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Recent advances in precision measurement & pointing control of spacecraft

Chinese Journal of Aeronautics 2021年第10期34卷 191-209页

作者： Lin LI Li YUAN Li WANG Ran ZHENG Yanpeng WU Xiaoyan WANG Space Optoelectronic Measurement and Perception Lab. Beijing Institute of Control EngineeringBeijing 100190China Science and Technology on Space Intelligent Control Laboratory Beijing 100094China China Academy of Space Technology Beijing 100094China

There exists an increasing need for precision measurement&pointing control and extreme motion stability for current and future space systems,e.g.,Ultra-Performance Spacecraft(UPS).Some notable technologies of realizing Ultra-Pointing(UP)ability have been developed particularly for Ultra-accuracy Ultra-stability Ultra-agility(3 U)spacecraft over recent ***,Multilevel Compound Pointing control Techniques(MCPCTs)are deployed in aerospace engineering,especially in astronomical observation satellites and Earth observation *** controllers and/or algorithms,which are a key factor of MCPCTs for 3 U spacecraft,especially the jitter phenomena that commonly exist in a UPS Pointing control System(PCS),have also been effectively used in some UP spacecraft for a number of ***-vibration suppression approaches,however,are often proposed to deal with low-level mechanical vibration or disturbance in the microgravity environment that is common for *** latter approach potentially is one of the most practical UP techniques for 3 U *** emerging advanced Disturbance-Free Payload(DFP)satellites that exploit the benefits of non-contact actuators have also been reported in the *** represents an interesting and highly promising approach for solving some challenging problems in the *** paper serves as a state-of-the-art review of UP technologies and/or methods which have been developed,mainly over the last decade,specifically for or potentially could be used for 3 U spacecraft pointing *** problems discussed in this paper are of reference significance to UPS and millisecond optical sensors,which are involved in Gaofeng Project,deep space exploration,manned space flight,and gravitational wave detection.

关键词： Disturbance-free payload Micro-vibration suppression Modern controllers or algorithms Pointingcontrol system Ultra-performance spacecraft

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Improved Generative Adversarial Network with Hybrid Attention Mechanism for Path Planning 42

Improved Generative Adversarial Network with Hybrid Attentio...

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42nd Chinese control Conference, CCC 2023

作者： Zhang, Yi-Fan Sun, Tao Ma, Song Dalian University of Technology Key Lab. of Intelligent Control and Optimization for Industrial Equipment of Ministry of Education Dalian116024 China Tsinghua University Department of Automation Beijing100084 China School of Control Science and Engineering Dalian University of Technology Dalian116024 China

ISBN: (纸本)9789887581543

Multi-agent path planning is one of the most challenging problems in the field of artificial intelligence. In this paper, an improved generative adversarial network model with hybrid attention mechanism for data-driven path planning is proposed. Firstly, by introducing spatial attention mechanism, positional attention mechanism and channel attention mechanism, a hybrid attention module is designed. This module not only establishes feature relationship between different locations, but also provides adaptive feature weights to highlight key information. Next, by embedding the hybrid attention module into the generative adversarial network, an improved generative adversarial network model is developed. The proposed model can capture effective feature information in the image and ensures that the generated path can evade obstacles accurately. Finally, some simulation results are provided to verify the superiority and accuracy of the model in path planning. © 2023 Technical Committee on control Theory, Chinese Association of Automation.

关键词： Motion planning

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RPBFT: A Scalab.e Consensus Mechanism for Large Blockchain systems 19th

RPBFT: A Scalable Consensus Mechanism for Large Blockchain S...

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19th EAI International Conference on Heterogeneous Networking for Quality, Reliability, Security and Robustness, QShine 2023

作者： Wang, Weizhe Tian, Daxin Duan, Xuting Zhou, Jianshan School of Transportation Science and Engineering Beihang University Beijing China State Key Lab of Intelligent Transportation System Beijing China Beijing Key Laboratory for Cooperative Vehicle Infrastructure Systems and Safety Control Beijing China Zhongguancun Laboratory Beijing China

ISBN: (纸本)9783031651250

As an emerging technology, blockchain has enabled trustworthy data sharing and efficient cooperation in many industries. It can also make data traceable and auditable, which perfectly meets the regulatory demands for data security and privacy. However, the employment of blockchain is limited in some fields due to the poor scalab.lity of the consensus mechanism. Therefore, this paper introduces a scalab.e consensus mechanism called RPBFT to improve the performance of large-scale systems. To demonstrate the advantage of RPBFT over classic consensus mechanism, we find a way to implement it in blockchain systems and conduct performance tests to evaluate the throughput and latency of the established systems. The results show that RPBFT is superior and more suitable for large-scale blockchain systems. © ICST Institute for Computer Sciences, Social Informatics and Telecommunications engineering 2024.

关键词： Blockchain Consensus mechanism Scalab.lity

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Development of Multi-Channel DXA Detector for Cone Beam Data Acquisition

Development of Multi-Channel DXA Detector for Cone Beam Data...

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IEEE Symposium on Nuclear Science (NSS/MIC)

作者： S. Lee J. Jung Y. Choi J. H. Jung S. Jang Department of Electronic Engineering Intelligent Signal Processing & Systems Lab.(ISPS) Sogang University Seoul Republic of Korea

ISBN: (数字)9798350388152

ISBN: (纸本)9798350388169

Linear-type fan beam detectors have been commonly used in dual-energy X-ray absorptiometry (DXA), which requires long scan time and high radiation exposure when imaging a large area. These problems could be resolved by employing array-type cone beam detectors that could provide a wide field-of-view with a single exposure. The purpose of this study was to develop an array-type multi-channel cone beam DXA detector consisting of SiPM based scintillation detector, analog signal processing circuit and FPGA based TOT. The detector was composed of an 8 × 8 array of 1 × 1 × 2 mm 3 LYSO coupled with an 8 × 8 array of 1 × 1 mm 2 SiPM. Analog signal processing circuit consisted of a resistor-based symmetric charge division readout to reduce the 64 signals of SiPMs to 16 and a diode-based time-over-threshold (ToT) to measure the time and energy information. A 16-ch tapped delay-line TDC was implemented in FPGA to measure the rising edge and the width of the ToT output. To evaluate the energy resolution of the cone beam DXA detector, the energy spectra were acquired using Am-241 and Co-57 point sources. The 64 energy spectra were also acquired using X-ray generator with 83 kVp and 0.2 mA and a Ce filter with K-edge absorption at 40.4 keV. The count variations of the low- and high-energy regions were measured for 5-minutes intervals over 30 minutes to evaluate the uniformity and stability of the detector. The energy resolutions were 25.6% and 18.1% at 60 keV and 122 keV, respectively. Two energy peaks in low- and high-energy regions were clearly discriminated in the 64 energy spectra. Average count variations of the low and high energy regions were 2.4% and 2.3%, respectively. These results indicated that the proposed cone beam DXA detector had sufficient energy resolution, uniformity and stability to discriminate low-energy X-rays and could be useful for cone beam DXA detector. For further study, expansion to 256-ch consisting of 4 modules of 64-ch detector is being studie

关键词： Semiconductor device measurement Particle beams Array signal processing Energy resolution Detectors Time measurement Circuit stability

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One-Shot Three-Dimensional Measurement Based on Spectral Interferometry Using a Digital Micromirror Device 16

One-Shot Three-Dimensional Measurement Based on Spectral Int...

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16th Pacific Rim Conference on Lasers and Electro-Optics, CLEO-PR 2024

作者： Zhang, Jinxu Shi, Liheng Gu, Yingying Zhang, Donglai Yin, Lu Wu, Guanhao Tsinghua University State Key Laboratory of Precision Measurement Technology and Instruments Department of Precision Instrument Beijing100084 China Beijing Institute of Control Engineering Space Optoelectronic Measurement and Perception Lab. Beijing100190 China China Academy of Space Technology National Key Laboratory of Space Intelligent Control Beijing100094 China

We present a one-shot 3D spectral interferometry technique using a digital micromirror device. By encoding the distribution of the spatial light field, this approach enables 3D imaging of step structures within 27 ms.... 详细信息

ISBN: (纸本)9798350372076

关键词： Interferometry

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Image motion and experimental study of a 0.1″space pointing measuring instrument for micro-vibration conditions

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Chinese Journal of Aeronautics 2023年第2期36卷 191-200页

作者： Lin LI Li YUAN Li WANG Miaomiao WANG Xiaoxue GONG Jie SUI Yanpeng WU Ran ZHENG Space Optoelectronic Measurement and Perception Lab. Beijing Institute of Control EngineeringBeijing 100190China China Academy of Space Technology Beijing 100094China Science and Technology on Space Intelligent Control Laboratory Beijing 100094China University of Chinese Academy of Sciences Beijing 100049China Changchun Institute of Optics Fine Mechanics and PhysicsChinese Academy of SciencesChangchun 130033China Chang Guang Satellite Technology Co. Ltd.Changchun130102China

There exists an increasing need for Milli-Arc-Seconds(MAS)accuracy pointing measurement for current and future space *** meet the 0.1″space pointing measurement accuracy requirements of spacecraft in future,the influence of spacecraft micro-vibration on a 0.1″Space Pointing Measuring Instrument(SPMI)is studied.A Quasi-Zero Stiffness Device(QZSD)with adaptive adjustment and variable stroke was ***,a series of micro-vibration experiments of the SPMI were carried *** influence of the micro-vibration generated by Guidance Navigation control(GNC)attitude control components under different attitudes on the SPMI was *** spread function of image motion in micro-vibration was also ***,the changes of image motion under the micro-vibration environment were evaluated by extracting the gray centroid of the images,and the experiment processes and results are deeply *** results show that the firstorder frequency of the QZSD system is 0.114 Hz,and it is induced by a double pendulum system;the image motion of single flywheel spinning reached 0.015 pixels;whilst the image motion reached 0.03 pixels when three flywheels are combined *** latest findings provide a beneficial theoretical and technical support for the development of spacecraft with 0·1″pointing accuracy.

关键词： Image motion Micro-vibration Milli-arc-seconds Quasi-zero stiffness device Space pointing measuring instrument

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Nonlinear Active Disturbance Rejection control for Vehicle Active Suspension System 3

Nonlinear Active Disturbance Rejection Control for Vehicle A...

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3rd International Conference on Electronic Information engineering and Computer Science, EIECS 2023

作者： Dai, Xianglian Zhao, Chunzhe Xu, Rong Chongqing Three Gorges University School of Electronics and Information Engineering Wanzhou China Chongqing Three Gorges University Chongqing Engineering Research Center of Internet of Things and Intelligent Control Technology Key Lab. of Intelligent Info. Proc. and Contr. of Chongqing Munic. Institutions of Higher Education Wanzhou China

ISBN: (纸本)9798350316674

Nonlinear active disturbance rejection control (ADRC) is designed for the suspension system of the quarter vehicle model with the two-degree freedom. It is compared with other active suspension systems based on PID and linear ADRC scheme. The variance of the errors reveals that the nonlinear ADRC suspension system promotes the vehicle acceleration, the suspension dynamic disturbance, and wheel dynamic load. © 2023 IEEE.

关键词： active disturbance rejection control active suspension system extended state observe tracking differentiator

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An FPGA-SoC based Hardware Acceleration of Convolutional Neural Networks 9

An FPGA-SoC based Hardware Acceleration of Convolutional Neu...

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9th IEEE International Conference on Sciences of Electronics, Technologies of Information and Telecommunications, SETIT 2022

作者： Bouaafia, Soulef Messaoud, Seifeddine Khemiri, Randa Sayadi, Fatma Ezahra Monastir University Lab. Electronics and Microelectronics Faculty of Sciences of Monastir Monastir Tunisia Sousse University Lab. Networked Objects Control and Communication Systems National Engineering School of Sousse Sousse Tunisia

ISBN: (数字)9781728184425

ISBN: (纸本)9781728184425

Deep learning has evolved as a discipline that has demonstrated its capacity and usefulness in tackling complicated learning issues as a result of recent improvements in digital technology and the availab.lity of authentic data. Convolutional neural networks (CNNs) in particular have demonstrated their usefulness in image processing and computer vision applications. They do, however, need heavy CPU operations and memory bandwidth, which prevents general-purpose CPUs from attaining desirable performance levels. To boost CNN throughput, hardware accelerators such as application-specific integrated circuits (ASICs), field programmable gate arrays (FPGAs), and graphics processing units (GPUs) have been deployed. FPGAs, in particular, have lately been used to accelerate the development of deep learning networks due to their ability to optimize parallelism and power efficiency. Based on hardware-software architecture, this research provides a CNN acceleration model for video compression applications. Vivado High Level Synthesis is used to accelerate the CNN model in order to develop Intellectual Property (IP) cores. © 2022 IEEE.

关键词： Convolutional neural networks

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Design of Recursive Filtering Scheme via An Improved Weighted Try-Once Discard Protocol 6

Design of Recursive Filtering Scheme via An Improved Weighte...

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6th International Conference on Industrial Artificial Intelligence, IAI 2024

作者： Zheng, Kaiwen Hu, Jun Du, Junhua Yu, Hui Harbin University of Science and Technology Department of Applied Mathematics Harbin150080 China Harbin University of Science and Technology Heilongjiang Prov. Key Lab. of Optimization Control and Intelligent Analysis for Complex Systems Harbin150080 China School of Automation Harbin University of Science and Technology Harbin150080 China

ISBN: (纸本)9798350356618

This paper investigates the recursive filtering (RF) problem for stochastic multi-rate (MR) systems, where the information transmission is regulated by an improved weighted try-once-discard protocol (IWTODP). In order to reduce communication overhead and mitigate network congestion, the IWTODP is firstly proposed and designed to schedule the order of data transmission from the sensors. The main objective of this paper is to design a new RF scheme to minimize the upper bound (UB) on the filtering error (FE) covariance in each iteration step in the presence of IWTODP and MR sampling. In particular, an iterative way is given to provide the expression form of the gain of RF. Finally, the effectiveness of the proposed RF method is illustrated through simulation example. © 2024 IEEE.

关键词： Stochastic systems

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Transformer-Based Unsupervised Image Registration Using SSIM and Homography Loss for Steady Camera and Aerial Videos

Transformer-Based Unsupervised Image Registration Using SSIM...

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Iranian Conference on Electrical engineering (ICEE)

作者： Golnoosh Abdollahinejad Matin Hashemi Department of Electrical Engineering Learning and Intelligent Systems Lab. Sharif University of Technology Tehran Iran

Image registration is an essential and initial block in the pipeline of computer vision tasks and systems. It is defined as transforming a moving image into a target image with the minimum difference when aligned. Unlike previous work for general-purpose datasets, aerial images suffer from mechanical shakes, leading to deformed distortion similar to medical volumetric image registration task. Inspired by medical approaches, we use a Transformer-based network with a semi-unlimited receptive field Swin block to produce a general output for each pixel named flow matrix. Flow matrix is utilized instead of regressing parameters of transformation matrix with a fixed degree of freedom that cannot handle the structural difference between images. This leads to introducing a new loss function based on the Structural Similarity Index Measure (SSIM) and embedding Homography transformation as a regularization term. Combining a generalized-designed network and loss function based on problem definition significantly enhanced results.

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