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Pressure stimulated current in progressive failure process of combined coal-rock under uniaxial compression:Response and mechanism

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International Journal of Mining Science and Technology 2024年第2期34卷 227-243页

作者： Tiancheng Shan Zhonghui Li Xin Zhang Haishan Jia Xiaoran Wang Enyuan Wang Yue Niu Dong Chen Weichen Sun Dongming Wang State Key Laboratory of Coal Mine Disaster Prevention and Control China University of Mining and TechnologyXuzhou 221116China National Engineering Research Center for Coal Gas Control China University of Mining and TechnologyXuzhou 221116China School of Safety Engineering China University of Mining and TechnologyXuzhou 221116China State Key Laboratory for Fine Exploration and Intelligent Development of Coal Resources China University of Mining and TechnologyXuzhou 221116China State Key Laboratory of Intelligent Construction and Healthy Operation and Maintenance of Deep Underground Engineering China University of Mining and TechnologyXuzhou 221116China

Effective monitoring of the structural health of combined coal-rock under complex geological conditions by pressure stimulated currents(PSCs)has great potential for the understanding of dynamic disasters in underground *** reveal the effect of this way,the uniaxial compression experiments with PSC monitoring were conducted on three types of coal-rock combination samples with different strength *** mechanism explanation of PSCs are investigated by resistivity test,atomic force microscopy(AFM)and computed tomography(CT)methods,and a PSC flow model based on progressive failure process is *** influence of strength combinations on PSCs in the progressive failure process are *** results show the PSC responses between rock part,coal part and the two components are different,which are affected by multi-scale fracture characteristics and electrical *** the rock strength decreases,the progressive failure process changes obviously with the influence range of interface constraint effect decreasing,resulting in the different responses of PSC strength and direction in different parts to fracture *** PSC flow model is initially validated by the relationship between the accumulated charges of different *** results are expected to provide a new reference and method for mining design and roadway quality assessment.

关键词： Combined coal-rock Pressure stimulated current Progressive failure process Mechanism Flow model

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Optimizing Oil Distributor Port for Low-Pulsation Cam-Lobe Hydraulic Motors

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Chinese Journal of Mechanical Engineering 2024年第6期37卷 225-234页

作者： Yiman Duan Hao Tan Yu Fang Zhijian Zheng Junhui Zhang Bing Xu Qi Su Chao Zhang State Key Laboratory of Fluid Power and Mechatronic Systems Department of Mechanical EngineeringZhejiang UniversityHangzhou 310027China National Intelligent Manufacturing Equipment Quality Supervision and Inspection Center Ningbo 315800China

High-end equipment always operate in low-speed and heavy-load working environments,highlighting the need for cam-lobe hydraulic motors with excellent speed stability(1 MW).The successful operation of cam-lobe hydrauli... 详细信息

High-end equipment always operate in low-speed and heavy-load working environments,highlighting the need for cam-lobe hydraulic motors with excellent speed stability(<1 r/min)and ultrahigh-power rotary output(>1 MW).The successful operation of cam-lobe hydraulic motors relies on the circulation supply of high-and low-pressure ***,the switching between high-/low-pressure oil controlled by the oil distributor inevitably causes an obvious pressure impact and speed pulsation,which directly reduces the speed stability of hydraulic ***,an optimization design approach for the oil distributor port is proposed to minimize the speed pulsation of cam-lobe hydraulic *** the proposed approach,a simulation model that links the oil distributor port structural parameters with the hydraulic motor speed pulsation was developed to clarify the e ect of the oil distributor structural parameters on speed ***,an orthogonal analysis method was used to identify the optimized oil distributor port structural parameters while minimizing the hydraulic motor's speed pulsation as much as ***,several experiments were conducted to validate the e ectiveness and accuracy of the proposed optimization design *** experimental results indicate that the pulsation rate of the hydraulic motor equipped with the optimized oil distributor was 62.5%lower than that of the original motor at a working pressure of 25 MPa,which is consistent with the simulation results using the proposed optimization design *** findings of this study o er a feasible and e ective approach to guide the design optimization of the oil distributor port for low-pulsation hydraulic motors.

关键词： Engineering machinery Hydraulic motor Pulsation Oil distributor port Speed stability Optimization design

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Phase-Field Simulation of Sintering Process:A Review

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Computer Modeling in Engineering & Sciences 2024年第8期140卷 1165-1204页

作者： Ming Xue Min Yi State Key Laboratory ofMechanics and Control forAerospace Structures&Institute for Frontier Science&Key Laboratory for Intelligent Nano Materials and Devices of Ministry of Education&College of Aerospace Engineering Nanjing University of Aeronautics and Astronautics(NUAA)Nanjing210016China

Sintering,a well-established technique in powder metallurgy,plays a critical role in the processing of high melting point materials.A comprehensive understanding of structural changes during the sintering process is essential for effective product *** phase-field method stands out for its unique ability to simulate these structural *** its widespread application,there is a notable absence of literature reviews focused on its usage in sintering ***,this paper addresses this gap by reviewing the latest advancements in phase-field sintering models,covering approaches based on energy,grand potential,and entropy *** characteristics of various models are extensively discussed,with a specific emphasis on energy-based models incorporating considerations such as interface energy anisotropy,tensor-form diffusion mechanisms,and various forms of rigid particle motion during ***,the paper offers a concise summary of phase-field sintering models that integrate with other physical fields,including stress/strain fields,viscous flow,temperature field,and external electric *** conclusion,the paper provides a succinct overview of the entire content and delineates potential avenues for future research.

关键词： Phase-field model review sintering additive manufacturing

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Design and Theoretical Research on Aerial-Aquatic Vehicles:A Review

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Journal of Bionic Engineering 2023年第6期20卷 2512-2541页

作者： Yi Sun Xuefei Liu Kai Cao Huan Shen Qian Li Guangming Chen Jiajun Xu Aihong Ji Lab of Locomotion Bioinspiration and Intelligent Robots College of Mechanical and Electrical EngineeringState Key Laboratory of Mechanics and Control for Aerospace StructuresNanjing University of Aeronautics and Astronautics29 Yudao StreetNanjing210016China State Key Laboratory of Mechanics and Control for Aerospace Structures Nanjing University of Aeronautics and AstronauticsNanjing210016China

With the rapid development of unmanned aerial and underwater vehicles,various tasks,such as biodiversity monitoring,surveying,and mapping,as well as,search and rescue can now be completed in a single medium,either underwater or in the *** systematically examining the water–air cross-medium locomotion of organisms,there has been growing interest in the development of aerial-aquatic *** goal of this review is to provide a detailed outline of the design and cross-medium theoretical research of the existing aerial-aquatic vehicles based on the research on the organisms capable of transiting between water and *** these designs and theoretical frameworks have been validated in many aerial-aquatic vehicles,there are still many problems that need to be addressed,such as inflexible underwater motion and unstable medium *** a result,supplementation of the existing cross-medium biomimetic research,vehicle design,power selection,and cross-medium theory is urgently required to optimize the key technologies in ***,by summarizing the existing designs and theoretical approaches on aerial-aquatic vehicles,including biomimetic research on water–air cross-medium locomotion in nature,different power selections,and cross-medium theoretical research,the relative problems and development trends on aerial-aquatic vehicles were thoroughly explored,providing significant help for the subsequent research process.

关键词： Aerial-aquatic vehicle Cross-medium motion Power selection control theory Biomimetic

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Path Tracking controller Design of Automated Parking systems via NMPC with an Instructible Solution

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Chinese Journal of Mechanical Engineering 2024年第3期37卷 353-367页

作者： Liang Chen Zhaobo Qin Manjiang Hu Yougang Bian Xiaoyan Peng State Key Laboratory of Advanced Design and Manufacturing Technology for Vehicle College of Mechanical and Vehicle EngineeringHunan UniversityChangsha 410082China Wuxi Intelligent Control Research Institute of Hunan University Wuxi 214115China

Parking difficulties have become a social issue that people have to *** parking system is practicable for quick par operations without a driver which can also greatly reduces the probability of parking *** paper proposes a Lyapunov-based nonlinear model predictive controller embedding an instructable solution which is generated by the modified rear-wheel feedback method(RF-LNMPC)in order to improve the overall path tracking accuracy in parking ***,A discrete-time RF-LNMPC considering the position and attitude of the parking vehicle is proposed to increase the success rate of automated parking ***,the RF-LNMPC problem with a multi-objective cost function is solved by the Interior-Point Optimization,of which the iterative initial values are described as the instructable solutions calculated by combining modified rear-wheel feedback to improve the performance of local optimal ***,the details on the computation of the terminal constraint and terminal cost for the linear time-varying case is *** closed-loop stability is verified via Lyapunov techniques by considering the terminal constraint and terminal cost ***,the proposed RF-LNMPC is implemented on a selfdriving Lincoln MKZ platform and the experiment results have shown improved performance in parallel and vertical parking *** Monte Carlo analysis also demonstrates good stability and repeatability of the proposed method which can be applied in practical use in the near future.

关键词： Automated parking Path tracking controller Nonlinear model predictive control Monte Carlo analysis

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Learning-Based Predictive control of Switched Nonlinear systems via Koopman Modeling Approach

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Journal of systems Science & Complexity 2025年第2期38卷 691-716页

作者： NING Zepeng FANG Xu LI Yibei XIE Lihua School of Electrical and Electronic Engineering Nanyang Technological University Key Laboratory of Intelligent Control and Optimization for Industrial Equipment of Ministry of Education Dalian University of Technology Key Laboratory of Systems and Control Academy of Mathematics and Systems Science Chinese Academy of Sciences

This paper proposes a data-driven learning-based approach to predictive control for switched nonlinear systems subject to state and control constraints and external stochastic disturbances. A switched Koopman modeling framework is developed, where a multi-mode neural network for state lifting is trained simultaneously with Koopman operators and state reconstruction matrices for all *** framework facilitates the construction of the switched linear Koopman model in a transformed space and effectively captures the dynamics of the original nonlinear system. A switched predictive control strategy is then designed to regulate the switched Koopman model with constrained states and control inputs against both the stochastic disturbances and the uncertainties introduced by the lifting neural network. The proposed control scheme ensures mean-square stability and guarantees boundedness during the online phase. Furthermore, boundedness analysis is performed to determine the bounded set of the original system state across all admissible switching sequences. The effectiveness of the proposed methodology is demonstrated through a case study of a gene regulatory network.

关键词： Data-driven machine learning model predictive control stochastic systems switched Koopman model switched nonlinear systems

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Few-shot object detection via class encoding and multi-target decoding

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IET Cyber-systems and Robotics 2023年第2期5卷 1-14页

作者： Xueqiang Guo Hanqing Yang Mohan Wei Xiaotong Ye Yu Zhang State Key Laboratory of Industrial Control Technology College of Control Science and EngineeringZhejiang UniversityHangzhouChina Key Laboratory of Collaborative Sensing and Autonomous Unmanned Systems of Zhejiang Province HangzhouChina

The task of few‐shot object detection is to classify and locate objects through a few annotated *** many studies have tried to solve this problem,the results are still not *** studies have found that the class margin significantly impacts the classification and representation of the targets to be *** methods use the loss function to balance the class margin,but the results show that the loss‐based methods only have a tiny improvement on the few‐shot object detection *** this study,the authors propose a class encoding method based on the transformer to balance the class margin,which can make the model pay more attention to the essential information of the features,thus increasing the recognition ability of the ***,the authors propose a multi‐target decoding method to aggregate RoI vectors generated from multi‐target images with multiple support vectors,which can significantly improve the detection ability of the detector for multi‐target *** on Pascal visual object classes(VOC)and Microsoft Common Objects in Context datasets show that our proposed Few‐Shot Object Detection via Class Encoding and Multi‐Target Decoding significantly improves upon baseline detectors(average accuracy improvement is up to 10.8%on VOC and 2.1%on COCO),achieving competitive *** general,we propose a new way to regulate the class margin between support set vectors and a way of feature aggregation for images containing multiple objects and achieve remarkable *** method is implemented on mmfewshot,and the code will be available later.

关键词： Class Margin Few-Shot Object Detection Multi-Target Transformer

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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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An Effective Adaptive Large Neighborhood Search Algorithm for Multi-AGV Dispatching Problem in Matrix Manufacturing systems 21

An Effective Adaptive Large Neighborhood Search Algorithm fo...

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21st International Conference on Networking, Sensing and control, ICNSC 2024

作者： Li, Boyu Wu, Weimin Institute of Cyber-Systems and Control Zhejiang University State Key Laboratory of Industrial Control Technology Hangzhou China

ISBN: (纸本)9798350365221

With the increasing prevalence of automated guided vehicles (AGV s) in industry, the AG V dispatching has emerged as a research hotspot. Recently, matrix manufacturing systems (MMS) have been favored for their suitability in mass-customized production. However, fluctuating and diverse transport demands in MMS pose challenges for effective AGV scheduling. This paper investigates a multi-AGV dispatching problem (AGVDP) in MMS, involving time-constrained pick-up and delivery tasks. A mixed-integer linear programming model is developed to minimize total transportation costs, including travel distance, early arrival time, and utilized AGV s. To achieve this, an effective adaptive large neighborhood search algorithm (ALNS) is proposed. In ALNS, a scope-based nearest neighbor heuristic is introduced for initial construction. Diverse problem-specific operators are designed to generate large neighborhoods. To enhance ALNS's robustness to instance variations, an adaptive simulated annealing acceptance criterion is proposed. Computational experiments using a well-established benchmark validate the superiority of the proposed ALNS. © 2024 IEEE.

关键词： Simulated annealing

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Robustness and Push Recovery of Humanoid Robots Using Predictive and Whole-Body control

Robustness and Push Recovery of Humanoid Robots Using Predic...

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2024 IEEE International Conference on Unmanned systems, ICUS 2024

作者： Zhang, Shaojie Ni, Fenglei Li, Xueai Li, Xu Ji, Yi Shao, Xiangyu State Key Laboratory of Robotics and Systems Harbin Institute of Technology Harbin China Key Laboratory of Autonomous Intelligent Unmanned Systems Harbin Institute of Technology Harbin China

ISBN: (纸本)9798350384185

Robustness walking and recovery ability in uneven terrains and unexpected collisions are crucial for the practical application of humanoid ***, existing methods struggle to effectively balance stability, motion safety and walking *** paper proposes a hybrid control strategy combing Nonlinear Model Predictive control (NMPC) and Whole-Body control (WBC) to improve the robot's walking stability and reaction safety in collisions *** NMPC generates long-term and macroscopic movements, with capture point theory being utilized for foot placements determination under external *** this foundation, the WBC regulates the robot refinedly in real-time based on task priorities and *** verify the effectiveness of the proposed method, involving uneven terrain walking and external impacts rejection. © 2024 IEEE.

关键词： Anthropomorphic robots

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