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Flow and thermal modeling of liquid metal in expanded microchannel heat sink

Frontiers in Energy 2023年第6期17卷 796-810页

作者： Mingkuan ZHANG Xudong ZHANG Luna GUO Xuan LI Wei RAO Tianjin Key Laboratory for Advanced Mechatronic System Design and Intelligent Control School of Mechanical EngineeringTianjin University of TechnologyTianjin 300384China National Demonstration Center for Experimental Mechanical and Electrical Engineering Education Tianjin University of TechnologyTianjin 300384China Key Laboratory for Thermal Science and Power Engineering of the Ministry of Education Department of Engineering MechanicsTsinghua UniversityBeijing 100084China School of Mechanical Engineering Tianjin University of CommerceTianjin 300134China Institute of Refrigeration and Cryogenics Shanghai Jiao Tong UniversityShanghai 200240China Beijing Key Laboratory of CryoBiomedical Engineering and Key Laboratory of Cryogenics Beijing 100190China

Liquid metal-based microchannel heat sinks (MCHSs) suffer from the low heat capacity of coolant, resulting in an excessive temperature rise of coolant and heat sink when dealing with high-power heat dissipation. In this paper, it was found that expanded space at the top of fins could distribute the heat inside microchannels, reducing the temperature rise of coolant and heat sink. The orthogonal experiments revealed that expanding the top space of channels yielded similar temperature reductions to changing the channel width. The flow and thermal modeling of expanded microchannel heat sink (E-MCHS) were analyzed by both using the 3-dimensional (3D) numerical simulation and the 1-dimensional (1D) thermal resistance model. The fin efficiency of E-MCHS was derived to improve the accuracy of the 1D thermal resistance model. The heat conduction of liquid metal in Z direction and the heat convection between the top surface of fins and the liquid metal could reduce the total thermal resistance (Rt). The above process was effective for microchannels with low channel aspect ratio, low mean velocity (Um) or long heat sink length. The maximum thermal resistance reduction in the example of this paper reached 36.0%. The expanded space endowed the heat sink with lower pressure, which might further reduce the pumping power (P). This rule was feasible both when fins were truncated (h_(2) < 0, h_(2) is the height of expanded channel for E-MCHS) and when over plate was raised (h_(2) > 0).

关键词： liquid metal cooling heat sink expanded microchannel flow and thermal modeling

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Enhancing Traffic Flow Forecasting with Spatio-Temporal Information: A Case Study on Highway Networks in Belgium 8

Enhancing Traffic Flow Forecasting with Spatio-Temporal Info...

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8th International Conference on Instrumentation, control, and Automation, ICA 2023

作者： Fathurrahman, Muhammad Farhan Catteeuw, Arne Gautama, Sidharta Aguirre, Angel L. Joelianto, Endra Sutarto, Herman Y. Ghent University Engineering and Product Design Department of Industrial Systems Ghent Belgium Department of Intelligent System Bandung Indonesia FlandersMake@UGent-Corelab ISyE Lommel Belgium Institut Teknologi Bandung Instrumentation and Control Research Group Faculty of Industrial Technology Bandung Indonesia

ISBN: (纸本)9798350301274

As the number of vehicles continues to increase every year, it is crucial to monitor traffic conditions effectively. Traffic forecasting serves as a valuable method in traffic management to support decision making. This study investigates the impact of utilizing spatio-Temporal data for traffic flow forecasting, as opposed to forecasting each location individually. We compare spatio-Temporal Long Short-Term Memory (LSTM), a machine-learning technique that utilizes spatially correlated sensor data in a network, and compare this to conventional LSTM and Seasonal ARIMA (SARIMA). Experiments have been conducted on counting loop data of a highway network in Belgium. We have investigated the performances of the forecasting model for different prediction horizons. The results show that spatial information improves the performance of the forecasting model and reduces the training time required. Further analysis show that the spatio-Temporal LSTM improves majorities of detectors while the minorities detectors are degraded which imply the importances of network selection. The computational load of the spatio-Temporal LSTM model is minimally impacted by the number of sensors in the network thus making it scalable. The results show that longer prediction horizons degrade the forecasting performance but the impact up to a 12 hour-horizon is not significant. © 2023 IEEE.

关键词： Long short-term memory

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A Target Trajectory Prediction Method in Air Combat Based on Wavelet-Attention-GRU Under the Frenet Frame

A Target Trajectory Prediction Method in Air Combat Based on...

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2024 IEEE International Conference on systems, Man, and Cybernetics, SMC 2024

作者： Zhang, An Mao, Zeming Xu, Haiyu Fan, Qiucen Bi, Wenhao Yan, Yuwen School of Aeronautics Northwestern Polytechnical University Department of Integrated Technology and Control Engineering Shaanxi Xi'an710072 China Northwestern Polytechnical University National Key Laboratory of Aircraft Configuration Design Shaanxi Xi'an710072 China Shanghai Zhongchuan SDT-NERCCo. Ltd. Department of Mission System Shanghai201114 China

ISBN: (纸本)9781665410205

The target trajectory prediction method can assist pilots in situation awareness and provide support for decision-making to improve the capacity to gain the advantage during high dynamic within-visual-range air combat. Aiming at the problem of traditional methods based on the Cartesian frame, such as the low utilization of training data and the weak generalization, and the low accuracy of the existing time series prediction models, a target trajectory prediction method in air combat based on Wavelet-Attention-GRU under the Frenet frame is proposed. In this method, the air combat features are described via the spatial trajectory curve based on the Frenet frame;the target trajectory prediction model is established by combining the GRU network with the improved multi-head self-attention mechanism by adding wavelet transform. Finally, the one-to-one within-visual-range air combat dataset obtained via the high-fidelity air combat simulator is applied to train and test the trajectory prediction model. © 2024 IEEE.

关键词： Trajectories

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On the Equivalence Between Prescribed Performance control and control Barrier Functions

On the Equivalence Between Prescribed Performance Control an...

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American control Conference (ACC)

作者： Ryo Namerikawa Adrian Wiltz Farhad Mehdifar Toru Namerikawa Dimos V. Dimarogonas Department of System Design Engineering Keio University Kanagawa Japan Division of Decision and Control Systems KTH Royal Institute of Technology Stockholm Sweden

ISBN: (数字)9798350382655

ISBN: (纸本)9798350382662

In this paper, we show that Prescribed Performance control (PPC) is a model-free control Barrier Function (CBF)-based control approach. Specifically, we establish that a function utilized in the PPC design is a Time-Varying Reciprocal control Barrier Function (TVRCBF). We demonstrate that PPC satisfies the same gradient condition that is well-known in the CBF literature, ensuring forward invariance. As a result, the control inputs generated by the PPC law belong to the input set characterized by the TVRCBF. Apart from assuming a certain controllability property, no further knowledge on the system dynamics is required. Our theoretical findings improve the understanding of the relationship between PPC and other CBF-based controllers. The theoretical results are validated through numerical simulations.

关键词： system dynamics Numerical simulation controllability Vectors

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Nodes2STRNet for structural dense displacement recognition by deformable mesh model and motion representation

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International Journal of Mechanical system Dynamics 2023年第3期3卷 229-250页

作者： Jin Zhao Hui Li Yang Xu Key Lab of Smart Prevention and Mitigation of Civil Engineering Disasters of the Ministry of Industry and Information Technology Harbin Institute of TechnologyHarbinChina Key Lab of Structures Dynamics Behavior and Control of the Ministry of Education Harbin Institute of TechnologyHarbinChina School of Civil Engineering Harbin Institute of TechnologyHarbinChina Department of System Design and Simulation Goldwind Science and Technology Co.Ltd.BeijingChina

Displacement is a critical indicator for mechanical systems and civil *** vision-based displacement recognition methods mainly focus on the sparse identification of limited measurement points,and the motion representation of an entire structure is very *** study proposes a novel Nodes2STRNet for structural dense displacement recognition using a handful of structural control nodes based on a deformable structural three-dimensional mesh model,which consists of control node estimation subnetwork(NodesEstimate)and pose parameter recognition subnetwork(Nodes2PoseNet).NodesEstimate calculates the dense optical flow field based on FlowNet 2.0 and generates structural control node ***2PoseNet uses structural control node coordinates as input and regresses structural pose parameters by a multilayer perceptron.A self-supervised learning strategy is designed with a mean square error loss and L2 regularization to train *** effectiveness and accuracy of dense displacement recognition and robustness to light condition variations are validated by seismic shaking table tests of a four-story-building *** studies with image-segmentation-based Structure-PoseNet show that the proposed Nodes2STRNet can achieve higher accuracy and better robustness against light condition *** addition,NodesEstimate does not require retraining when faced with new scenarios,and Nodes2PoseNet has high self-supervised training efficiency with only a few control nodes instead of fully supervised pixel-level segmentation.

关键词： structural dense displacement recognition deformable structural mesh model deep-learning-based monocular vision self-supervised learning

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An Integrated Calibration Scheme for Attitude Benchmark of Micro-nano Satellites and Its Experiments Based on In-Orbit Data

An Integrated Calibration Scheme for Attitude Benchmark of M...

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Automation, control and Robotics engineering (CACRE), International Conference on

作者： Mingqun Li Tong Luo Shaokai Wang He Li Yongjun Lei Qinghua Jiang Research and Development Center Beijing Institute of Control Engineering Beijing China System Design Department Beijing Institute of Control Engineering Beijing China Software Development Department Beijing Institute of Control Engineering Beijing China

The integrated calibration method of micro-nano satellite attitude benchmark is studied. Considering the magnetic effects and residual magnetism caused by the complex magnetic environment of the satellite, an accurate measurement model for magnetometers was adopted. By using the relationship between the measured and theoretical values of the geomagnetic field, the residual magnetism and magnetic sensitivity coefficients in the magnetometer measurement model were calibrated, through the least square method of uncertain parameters of the calibration. After modeling the installation error of the solar sensor, the calibration of the solar sensor is completed, so as to realize the integrated calibration of the attitude benchmark of the micro-nano satellite. Finally, this article conducted ground experiments using telemetry data from an in orbit satellite. The experimental results showed that the proposed method reduced sensor measurement errors, improved sensor benchmark consistency, and improved attitude determination accuracy from around 10 degrees to better than 0.2 degrees, verifying the effectiveness of the proposed method.

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Perturbation Event Oriented Dynamic Task Scheduling Algorithm for Parallel Testing of control systems

Perturbation Event Oriented Dynamic Task Scheduling Algorith...

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International Conference on Sensing, Diagnostics, Prognostics, and control (SDPC)

作者： Jingyi Chen Shenhang Wang Xiaoxuan Tong Gang Xiang Yang Yu Ziyuan Zhan School of Electronic and Information Engineeer Harbin Institute of Technology Harbin China System Design Department Beijing Aerospace Automatic Control Institute Beijing China Beijing Aerospace Automatic Control Institute Beijing China Department of System Engineering Beijing Aerospace Automatic Control Institute Beijing China

ISBN: (数字)9798350388855

ISBN: (纸本)9798350388862

Task scheduling algorithms are key to research and practice in parallel testing techniques, especially in control system applications. The complexity of control system testing requires higher scheduling efficiency. However, perturbation events caused by test equipment problems, data transmission obstacles, or task changes are almost unavoidable and may reduce the scheduling effectiveness or even lead to system crashes. Therefore, in this paper, based on the analysis of the dynamic test scheduling model, a disturbance factor is designed to judge the urgency of disturbance events for evaluating the dynamic scheduling cycle. On this basis, based on the comprehensive rescheduling index, a suitable adjustment strategy is selected to formulate the dynamic test scheduling scheme. The experimental results show that the algorithm proposed in this paper can achieve fast response capability for different disturbance events and exhibit good adaptivity.

关键词： Scheduling algorithms Perturbation methods Heuristic algorithms Dynamic scheduling control systems Computer crashes Sensors Test equipment Indexes Data communication

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Dynamic area coverage for Multi-USV with fully connected constraint based on game theory

Dynamic area coverage for Multi-USV with fully connected con...

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2022 Chinese Automation Congress, CAC 2022

作者： Han, Xiao Chen, Huan Gao, Yufeng Ma, Guangfu Wu, Shuanghong Hao, Wenxin Harbin Institute of Technology Department of Control Science and Engineering Harbin China China Ship Development and Design Center Wuhan China China Academy of Space Technology The Beijing Institute of Spacecraft System Engineering Beijing China

ISBN: (纸本)9781665465335

This paper proposes a novel method to solve the problem of regional surveys on the ocean in a complex environment. In order to solve this challenging regional survey problem considering fully connected, a new method combined artificial potential field and game theory is designed to maximize the coverage ratio. This paper gives the mathematical model of information transfer between two unmanned surface vehicles(USVs), and then the motion strategy of USVs is given based on the idea of game theory. The area coverage task of the multi-USV system is realized by a control method similar to the artificial potential field method. © 2022 IEEE.

关键词： Game theory

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Research on geomembrane leakage detection method based on quadruped robot

Research on geomembrane leakage detection method based on qu...

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2024 China Automation Congress, CAC 2024

作者： Zhang, Pengcheng Hu, Ningning Wang, Xiao Xi, Qingbiao Zhao, Haohao Wu, Xingchen Qin, Linfeng Yuan, Dongli Investigation & Testing Research Institute Shanghai Investigation Design & Research Institute Co. Ltd. Shanghai China System Department 2 Xi'an ASN Technology Group Co. Ltd Xi'an China School of Electronic and Control Engineering Chang'an University Xi'an China School of Automation Northwestern Polytechnical University Xi'an China

ISBN: (纸本)9798350368604

Aiming at the problem of leakage detection of seepage control geomembranes in landfills, a fully autonomous dipole method detection system based on a quadruped robot equipped with a dipole sensor is designed. The feasibility and superiority of using a quadruped robot are analyzed on the basis of the detection principle of the dipole method. Due to the problems existing in the process of upgrading the artificial static detection to autonomous dynamic detection, a dynamic detection method based on a quadruped robot is designed while the structure construction of the dipole method on the quadruped robot is completed. The experimental results show that the efficiency of geomembrane leakage detection can be improved with detection system method employed in this paper. © 2024 IEEE.

关键词： Geomembranes

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Rational design of chemically complex metallic glasses by hybrid modeling guided machine learning

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npj Computational Materials 2021年第1期7卷 1242-1251页

作者： Z.Q.Zhou Q.F.He X.D.Liu Q.Wang J.H.Luan C.T.Liu Y.Yang Department of Mechanical Engineering College of EngineeringCity University of Hong KongKowloonHong KongChina College of Mechatronics and Control Engineering Shenzhen UniversityShenzhenChina Laboratory for Structures Institute of Materials ScienceShanghai UniversityShanghaiChina Department of Materials Science and Engineering College of EngineeringCity University of Hong KongKowloonHong KongChina Department of Advanced Design and System Engineering College of EngineeringCity University of Hong KongChina

The compositional design of metallic glasses(MGs)is a long-standing issue in materials science and ***,traditional experimental approaches based on empirical rules are time consuming with a low *** this work,we successfully developed a hybrid machine learning(ML)model to address this fundamental issue based on a database containing~5000 different compositions of metallic glasses(either bulk or ribbon)reported since *** the prior works relying on empirical parameters for featurization of data,we designed modeling guided data descriptors in line with the recent theoretical models on amorphization in chemically complex alloys for the development of the hybrid classification-regression ML *** hybrid ML modeling was validated both numerically and *** importantly,it enabled the discovery of MGs(either bulk or ribbon)through the ML-aided deep search of a multitude of quaternary to scenery alloy *** computational framework herein established is expected to accelerate the design of MG compositions and expand their applications by probing the complex and multi-dimensional compositional space that has never been explored before.

关键词： alloy glasses metallic

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