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An adaptive large neighborhood search for the multi-point dynamic aggregation problem

Control Theory and technology 2024年第3期22卷 360-378页

作者： Shengyu Lu Bin Xin Jie Chen Miao Guo School of Automation Beijing Institute of TechnologyBeijing 100081China National Key Lab of Autonomous Intelligent Unmanned Systems Beijing 100081China Department of Control Science and Engineering Tongji UniversityShanghai 201804China

The multi-point dynamic aggregation(MPDA)problem is a challenging real-world *** the MPDA problem,the demands of tasks keep changing with their inherent incremental rates,while a heterogeneous robot fleet is required to travel between these tasks to change the time-varying state of each *** robots are allowed to collaborate on the same task or work separately until all tasks are *** is challenging to generate an effective task execution plan due to the tight coupling between robots abilities and tasks'incremental rates,and the complexity of robot *** effectiveness consideration,we use the variable length encoding to avoid redundancy in the solution *** creatively use the adaptive large neighborhood search(ALNS)framework to solve the MPDA *** the proposed algorithm,high-quality initial solutions are generated through multiple problem-specific solution construction *** heuristics are also used to fix the broken solution in the novel integrated decoding-construction repair process of the ALNS *** results of statistical analysis by the Wilcoxon rank-sum test demonstrate that the proposed ALNS can obtain better task execution plans than some state-of-the-art algorithms in most MPDA instances.

关键词： Adaptive large neighborhood search(ALNS) Multi-point dynamic aggregation(MPDA) Heuristic solution construction Multi-robot collaboration

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Extinction Chains Reveal Intermediate Phases Between the Safety and Collapse in Mutualistic Ecosystems

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Engineering 2024年第12期43卷 89-98页

作者： Guangwei Wang Xueming Liu Ying Xiao Ye Yuan Linqiang Pan Xiaohong Guan Jianxi Gao Hai-Tao Zhang The MOE Engineering Research Center of Autonomous Intelligent Unmanned Systems State Key Laboratory of Digital Manufacturing Equipment and TechnologySchool of Artificial Intelligence and AutomationHuazhong University of Science and TechnologyWuhan 430074China Guangdong HUST Industrial Technology Research Institute Huazhong University of Science and TechnologyDongguan 523808China Guangdong Provincial Engineering Technology Center of Autonomous Unmanned Vessels Dongguan 523808China MOE Key Laboratory of Intelligent Networks and Network Security&State Key Laboratory of Manufacturing Systems Xi’an Jiaotong UniversityXi’an 710049China Tsinghua National Laboratory of Information Science and Technology Department of AutomationTsinghua UniversityBeijing 100084China Department of Computer Science Rensselaer Polytechnic InstituteTroyNY 12180USA

Ecosystems are undergoing unprecedented persistent deterioration due to unsustainable anthropogenic human activities,such as overfishing and deforestation,and the effects of such damage on ecological stability are *** recent advances in experimental and theoretical studies on regime shifts and tipping points,theoretical tools for understanding the extinction chain,which is the sequence of species extinctions resulting from overexploitation,are still lacking,especially for large-scale nonlinear networked *** this study,we developed a mathematical tool to predict regime shifts and extinction chains in ecosystems under multiple exploitation situations and verified it in 26 real-world mutualistic networks of various sizes and *** discovered five phases during the exploitation process:safe,partial extinction,bistable,tristable,and collapse,which enabled the optimal design of restoration strategies for degraded or collapsed *** validated our approach using a 20-year dataset from an eelgrass restoration ***,we also found a specific region in the diagram spanning exploitation rates and competition intensities,where exploiting more species helps increase *** computational tool provides insights into harvesting,fishing,exploitation,or deforestation plans while conserving or restoring the biodiversity of mutualistic ecosystems.

关键词： Complex system Network science Overexploitation Regime shift Metastability

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A thermodynamics-consistent spatiotemporally-nonlocal model for microstructure-dependent heat conduction

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Applied Mathematics and Mechanics(English Edition) 2024年第11期45卷 1929-1948页

作者： Yu ZHANG Daming NIE Xuyao MAO Li LI Zhejiang Lab Hangzhou310058China Wuhan Second Ship Design and Research Institute Wuhan430064China State Key Laboratory of Intelligent Manufacturing Equipment and Technology School of Mechanical Science and EngineeringHuazhong University of Science and TechnologyWuhan430074China

The spatiotemporally-nonlocal phenomena in heat conduction become significant but challenging for metamaterials with artificial ***,the microstructure-dependent heat conduction phenomena are captured under the hypothesis of spatiotemporally local *** capture the microstructure-dependent heat conduction phenomena,a generalized nonlocal irreversible thermodynamics is proposed by removing both the temporally-local and spatially-local equilibrium hypotheses from the classical irreversible *** generalized nonlocal irreversible thermodynamics has intrinsic length and time parameters and thus can provide a thermodynamics basis for the spatiotemporally-nonlocal law of heat *** remove the temporallylocal equilibrium hypothesis,the generalized entropy is assumed to depend not only on the internal energy but also on its first-order and high-order time *** remove the spatially local equilibrium hypothesis,the thermodynamics flux field in the dissipation function is assumed to relate not only to the thermodynamics force at the reference point but also to the thermodynamics force of the neighboring *** the developed theoretical framework,the thermodynamics-consistent spatiotemporally-nonlocal models can then be developed for heat transfer *** examples are provided to illustrate the applications of steady-state and transient heat conduction problems.

关键词： nonlocality spatiotemporal nonlocality irreversible thermodynamics heat transfer metamaterial

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Online Path Planning of Messenger UAV in Air-Ground Coordination Over Urban Areas

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IEEE Transactions on Vehicular technology 2024年第5期74卷 7135-7151页

作者： Wang, Yuyang Xin, Bin Ding, Yulong He, Bin Chen, Jie Beijing Institute of Technology School of Automation Beijing100081 China Ministry of Education Frontiers Science Center for Intelligent Autonomous Systems Shanghai China National Key Lab of Autonomous Intelligent Unmanned Systems Beijing100081 China Tongji University Department of Control Science and Engineering Shanghai200092 China

Fast-moving unmanned aerial vehicle (UAV), serving as a messenger to visit ground vehicles (GVs) for information relays, can be applied to complex tasks in urban environments, such as air-ground cooperative urban rescue and UAV-assisted data collection. Existing work ensures that the UAV visits all GVs by assuming that it knows the motion parameters of GVs (e.g., velocities or paths) at any given time. However, in practice, GVs may not move with anticipated velocities due to motion uncertainties. This UAV path planning problem can be formulated as a Dynamic Dubins Traveling Salesman Problem with Uncertain Neighborhoods (DDTSPUN). The problem involves variables with complex interdependencies (e.g., the visiting sequence of the UAV to GVs and the access location of the UAV to GVs) and requires solving a sequence of uncertain encounter problems. To address the uncertainty in GV motion, we define robust neighborhoods and corridors and prove that the UAV can revisit GVs reliably by visiting these areas. By flying the UAV through robust areas, the DDTSPUN can be transformed into a deterministic optimization problem, namely Revisit-time-constrained Dubins Traveling Salesman Problem with Neighborhood (RDTSPN), which provides a simplified model and compresses the solution space. To address the RDTSPN, we propose an online heuristic path planning algorithm. It incorporates a gradient-based method for visiting robust neighborhoods and a sampling-based search strategy along robust corridors to obtain the Dubins paths of the UAV that achieve robust visit for each GV. Finally, the computational experiments, including representative instances, random instances with different scales, and an instance generated using real-world data, demonstrate its advantages over other state-of-the-art algorithms in obtaining the shortest path that satisfies UAV curvature constraints while ensuring robust access to all GVs. © 1967-2012 IEEE.

关键词： Traveling salesman problem

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Fabrication of bamboo-inspired continuous carbon fiber-reinforced SiC composites via dual-material thermally assisted extrusion-based 3D printing

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材料科学技术（英文版） 2025年第5期208卷 92-103页

作者： Sai Li Haitian Zhang Zhongliang Lu Fusheng Cao Ziyao Wang Yan Liu Xiaohui Zhu Shuai Ning Kai Miao Shaoyu Qiu Dichen Li State Key Laboratory for Manufacturing Systems Engineering School of Mechanical EngineeringXi'an Jiaotong UniversityXi'an 710049China State Key Laboratory for Manufacturing Systems Engineering School of Mechanical EngineeringXi'an Jiaotong UniversityXi'an 710049China School of Intelligent Manufacturing Modern Industry Xinjiang UniversityUrumqi 830046China Science and Technology on Reactor Fuel and Materials Laboratory Nuclear Power Institute of ChinaChengdu 610213China

Ceramic matrix composites(CMCs)structural components encounter the dual challenges of severe mechanical conditions and complex electromagnetic environments due to the increasing demand for stealth technology in aerospace *** address various functional requirements,this study integrates a biomimetic strategy inspired by gradient bamboo vascular bundles with a novel dual-material 3D print-ing *** distinct bamboo-inspired structural configurations Cf/SiC composites are designed and manufactured,and the effects of these different structural configurations on the CVI process are *** method is utilized to characterize the relationship between interface bonding strength and mechanical *** results reveal that the maximum flexural strength and fracture toughness reach 108.6±5.2 MPa and 16.45±1.52 MPa m1/2,respectively,attributed to the enhanced crack propagation resistance and path caused by the weak fiber-matrix ***,the bio-inspired configuration enhances the dielectric loss and conductivity loss,exhibiting a minimum reflection loss of-24.3 dB with the effective absorption band of 3.89 *** work introduces an innovative biomimetic strategy and 3D printing method for continuous fiber-reinforced ceramic composites,expanding the ap-plication of 3D printing technology in the field of CMCs.

关键词： 3D printing Cf/SiC composites Mechanical properties Electromagnetic wave absorption

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D-scheduler:A scheduler in time-triggered distributed system through decoupling dependencies between tasks and messages

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Science China(Technological Sciences) 2024年第1期67卷 183-196页

作者： YANG TingTing ZHANG YuQi YUE FengLai WUNIRI QiQiGe TONG Chao School of Computer Science&Engineering Beihang UniversityBeijing 100191China State Key Laboratory of Virtual Reality Technology and Systems Beihang UniversityBeijing 100191China National Innovation Center of Intelligent and Connected Vehicles Beijing 100176China

Time-triggered architecture,as a mainstream design of the distributed real-time system,has been successfully applied in the aerospace,automotive and mechanical ***,time-triggered scheduling is a challenging NP-hard *** are few studies that could quickly solve the scheduling problem of large distributed time-triggered *** solve this problem,a communication affinity parameter is defined in this paper to describe the degree of bias of the shaper task towards sending or receiving *** on this,an innovative task-message decoupling model named D-scheduler is built to reduce the computation complexity of the scheduling problem in large-scale ***,we provide mathematical proof that our model is a convex optimization that is easy to solve with existing computational *** experiments substantiate the efficacy of the *** dramatically reduces the scheduling complexity of large-scale real-time systems with a small loss of solving space compared to the federal scheduler.

关键词： time-triggered architecture time-triggered scheduling communication affinity parameter task-message decoupling model

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Distilling Siamese Trackers with Attention Mask 41

Distilling Siamese Trackers with Attention Mask

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第41届中国控制会议

作者： Han Sun Yongqiang Bai Wenbo Zhang State Key Lab of Intelligent Control and Decision of Complex Systems and School of Automation Beijing Institute of Technology

ISBN: (数字)9789887581536

ISBN: (纸本)9781665482561

In recent years,the introduction of Siamese network has brought new vitality to the object tracking ***,high-performance Siamese trackers cannot run at a real-time speed on mobile devices due to their complex and huge *** distillation is a common and effective model compression method,but it is difficult to be applied to the challenging task like object *** find out the fundamental cause is that the imbalance between the foreground and background in the object tracking task,which aggravates the problem of insufficient feature extraction ability of small ***,we propose the attention mask distillation(AMD) to help the student tracker focus on the foreground area faster and more *** attention mask can be easily obtained from the feature maps and brings fine-granularity to the traditional binary *** experimental results on OTB100 and VOT2018 show that our method enables the student tracker perform as well as the teacher *** the same time,it's able to run on the CPU at a hyper-real-time of 66 fps and achieves nearly 9 times model compression *** low computational and storage costs make it possible to deploy high-performance trackers on resource-constrained platforms.

关键词： Object Tracking Siamese Network Knowledge Distillation Attention Mask

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Experimental investigations on structural improvement of morphing mechanism for nose cone of aerospace vehicle adopting a bionic redundant constraint strategy

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Science China(Technological Sciences) 2023年第4期66卷 1075-1095页

作者： ZHANG YuLing LI ChengXiang ZHANG Yan CAI QiaoYan YAN ShaoZe Division of Intelligent and Biomechanical Systems State Key Laboratory of Tribology in Advanced EquipmentDepartment of Mechanical EngineeringTsinghua UniversityBeijing 100084China China Academy of Launch Vehicle Technology Beijing 100071China

Aerospace vehicles have recently received great attention for their completely reusable in aviation and *** achieve the optimal aerodynamic performance of the aerospace vehicle,the nose cone needs to change its aerodynamic shape under different flight ***,the structural design of a morphing nose cone that is capable of changing aerodynamic shape adaptively and withstanding prescribed aerodynamic loads remains an ongoing *** overcome this issue and to further advance our previous work,the motion performance of a morphing nose cone inspired by the deformation mechanism of the honeybee abdomen was tested to evaluate the deformation ability and bearing *** dynamic prediction analysis of the morphing nose cone with a clearance joint and flexible links was then investigated to elucidate the crucial issues in the deformation *** improve the motion performance,a performance improvement scheme based on redundant constraints drawn from the muscle distribution of the honeybee abdomen was ***,the structural stiffness,dynamic analysis,and experimental testing of the improved morphing nose cone were *** experimental results indicate that the extension and contraction ratios and bending angles of the improved morphing nose cone under loads of 0,10,and 25 kg loads improve by 1.51%and 2.329°,2.78%and-1.902°,and 5.06%and 1.111°,respectively,verifying the rationality and effectiveness of the performance improvement *** work provides a new reference for the design of the morphing structure for aerospace vehicles.

关键词： morphing nose cone experimental investigation dynamic analysis performance improvement bionic design

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Learning to Solve Multi-AGV Scheduling Problem with Pod Repositioning Optimization in RMFS 25

Learning to Solve Multi-AGV Scheduling Problem with Pod Repo...

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25th IEEE International Conference on Industrial technology, ICIT 2024

作者： Zhou, Xuan Shi, Xiang Chu, Wenqing Jiang, Jingchen Zhang, Lele Deng, Fang School Of Automation Beijing Institute Of Technology State Key Lab Of Autonomous Intelligent Unmanned Systems Beijing100081 China Beijing Institute Of Technology Chongqing Innovation Center Chongqing401120 China

ISBN: (纸本)9798350340266

This paper studies a novel non-deterministic polynomial-hard (NP-hard) warehouse optimization problem, the multi-automated guided vehicle (multi-AGV) scheduling problem with pod repositioning optimization (MAS-PR), in a robotic mobile fulfillment system (RMFS). A major challenge in MAS-PR is that the storage assignment of pods and the task allocation decision of AGVs are closely coupled. To address this problem, an end-to-end Problem-Specific Mask-based Deep Reinforcement Learning (PSMDRL) method is proposed in this paper. In PSMDRL, we transform the MAS-PR into a Markov Decision Process (MDP) model, and then use an attention-based network model to learn the efficient allocation and retrieval policy. A mask strategy with problem-specific knowledge and a model structure with decoder embedding are designed to further improve the efficiency and effectiveness. Experimental results demonstrate that the proposed PSMDRL is more effective and efficient than the representative algorithms in solving the MAS-PR problem. © 2024 IEEE.

关键词： Reinforcement learning

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Higher-order properties and extensions for indirect MRAC and APPC of linear systems

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Science China(Information Sciences) 2024年第4期67卷 218-238页

作者： Yanjun ZHANG Zhipeng ZHANG Jian SUN Lei WANG Kangkang ZHANG National Key Lab of Autonomous Intelligent Unmanned Systems Beijing Institute of Technology School of Automation Beijing Institute of Technology Beijing Institute of Technology Chongqing Innovation Center College of Control Science and Engineering Zhejiang University Department of Electrical and Electronic Engineering Imperial College London KIOS Research and Innovation Center of Excellence University of Cyprus

Recently, a reference derived some new higher-order output tracking properties for direct model reference adaptive control（MRAC） of linear time-invariant（LTI） systems: limt→∞ e（i）（t） = 0, i = 1,..., n*-1, where n*and e（i）（t） denote the relative degree of the system and the i-th derivative of the output tracking error, respectively. However, a naturally arising question involves whether indirect adaptive control（including indirect MRAC and indirect adaptive pole placement control） of LTI systems still has higher-order tracking properties. Such properties have not been reported in the literature. Therefore, this paper provides an affirmative answer to this question. Such higher-order tracking properties are new discoveries since they hold without any additional design conditions and, in particular, without the persistent excitation condition. Given the higher-order properties, a new adaptive control system is developed with stronger tracking features.（1） It can track a reference signal with any order derivatives being unknown.（2） It has higher-order exponential or practical output tracking properties.（3） Finally, it is different from the usual MRAC system, whose reference signal's derivatives up to the n*order are assumed to be known. Finally, two simulation examples are provided to verify the theoretical results obtained in this paper.

关键词： higher-order tracking indirect adaptive control model reference adaptive control adaptive pole placement control

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