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Target localization method of non-cooperative spacecraft on on-orbit service

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Chinese Journal of Aeronautics 2022年第11期35卷 336-348页

作者： Yingxiao LI ju huo Ping MA Ruiye JIANG Control and Simulation Center Harbin Institute of TechnologyHarbin 150001 China

With the explosion of the number of meteoroid/orbital debris in terrestrial space in recent years, the detection environment of spacecraft becomes more complex. This phenomenon causes most current detection methods based on machine learning intractable to break through the two difficulties of solving scale transformation problem of the targets in image and accelerating detection rate of high-resolution images. To overcome the two challenges, we propose a novel noncooperative target detection method using the framework of deep convolutional neural ***, a specific spacecraft simulation dataset using over one thousand images to train and test our detection model is built. The deep separable convolution structure is applied and combined with the residual network module to improve the network’s backbone. To count the different shapes of the spacecrafts in the dataset, a particular prior-box generation method based on K-means cluster algorithm is designed for each detection head with different scales. Finally, a comprehensive loss function is presented considering category confidence, box parameters, as well as box confidence. The experimental results verify that the proposed method has strong robustness against varying degrees of luminance change, and can suppress the interference caused by Gaussian noise and background complexity. The mean accuracy precision of our proposed method reaches 93.28%, and the global loss value is 13.252. The comparative experiment results show that under the same epoch and batchsize, the speed of our method is compressed by about 20% in comparison of YOLOv3, the detection accuracy is increased by about 12%, and the size of the model is reduced by nearly 50%.

关键词： Spacecraft service High resolution image Object detection Complex environment Lightweight model

Novel camera calibration method based on invariance of collinear points and pole-polar constraint

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Journal of Systems Engineering and Electronics 2023年第3期34卷 744-753页

作者： WEI Liang ZHANG Guiyang huo ju XUE Muyao School of Electrical Engineering and Automation Harbin Institute of TechnologyHarbin 150001China School of Mechanical Engineering Changshu Institute of TechnologySuzhou 215500China Space Propulsion Technology Research Institute Shanghai Academy of Spaceflight TechnologyShanghai 201109China

To address the eccentric error of circular marks in camera calibration,a circle location method based on the invariance of collinear points and pole–polar constraint is proposed in this ***,the centers of the ellipses are extracted,and the real concentric circle center projection equation is established by exploiting the cross ratio invariance of the collinear ***,since the infinite lines passing through the centers of the marks are parallel,the other center projection coordinates are expressed as the solution problem of linear *** problem of projection deviation caused by using the center of the ellipse as the real circle center projection is addressed,and the results are utilized as the true image points to achieve the high precision camera *** demonstrated by the simulations and practical experiments,the proposed method performs a better location and calibration performance by achieving the actual center projection of circular *** relevant results confirm the precision and robustness of the proposed approach.

关键词： camera calibration cross ratio invariance infinite lines eccentricity error compensate

Non-cooperative target pose estimation based on improved iterative closest point algorithm

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Journal of Systems Engineering and Electronics 2022年第1期33卷 1-10页

作者： ZHU Zijian XIANG Wenhao huo ju YANG Ming ZHANG Guiyang WEI Liang Department of Astronautics Harbin Institute of TechnologyHarbin 150006China Department of Electrical Engineering and Automation Harbin Institute of TechnologyHarbin 150006China Systems Engineering Research Institute China State Shipbuilding Corporation LimitedBeijing 100036China

For localisation of unknown non-cooperative targets in space,the existence of interference points causes inaccuracy of pose estimation while utilizing point cloud *** address this issue,this paper proposes a new iterative closest point(ICP)algorithm combined with distributed weights to intensify the dependability and robustness of the non-cooperative target *** interference points in space have not yet been extensively studied,we classify them into two broad categories,far interference points and near interference *** the former,the statistical outlier elimination algorithm is *** the latter,the Gaussian distributed weights,simultaneously valuing with the variation of the Euclidean distance from each point to the centroid,are commingled to the traditional ICP *** each iteration,the weight matrix W in connection with the overall localisation is obtained,and the singular value decomposition is adopted to accomplish high-precision estimation of the target ***,the experiments are implemented by shooting the satellite model and setting the position of interference *** outcomes suggest that the proposed algorithm can effectively suppress interference points and enhance the accuracy of non-cooperative target pose *** the interference point number reaches about 700,the average error of angle is superior to 0.88°.

关键词： non-cooperative target pose estimation iterative closest point(ICP) Gaussian weight

Calibration of Camera with Large Field-of-View Based on Flexible Planar Target

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Journal of Harbin Institute of Technology(New Series) 2013年第4期20卷 14-20页

作者： ju huo Wen-Bo Dong Ning Yang Wu-Kang Lin Dept.of Electrical Engineering Harbin Institute of Technology Control and Simulation Center Harbin Institute of Technology

For high precision calibration of camera with large field-of-view,massive calibration points will be needed if traditional methods are selected,which makes the calibration complex and *** order to solve this problem,a calibration method based on flexible planar target is *** this method,distortion factor is firstly acquired by the invariance of cross ratio,and existing feature points are adjusted with the distortion ***,a large number of points that will be used for the calibration are constructed with the adjusted feature ***,Tsai method is modified so as to reduce the complexity of calibration,which makes the process *** simulation and real experiments show that the method proposed in this paper is simple,linear,accurate and robust,and the precision of this method is close to that of Tsai method using abundant *** method can satisfy the requirement of high precision calibration for camera with large field-of-view.

关键词： large field-of-view calibration distortion factor flexible planar target linear two-step method

Information entropy-based fitting of the disease trajectory of brain ischemia-induced vascular cognitive impairment

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Neural Regeneration Research 2012年第9期7卷 697-702页

作者： Lin Liu ju huo Ying Zhao Yu Tian College of Pharmacy Harbin University of Commerce Harbin 150076 Heilongjiang Province China Department of Electrical Engineering Harbin Institute of Technology Harbin 150001 Heilongjiang Province China

The present study investigated the disease trajectory of vascular cognitive impairment using the entropy of information in a neural network mathematical simulation based on the free radical and excitatory amino acids theories. Glutamate, malondialdehyde, and inducible nitric oxide synthase content was significantly elevated, but acetylcholine, catalase, superoxide dismutase, glutathione peroxidase and constitutive nitric oxide synthase content was significantly decreased in our vascular cognitive impairment model. The fitting curves for each factor were obtained using Matlab software. Nineteen, 30 and 49 days post ischemia were the main output time frames of the influence of these seven factors. Our results demonstrated that vascular cognitive impairment involves multiple factors. These factors include excitatory amino acid toxicity and nitric oxide toxicity. These toxicities disrupt the dynamic equilibrium of the production and removal of oxygen free radicals after cerebral ischemia, reducing the ability to clear oxygen free radicals and worsening brain injury.

关键词： vascular cognitive impairment bilateral ligation of the common carotid artery acetylcholine nitric oxide synthase free radical glutamate

“距离”与艺术实践:阿尔都塞文艺批评中“群众”概念的展开

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文艺理论研究 2020年第3期41卷 201-209页

作者：霍炬陕西师范大学文学院陕西省西安市710119

阿尔都塞对政治性的"群众"概念进行了理论厘清,申明在斗争中被联合起来的各阶级群众既是行动起点,也是理论归宿,因此在"西方马克思主义"的思想脉络中独树一帜。本文从文艺批评论述出发,强调阿尔都塞对当代批评理论中的"作者""形式"和"... 详细信息

阿尔都塞对政治性的"群众"概念进行了理论厘清,申明在斗争中被联合起来的各阶级群众既是行动起点,也是理论归宿,因此在"西方马克思主义"的思想脉络中独树一帜。本文从文艺批评论述出发,强调阿尔都塞对当代批评理论中的"作者""形式"和"间离效果"等概念的重新定位,用"距离"理论说明围绕着群众运动的意识形态实践如何介入现实和发挥现实功能,对"群众"概念的历史脉络、阿尔都塞文艺批评的理论斗争内容、他在当时新艺术实践中发现的积极内容以及哲学-艺术实践整体中的有机联系等问题展开论述。

关键词：阿尔都塞群众距离意识形态

High Precision and Noise Resistance Estimation Based on Optimized GOI Algorithm for Rocket Nozzle

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High Precision and Noise Resistance Estimation Based on Opti...

飞行器仿真测试中合作目标投影光斑的跟踪识别

第37届中国控制会议

作者： Xing Zhou ju huo Guiyang Zhang School of Electrical Engineering and Automation Harbin Institute of Technology School of Astronautics Harbin Institute of Technology

This paper is concerned with the rocket nozzle working environment with many interference factors, upon which a high precision and noise resistance algorithm for pose estimation is proposed. The optimized generalized orthogonal iterative（GOI） algorithm is utilized for iterative solution such that it avoids the poor convergence or convergence failure problem caused by the weak perspective projection. The proposed technique only needs to observe the rocket nozzle at different orientations and the objective function based on the collinear error is established, thus the estimated parameters can be obtained subsequently. Finally, simulation and practical experiments are carried out simultaneously. By using the improved algorithm, within a space of 2 m u2 m u4 m, the maximum static error of the swing angles is superior to 0.085 and the maximum dynamic error is less than 0.13°. The results verify the high accuracy and noise resistance performance of the proposed approach.

关键词： Binocular vision CCD camera pose estimation optimized GOI algorithm rocket nozzle

来源： cnki会议评论

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光学精密工程 2015年第8期23卷 2134-2142页

作者：霍炬杨宁杨明哈尔滨工业大学电气工程系黑龙江哈尔滨150001 哈尔滨工业大学控制与仿真中心黑龙江哈尔滨150080

针对飞行器仿真测试中合作目标投影光斑的跟踪识别问题,提出了一种投影光斑跟踪识别新方法,该方法主要由预测、识别及修正3个阶段组成。预测阶段主要结合投影光斑运动特点对传统卡尔曼滤波进行改进,提高投影光斑的位置预测精度。识别阶... 详细信息

针对飞行器仿真测试中合作目标投影光斑的跟踪识别问题,提出了一种投影光斑跟踪识别新方法,该方法主要由预测、识别及修正3个阶段组成。预测阶段主要结合投影光斑运动特点对传统卡尔曼滤波进行改进,提高投影光斑的位置预测精度。识别阶段则根据投影光斑位置的预测值,分两种情况对光斑进行处理:如果下一时刻投影光斑在视场内,则根据相应的判别准则和匹配策略在下一时刻图像中快速搜索投影光斑的最优匹配光斑;如果下一时刻投影光斑在视场外,则根据测量系统相关信息,对视场外投影光斑在图像平面上的位置进行求解,并将求解结果加入相应的运动轨迹,实现对视场外投影光斑的跟踪识别。在完成投影光斑的跟踪识别后,根据跟踪识别结果对投影光斑相关参数进行修正。仿真实验和实际实验结果表明,本文方法能够有效跟踪识别飞行器仿真测试中合作目标的投影光斑,其最大跟踪识别误差不超过2.5pixel,即使跟踪识别过程中存在投影光斑进出视场的情况也不受影响。

关键词：飞行器仿真测试视觉测量运动参数合作目标投影光斑跟踪识别

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基于多层次信息交互的多目标粒子群优化算法

控制与决策 2016年第5期31卷 907-912页

作者：杨宁霍炬杨明哈尔滨工业大学控制与仿真中心哈尔滨150001 哈尔滨工业大学电气工程系哈尔滨150001

为提高多目标优化算法的收敛性和多样性,提出一种基于多层次信息交互的多目标粒子群优化算法.在该算法中,整个优化过程可分为标准粒子群优化层、粒子进化与学习层和档案信息交换层3个层次.粒子进化与学习层保证了每次迭代都能得到更好... 详细信息

为提高多目标优化算法的收敛性和多样性,提出一种基于多层次信息交互的多目标粒子群优化算法.在该算法中,整个优化过程可分为标准粒子群优化层、粒子进化与学习层和档案信息交换层3个层次.粒子进化与学习层保证了每次迭代都能得到更好的粒子位置;档案信息交换层可以提供更好的全局最优.优化算法各个层次之间通过信息交互,共同提高算法的收敛性和多样性.与NSGA-Ⅱ和MOPSO算法的对比分析表明,所提出算法具有良好的性能,能够有效解决多目标优化问题.

关键词：多目标优化多层次信息交互粒子群优化收敛性多样性