods for mechanical LiDAR are not completely applicable in MEMS LiDAR due to different sources of angle errors, a neural network-based method for fast angle calibration of MEMS LiDAR is proposed. The calibration field only consists of a rotating platform and an angular reflector. By modelling the calibration field and analyzing the error sources of MEMS LiDAR, including the mounting error, the nonlinear error, and the systematic error, a neural network model was then developed to correct the angle measurement errors. The experimental results show that the method is reasonable and effective and is able to achieve fast angle calibration of MEMS LiDAR. © 2021 IEEE.

关键词： MEMS

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Neighbor Feature Variance (Nfv) Based Feature Point Selection Method for Three Dimensional (3d) Registration of space Target

SSRN

引用

SSRN 2023年

作者： Zhou, Yier Li, Xiaolu Hu, Haixia Su, Lixuan Du, Hang Fu, Wenming Xu, Lijun School of Instrumentation and Optoelectronic Engineering Beihang University Beijing100191 China Lab of Space Optoelectronic Measurement & Perception Beijing Institute of Control Engineering Beijing100191 China

Point clouds based three dimensional (3D) registration for the space target pose estimation requires high precision and noise robustness. To enhance the registration accuracy, a novel neighbor feature variance (NFV) based feature points selection method is proposed to provide the high precision input for registration, generating more accurate correspondences by ranking point's NFV, for removing the redundant points and remaining more salient points. In coarse registration, the truncated least squares estimation and semidefinite relaxation (TEASER) algorithm is used to improve the accuracy of coarse registration and reduce the adverse effects caused by sparsity and noise of point cloud. In fine registration, the iterative closest point (ICP) algorithm is applied to estimate the pose transformation. The experimental results show that the maximum translation error and maximum rotation error are less than 0.019m and 0.129°, and the mean translation and rotation errors can be reduced by 69.85% and 60.58%, respectively. © 2023, The Authors. All rights reserved.

关键词： Errors

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RGB-D Instance Segmentation-based Suction Point Detection for Grasping

RGB-D Instance Segmentation-based Suction Point Detection fo...

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2022 IEEE International Conference on Robotics and Biomimetics, ROBIO 2022

作者： Fu, Yeyu Sun, Ting Wang, Li Yu, Shijie Deng, Lei Chen, Baohua Li, Lin Xie, Yusen Deng, Shuixin Yin, Hanxi Beijing Information Science & Technology University Joint International Research Laboratory of Advanced Photonics and Elextronics Beijing China Beijing Institute of Control Engineering Space Optoelectronic Measurement and Perception Lab. Department of Perception Zhong-guancun Open Lab. Beijing China Tsinghua University Department of Automation Beijing China

ISBN: (纸本)9781665481090

Suction is a common way for robots to pick objects in industry, which has higher stability and reliability. However, it is necessary to evaluate the suction position on the object's surface when dealing with objects of different shapes. The previous method decouples it into a two-stage suction point detection and objects classification process, making the task more complex and time-consuming. On the other hand, there are significant challenges in acquiring training data. To address that, we propose an object instance segmentation-based suction grasping point detection method. Instance segmentation, as an object pixel-level perception method, can classify objects and find the orientation of objects in the plane, which is more efficient than simple classification. Specifically, our method generate a suction heatmap and object instance segmentation from RGB-D inputs and find the suction grasping position of each object after candidate points screening. To generate the training data, a heatmap mask based on 2D Gaussian-encoded is used to annotate the suction grasping ground truth. We evaluate each object's predicted suction grasping point results and conduct grasping experiments in real environments. The suction grasping success rate of 94% in dense scenes demonstrates the remarkable performance of the proposed method. © 2022 IEEE.

关键词： Object detection

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