中国空间科学技术最新文献_第2页

DB Regulate FAK Pathway to Protect Rat BBB Dysfunction Induced by Simulated Microgravity DB调节FAK通路保护模拟微重力致大鼠血脑屏障功能障碍

4区工程技术

中国空间科学技术 Pub Date : 2023-09-09 DOI: 10.34133/space.0071

Ranran Yan, YuShi Zhang, YongZhi Li, JiaPing Wang, Bibi Hajira, YuLin Deng, Yujuan Li

引用次数: 0

Volcanism and Deep Structures of the Moon 火山活动和月球的深层结构

4区工程技术

中国空间科学技术 Pub Date : 2023-01-01 DOI: 10.34133/space.0076

Jiannan Zhao, Le Qiao, Feng Zhang, Yuefeng Yuan, Qian Huang, Jianguo Yan, Yuqi Qian, Yongliao Zou, Long Xiao

引用次数: 0

Orbit determination and thrust estimation for non-cooperative target using angles-only measurement 基于角度测量的非合作目标定轨与推力估计

4区工程技术

中国空间科学技术 Pub Date : 2023-01-01 DOI: 10.34133/space.0073

Zhixun Zhang, Leizheng Shu, Keke Zhang, Zhencai Zhu, Meijiang Zhou, Xinwei Wang, Weidong Yin

{"title":"Orbit determination and thrust estimation for non-cooperative target using angles-only measurement","authors":"Zhixun Zhang, Leizheng Shu, Keke Zhang, Zhencai Zhu, Meijiang Zhou, Xinwei Wang, Weidong Yin","doi":"10.34133/space.0073","DOIUrl":"https://doi.org/10.34133/space.0073","url":null,"abstract":"The classical interactive multimodel (IMM) algorithm has some disadvantages in tracking a noncooperative continuous thrust maneuvering spacecraft, such as poor steady-state accuracy, difficult selection of subfilter parameters, and mismatched model jump. To address the abovementioned problems, a variable-dimensional adaptive IMM strong tracking filtering algorithm (VAIMM-STEKF) is proposed to estimate the spacecraft’s position, velocity, and maneuvering acceleration state. VAIMM-STEKF contains 2 models, model 1 and model 2, which correspond to the tracking of the spacecraft in maneuvering and nonmaneuvering situations. Model 1 estimates the position and velocity of the spacecraft to ensure tracking accuracy when no maneuver occurs. Model 2 is a strong tracking filter with an augmented state. The adaptive IMM algorithm adjusts the fixed Markov transfer matrix in real time according to the model output probability. According to the different states of the spacecraft, the corresponding model interactive fusion method, together with the strong tracking filter, is adopted to ensure fast tracking when the spacecraft state changes. This method can also adapt to continuous thrust maneuvering spacecraft with different orders of magnitude. Simulation results show that the position accuracy of VAIMM-STEKF can be improved by approximately 27% and the speed accuracy can be enhanced by approximately 17% under different levels of maneuvering acceleration compared with those of the IMM algorithm. The convergence speed of VAIMM-STEKF is also better than the IMM algorithm.","PeriodicalId":44234,"journal":{"name":"中国空间科学技术","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135355358","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Dynamics and Control of Flexible Satellite using Reaction Sphere Actuators 基于反球作动器的柔性卫星动力学与控制

4区工程技术

中国空间科学技术 Pub Date : 2023-01-01 DOI: 10.34133/space.0077

Javad Tayebi, Ti Chen, Hao Wang

引用次数: 1

Dynamics and FNTSM control of spacecraft with a film capture pocket system 基于薄膜捕获口袋系统的航天器动力学与FNTSM控制

4区工程技术

中国空间科学技术 Pub Date : 2023-01-01 DOI: 10.34133/space.0079

Zhuoran Huang, Chao Tang, Qiang Yu, Khaliel Saleh Mohamed Shehata, Cheng Wei

{"title":"Dynamics and FNTSM control of spacecraft with a film capture pocket system","authors":"Zhuoran Huang, Chao Tang, Qiang Yu, Khaliel Saleh Mohamed Shehata, Cheng Wei","doi":"10.34133/space.0079","DOIUrl":"https://doi.org/10.34133/space.0079","url":null,"abstract":"To solve the problem of space debris, a film capture pocket system is designed in this paper. The film capture pocket is more flexible and reliable, compared with the space rope net. The film capture pocket system contains many flexible structures that are prone to large deformation and vibration during movement. The deformation causes large disturbances to the service spacecraft. It is necessary to establish an accurate rigid-flexible coupling dynamic model for quantitative analysis of disturbances. First, a film dynamic model is developed using high-order absolute nodal coordinate formulation. Second, an attitude tracking control law is designed by using the fast nonsingular terminal sliding mode controller and fixed time dilation observer (FxESO). Finally, combining dynamics and control principles, a virtual prototype of spacecraft with film capture pocket system is established. The simulation results show that higher-order absolute nodal coordinate formulation elements have better convergence, compared to ABAQUS finite element analysis. Meanwhile, the dynamic model simulates the deformation and vibration states of large flexible structures, during the spacecraft maneuver. The FxESO can estimate and compensate the complex disturbance. The error under fast nonsingular terminal sliding mode + FxESO control law converge more rapidly than the nonsingular terminal sliding mode + expansion observer control law. The final spacecraft attitude tracking error is about 10 −4 , indicating the effectiveness of the controller.","PeriodicalId":44234,"journal":{"name":"中国空间科学技术","volume":"46 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135699127","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Unsupervised interpolation recovery method for spectrum anomaly detection and localization 光谱异常检测与定位的无监督插值恢复方法

4区工程技术

中国空间科学技术 Pub Date : 2023-01-01 DOI: 10.34133/space.0082

Yishi Huang, Shuai Yuan, Naijin Liu, Qing Li, Wenyu Liang, Lei Liu

{"title":"Unsupervised interpolation recovery method for spectrum anomaly detection and localization","authors":"Yishi Huang, Shuai Yuan, Naijin Liu, Qing Li, Wenyu Liang, Lei Liu","doi":"10.34133/space.0082","DOIUrl":"https://doi.org/10.34133/space.0082","url":null,"abstract":"With the growing efficiency of the use of unlicensed spectrum, the challenge of ensuring spectrum security has become increasingly daunting. Spectrum managers aim to accurately and efficiently detect and recognize anomaly behaviors in the spectrum. In this study, we propose a novel framework for spectrum anomaly detection and localization by spectrum interpolation recovery. Spectrum interpolation recovery refers to the recovery of the rest of the spectrum distribution based on a part of the spectrum distribution, which is achieved through a masked autoencoder (MAE) model with a core of multi-head self-attention (MHSA) mechanism. The spectrum interpolation recovery method restores the region where the masked abnormal signals are present, yielding anomaly-free results, with the difference between the restored and the masked representing the anomaly signals. The proposed method has been demonstrated to effectively reduce model-induced over-recovery of anomalous signals and dilute large-scale generation errors caused by anomalies, thereby improving the detection and localization performance of anomaly signals, and improving the area under the receiver operating characteristic curve (AUC) and the area under the precision–recall curve (AUPRC) by 0.0382 (3.68%) and 0.1992 (68.90%), respectively. On a designed dataset containing 3 variables of interference-to-signal ratio (ISR), signal-to-noise ratio (SNR), and anomaly type, the total recall of anomaly detection and localization at a 5% false alarm rate reached 0.8799 and 0.5536, respectively. Furthermore, a comparative study among different methods demonstrates the effectiveness and rationality of the proposed method.","PeriodicalId":44234,"journal":{"name":"中国空间科学技术","volume":"130 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135845953","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Unsupervised Spectrum Anomaly Detection Method for Unauthorized Bands 非授权频段的无监督频谱异常检测方法

IF 0.9 4区工程技术

中国空间科学技术 Pub Date : 2022-02-21 DOI: 10.34133/2022/9865016

Yu Tian, Haihua Liao, Jing Xu, Ya Wang, Shuai Yuan, Naijin Liu

{"title":"Unsupervised Spectrum Anomaly Detection Method for Unauthorized Bands","authors":"Yu Tian, Haihua Liao, Jing Xu, Ya Wang, Shuai Yuan, Naijin Liu","doi":"10.34133/2022/9865016","DOIUrl":"https://doi.org/10.34133/2022/9865016","url":null,"abstract":"With the rapid development of wireless communication, spectrum plays increasingly important role in both military and civilian fields. Spectrum anomaly detection aims at detecting emerging anomaly signals and spectrum usage behavior in the environment, which is indispensable to secure safety and improve spectrum efficiency. However, spectrum anomaly detection faces many difficulties, especially for unauthorized frequency bands. In unauthorized bands, the composition of spectrum is complex and the anomaly usage patterns are unknown in prior. In this paper, a Variational Autoencoder- (VAE-) based method is proposed for spectrum anomaly detection in unauthorized bands. First of all, we theoretically prove that the anomalies in unauthorized bands will introduce Background Noise Enhancement (BNE) effect and Anomaly Signal Disappearance (ASD) effects after VAE reconstruction. Then, we introduce a novel anomaly metric termed as percentile (PER) score, which focuses on capturing the distribution variation of reconstruction error caused by ASD and BNE. In order to verify the effectiveness of our method, we developed an ISM Anomaly Detection (IAD) dataset. The proposed PER score achieves superior performance against different type of anomalies. For QPSK type anomaly, our method increases the recall rate from 80% to 93% while keeping a false alarm rate of 5%. The proposed method is beneficial to broadband spectrum sensing and massive spectrum data processing. The code will be released at :QXSLAB/vae_ism_ano.git.","PeriodicalId":44234,"journal":{"name":"中国空间科学技术","volume":"27 4 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2022-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83507891","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Mission Design of an Aperture-Synthetic Interferometer System for Space-Based Exoplanet Exploration 天基系外行星探测孔径合成干涉仪系统的任务设计

IF 0.9 4区工程技术

中国空间科学技术 Pub Date : 2022-02-17 DOI: 10.34133/2022/9835234

F. Jia, Xiangyu Li, Zhuoxi Huo, D. Qiao

{"title":"Mission Design of an Aperture-Synthetic Interferometer System for Space-Based Exoplanet Exploration","authors":"F. Jia, Xiangyu Li, Zhuoxi Huo, D. Qiao","doi":"10.34133/2022/9835234","DOIUrl":"https://doi.org/10.34133/2022/9835234","url":null,"abstract":"In recent years, exoplanet detection has become the technological frontier in the field of astronomy, because it provides evidence of the origin of life and the future human habitable exoplanet. Deploying several satellites to form an aperture-synthetic interferometer system in space may help discover “another Earth” via interferometry and midinfrared broadband spectroscopy. This paper analyzes a space-based exoplanet exploration mission in terms of the scientific background, mission profile, trajectory design, and orbital maintenance. First, the system architecture and working principle of the interferometer system are briefly introduced. Secondly, the mission orbit and corresponding transfer trajectories are discussed. The halo orbit near the Sun-Earth L2 (SEL2) orbit is chosen as the candidate mission orbit. The low-energy transfer via stable invariant manifold with multiple perigees is designed, and the proper launch windows are presented. A speed increment less than 10 m/s is imposed for each transfer to achieve the insertion of the halo orbit. Finally, the tangent targeting method (TTM) is applied for high-precision formation maintenance with the whole velocity increments of less than 5×10−4 m/s for each spacecraft when the error bound is 0.1 m. The overall fuel budget during the mission period is evaluated and compared. The design in this paper will provide technical support and reliable reference for future exoplanet exploration missions.","PeriodicalId":44234,"journal":{"name":"中国空间科学技术","volume":"33 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2022-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90077785","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 3

Numerical Simulation of Decompression Process of a Mars Rover in the Launch Phase 火星探测器发射阶段减压过程的数值模拟

IF 0.9 4区工程技术

中国空间科学技术 Pub Date : 2022-02-02 DOI: 10.34133/2022/9827483

Weizhang Wang, W. Rao, Qi Li, H. Yan, Rui Zhao

引用次数: 1

Study on Effect of Aerodynamic Configuration on Aerodynamic Performance of Mars Ascent Vehicles 气动构型对火星上升飞行器气动性能的影响研究

IF 0.9 4区工程技术

中国空间科学技术 Pub Date : 2022-01-29 DOI: 10.34133/2022/9790131

Qi Li, Wu Yuan, Rui Zhao, Haogong Wei

引用次数: 4