检索结果-内蒙古大学图书馆

Optical trapping capability of tornado circular Pearcey beams

Chinese Physics B 2024年第5期33卷 401-407页

作者：刘娜娜唐晓莹刘舜禹梁毅 Guangxi Key Laboratory for Relativistic Astrophysics Center on Nanoenergy ResearchGuangxi Colleges and Universities Key Laboratory of Blue Energy and Systems IntegrationSchool of Physical Science and TechnologyGuangxi UniversityNanning 530004China State Key Laboratory of Featured Metal Materials and Lifecycle Safety for Composite Structures Nanning 530004China

We systemically investigate optical trapping capability of a kind of tornado waves on Rayleigh *** tornado waves are named as tornado circular Pearcey beams(TCPBs)and produced by combining two circular Pearcey beams with different *** theoretical exploration delves into various aspects,including the propagation dynamics,energy flux,orbital angular momentum,trapping force,and torque characteristics of *** results reveal that the orbital angular momentum,trapping force,and torque of these beams can be finely tuned through the judicious manipulation of their topological charges(l_(1)and l_(2)).Notably,we observe a precise control mechanism wherein the force diminishes with|l_(1)+l_(2)|and|l_(1)-l_(2)|,while the torque exhibits enhancement by decreasing solely with|l_(1)+l_(2)|or increasing with|l_(1)-l_(2)|.These results not only provide quantitative insights into the optical trapping performance of TCPBs but also serve as a valuable reference for the ongoing development of innovative photonic tools.

关键词： trapping capability tornado beams autofocusing

来源：评论

学校读者我要写书评

暂无评论

Data-Driven Robust Model Predictive Control for Pose Tracking of Redundant Manipulators

Data-Driven Robust Model Predictive Control for Pose Trackin...

引用

2024 IEEE International Conference on robotics and Biomimetics, ROBIO 2024

作者： Chen, Zhaoyang Ni, Fenglei Min, Kang Liu, Hong Harbin Institute of Technology State Key Laboratory of Robotics and System Heilongjiang Province Harbin150001 China

ISBN: (纸本)9781665481090

In this paper, we present a data-driven robust model predictive control (DD-RMPC) method for pose tracking of redundant manipulators. Firstly, a MPC-based trajectory tracking framework is established, in which the joint limits at three different levels (angle, velocity, and acceleration) are satisfied. Secondly, to deal with the system model's uncertainty, accelerate the error convergence speed, and reduce tracking errors, a novel data-driven RMPC is proposed, in which the system's input-output data are used to compensate for the conservatism of the system. Finally, the simulation results on a seven degrees of freedoms (DOFs) redundant manipulator show that DD-RMPC provides a faster error convergence rate and achieves smaller pose tracking errors than that of the comparison methods. © 2024 IEEE.

关键词： Predictive control systems

来源：评论

学校读者我要写书评

暂无评论

Intelligent design of mechanical metamaterials: a GCNN-based structural genome database approach

引用

National Science Review 2025年第4期12卷 268-281页

作者： Wenyu Hao Zongliang Du Xiuquan Hou Yilin Guo Chang Liu Weisheng Zhang Huajian Gao Xu Guo State Key Laboratory of Structural Analysis Optimization and CAE Software for Industrial EquipmentDepartment of Engineering Mechanics Dalian University of Technology Ningbo Institute of Dalian University of Technology Institute of Artificial Intelligence and Robotics Xi'an Jiaotong University Mechano-X Institute Applied Mechanics LaboratoryDepartment of Engineering Mechanics Tsinghua University

The reciprocal mapping between the geometry and properties of a unit cell is crucial for the intelligent and inverse design of advanced materials and structural *** classical homogenization-based numerical methods,this paper presents an efficient and accurate mapping between the geometry and properties of a class of unit cells described by moving morphable components,achieved via a graph convolutional neural *** leads to a structural genome database(SGD) approach for the intelligent design of mechanical *** the SGD approach,metamaterials exhibiting the Hashin-Shtrikman upper bound of bulk modulus,auxetic behavior and the unimodal property have been created,with design efficiency improved by 3-4 orders of ***,transfer learning and a small amount of training data allow the SGD to predict non-local behaviors beyond a unit cell,such as optimized unit cells with critical buckling strength enhanced by nearly 200% and a bandgap metamaterial with a relative bandgap width of 51%.Experimentally validated optimized metamaterials demonstrate auxetic behavior and superior buckling *** proposed SGD approach holds promise for the advanced design of multi-scale and multi-physics systems.

关键词： mechanical metamaterial structural genome database moving morphable component graph convolutional neural network structure-property mapping

来源：评论

学校读者我要写书评

暂无评论

Model-guided 3D stitching for augmented virtual environment

引用

Science China(Information Sciences) 2023年第1期66卷 115-130页

作者： Zhong ZHOU Ming MENG Yi ZHOU Zhe ZHU Jingdi YOU State Key Laboratory of Virtual Reality Technology and Systems Beihang University Department of Radiology Duke University Beijing Big View Technology Co. Ltd.

Image and video stitching have made tremendous progress in the construction of wide field-of-view(FOV). However, some long-term challenges still exist, including wide baselines between cameras,large parallaxes, and low texture in overlapping areas. The augmented virtual environment(AVE) captures videos as live textures of 3D models in a virtual environment, and provides another 3D solution to overcome the aforementioned challenges. Existing AVE methods primarily follow from video projection, and cannot produce satisfactory stitching results compared with image stitching. In this paper, we propose a novel model-guided 3D stitching algorithm for AVE. The algorithm recovers an approximate 3D model for each video streaming and optimizes the warping of the models to meet the requirements of feature point matching of the 3D models from adjacent videos. Compared with previous state-of-the-art methods, experiment results illustrate that our method significantly improves the stitching quality.

关键词： 3D stitching video model multiple video visualization augmented virtual environment

来源：评论

学校读者我要写书评

暂无评论

Indentation of a Plate on a Thin Transversely Isotropic Elastic Layer

引用

Acta Mechanica Solida Sinica 2025年第2期38卷 331-340页

作者： Juyao Li Guozheng Zhang Liu Wang Zhaohe Dai State Key Laboratory for Turbulence and Complex Systems Department of Mechanics and Engineering ScienceCollege of EngineeringPeking UniversityBeijing100871China CAS Key Laboratory of Mechanical Behaviour and Design of Materials Department of Modern MechanicsUniversity of Science and Technology of ChinaHefei230026AnhuiChina State Key Laboratory of Nonlinear Mechanics Institute of MechanicsChinese Academy of ScienceBeijing100190China

This work investigates the indentation response of an elastic plate resting upon a thin,transversely isotropic elastic layer supported by a rigid *** a scenario is encountered across a range of length scales from piezoresistive tests on graphite nanoflakes to the bending of floating ice shelves atop seabed,where the elastic layer commonly exhibits certain *** first develop an approximate model to describe the elastic response of a transversely isotropic layer by exploiting the slenderness of the *** show that this approximate model can be reduced to the classic compressible Winkler foundation model as the elastic constants of the layer are set *** then investigate the combined response of an elastic plate on the transversely isotropic elastic *** by the simplicity of our proposed approximate model,we can derive simple analytical solutions for the cases of small and large indenter *** analytical results agree well with numerical calculations obtained via finite element methods,as long as the system is sufficiently slender in a mechanical *** results offer quantitative insights into the mechanical behavior of numerous semiconductor materials characterized by transverse isotropy and employed with slender geometries in various practical applications where the thin layer works as conductive and functional layers.

关键词： Indentation Elastic layers-Transversely isotropic Winkler foundation Graphite

来源：评论

学校读者我要写书评

暂无评论

Multi-Objective Optimization of VBHF in Deep Drawing Based on the Improved QO-Jaya Algorithm

引用

Chinese Journal of Mechanical Engineering 2024年第1期37卷 189-202页

作者： Xiangyu Jiang Zhaoxi Hong Yixiong Feng Jianrong Tan State Key Laboratory of Fluid Power and Mechatronic Systems Zhejiang UniversityHangzhou 310027China Key Laboratory of Advanced Manufacturing Technology of Zhejiang Province Zhejiang UniversityHangzhou 310027China Ningbo Innovation Center Zhejiang UniversityNingbo 315100China

Blank holder force(BHF)is a crucial parameter in deep drawing,having close relation with the forming quality of sheet ***,there are different BHFs maintaining the best forming effect in different stages of deep *** variable blank holder force(VBHF)varying with the drawing stage can overcome this problem at an *** optimization of VBHF is to determine the optimal BHF in every deep drawing *** this paper,a new heuristic optimization algorithm named Jaya is introduced to solve the optimization *** improved“Quasi-oppositional”strategy is added to Jaya algorithm for improving population ***,an innovated stop criterion is added for better ***,the quality evaluation criteria for wrinkling and tearing are ***,the Kriging models are developed to approximate and quantify the relation between VBHF and forming defects under random ***,the optimization models are established and solved by the improved QO-Jaya algorithm.A VBHF optimization example of component with complicated shape and thin wall is studied to prove the effectiveness of the improved Jaya *** optimization results are compared with that obtained by other algorithms based on the TOPSIS method.

关键词： Variable blank holder force Multi-objective optimization QO-Jaya algorithm Algorithm stop criterion

来源：评论

学校读者我要写书评

暂无评论

OFDM-structure based waveform designs for integrated sensing and communication

引用

Science China(Information Sciences) 2025年第5期68卷 267-284页

作者： Jiaqi LIU Ping YANG Ke JIANG Jiarong ZHAO Wei XIANG Jianping WEI Ruixiang DUAN Saviour ZAMMIT Tony Q.S.QUEK National Key Laboratory of Wireless Communications University of Electronic Science and Technology of China School of Computing Engineering and Mathematical Sciences La Trobe University Meituan Academy of Robotics Department of Communications and Computer Engineering University of Malta Information Systems Technology and Design Pillar Singapore University of Technology and Design

The future sixth-generation(6G) paradigm aims to seamlessly integrate communication and environmental sensing capabilities into a single radio signal, promising improved efficiency and cost-effectiveness through simultaneous data communications and environmental perception. At the core of this evolution, orthogonal frequency division multiplexing(OFDM) and its advanced waveforms emerge as pivotal for integrated sensing and communications(ISAC). This study introduces a concise and unified ISAC waveform design framework based on orthogonal multicarriers. This framework supports versatile applications of OFDM and its derivative waveforms within a generalized ISAC system, marking a significant leap in integrating communication and sensing capabilities. A distinguishing feature of this framework is its adaptability,allowing users to intelligently select modulation strategies based on their specific environmental needs. This adaptability optimizes performance across diverse scenarios. Central to our innovations is the proposal of discrete Fourier transformspread OFDM with index modulation(DFT-S-OFDM-IM). This framework is paired with newly proposed signal processing methods for single-input single-output and multiple-input multiple-output(MIMO) systems. Extensive evaluations highlight DFT-S-OFDM-IM's superiority, including dramatically reduced peak-to-average power ratios(PAPRs), competitive communication performance, and exceptional sensing capabilities, striking an elegant balance between communication capacity and environmental sensing precision.

关键词： DFT-S-OFDM-IM index modulation integrated sensing and communication OFDM

来源：评论

学校读者我要写书评

暂无评论

Enhancing Ultrasound Scanning Skills in a Leader-Follower Robotic System through Expert Hand Impedance Regulation

引用

IEEE Journal of Biomedical and Health Informatics 2025年 PP卷 PP页

作者： Niu, Baoshan Yang, Dapeng Zhang, Le Ji, Yiming Jiang, Li Liu, Hong Harbin Institute of Technology State Key Laboratory of Robotics and Systems Harbin150080 China

Traditional breast cancer surgeries require collaboration between ultrasound (US) doctors and surgeons, making the procedure complex and treating physicians prone to fatigue. In leader-follower robotic surgery, a surgeon controls an US robotic arm and an instrument robotic arm with their left and right hands, enabling independent surgical performance. However, the lack of US scanning skills among surgeons, as well as the physical separation in leader-follower operations, can negatively impact both the scanning and surgical outcomes. This paper proposes a robot-assisted scheme based on dynamic arm impedance compensation (IC) that references expert arm stiffness to compensate for novice arm stiffness. The impedance compensator adjusts the compensation strategy according to the scanning area and scanning stage. The impedance force generator estimates the scanning direction via Kalman filtering and applies stiffness and damping forces in the vertical direction to suppress tremors and other involuntary movements. The experimental results revealed that during the coarse and fine scanning phases, the probe position variance decreased by 57.9% and 73.6%, the contact force variance decreased by 55.2% and 42.5%, and the US image confidence increased by 22.0% and 23.8%, respectively. Compared with traditional filtering compensation (FC) schemes, this approach reduces the average position variance and contact force variance by 32.0% and 25.3%, respectively, and increases confidence by 7.3%. In a no-compensation test, the IC training group outperformed the FC group. This scheme can assist leader-follower US scanning and rapidly improve surgical skills. © 2013 IEEE.

关键词： Robotic surgery

来源：评论

学校读者我要写书评

暂无评论

Multiplayer Reach-Avoid Differential Games in 3D Space Inspired by Harris'Hawks'Cooperative Hunting Tactics

引用

Research 2024年第2期2023卷 41-54页

作者： Wanying Ruan Haibin Duan Yongbin Sun Wanmai Yuan Jie Xia State Key Laboratory of Virtual Reality Technology and Systems School of Automation Science and Electrical EngineeringBeihang UniversityBeijingChina Peng Cheng Laboratory ShenzhenChina Information Science Academy of CETC BeijingChina

This paper investigates a multiplayer reach-avoid differential game in 3-dimensional(3D)space,which involves multiple pursuers,multiple evaders,and a designated target *** evaders aim to reach the target region,while the pursuers attempt to guard the target region by capturing the *** class of research holds significant practical ***,the complexity of the problem escalates substantially with the growing number of players,rendering its solution extremely *** this paper,the multiplayer game is divided into many subgames considering the cooperation among pursuers,reducing the computational burden,and obtaining numerically tractable strategies for ***,the Apollonius sphere,a fundamental geometric tool for analyzing the 3D differential game,is formulated,and its properties are *** on this,the optimal interception point for the pursuer to capture the evader is derived and the winning conditions for the pursuer and evader are ***,based on the Apollonius sphere,the optimal state feedback strategies of players are designed,and simultaneously,the optimal one-to-one pairings are ***,the Value function of the multiplayer reach-avoid differential game is explicitly given and is proved to satisfy Hamilton-Jacobi-Isaacs(HJI)***,the matching algorithm for the case with pursuers outnumbered evaders is provided through constructing a weighted bipartite graph,and the cooperative tactics for multiple pursuers are proposed,inspired by the Harris'Hawks intelligent cooperative hunting ***,numerical simulations are conducted to illustrate the effectiveness of the theoretical results for both cases where the number of adversary players is equal and unequal between the 2 groups.

关键词： holds satisfy rendering

来源：评论

学校读者我要写书评

暂无评论

GCA-Net: A Global Context Aggregation Network for Effective Optical Flow 49

GCA-Net: A Global Context Aggregation Network for Effective ...

引用

49th Annual Conference of the IEEE Industrial Electronics Society, IECON 2023

作者： Xie, Tao Gao, Jinghan Wang, Ke Li, Ruifeng Harbin Institute of Technology State Key Laboratory of Robotics and System Harbin China

ISBN: (纸本)9798350331820

Optical flow seeks to estimate the per-pixel 2D motion between two frames by identifying corresponding pixels. Current flow estimators typically involve per-pixel feature extraction, multi-scale 4D correlation volume construction, and iterative flow field updates through a Conv-GRU module. However, the locality of convolutional features in these methods renders the calculated correlations vulnerable to different noises. In addition, the Conv-GRU module of these methods is only executed with a convolution layer, which is incapable of exploiting context clues from larger window sizes even inside the image being queried itself, thus raising it more difficult for the model to process images with challenging regions, e.g., textureless areas. To this end, we introduce GCA-Net, a global context aggregation network for credible yet effective optical flow estimation. More specifically, we propose a highly efficient multi-scale transformer (MSFormer) layer which enables the per-pixel feature to aggregate long-range information from other features, hence building more accurate 4D correlation volumes. Besides, we develop an attention-enhanced Conv-GRU block (AttGRU) that can incorporate information alongside a larger context window even within itself empowering our network to estimate optical flow in even the most challenging regions. Experimentally, we demonstrate that GCA-Net outperforms previous state-of-the-art methods by large margins on Sintel (Final) and KITTI 2015 (background and foreground) benchmarks. © 2023 IEEE.

关键词： Optical flows

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：