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Adaptive entry guidance for the Tianwen-1 mission

Astrodynamics 2022年第1期6卷 17-26页

作者： Minwen Guo Xiangyu Huang Maodeng Li Jinchang Hu Chao Xu Beijing Institute of Control Engineering Beijing 100094China National Key Laboratory of Science and Technology on Space Intelligent Control Beijing 100094China

To meet the requirements of the Tianwen-1 mission,adaptive entry guidance for entry vehicles,with low lift-to-drag ratios,limited control authority,and large initial state bias,was ***,the entry guidance law is divided into four distinct phases:trim angle-of-attack phase,range control phase,heading alignment phase,and trim-wing deployment *** the range control phase,the predictor–corrector guidance algorithm is improved by planning an on-board trajectory based on the Mars Science laboratory(MSL)entry guidance *** nominal trajectory was designed and described using a combination of the downrange value and other states,such as drag acceleration and altitude *** a large initial state bias,the nominal downrange value was modified onboard by weighing the landing accuracy,control authority,and parachute deployment *** biggest advantage of this approach is that it allows the successful correction of altitude errors and the avoidance of control *** overview of the optimal trajectory design process,including a discussion of the design of the initial flight path angle,relevant event trigger,and transition conditions between the four phases,was also ***,telemetry data analysis and post-flight assessment results were used to illustrate the adaptive guidance law,create good conditions for subsequent parachute reduction and power reduction processes,and gauge the success of the mission.

关键词： Tianwen-1 mission adaptive entry guidance on-board trajectory planning telemetry data analysis post-flight assessment

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End-to-end Mars entry,descent,and landing modeling and simulations for Tianwen-1 guidance,navigation,and control system

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Astrodynamics 2022年第1期6卷 53-67页

作者： Chao Xu Xiangyu Huang Minwen Guo Maodeng Li Jinchang Hu Xiaolei Wang Beijing Institute of Control Engineering Beijing 100094China National Key Laboratory of Science and Technology on Space Intelligent Control Beijing 100094China

On May 15,2021,the Tianwen-1 lander successfully touched down on the surface of *** ensure the success of the landing mission,an end-to-end Mars entry,descent,and landing(EDL)simulator is developed to assess the guidance,navigation,and control(GNC)system performance,and determine the critical operation and lander *** high-fidelity models of the Mars atmosphere,parachute,and lander system that are incorporated into the simulator are *** the developed simulator,simulations of the Tianwen-1 lander EDL are *** results indicate that the simulator is valid,and the GNC system of the Tianwen-1 lander exhibits excellent performance.

关键词： Mars entry,descent,and landing(EDL) modeling and simulation Tianwen-1 lander guidance,navigation,and control(GNC)

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Entry vehicle control system design for the Tianwen-1 mission

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Astrodynamics 2022年第1期6卷 27-37页

作者： Jinchang Hu Xiangyu Huang Maodeng Li Minwen Guo Chao Xu Yu Zhao Wangwang Liu Xiaolei Wang Beijing Institute of Control Engineering Beijing 100094China National Key Laboratory of Science and Technology on Space Intelligent Control Beijing 100094China

The entry vehicle for the Tianwen-1 mission successfully landed on the surface of Mars at 7:18 AM BJT on May 15,*** successful landing made China the first country to orbit,land,and release a rover in their first attempt at the Mars *** guidance,navigation,and control(GNC)system plays a crucial role in the entry,descent,and landing(EDL)*** study focused on the attitude control component of the GNC system *** EDL phase can be divided into several sub-phases,namely the angle of attack control phase,lift control phase,parachute descent phase,and powered descent *** sub-phase has unique attitude control requirements and *** paper introduces the key aspects of designing attitude controllers for each ***,flight results are presented and analyzed.

关键词： Tianwen-1 Mars landing attitude control robust control fault diagnosis

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Group Hybrid Coordination control of Multi-Agent Systems With Time-Delays and Additive Noises

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IEEE/CAA Journal of Automatica Sinica 2023年第3期10卷 737-748页

作者： Chuanjian Li Xiaofeng Zong School of Automation China University of GeosciencesWuhan 430074 Hubei Key Laboratory of Advanced Control and Intelligent Automation for Complex Systems Wuhan 430074 the Engineering Research Center of Intelligent Technology for Geo-Exploration Ministry of EducationWuhan 430074China IEEE

A new kind of group coordination control problemgroup hybrid coordination control is investigated in this *** group hybrid coordination control means that in a whole multi-agent system(MAS)that consists of two subgroups with communications between them,agents in the two subgroups achieve consensus and containment,*** MASs with both time-delays and additive noises,two group control protocols are proposed to solve this problem for the containment-oriented case and consensus-oriented case,*** developing a new analysis idea,some sufficient conditions and necessary conditions related to the communication intensity betw een the two subgroups are obtained for the following two types of group hybrid coordination behavior:1)Agents in one subgroup and in another subgroup achieve weak consensus and containment,respectively;2)Agents in one subgroup and in another subgroup achieve strong consensus and containment,*** is revealed that the decay of the communication impact betw een the two subgroups is necessary for the consensus-oriented ***,the validity of the group control results is verified by several simulation examples.

关键词： Additive noises consensus control containment control group hybrid coordination control multi-agent systems(MASs) time-delays

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Leader-following consensus control for multi-agent systems under DoS attacks and average dwell time switching topology

Leader-following consensus control for multi-agent systems u...

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2024 China Automation Congress, CAC 2024

作者： Yuan, Li Liu, Shuai Li, Panshuo Guangdong Provincial Key Laboratory of Intelligent Decision and Cooperative Control Guangdong-Hong Kong Joint Laboratory for Intelligent Decision and Cooperative Control School of Automation Guangdong University of Technology Guangzhou Guangzhou510006 China

ISBN: (纸本)9798350368604

This article studies the leader-following consensus problem of multi-agent systems (MASs) in the presence of denial-of-service (DoS) attacks and switching topology. The problem that all edges of one follower are blocked under each attack is considered in this work. By using the multiple Lyapunov functions approach and average dwell time switching technique, a piecewise consensus protocol is designed. Sufficient conditions are established for the consensus of linear MAS. Moreover, the lower bound of average dwell time of the switching topology is determined under DoS attacks. Finally, we provided simulations to validate our theoretical finding. © 2024 IEEE.

关键词： Multi agent systems

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Powered-descent landing GNC system design and flight results for Tianwen-1 mission

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Astrodynamics 2022年第1期6卷 3-16页

作者： Xiangyu Huang Chao Xu Jinchang Hu Maodeng Li Minwen Guo Xiaolei Wang Yu Zhao Baocheng Hua Yunpeng Wang Beijing Institute of Control Engineering Beijing 100094China National Key Laboratory of Science and Technology on Space Intelligent Control Beijing 100094China

The powered-descent landing(PDL)phase of the Tianwen-1 mission began with composite backshell–parachute(CBP)separation and ended with landing-rover *** main tasks of this phase were to reduce the velocity of the lander,perform the avoidance maneuver,and guarantee a soft *** PDL phase overcame many challenges:performing the divert maneuver to avoid collision with the CBP while simultaneously avoiding large-scale hazards;slowing the descent from approximately 95 to 0 m/s;performing the precise hazard-avoidance maneuver;and placing the lander gently and safely on the surface of *** architecture and algorithms of the guidance,navigation,and control system for the PDL phase were designed;its execution resulted in Tianwen-1’s successful touchdown in the morning of 15 May ***,the Tianwen-1 mission achieved a historic autonomous landing with simultaneous hazard and CBP avoidance.

关键词： Tianwen-1 powered-descent landing(PDL) guidance,navigation,and control(GNC) backshell avoidance hazard avoidance

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Distributed robust iterative learning control for AC microgrids with external disturbances

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Science China(Information Sciences) 2025年

作者： Hongyu SU Jingang LAI School of Artificial Intelligence and Automation Key Laboratory of Image Processing and Intelligent ControlMinistry of Education Huazhong University of Science and Technology

This study proposes a distributed secondary control scheme based on distributed robust iterative learning control(DRILC) for islanded alternating current(AC) microgrids subjected to external disturbances. By employing the decoupled sliding mode consensus approach, voltage regulation, frequency restoration, and accurate active power sharing can be achieved within a finite time on the proposed novel integral terminal sliding mode(ITSM) manifold. Furthermore, the appropriate iterative update law in the ITSM-based controller is utilized to learn and eliminate external disturbances as effectively as possible. In the proposed control scheme, the iterative learning control and sliding mode control are designed to function in a complementary manner, which enhances the performance of the secondary control scheme for multi-objective regulations. The stability criteria and robustness to external disturbances of the closed-loop microgrid system in the iteration and time domains are also rigorously derived with the help of the Lyapunov direct method. Finally, the effectiveness of the proposed secondary control scheme is validated by case studies of an islanded AC microgrid test system in the MATLAB/SimPowerSystems software environment.

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Robust Fixed-time Composite controller Design with the Unknown System Dynamics Estimator for Nonlinear Robotic Manipulator Systems 24

Robust Fixed-time Composite Controller Design with the Unkno...

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2nd International Conference on Frontiers of intelligent Manufacturing and Automation, CFIMA 2024

作者： Li, Siyan Xing, Yashan Na, Jing Li, Qi Faculty of Mechanical and Electrical Engineering Yunnan Key Laboratory of Intelligent Control and Application Kunming University of Science and Technology Yunnan China

ISBN: (纸本)9798400710681

In this paper, a robust fixed-time composite control scheme based on an Unknown System Dynamics Estimator (USDE) is proposed. The proposed control method guarantees the tracking error convergence in a fixed-time for nonlinear robotic manipulators with unknown dynamics and disturbance. To address the existence of uncertainties, first, a simple structure of USDE by a low-pass filtering operation is constructed without using acceleration signals, Which is adjusted for only one filter coefficient. Then, the USDE compensate the estimated value into the robust fixed-time composite controller. The composite controller contains a fixed time control term, a robust control term, and a computed torque control term. By the fixed-time control term, the upper bound on the convergence time is independent of the initial conditions of the system, which ensures fast-tracking tasks for the robot manipulator. And the robust control term is used to reduce the impact of USDE estimation errors. The stability of the closed-loop system is demonstrated through Lyapunov criteria. The validity of the proposed method is verified by simulation. © 2024 Copyright held by the owner/author(s).

关键词： Stability criteria

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Revealing the atomic mechanism of diamond–iron interfacial reaction

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Carbon Energy 2024年第3期6卷 255-263页

作者： Yalun Ku Kun Xu Longbin Yan Kuikui Zhang Dongsheng Song Xing Li Shunfang Li Shaobo Cheng Chongxin Shan Henan Key Laboratory of Diamond Optoelectronic Materials and Devices Key Laboratory of Material PhysicsMinistry of EducationSchool of Physics and MicroelectronicsZhengzhou UniversityZhengzhouChina Department of Mechanical Engineering Stanford UniversityStanfordCaliforniaUSA Information Materials and Intelligent Sensing Laboratory of Anhui Province Key Laboratory of Structure and Functional Regulation of Hybrid Materials of Ministry of EducationInstitutes of Physical Science and Information TechnologyAnhui UniversityHefeiChina Institute of Quantum Materials and Physics Henan Academy of SciencesZhengzhouChina

Diamond,with ultrahigh hardness,high wear resistance,high thermal conductivity,and so forth,has attracted worldwide ***,researchers found emergent reactions at the interfaces between diamond and ferrous materials,which significantly affects the performance of diamond-based ***,combing experiments and theoretical calculations,taking diamond–iron(Fe)interface as a prototype,the counter-diffusion mechanism of Fe/carbon atoms has been ***,it is identified that Fe and diamond first form a coherent interface,and then Fe atoms diffuse into diamond and prefer the carbon vacancies ***,the relaxed carbon atoms diffuse into the Fe lattice,forming Fe_(3)***,graphite is observed at the Fe_(3)C surface when Fe_(3)C is over-saturated by carbon *** present findings are expected to offer new insights into the atomic mechanism for diamondferrous material's interfacial reactions,benefiting diamond-based device applications.

关键词： coherent interface counter-diffusion diamond iron phase transition

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Fine-Grained Emotion Prediction for Movie and Television scene images

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The Journal of China Universities of Posts and Telecommunications 2024年第3期31卷 43-55页

作者： Su Zhibin Zhou Xuanye Liu Bing Ren Hui State Key Laboratory of Media Convergence and Communication Communication University of ChinaBeijing 100024China Key Laboratory of Acoustic Visual Technology and Intelligent Control System Communication University of ChinaBeijing 100024China School of Information and Communication Engineering Communication University of ChinaBeijing 100024China

For the task of content retrieval,analysis and generation of film and television scene images in the field of intelligent editing,fine-grained emotion recognition and prediction of images is of great *** this paper,the fusion of traditional perceptual features,art features and multi-channel deep learning features are used to reflect the emotion expression of different levels of the *** addition,the integrated learning model with stacking architecture based on linear regression coefficient and sentiment correlations,which is called the LS-stacking model,is proposed according to the factor association between multi-dimensional *** experimental results prove that the mixed feature and LS-stacking model can predict well on the 16 emotion categories of the self-built image *** study improves the fine-grained recognition ability of image emotion by computers,which helps to increase the intelligence and automation degree of visual retrieval and post-production system.

关键词： fine-grained emotion prediction movie and television scene images stacking model linear regression

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