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A variable structure passivity control method for elastic joint robots based on cascaded high-order state estimation

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Science China(Technological Sciences) 2024年第2期67卷 395-407页

作者： ZHANG JieXin NIE PingYun ZHANG bo State Key Laboratory of Mechanical System and Vibration School of Mechanical EngineeringShanghai Jiao Tong UniversityShanghai200240China

Passivity-based controllers are widely used to facilitate physical interaction between humans and elastic joint robots,as they enhance the stability of the interaction ***,the joint position tracking performance can be limited by the structures of these controllers when the system is faced with uncertainties and rough high-order system state measurements(such as joint accelerations and jerks).This study presents a variable structure passivity(VSP)control method for joint position tracking of elastic joint robots,which combines the advantages of passive control and variable structure *** method ensures the tracking error converges in a finite time,even when the system faces *** method also preserves the passivity of the ***,a cascaded observer,called CHOSSO,is also proposed to accurately estimate high-order system states,relying only on position and velocity *** observer allows independent implementation of disturbance compensation in the acceleration and jerk estimation *** particular,the observer has an enhanced ability to handle fast time-varying disturbances in physical human-robot *** effectiveness of the proposed method is verified through simulations and experiments on a lower limb rehabilitation robot equipped with elastic joints.

关键词： motion control elastic joint robot finite-time convergence high-order system state estimation physical human-robot interaction

Automated regression test method for scientific computing libraries:Illustration with SPHinXsys

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Journal of Hydrodynamics 2024年第3期36卷 466-478页

作者： bo Zhang Chi Zhang Xiangyu Hu TUM School of Engineering and Design Technical University of MunichMunichGermany

Scientific computing libraries,whether in-house or open-source,have witnessed enormous progress in both engineering and scientific ***,it is important to ensure that modifications to the source code,prompted by bug fixing or new feature development,do not compromise the accuracy and functionality that have been already validated and *** paper introduces a method for establishing and implementing an automatic regression test environment,using the open-source multi-physics library SPHinXsys as an illustrative ***,a reference database for each benchmark test is generated from observed data across multiple *** comprehensive database encapsulates the maximum variation range of metrics for different strategies,including the time-averaged,ensemble-averaged,and dynamic time warping *** accounts for uncertainties arising from parallel computing,particle relaxation,physical instabilities,and ***,new results obtained after source code modifications undergo testing based on a curve-similarity comparison against the reference *** the source code is updated,the regression test is automatically executed for all test cases,providing a comprehensive assessment of the validity of the current *** regression test environment has been successfully implemented in all dynamic test cases within SPHinXsys,including fluid dynamics,solid mechanics,fluid-structure interaction,thermal and mass diffusion,reaction-diffusion,and their multi-physics couplings,and demonstrates robust capabilities in testing different *** is noted that while the current test environment is built and implemented for a particular scientific computing library,its underlying principles are generic and can be easily adapted for use with other libraries,achieving equal effectiveness.

关键词： Scientific computing open-source library verification and validation regression test automatic test environment curve similarity comparison smoothed particle hydrodynamics

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融合多尺度及注意力机制的表面缺陷检测算法

空间控制技术与应用 2023年第6期49卷 94-103页

作者：步斌张梦怡王超王村松薄翠梅彭浩山东兖矿智能制造有限公司济宁272004 南京工业大学南京211800

发动机的叶轮叶片是空间航天器推进系统的关键组件,对空间任务的顺利完成起到至关重要的作用.叶轮叶片表面缺陷具有尺寸小、种类多等特点,容易造成误检和漏检.提出一种融合多尺度特征及注意力机制的缺陷检测算法(EF-centerNet),采用轻... 详细信息

发动机的叶轮叶片是空间航天器推进系统的关键组件,对空间任务的顺利完成起到至关重要的作用.叶轮叶片表面缺陷具有尺寸小、种类多等特点,容易造成误检和漏检.提出一种融合多尺度特征及注意力机制的缺陷检测算法(EF-centerNet),采用轻量级的EPSANet网络作为CenterNet算法的主干,有效融合PSA分割注意力机制,关注更重要的缺陷特征,增强网络的特征提取能力;同时在主干特征提取网络输出的特征层后添加FPN结构,进一步融合多尺度信息,即低分辨率的高层语义信息和高分辨率的低层特征信息,从而提升算法的缺陷检测精度.实验结果表明,所提出的EF-CenterNet算法在自制数据集上检测精度达到96.74%,比基线CenterNet算法指标提升了1.81%,在公共数据集上检测精度达到77.37%,比基线CenterNet算法指标提升了1.99%.

关键词：叶轮叶片缺陷检测注意力机制多尺度深度学习

Intersection theory rules symbology

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Science China(Physics,Mechanics & Astronomy) 2024年第2期67卷 93-104页

作者： Jiaqi Chen bo Feng Lilin Yang Beijing Computational Science Research Center Beijing 100084China Zhejiang Institute of Modern Physics School of PhysicsZhejiang UniversityHangzhou 310027China Peng Huanwu Center for Fundamental Theory Hefei 230026China

We propose a novel method to determine the structure of symbols for any family of polylogarithmic Feynman *** the d log-bases and simple formulas for the leading order and next-to-leading contributions to the intersection numbers,we give a streamlined procedure to compute the entries in the coefficient matrices of canonical differential equations,including the symbol letters and the rational *** also provide a selection rule to decide whether a given matrix element must be *** symbol letters are deeply related to the poles of the integrands and also have interesting connections to the geometry of Newton *** method can be applied to many cutting-edge multi-loop *** simplicity of our results also hints at the possible underlying structure in perturbative quantum field theories.

关键词： scattering amplitude Feynman integral symbology

Finite-time tracking control of heterogeneous multi-AUV systems with partial measurements and intermittent communication

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Science China(Information Sciences) 2024年第5期67卷 165-182页

作者： bo CHEN Jiangping HU Bijoy Kumar GHOSH School of Automation Engineering University of Electronic Science and Technology of China Key Laboratory of Intelligent Analysis and Decision on Complex Systems Chongqing University of Posts and Telecommunications Yangtze Delta Region Institute (Huzhou) University of Electronic Science and Technology of China Department of Mathematics and Statistics Texas Tech University

The development of a distributed trajectory-tracking control strategy that is independent of velocity measurements is critical to achieving finite-time tracking control of autonomous underwater vehicle(AUV) systems. In this study, a group of heterogeneous AUV systems with intermittent communication links is considered and a finite-time trajectory-tracking control strategy is developed. The strategy includes two observers and one controller proposed for each follower-AUV. The first observer, a hybrid finite-time observer,estimates the state of the leader, whereas the second observer, which relies only on the position measurement,is proposed to estimate the states of the follower-AUV itself. In addition, a distributed trajectory-tracking controller is designed using the states estimated by the intermittent communication network even without velocity measurements. A homogeneous technique is utilized to prove that all followers can track the leader in a finite time. Finally, the effectiveness of the developed finite-time tracking control strategy is illustrated by numerical simulations.

关键词： distributed observer finite-time tracking homogeneous technique intermittent communication multiple heterogeneous AUVs

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

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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

Reversibly sensitizing-storing-releasing ^(1)O_(2) within a single platinum(Ⅱ)-acetylide-based metallacycle molecule via laser power modulation

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Science China Chemistry 2024年第2期67卷 604-611页

作者： Ruyi Zhou Wen Lv bo Li bo Yu Sudi Zhang Yucheng Zhou Shujuan Liu Qiang Zhao State Key Laboratory of Organic Electronics and Information Displays&Jiangsu Key Laboratory for Biosensors Institute of Advanced Materials(IAM)&Institute of Flexible Electronics(Future Technology)Nanjing University of Posts and Telecommunications(NUPT)Nanjing210023China College of Electronic and Optical Engineering&College of Flexible Electronics(Future Technology) Jiangsu Province Engineering Research Center for Fabrication and Application of Special Optical Fiber Materials and DevicesNanjing University of Posts and Telecommunications(NUPT)Nanjing210023China

Tumor hypoxia severely limits the therapeutic efficacy of photodynamic therapy(PDT) for solid tumors,which is highly dependent on tissue oxygen *** this study,we developed a platinum(Ⅱ)-acetylide-based metallacycle compound bearing six 1,4-dimethylnaphthalenes(DMN) groups,and controlled the photodynamic and photothermal effects of the compound by adjusting the power of 730 nm laser to achieve reversible sensitization,storage and release of 1~O_(2) within a single *** compound formed nanoparticles by self-assembly and exhibited good water solubility and *** laser irradiation,the strong spin-orbit coupling of platinum atoms in the metallacycle facilitated 1~O_(2) *** produced 1~O_(2) was captured by the DMN carriers and transported into the hypoxic tumor,where 1~O_(2) release was triggered owing to the good photothermal effect of the extended conjugation of the *** therapy,the metallacycle serving as a photosensitizer,1~O_(2) carrier,and photothermal reagent,achieved the synergistic therapy of PDT/PTT,demonstrating the versatility of the *** study proposes a new strategy to develop phototherapy agents that are suitable for hypoxic tumors.

关键词： metallacycles singlet oxygen endoperoxides near-infrared absorption synergistic treatment

基于重构技术工业故障诊断OPC数据平台的设计

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计算机与应用化学 2009年第8期26卷 993-997页

作者：杨海荣薄翠梅蒋荪华张广明南京工业大学自动化学院江苏南京210009 苏州中材非金属矿工业设计研究院江苏苏州215004

当今日益飞速发展的自动化控制技术使得工厂的自动化程度越来越高,然而带来的问题就是一旦检测设备发生故障,会带来控制系统的崩溃,轻则带来经济损失重则造成工业事故。本文就工业故障诊断技术利用OPC(OLE for processing Control)技术... 详细信息

当今日益飞速发展的自动化控制技术使得工厂的自动化程度越来越高,然而带来的问题就是一旦检测设备发生故障,会带来控制系统的崩溃,轻则带来经济损失重则造成工业事故。本文就工业故障诊断技术利用OPC(OLE for processing Control)技术设计1种容错控制数据平台来解决这一问题。通过OPC服务获得工业现场数据,利用故障诊断技术对工业数据进行诊断,检测辨识故障传感器,隔离故障传感器,采用已知数据回归法(KnownDataRegression)重构故障数据,作为上层控制软件的输入从而可以使控制系统稳定运行,故障监控软件给操作人员发出检修信号。实验室仿真结果表明该平台可以稳定运行,这为故障诊断和容错技术实际工程应用奠定了基础。

关键词： OPC技术故障诊断主动容错控制数据重构传感器故障

Numerical Investigations on the Resonance Errors of Multiscale Discontinuous Galerkin Methods for One-Dimensional Stationary Schrödinger Equation

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Communications on Applied Mathematics and Computation 2024年第1期6卷 311-324页

作者： bo Dong Wei Wang Department of Mathematics University of Massachusetts DartmouthNorth DartmouthMA02747USA Department of Mathematics and Statistics Florida International UniversityMiamiFL33199USA

In this paper,numerical experiments are carried out to investigate the impact of penalty parameters in the numerical traces on the resonance errors of high-order multiscale discontinuous Galerkin(DG)methods(Dong et *** J Sci Comput 66:321–345,2016;Dong and Wang in J Comput Appl Math 380:1–11,2020)for a one-dimensional stationary Schrödinger *** work showed that penalty parameters were required to be positive in error analysis,but the methods with zero penalty parameters worked fine in numerical simulations on coarse *** this work,by performing extensive numerical experiments,we discover that zero penalty parameters lead to resonance errors in the multiscale DG methods,and taking positive penalty parameters can effectively reduce resonance errors and make the matrix in the global linear system have better condition numbers.

关键词： Discontinuous Galerkin(DG)method Multiscale method Resonance errors One-dimensional Schrödinger equation