检索结果-南通市图书馆

维普期刊数据库

Tactile-sensing-based robotic grasping stability analysis

在线全文

学校读者我要写书评

暂无评论

science china(Technological sciences) 2024年第6期67卷 1817-1828页

作者： HUANG YanJiang WANG HaoNan ZHANG XianMin Guangdong Provincial Key Laboratory of Precision Equipment and Manufacturing Technology South China University of TechnologyGuangzhou510640China

Tactile signals play a crucial role in enabling robots to successfully manipulate unfamiliar *** robots to grasp unknown objects securely and without causing damage,it is essential that they can analyze grasping stability in real time through tactile signals and respond *** study introduces a novel method for analyzing the stability of robotic hand grasping,utilizing the Wilcoxon signed rank *** efficacy of this method is demonstrated through its static and dynamic performance,and evaluated across a series of *** findings of this research highlight the method’s ability to accurately detect when an object begins to slip from the robot’s *** this method allows the gripper to maintain a secure hold on objects by applying the minimal necessary *** also enables the gripper to dynamically adjust the force it applies in real time,thus preventing the object from slipping during the movement of the robotic ***,the gripper demonstrates the ability to stably grasp objects of varied weights and with unknown characteristics,showcasing the versatility and effectiveness of the proposed method.

关键词： grasping stability manipulation tactile sensors

维普期刊数据库

Compression and stretching of ring vortex in a bulk nonlinear medium

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2024年第2期33卷 264-270页

作者：来娴静蔡晓鸥邵雅斌王悦悦 Department of Basic science Zhejiang Shuren UniversityHangzhou 310015China School of sciences Zhejiang A&F UniversityHangzhou 311300China

We explore the nonlinear gain coupled Schrödinger system through the utilization of the variables separation method and ansatz *** employing these approaches,we generate hierarchies of explicit dissipative vector vortices(DVVs)that possess diverse vorticity *** fundamental characteristics of the DVVs are examined,encompassing amplitude profiles,energy fluxes,parameter effects,as well as linear and dynamic stability.

关键词： vector optical vortices dissipative nonlinear gain

维普期刊数据库

Dynamic analysis of beta oscillations in Parkinsonian neural networks with the pedunculopontine nucleus under optogenetic control

在线全文

学校读者我要写书评

暂无评论

Acta Mechanica Sinica 2024年第6期40卷 125-140页

作者： Yuzhi Zhao Honghui Zhang Ying Yu Lin Du Zichen Deng School of Mathematics and Statistics Northwestern Polytechnical UniversityXi’an710072China School of Aeronautic science and Engineering Beihang UniversityBeijing100191China School of Aeronautics Northwestern Polytechnical UniversityXi’an710072China

Clinical experiments have proven that the pedunculopontine nucleus(PPN)plays a crucial role in the modulation of beta oscillations in Parkinson’s disease(PD).Here,we propose a new computational framework by introducing the PPN and related synaptic connections to the classic basal ganglia-thalamo-cortical ***,the improved model can not only simulate the basic saturated and beta activities mentioned in previous studies but also produce the normal alpha rhythm that is much closer to physiological ***,the results show that Parkinsonian oscillation activities can be controlled and modulated by the connection strength between the PPN and the globus pallidus internal nucleus(GPi)and the subthalamic nucleus(STN),supporting the fact that PPN is overinhibited in ***,the internal mechanism underlying these state transitions is further explained from the perspective of ***,both deep brain stimulation(DBS)and optogenetic technology are considered effective in terms of abnormal *** when a low-frequency DBS is added to the PPN,beta oscillations can be suppressed,but it is excited again as the DBS’s frequency gradually increases to a larger *** results coincide with the experimental results that low-frequency stimulation of the PPN is effective,and verify the rationality of the ***,we show that optogenetic stimulation of the globus pallidus external(GPe)expressing excitatory channelrhodopsin(ChR2)can effectively inhibit beta oscillations,whereas exciting the STN and PPN has a limited *** results are consistent with experimental reports suggesting that the symptoms of PD’s movement disorder can be alleviated under the GPe-ChR2,but not STN-ChR2,*** the functional role of the PPN and the feasibility of optogenetic stimulation remain to be clinically explored,the results obtained help us understand the mechanisms of beta oscillations in PD.

关键词： Pedunculopontine nucleus Beta oscillations Optogenetic Deep brain stimulation Parkinson’s disease

Study on 6-DOF active vibration-isolation system of the ultra-precision turning lathe based on GA-BP-PID control for dynamic loads

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Advances in Manufacturing 2024年第1期12卷 33-60页

作者： Bo Wang Zhong Jiang Pei-Da Hu Department of Precision Instrument Tsinghua UniversityBeijing100084People’s Republic of China Institute of Machinery Manufacturing Technology China Academy of Engineering PhysicsMianyang621900SichuanPeople’s Republic of China

The vibration disturbance from an external environment affects the machining accuracy of ultra-precision machining *** active vibration-isolation systems(AVIS)have been developed based on static *** a vibration-isolation load changes dynamically during ultra-precision turning lathe machining,the system parameters change,and the efficiency of the active vibration-isolation system based on the traditional control strategy *** solve this problem,this paper proposes a vibration-isolation control strategy based on a genetic algorithm-back propagation neural network-PID control(GA-BP-PID),which can automatically adjust the control parameters according to the machining ***-isolation simulations and experiments based on passive vibration isolation,a PID algorithm,and the GA-BP-PID algorithm under dynamic load machining conditions were *** experimental results demonstrated that the active vibration-isolation control strategy designed in this study could effectively attenuate vibration disturbances in the external environment under dynamic load *** design is reasonable and feasible.

关键词： Ultra-precision diamond turning lathe Active vibration isolation Six degrees of freedom Dynamic load Genetic algorithm-back propagation neural network-PID(GA-BP-PID)control

Vortex identification based on the Liutex method and its effect on fish passage upstream

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Hydrodynamics 2024年第1期36卷 130-141页

作者： Chun-ying Shen Rui-guo Yang Xiao-tao Shi Ming-ming Wang Shi-hua He Faculty of Electrical Power Engineering Kunming University of Science and TechnologyKunming650500China Hubei International science and Technology Cooperation Base of Fish Passage China Three Gorges UniversityYichang443002China Shanghai Investigation Design and Research Institute Co.LtShanghai200434China

Fishway research is important for mitigating the fragmentation of river habitats caused by hydraulic *** vertical slit fishway is a broadly used fishway type because of its high efficiency and adaptability to water ***,the resulting vortex current disrupts the fish passage hence directly affecting fish *** study aims to accurately capture the vortex structure in the fishway and analyze the effect of vortex elements(vortex structure,vortex intensity,etc.)on *** conducted an analysis of the 3-D current flow field in the fishway through the utilization of an experimental model and the large eddy simulation(LES)***,we captured the vortex information in the fishway at different flow rates using the Liutex vortex identification method and investigated the effect of the vortex on fish *** results revealed that the structures inside the fishway pool occupy most of the room,however,the areas with higher vortex strength were primarily located in the vortex near the vertical seam and the mainstream,the vortex strength inside the fishway gradually increases with increasing flow,suppressing fish *** experienced significantly increased resistance when encountering strong *** suggests that the vortex may act as a physical barrier to fish *** findings highlight the potential negative effects of vortex on fish movement and reiterate the importance of understanding vortex dynamics for aquatic environmental *** an effective tool for identifying vortices in fluid flow,the Liutex method demonstrates features of vortex within the fishway,thereby providing important insights into the interaction between fluid dynamics and aquatic organisms.

关键词： Vertical slit fishway vortex identification method Liutex large eddy simulation(LES) fish experiment computational fluid dynamics

On the size generalizibility of graph neural networks for learning resource allocation

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

science china(Information sciences) 2024年第4期67卷 239-254页

作者： Jiajun WU Chengjian SUN Chenyang YANG Beihang University School of Electronics and Information Engineering

Size generalization is important for learning resource allocation policies in wireless systems with time-varying scales. If a neural network for learning a wireless policy is not generalizable to the size of its input, it has to be re-trained whenever the system scale changes, which hinders its practical use due to the unaffordable training costs. Graph neural networks(GNNs) have been shown with size generalization ability empirically when optimizing resource allocation. Yet, are GNNs naturally size generalizable? In this paper,we argue that GNNs are not always size generalizable for resource allocation. We find that the aggregation and activation functions of the GNNs for learning a class of wireless policies play a key role in their size generalization ability. We take the GNN with the mean aggregator, called mean-GNN, as an example to reveal a size generalization condition. To demonstrate how to satisfy the condition, we learn power and bandwidth allocation policies for ultra-reliable low-latency communications and show that selecting or pretraining the activation function in the output layer of mean-GNN can make the GNN size *** results validate our analysis and evaluate the performance of the learned policies.

关键词： size generalization graph neural networks resource allocation permutation equivariance

Numerical analysis of the correlation between fluid dynamic modes and hydrodynamic noise in flows around a three-dimensional circular cylinder

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Hydrodynamics 2024年第1期36卷 119-129页

作者： Jia-jia Qin Ming-xin Zou Yuan Zhuang De-cheng Wan Computational Marine Hydrodynamics Lab(CMHL) School of Naval ArchitectureOcean and Civil EngineeringShanghai Jiao Tong UniversityShanghai200240China Wuhan Second Ship Design and Research Institute Wuhan430205China

The flow around a circular cylinder for Re=1000 is characterized by flow separation and Karman vortex *** typical flow features can be captured to study the correlation between fluid fields and sound *** this paper,the three-dimensional circular cylinder is taken as the research object,and the probes of surface fluctuating pressure and far field sound pressure are arranged every 10°.The directional diagram and the coherence of fluctuating pressure and sound pressure are *** relationship between the flow mode and hydrodynamic noise is studied by using dynamic mode decomposition(DMD).The characteristics of the dipole and quadrupole sound source term of a long span cylinder are *** results show that at the angles between 30°–120°and 190°–350°,the fluctuating pressure contributes more to the generation of dipole *** quadrupole sound source shows three-dimensional effects,which is more obvious in a cylinder with large spanwise length.

关键词： Pressure coherence dynamic mode decomposition flow-sound correlation circular cylinder

Numerical investigation on compressible flow around a cylinder in proximity to the heated wall

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Hydrodynamics 2024年第3期36卷 519-533页

作者： Yu-lu Liu Jun-wang Qu Yi-zhou Tao Yong-guang Lyu Xiang Qiu Shanghai Institute of Technology School of ScienceShanghai201418China Shanghai Key Laboratory of Mechanics in Energy Engineering Shanghai Institute of Applied Mathematics and MechanicsSchool of Mechanics and Engineering ScienceShanghai UniversityShanghai200072China

In this study,direct numerical simulations were conducted to investigate the compressible flow around a circular cylinder near a heated wall at a Reynolds number(Re)of 500 and a Mach number(Ma)of *** heating ratio T^(*)ranging from 1.0 to 1.6 represents the different situations of a heated wall,whereas the gap ratio ranges from 0.3 to *** study analyzed the impact of heating effect and wall proximity on flow characteristics and aerodynamic *** results indicated that the stability of the flow was enhanced as the gap ratio decreased or the heating ratio *** the calculation of enstrophy,it was found that the strength of shedding vortices weakens with a decrease in gap ratio or an increase in heating ***,the mean drag coefficient decreases as the heating ratio increases or the gap ratio *** contrast,the mean lift coefficient initially decreases and then increases as the gap ratio ***,the drag reduction mechanism was analyzed by examining the pressure distribution on the surface of the cylinder.

关键词： Compressible flow wall proximity heating effect stability enstrophy

ControlService: a containerized solution for control-algorithm-as-a-service in cloud control systems

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

science china(Information sciences) 2024年第8期67卷 172-189页

作者： Chenggang SHAN Runze GAO Zhen YANG Wei ZHANG Yuanqing XIA School of Artificial Intelligence Zaozhuang University School of Automation Beijing Institute of Technology

As an extension of networked control systems, cloud control systems(CCSs) have emerged as a new control paradigm to improve the service quality of emerging control missions, such as data-driven modeling and automated vehicles. Existing studies have used the workflow-based restructured method to optimize the computation-intensive algorithms in the CCSs. However, the challenges here are how to define and submit these algorithms' workflows as cloud services and execute these algorithms' workflows in a containerized manner. Based on these challenges, we propose a containerized solution for the control-algorithm-as-a-service(C3aS) in the CCSs, namely Control Service. It offers the control algorithm as a cloud workflow service and uses a customized workflow engine to realize the containerized execution. First, we employ a cloud workflow representation method to define a control algorithm into an abstract cloud workflow form. Afterward, we provide a cloud service representation of the abstract cloud workflow. Next, we design a workflow engine and submit the cloud service to this workflow engine to implement containerized execution of this cloud service in the CCSs. In the experiment, we discuss the cloud service form and containerized implementation of the subspace identification method. Experimental results show that the proposed Control Service has significant performance advantages in computational time, reduction percentage, and speedup ratio compared with the baseline method.

关键词： cloud control systems control-algorithm-as-a-service containerization workflow engine cloud workflow service subspace identification

同方期刊数据库