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

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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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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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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DFIMat: Decoupled Flexible Interactive Matting in Multi-person Scenarios 17th

DFIMat: Decoupled Flexible Interactive Matting in Multi-per...

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17th Asian Conference on Computer Vision, ACCV 2024

作者： Jiao, Siyi Zeng, Wenzheng Gao, Changxin Sang, Nong Key Laboratory of Image Processing and Intelligent Control School of Artificial Intelligence and Automation Huazhong University of Science and Technology Wuhan China

ISBN: (纸本)9789819609710

Interactive portrait matting refers to extracting the soft portrait from a given image that best meets the user’s intent through their inputs. Existing methods often underperform in complex scenarios, mainly due to three factors. (1) Most works apply a tightly coupled network that directly predicts matting results, lacking interpretability and resulting in inadequate modeling. (2) Existing works are limited to a single type of user input, which is ineffective for intention understanding and also inefficient for user operation. (3) The multi-round characteristics have been under-explored, which is crucial for user interaction. To alleviate these limitations, we propose DFIMat, a decoupled framework that enables flexible interactive matting. Specifically, we first decouple the task into 2 sub-ones: localizing target instances by understanding scene semantics and the flexible user inputs, and conducting refinement for instance-level matting. We observe a clear performance gain from decoupling, as it makes sub-tasks easier to learn, and the flexible multi-type input further enhances both effectiveness and efficiency. DFIMat also considers the multi-round interaction property, where a contrastive reasoning module is designed to enhance cross-round refinement. Another limitation for multi-person matting task is the lack of training data. We address this by introducing a new synthetic data generation pipeline that can generate much more realistic samples than previous arts. A new large-scale dataset SMPMat is subsequently established. Experiments verify the significant superiority of DFIMat. With it, we also investigate the roles of different input types, providing valuable principles for users. Our code and dataset will be public. © The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2025.

关键词： Large datasets

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Adaptive Task Allocation for Multi-UAV Systems Using a Novel Dynamic Distributed Algorithm

Adaptive Task Allocation for Multi-UAV Systems Using a Novel...

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2024 China Automation Congress, CAC 2024

作者： Zhou, Cheng Li, Nuo Yang, Shuqi Yu, Lianbo Lian, Lei Wang, Dong Wang, Wei Key Laboratory of Intelligent Control and Optimization for Industrial Equipment Ministry of Education School of Control Science and Engineering Dalian University of Technology Dalian China

ISBN: (纸本)9798350368604

This paper introduces the Dynamic Efficient Distributed Performance Impact (DEDPI) algorithm for optimizing task allocation in multi-UAV systems operating in dynamic environments. The algorithm overcomes the limitations of existing approaches, specifically the suboptimal solutions of dynamic task algorithms and the computational inefficiencies of extending static algorithms to dynamic contexts, by dynamically adjusting task queues and employing a novel objective function to enhance resource allocation and responsiveness. Experimental results demonstrate that DEDPI significantly increases the number of completed tasks while reducing the average task execution cost, providing an effective solution for real-time, mission-critical UAV operations. © 2024 IEEE.

关键词： Resource allocation

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Design of Pole-Combined Coreless Axial Flux Permanent Magnet Synchronous Motor for Collaborative Robot Application 11th

Design of Pole-Combined Coreless Axial Flux Permanent Magnet...

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11th Frontier Academic Forum of Electrical Engineering, FAFEE 2024

作者： Wang, Xiaocan Luo, Gang Xu, Zeyuan Xiamen Key Laboratory of Frontier Electric Power Equipment and Intelligent Control Xiamen University of Technology Fujian Xiamen361000 China

ISBN: (纸本)9789819788194

Axial flux permanent magnet synchronous motor(AFPM) has small axial volume, high output torque and excellent reliability. In this paper, a new design scheme for the collaborative robotic joint is proposed with it. Due to the narrow installation space of the motor, the Halbach array with 90° magnetizing angle is selected to enhance the air-gap magnetic field magnetism. However, the waveform of the air-gap magnetic field is not well sinusoidal because of large harmonic content while the NdFeB permanent magnet material is expensive. To solve above problems, a special Halbach structure combining ferrite and NdFeB permanent magnets is introduced. Three kinds of permanent magnet combination structures are given, and the optimal combination is determined by three-dimensional finite element method which establishes the motor model. The results show that the designed coreless axial flux joint motor has high power density and compact structure The results show that the designed articulated motor has high power density and compact structure. In addition, after comparison with the basic permanent magnet structure motor, the permanent magnet combination Halbach can effectively reduce the motor cost and strengthen the motor stability. © Beijing Paike Culture Commu. Co., Ltd. 2025.

关键词： Permanent magnets

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Reconfigurability Evaluation of VSCMG Based on Power Consumption Constraint

Reconfigurability Evaluation of VSCMG Based on Power Consump...

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2023 China Automation Congress, CAC 2023

作者： Cheng, Zhaoyang Qin, Dongdong Wang, Danna Zhang, Zhouburan Peng, Rui Shanghai Aerospace Control Technology Insititute Shanghai China Shanghai Key Laboratory of Aerospace Intelligent Control Technology Shanghai China

ISBN: (纸本)9798350303759

In this paper, a reconfigurability evaluation method for Variable Speed control Moment Gyroscope (VSCMG) based on power consumption constraint is proposed. Based on the spacecraft attitude dynamics model and the VSCMGs system model, the spacecraft state space equation is established with the VSCMGs system fault factor vector. And then, by judging the controllability and power consumption performance of the system, a multiple composite reconfigurability evaluation method based on power consumption and reliability constraints is designed. Finally, the simulation analysis of whether the VSCMGs system has reconfiguration after failure is carried out, and the simulation results are in line with the actual situation, which verifies the correctness and effectiveness of the evaluation method. © 2023 IEEE.

关键词： Electric power utilization

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Research on surface defect detection of aerospace electronic components based on machine vision 3

Research on surface defect detection of aerospace electronic...

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3rd International Conference on Optics and Communication technology, ICOCT 2023

作者： Zhang, Weiwei Pei, Zhonghai Liu, Kairong Lu, Jinglin Shanghai Aerospace Control Technology Institute Shanghai China Shanghai Key Laboratory of Space Intelligent Control Technology Shanghai China

ISBN: (纸本)9781510672529

Aiming at the problems of low detection efficiency and high labor cost for manual aerospace electronic components surface, this paper proposes a surface defect detection method based on machine vision. Firstly, based on the design of the components surface defect detection device, the characteristics of the surface image are analyzed. Then, the image is preprocessed by bilateral filtering algorithm and morphological operation, and the edge is removed while the noise is removed. Finally, the fast adaptive threshold is adopted. Segmentation to achieve defect detection on the components surface. The experimental results show that the detection method has a good detection effect on the surface of the components. The detection rate and false detection rate are 3.2% and3.8%, respectively, which provides a feasible solution for the detection of defects on the surface of aerospace electronic products. Has a certain practical value. © 2023 SPIE.

关键词： Computer vision

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Plunger motor fault analysis method based on improved wavelet packet threshold denoising and feature signal extraction

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Noise and Vibration Worldwide 2025年第3期56卷 186-202页

作者： Hui, Huang Guo, Yi Xu, Chen Su, Junshou Huang, Qiufang Yuzheng, Li Key Laboratory of Fluid Power and Intelligent Electro-Hydraulic Control Fuzhou University Fuzhou China XCMG State Key Laboratory Technology Co. Ltd. Xuzhou China Fulongma Group Co. Ltd Longyan China

Aiming at the characteristics of dense noise sources, cross noise frequency, and non-linearity and non-stationarity of the acoustic signal inside the plunger motor, an improved wavelet packet threshold denoising combined with ensemble empirical modal analysis and Hilbert transform is proposed as the feature signal extraction method. By collecting vibration signals of both fault free and faulty motors under normal operation, constructing a wavelet packet secondary decomposition structure and thresholding to analyze and denoise the collected signals, and then using an improved signal processing method to obtain the true characteristic signal frequency of the plunger motorThe novelty of this study lies in the integration of advanced signal processing techniques to enhance fault detection accuracy by effectively handling noise and extracting characteristic frequencies in complex operational environments. Experimental validation shows that the proposed method effectively enhances the feature extraction of plunger motors, providing a reliable basis for fault diagnosis. © The Author(s) 2025.

关键词： Wavelet decomposition

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Multi-Level Robotic Pouring Using Offline Reinforcement Learning

Multi-Level Robotic Pouring Using Offline Reinforcement Lear...

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2024 IEEE International Conference on Robotics and Biomimetics, ROBIO 2024

作者： Zhang, Xiaoxiong Liu, Junwei Zhang, Wei School of System Design and Intelligent Manufacturing Southern University of Science and Technology Shenzhen Key Laboratory of Control Theory and Intelligent Systems Shenzhen518055 China

ISBN: (纸本)9781665481090

This paper presents a novel learning-based method for a robotic manipulator to achieve liquid pouring across different liquid levels using only visual sensors. Previous works have relied on either online reinforcement learning or imitation learning, which are limited by sim-to-real gaps or data efficiency. In this paper, we propose to combine supervised learning and offline reinforcement learning, utilizing a human demonstration dataset containing only successful pouring at the highest level. Specifically, our approach employs supervised learning for a visual classifier, transforming the visual input into a categorical distribution over liquid levels. The offline reinforcement learning method is applied to a binary-conditioned control policy, which takes a binary signal and the robot's proprioception as inputs to determine the action. The binary signal indicates whether the desired liquid level has been reached based on the target liquid level. Through experiments, our method demonstrates superior effectiveness compared to a state-of-the-art imitation learning algorithm. Moreover, tests in unseen scenarios and multiple liquid level commands verify the generalization and transferability of our approach. © 2024 IEEE.

关键词： Self-supervised learning

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