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arXiv 2025年

作者： Huang, Huayu Guan, Banglei Shang, Yang Yu, Qifeng College of Aerospace Science and Engineering National University of Defense Technology Changsha China Hunan Provincial Key Laboratory of Image Measurement and Vision Navigation National University of Defense Technology Changsha China

The motion measurement of point targets constitutes a fundamental problem in photogrammetry, with extensive applications across various engineering domains. Reconstructing a point’s 3D motion just from the images captured by only a monocular camera is unfeasible without prior assumptions. Under limited observation conditions such as insufficient observations, long distance, and high observation error of platform, the least squares estimation faces the issue of ill-conditioning. This paper presents an algorithm for reconstructing 3D trajectories of moving points using a monocular camera. The motion of the points is represented through temporal polynomials. Ridge estimation is introduced to mitigate the issues of ill-conditioning caused by limited observation conditions. Then, an automatic algorithm for determining the order of the temporal polynomials is proposed. Furthermore, the definition of reconstructability for temporal polynomials is proposed to describe the reconstruction accuracy quantitatively. The simulated and real-world experimental results demonstrate the feasibility, accuracy, and efficiency of the proposed method. Copyright © 2025, The Authors. All rights reserved.

关键词： Trajectories

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High-precision visual navigation device calibration method based on collimator

arXiv

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arXiv 2025年

作者： Liang, Shunkun Tan, Dongcai Guan, Banglei Li, Zhang Dai, Guangcheng Pan, Nianpeng Shen, Liang Shang, Yang Yu, Qifeng College of Aerospace Science and Engineering National University of Defense Technology Hunan Changsha410073 China Hunan Provincial Key Laboratory of Image Measurement and Vision Navigation Hunan Changsha410073 China North Navigation Control Technology Co. Ltd Beijing Beijing 100176 China

Visual navigation devices require precise calibration to achieve high-precision localization and navigation, which includes camera and attitude calibration. To address the limitations of time-consuming camera calibration and complex attitude adjustment processes, this study presents a collimator-based calibration method and system. Based on the optical characteristics of the collimator, a single-image camera calibration algorithm is introduced. In addition, integrated with the precision adjustment mechanism of the calibration frame, a rotation transfer model between coordinate systems enables efficient attitude calibration. Experimental results demonstrate that the proposed method achieves accuracy and stability comparable to traditional multi-image calibration techniques. Specifically, the re-projection errors ≤ 0.1463 pixels and average attitude angle errors ≤ 0.0586 ° with a standard deviation ≤ 0.0257 °, demonstrating high precision and robustness. Copyright © 2025, The Authors. All rights reserved.

关键词： Cameras

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Pose optimization based on integral of the distance between line segments

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Science China Technological Sciences 2016年第1期59卷 135-148页

作者： ZHANG YueQiang LI Xin LIU HaiBo SHANG Yang YU QiFeng College of Aerospace Science and Engineering National University of Defense Technology Hunan Provincial Key Laboratory of Image Measurement and Vision Navigation

In this paper, new solutions for the problem of pose estimation from correspondences between 3D model lines and 2D image lines are proposed. Traditional line-based pose estimation methods rely on the assumption that the noises(perpendicular to the line) for the two endpoints are statistically independent. However, these two noises are in fact negatively correlated when the image line segment is fitted using the least-squares technique. Therefore, we design a new error function expressed by the average integral of the distance between line segments. Three least-squares techniques that optimize both the rotation and translation simultaneously are proposed in which the new error function is exploited. In addition, Lie group formalism is utilized to describe the pose parameters, and then, the optimization problem can be solved by means of a simple iterative least squares method. To enhance the robustness to outliers existing in the match data, an M-estimation method is developed to convert the pose optimization problem into an iterative reweighted least squares problem. The proposed methods are validated through experiments using both synthetic and real-world data. The experimental results show that the proposed methods yield a clearly higher precision than the traditional methods.

关键词： machine vision perspective-n-line problem line distance function pose optimization M-estimation

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Multiple rotation averaging using only the relative rotation angle

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Science China(Technological Sciences) 2023年第10期66卷 2978-2985页

作者： LI Bin SHANG Yang GUAN BangLei LIANG ShunKun SUN XiaoLiang YU QiFeng College of Aerospace Science and Engineering National University of Defense TechnologyChangsha 410073China Hunan Provincial Key Laboratory of Image Measurement and Vision Navigation Changsha 410073China

In this work,we propose multiple rotation averaging using only the relative rotation angle,which is a straightforward camera pose optimization *** use the axis-angle representation to parameterize the rotation and use only relative rotation angles to constrain absolute rotations instead of complete relative *** used with an inertial measurement unit(IMU),our method can obviate the need to estimate and maintain extrinsic parameters between the camera and *** advantage makes our method immune to extrinsic parameters and *** performed extensive evaluations on both synthetic data and publicly available real datasets,which showed that our method was comparable with the state-of-the-art method and achieved a significant gain in accuracy for the visual measurement when applied to the case in which the camera and IMU are tightly fixed.

关键词： multiple rotation averaging pose optimization relative rotation angle IMU

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Hull deformation measurement for spacecraft TT&C ship by Photogrammetry

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Science China(Technological Sciences) 2015年第8期58卷 1339-1347页

作者： LIU HaiBo SUN Cong ZHANG YueQiang LIU XinMing LIU JinBo ZHANG XiaoHu YU QiFeng College of Aerospace Science and Engineering National University of Defense Technology Hunan Provincial Key Laboratory of Image Measurement and Vision Navigation China Satellite Maritime Tracking and Control Department

When voyaging,ships are subject to inevitable hull deformations caused by the changes in the environmental temperature and external *** are a crucial source of errors when measuring data using a spacecraft tracking,telemetry,and control(TT&C) ship.A prototype system based on photogrammetry was developed for the real-time measurement of a spacecraft TT&C ship's hull *** system has high accuracy,a simple structure,and convenient maintenance,and requires few changes to the ship's *** improve its performance,an estimation approach is proposed for hull deformation *** the proposed approach,the central positions of cross spots in successive frames can be predicted based on the prediction of the camera's attitude,and their extract locations can be found by defining a series of small windows around each predictive ***,the optimal estimate of the camera's attitude is updated by the designed extended Kalman filter using the extracted cross spots and their corresponding local coordinates,with which the hull deformation angles can be *** verify the proposed measurement approach,its performance was tested during the normal sailing,floating,and rocking on the sea of a spacecraft TT&C *** experimental testing results demonstrated that the proposed approach performs well in terms of accuracy and *** can satisfy the hull deformation measurement requirement for a spacecraft TT&C ship in real time.

关键词： photogrammetry ship deformation spacecraft TT&C ship EKF

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Precise monocular vision-based pose measurement system for lunar surface sampling manipulator

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Science China(Technological Sciences) 2019年第10期62卷 1783-1794页

作者： WANG Gang SHI ZhongChen SHANG Yang SUN XiaoLiang ZHANG WenLong YU QiFeng College of Aerospace Science and Engineering National University of Defense TechnologyChangsha410073China Hunan Provincial Key Laboratory of Image Measurement and Vision Navigation Changsha410073China

Space manipulator has been playing an increasingly important role in space exploration due to its flexibility and versatility. This paper is to design a vision-based pose measurement system for a four-degree-of-freedom(4-DOF) lunar surface sampling manipulator relying on a monitoring camera and several fiducial markers. The system first employs double plateaus histogram equalization for the markers to improve the robustness to varying noise and illumination. The markers are then accurately extracted in sub-pixel based on template matching and curved surface fitting. Finally, given the camera parameters and 3D reference points, the pose of the manipulator end-effector is solved from the 3D-to-2D point correspondences by combining a plane-based pose estimation method with rigid-body transformation. Experiment results show that the system achieves highprecision positioning and orientation performance. The measurement error is within 3 mm in position, and 0.2° in orientation,meeting the requirements for space manipulator operations.

关键词： vision-based pose measurement pose estimation lunar surface sampling sub-pixel corner detection Chang’e 5

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Non-contact optical dynamic measurements at different ranges:a review

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Acta Mechanica Sinica 2021年第4期37卷 537-553,I0001页

作者： Yu Fu Yang Shang Wenxin Hu Bin Li Qifeng Yu Shenzhen Key Laboratory of Intelligent Optical Measurement and Detection Shenzhen UniversityShenzhen 518060China Hunan Provincial Key Laboratory of Image Measurement and Vision Navigation College of Aerospace Science and EngineeringNational University of Defense TechnologyChangsha 410073China

Optical dynamic measurements are widely used for non-contact vibration,continuous deformation,or moving *** measurement techniques were developed for different deformation *** paper reviews three types of technique for different measurement ranges:interferometric techniques for deformation or vibration(nanometer to submillimeter amplitude)whose measurement accuracies rely on phase extraction of interferometric signal;imaging based techniques for deformation or vibration(micrometer to centimeter amplitude)with the aid of moire,structured light,and man-made speckles,whose sensitivities is from 1/100 to 1/10 pixel;and videometrics for large deformation or movement detection(greater than centimeter amplitude).Many research groups have improved measurement capabilities for these three techniques to meet particular industrial application requirements.

关键词： Vibration measurement Laser interferometry Digital image correlation High-speed imaging Videometrics

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High-accuracy real-time satellite pose estimation for in-orbit applications

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Chinese Journal of Aeronautics 2025年第6期38卷

作者： WANG, Zi WANG, Jinghao YU, Jiyang LI, Zhang YU, Qifeng College of Aerospace Science and Engineering National University of Defense Technology Changsha410000 China Hunan Provincial Key Laboratory of Image Measurement and Vision Navigation Changsha410073 China Beijing Institute of Spacecraft System Engineering Beijing100094 China

vision-based relative pose estimation plays a pivotal role in various space missions. Deep learning enhances monocular spacecraft pose estimation, but high computational demands necessitate model simplification for onboard systems. In this paper, we aim to achieve an optimal balance between accuracy and computational efficiency. We present a Perspective-n-Point (PnP) based method for spacecraft pose estimation, leveraging lightweight neural networks to localize semantic keypoints and reduce computational load. Since the accuracy of keypoint localization is closely related to the heatmap resolution, we devise an efficient upsampling module to increase the resolution of heatmaps with minimal overhead. Furthermore, the heatmaps predicted by the lightweight models tend to show high-level noise. To tackle this issue, we propose a weighting strategy by analyzing the statistical characteristics of predicted semantic keypoints and substantially improve the pose estimation accuracy. The experiments carried out on the SPEED dataset underscore the prospect of our method in engineering applications. We dramatically reduce the model parameters to 0.7 M, merely 2.5% of that required by the top-performing method, and achieve lower pose estimation error and better real-time performance. © 2025

关键词： Space applications

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Structure extraction of straight wing aircraft using consistent line clustering 2

Structure extraction of straight wing aircraft using consist...

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2nd International Conference on image, vision and Computing, ICIVC 2017

作者： Luo, Jing Xichao, Teng Xiaohu, Zhang Lijun, Zhong Hunan Provincial Key Laboratory of Image Measurement and Vision Navigation National University of Defense Technology Changsha China

ISBN: (纸本)9781509062379

In this paper, we propose a new method to automatically extract the main structure (fuselage and wings) of straight wing aircraft in photographic images using line clustering. We exploit the location, length and orientation features (parallel constraint) of line segments to group them into line clusters. The different line clusters correspond to the different structure of straight wing aircraft, and we can extract fuselage and wing of straight wing aircraft accordingly. We adopt line segment detector to extract line features, mean-shift and k-means++ approaches are applied to group line segments. The experimental results demonstrate that our method is effective for the structure extraction of straight wing aircraft. © 2017 IEEE.

关键词： Extraction

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Accurate Aspect Ratio Estimation in Scale Adaptive Tracking 3

Accurate Aspect Ratio Estimation in Scale Adaptive Tracking

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2021 3rd International Conference on Electronic Engineering and Informatics, EEI 2021

作者： Lu, Weikang Su, Ang Zhang, Wenlong Shang, Yang College of Aerospace Science and Engineering National University of Defense Technology Hunan Changsha410073 China Hunan Provincial Key Laboratory of Image Measurement and Vision Navigation Hunan Changsha410073 China

In visual object tracking, robust scale estimation is always a challenging problem. Because of the fast movement of the target, the background, the relative distance and relative azimuth angle between the target and the background usually change greatly. However, traditional correlation filtering tracking method cannot track the target accurately or even lose the target when the target scale and aspect ratio change. To address these problems, this paper adds two independent filters for the length and width scale estimation to complete the adaptive tracking on the basis of the translation filter. The experimental results in the public data set show that: compared with the original trackers, our method improves the tracking accuracy significantly, and meets the needs of real-time target tracking. © Published under licence by IOP Publishing Ltd.

关键词： Aspect ratio

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