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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 registration.To 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 localisation.As interference points in space have not yet been extensively studied,we classify them into two broad categories,far interference points and near interference points.For the former,the statistical outlier elimination algorithm is employed.For 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 algorithm.In 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 pose.Finally,the experiments are implemented by shooting the satellite model and setting the position of interference points.The outcomes suggest that the proposed algorithm can effectively suppress interference points and enhance the accuracy of non-cooperative target pose estimation.When 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

Multi-camera calibration method based on minimizing the difference of reprojection error vectors

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Journal of Systems Engineering and Electronics 2018年第4期29卷 844-853页

作者： huo ju LI Yunhui YANG Ming School of Electrical Engineering Harbin Institute of Technology Control and Simulation Center Harbin Institute of Technology

In order to achieve a high precision in three-dimensional（3D） multi-camera measurement system, an efficient multi-cameracalibration method is proposed. A stitching method of large scalecalibration targets is deduced, and a fundamental of multi-cameracalibration based on the large scale calibration target is provided.To avoid the shortcomings of the method, the vector differencesof reprojection error with the presence of the constraint conditionof the constant rigid body transformation is modelled, and mini-mized by the Levenberg-Marquardt （LM） method. Results of thesimulation and observation data calibration experiment show thatthe accuracy of the system calibrated by the proposed methodreaches 2 mm when measuring distance section of 20 000 mmand scale section of 7 000 mm × 7 000 mm. Consequently, theproposed method of multi-camera calibration performs better thanthe fundamental in stability. This technique offers a more uniformerror distribution for measuring large scale space.

关键词： vision measurement multi-camera calibration field stitching vector error

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 network.Firstly, 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

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“双一流”背景下的“电路”课程建设探索

电气电子教学学报 2024年第1期46卷 49-53页

作者：霍炬李琰杨旭强哈尔滨工业大学电气工程及自动化学院哈尔滨150001

为建设和落实一批世界一流大学和一流学科的目标,以“电路”课程为例,针对课程中存在的痛点问题,课程团队遵循“以学生为中心,学生发展成效驱动”的创新教学理念,以电路内容为主线筑牢学生工程基础,融入课程思政,采用课前、课中、课后... 详细信息

为建设和落实一批世界一流大学和一流学科的目标,以“电路”课程为例,针对课程中存在的痛点问题,课程团队遵循“以学生为中心,学生发展成效驱动”的创新教学理念,以电路内容为主线筑牢学生工程基础,融入课程思政,采用课前、课中、课后全程智慧教学和多元互动的方式,全方位评价学生能力,形成了“素质教育、知识引领”的双主线和“虚实结合、多元互动、强基立本、成效为先”的教学特色。

关键词：创新教学多元互动虚实结合

Atmospheric fate of typical liquid crystal monomers in the tropospheric gas,liquid,and granular phases

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Journal of Environmental Sciences 2024年第2期136卷 348-360页

作者： Yanru huo Zexiu An Mingxue Li Jinchan Jiang Yuxin Zhou ju Xie Jianguo Zhang Maoxia He Environment Research Institute Shandong UniversityQingdao 266237China College of Plant Protection Hebei Agricultural UniversityBaoding 071000China School of Chemistry and Chemical Engineering Yangzhou UniversityYangzhou 225002China Jinan Environmental Research Academy Jinan 250000China

Mineral aerosol particles significantly impact environmental risk prediction of liquid crystal monomers(LCMs).In this work,we investigated the reaction mechanisms and kinetics of three typical LCMs(4-cyano-3,5-difluorophenyl 4-ethylbenzoate(CEB-2F),4-cyano-3-fluorophenyl 4-ethylbenzoate(CEB-F),and 4-cyanophenyl 4-ethylbenzoate(CEB))with ozone(O_(3))in the atmospheric gas,liquid,and particle phases employing density functional theory(DFT).Here,O_(3)is prone to add to the benzene ring without F atom(s)in the selected LCMs.The ozonolysis products are aldehydes,carboxylic acids,epoxides,and unsaturated hydrocarbons containing aromatic rings.Those products undergo secondary ozonolysis to generate small molecular compounds such as glyoxal,which is beneficial for generating secondary organic aerosol(SOA).Titanium dioxide(TiO_(2)),an essential component of mineral aerosol particles,has good adsorption properties for LCMs;however,it slightly reduces the reactivity with O_(3).At 298 K,the reaction rate constant of the selected LCMs reacting with O_(3)in the gas and atmospheric liquid phases is(2.74–5.53)×10^(-24)cm^(3)/(mol·sec)and 5.58×10^(-3)–39.1 L/(mol·sec),while CEB-2F reacting with O_(3)on(TiO_(2))_(6)cluster is 1.84×10^(-24)cm^(3)/(mol·sec).The existence of TiO_(2)clusters increases the persistence and long-distance transportability of LCMs,which enlarges the contaminated area of LCMs.

关键词： Liquid crystal monomers(LCMs) Ozonolysis TiO_(2)clusters Adsorption Toxicity assessment

Noise-Elimination of Electrocardiogram Based on Wavelet Transform

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Noise-Elimination of Electrocardiogram Based on Wavelet Tran...

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

第三届国际仪器科学技术学术研讨会

作者： huo ju LIU Jin-qi YANG Ming Harbin Institute of Technology Harbin 150001 China

External counter-pulsation can achieve the unwounded external counter-pulsation by means of controlling gasbag mechanism’s inflation and deflation. That’s why eliminating noise, rightly collecting QRS

关键词： external counter-pulsation electrocardiogram Daubechies wavelet filter

来源： cnki会议评论

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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

Reconcile the contradictory wettability requirements for the reduction and oxidation half-reactions in overall CO_(2) photoreduction via alternately hydrophobic surfaces

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Journal of Energy Chemistry 2024年第6期93卷 202-212,I0006页

作者： Hailing huo Ting Hu Chengxi Huang Fang Wu Tongyu Wang Xuan Liu Liang Zhang Qiang ju Zhiqing Zhong Hongbin Xing Erjun Kan Ang Li MIIT Key Laboratory of Semiconductor Microstructure and Quantum Sensing Nanjing University of Science and TechnologyNanjing 210094JiangsuChina College of Information Science and Technology Nanjing Forestry UniversityNanjing 210037JiangsuChina

The overall photocatalytic CO_(2) reduction reaction(OPCRR)that can directly convert CO_(2) and H_(2)O into fuels represents a promising renewable energy conversion technology.As a typical redox reaction,the OPCRR involves two half-reactions:the CO_(2) reduction half-reaction(CRHR)and the water oxidation half-reaction(WOHR).Generally,both half-reactions can be promoted by adjusting the wettability of catalysts.However,there is a contradiction in wettability requirements for the two half-reactions.Specifically,CRHR prefers a hydrophobic surface that can accumulate more CO_(2) molecules on the active sites,ensuring the appropriate ratio of gas-phase(CO_(2))to liquid-phase(H_(2)O)reactants.Conversely,the WOHR prefers a hydrophilic surface that can promote the departure of the gaseous product(O_(2))from the catalyst surface,preventing isolation between active sites and the reactant(H_(2)O).Here,we successfully reconciled the contradictory wettability requirements for the CRHR and WOHR by creating an alternately hydrophobic catalyst.This was achieved through a selectively hydrophobic modification method and a charge-transfer-control strategy.Consequently,the collaboratively promoted CRHR and WOHR led to a significantly enhanced OPCRR with a solar-to-fuel conversion efficiency of 0.186%.Notably,in ethanol production,the catalyst exhibited a 10.64-fold increase in generation rate(271.44μmol g^(-1)h~(-1))and a 4-fold increase in selectivity(55.77%)compared to the benchmark catalyst.This innovative approach holds great potential for application in universal overall reactions involving gas participation.

关键词： Hydrophobic Hydrophilic Gas transport Overall CO_(2)photoreduction Z-scheme

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 time-consuming.In order to solve this problem,a calibration method based on flexible planar target is proposed.In this method,distortion factor is firstly acquired by the invariance of cross ratio,and existing feature points are adjusted with the distortion factor.Then,a large number of points that will be used for the calibration are constructed with the adjusted feature points.Simultaneously,Tsai method is modified so as to reduce the complexity of calibration,which makes the process linear.The 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 points.The 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