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Distributed Multicircular Circumnavigation Control for UAVs with Desired Angular Spacing

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Defence Technology（防务技术） 2024年第1期31卷 429-446页

作者： Shixiong Li Xingling Shao wendong zhang Qingzhen zhang National Key Laboratory for Electronic Measurement Technology School of Instrument and ElectronicsNorth University of ChinaTaiyuan 030051China School of Automation Science and Electrical Engineering Beihang UniversityBeijing 100086China

This paper addresses a multicircular circumnavigation control for UAVs with desired angular spacing around a nonstationary *** defining a coordinated error relative to neighboring angular spacing,under the premise that target information is perfectly accessible by all nodes,a centralized circular enclosing control strategy is derived for multiple UAVs connected by an undirected graph to allow for formation behaviors concerning the moving ***,to avoid the requirement of target’s states being accessible for each UAV,fixed-time distributed observers are introduced to acquire the state estimates in a fixed-time sense,and the upper boundary of settling time can be determined offline irrespective of initial properties,greatly releasing the burdensome communication ***,with the aid of fixed-time distributed observers,a distributed circular circumnavigation controller is derived to force all UAVs to collaboratively evolve along the preset circles while keeping a desired angular *** is inferred from Lyapunov stability that all errors are demonstrated to be *** are offered to verify the utility of proposed protocol.

关键词： Angular spacing Distributed observer Multicircular circumnavigation Moving target UAVs

Multi-circular formation control with reinforced transient profiles for nonholonomic vehicles:A path-following framework

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Defence Technology（防务技术） 2024年第1期31卷 278-287页

作者： Jintao zhang Xingling Shao wendong zhang Zongyu Zuo School of Instrument and Electronics North University of ChinaTaiyuan 030051China State Key Laboratory of Dynamic Measurement Technology North University of ChinaTaiyuan 030051China Seventh Research Division School of Automation Science and Electrical EngineeringBeihang UniversityBeijing 100191China

This article investigates a multi-circular path-following formation control with reinforced transient profiles for nonholonomic vehicles connected by a digraph.A multi-circular formation controller endowed with the feature of spatial-temporal decoupling is devised for a group of vehicles guided by a virtual leader evolving along an implicit path,which allows for a circumnavigation on multiple circles with an anticipant angular *** addition,notice that it typically imposes a stringent time constraint on time-sensitive enclosing scenarios,hence an improved prescribed performance control(IPPC)using novel tighter behavior boundaries is presented to enhance transient capabilities with an ensured appointed-time convergence free from any *** significant merits are that coordinated circumnavigation along different circles can be realized via executing geometric and dynamic assignments independently with modified transient ***,all variables existing in the entire system are analyzed to be *** and experimental results are provided to validate the utility of suggested solution.

关键词： Multi-circular formation Reinforced transient profiles Nonholonomic vehicles Path following

Prescribed fast tracking control for flexible air-breathing hypersonic vehicles:An event-triggered case

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Chinese Journal of Aeronautics 2021年第11期34卷 200-215页

作者： Xingling SHAO Yi SHI wendong zhang Jiang ZHAO The Key Laboratory of Instrumentation Science&Dynamic Measurement Ministry of EducationNorth University of ChinaTaiyuan 030051China School of Instrument and Electronics North University of ChinaTaiyuan 030051China School of Automation Science and Electrical Engineering Beihang UniversityBeijing 100191China

In this paper,a prescribed fast tracking control scheme is proposed for Flexible Airbreathing Hypersonic Vehicles(FAHV)subject to lumped disturbances and limited *** maintain tracking errors of velocity and altitude converge to a predefined region with a prescribed time and release the transient intense fluctuations encountered in classical Prescribed Performance Control(PPC)using a fast decaying rate,a tracking differentiator-based PPC is presented,where the reaching time and the maximum time differentiation of preselected envelopes can be regulated as a prior via fixing an acceleration factor,so that a guaranteed fast convergence speed can be realized with reduced ***,to avoid the excessive occupation of limited resources(energy and communication)and guarantee a remarkable tracking accuracy,switching event-triggered mechanisms are constructed for FAHV control realization,which provide a promising way to pursue a desired level of tracking performance with a low energy ***,Uncertainty and Disturbance Estimators(UDE)and Sigmoid function-based Tracking Differentiators(STD)are employed to provide disturbance estimation and reference derivation with a low computational ***,robust control laws are designed to compensate for the sampling error induced by event-triggered conditions,meanwhile Zeno phenomena can be effectively *** simulation results and comparisons validate the effectiveness of the proposed scheme.

关键词： Flexible air-breathing hypersonic vehicle Prescribed performance control Switching event-triggered Tracking differentiator Uncertainty and disturbance estimator

A bioinspired,self-powered,flytrap-based sensor and actuator enabled by voltage triggered hydrogel electrodes

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Nano Research 2023年第7期16卷 10198-10205页

作者： Zhiliang Hou Xuebiao Li Xinru zhang wendong zhang Zhong Lin Wang Hulin zhang College of Information and Computer Taiyuan University of TechnologyTaiyuan 030024China School of Materials Science and Engineering Georgia Institute of TechnologyAtlantaGeorgia 30332USA Beijing Institute of Nanoenergy and Nanosystems Chinese Academy of SciencesBeijing 101400China

Because of its adaptive interfacial property,soft sensors/actuators can be used to perform more delicate tasks than their rigid ***,plant epidermis with a waxy cuticle layer challenges stable and high-fidelity non-invasive electrophysiology since the conventional electrodes are invasive,easily detached from plants,and require complicated setup ***,we report a bioinspired sensor and actuator created by using a conformable electrode interface as an electrical modulation unit on a Venus *** conformable electrode,by employing an adhesive hydrogel layer,can achieve the merits of low impedance,stretchable,biocompatible,reusable,and transparent enough for normal chlorophyll activity to *** to the high sensitivity of a flytrap to a triggering mechanical stimulation,a plant sensor matrix based on flytraps has been demonstrated by capturing the stimulated action potential(AP)signals from upper epidermis,which can orient honeybee colonies by their touch during collecting ***,via frequency-dependent AP modulation,an autonomous on-demand actuation on a flytrap is *** flytrap actuator can be controlled to responsively grasp tiny objects by the modulated signals triggered by a triboelectric nanogenerator(TENG).This work paves a way of developing autonomous plant-based sensors and actuators toward smart agriculture and intelligent robots.

关键词： self-powered hydrogel electrode sensor and actuator flytrap triboelectric nanogenerator

Obstacle-transformer: A trajectory prediction network based on surrounding trajectories

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IET Cyber-Systems and Robotics 2023年第1期5卷 1-8页

作者： wendong zhang Qingjie Chai Quanqi zhang Chengwei Wu Department of Control Science and Engineer Harbin Institute of TechnologyHarbinChina

Recurrent Neural Network,Long Short-Term Memory,and Transformer have made great progress in predicting the trajectories of moving *** the trajectory element with the surrounding scene features has been merged to improve performance,there still exist some problems to be *** is that the time series processing models will increase the inference time with the increase of the number of prediction *** problem is that the features cannot be extracted from the scene's image and point cloud in some ***,an Obstacle-Transformer is proposed to predict trajectory in a constant inference ***‘obstacle’is designed by the surrounding trajectory rather than images or point clouds,making Obstacle-Transformer more applicable in a wider range of *** are conducted on ETH and UCY datasets to verify the performance of our model.

关键词： deep-learning trajectory prediction transformer

Highly efficient photocatalytic NO removal and in situ DRIFTS investigation on SrSn(OH)_(6)

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Chinese Chemical Letters 2022年第3期33卷 1259-1262页

作者： wendong zhang Yun Wang Yi Wang Yi Liang Fan Dong Chongqing Key Laboratory of Inorganic Functional Materials Chongqing Key Laboratory of Green Synthesis and ApplicationChongqing Normal UniversityChongqing 401331China Yangtze Delta Region Institute(Huzhou)&Institute of Fundamental and Frontier Sciences University of Electronic Science and Technology of ChinaHuzhou 313001China State Centre for International Cooperation on Designer Low-carbon and Environmental Materials(CDLCEM) School of Materials Science and EngineeringZhengzhou UniversityZhengzhou 450001China

A novel SrSn(OH)_(6) photocatalyst with large plate and particle size were synthesized via a facile chemical precipitation method. The photocatalytic activity of the SrSn(OH)_(6) was evaluated by the removal of NO at ppb level under UV light irradiation. Based on the ESR measurements, SrSn(OH)_(6) photocatalyst was found to have the ability to generate the main active species of O_(2)^(·-), ^(·)OH and ^(1)O_(2) during the photocatalytic process. Moreover, SrSn(OH)_(6) photocatalyst not only exhibits high photocatalytic activity for NO removal (79.6%), but also has good stability after five cycles. The in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) was used to investigate the NO_(x) transfer pathway and the intermediate products distribution during the adsorption and photocatalytic NO oxidation process. The present work not only provides an efficient material for air pollutants purification at room temperature but also in-depth understanding of the mechanism involved in the photocatalytic NO removal process.

关键词： Highly efficient NO removal In situ DRIFTS investigation SrSn(OH)_(6) Reaction mechanism

Structure transformation induced bi-component Co–Mo/A-Co(OH)_(2)as highly efficient hydrogen evolution catalyst in alkaline media

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Nano Materials Science 2024年第5期6卷 565-575页

作者： Yingqing Ou Lu Liu Xiao Peng Lili zhang Zhongwen Ou wendong zhang Yunhuai zhang School of Chemistry and Chemical Engineering Chongqing UniversityChongqing400044China Department of Chemistry National University of SingaporeSingapore117543Singapore Institute of Sustainability for Chemicals Energy and Environment(ISCE2)Agency for ScienceTechnology and Research in Singapore(A*STAR)Singapore627833Singapore School of Physics Chongqing UniversityChongqing400044China College of Chemistry Chongqing Normal UniversityChongqing401331China Materials Science and Engineering College Sichuan University of Science&EngineeringZigong643000China Department of Military Infrastructure Army Logistics University of PLAChongqing401311China

Elucidating the inherent origins of the sluggish hydrogen evolution reaction(HER)kinetics in alkaline media and developing high-performance electrocatalysts are fundamental for the advances of conventional alkaline water electrolyzers and emerging anion exchange membrane(AEM)*** we present a facile electrochemical modification strategy for the synthesis of bi-component Co–Mo_((18%))/A-Co(OH)_(2)catalyst toward efficient HER catalysis in alkaline *** Co–Mo alloys with adjustable Mo/Co atomic ratio are first prepared by H2-assisted cathodic *** virtue of the appropriate electronic structure and hydrogen binding energy,Co–Mo_((18%))is the most HER active among the alloys and is further activated by a constant-current electrochemical modification *** characterizations reveal the formation of amorphous Co(OH)_(2)nanoparticles on the *** analysis combined with theoretical calculations reveal that the in-situ formed Co(OH)_(2)can efficiently promote the water dissociation,resulting in accelerated Volmer-step *** a result,the Co–Mo_((18%))/A-Co(OH)_(2)simultaneously achieves the optimization of the two factors dominating alkaline HER activity,i.e.,water dissociation and hydrogen adsorption/desorption via the bifunctional synergy of the *** high HER activity(η10 of 47 mV at 10 mA cm^(-2))of Co–Mo_((18%))/A-Co(OH)_(2)is close to benchmark Pt/C catalyst and comparable or superior to the most active non-noble metal catalysts.

关键词： Co-Mo_((18%))/A-Co(OH)_(2) Electrochemical modification Water dissociation Alkaline HER

基于Kriging模型的锥形气体静压轴承优化设计

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轴承 2025年第1期 14-22页

作者：张文栋石明辉秦东晨袁峰陈江义郑州大学机械与动力工程学院郑州450001

针对如何提升小孔节流式锥形气体静压轴承综合性能的问题,以气浮电主轴用锥形气体静压轴承承载力最大、气体消耗量最小为优化目标,考虑轴承尺寸和工况要求的约束条件,采用最优拉丁超立方法选取设计点,通过有限元法计算样本集,利用2种提... 详细信息

针对如何提升小孔节流式锥形气体静压轴承综合性能的问题,以气浮电主轴用锥形气体静压轴承承载力最大、气体消耗量最小为优化目标,考虑轴承尺寸和工况要求的约束条件,采用最优拉丁超立方法选取设计点,通过有限元法计算样本集,利用2种提高精度的加点策略构建针对优化目标的改进Kriging代理模型,最终使用非支配排序遗传算法获得最优解集。根据工况要求,通过权重系数法提出了3种优化方案,优化方案的气体消耗量分别降低至初始设计的28.85%,56.08%和73.87%;承载力则分别提升至初始设计的1.14,2.16和2.44倍;3种优化方案在中高转速下的性能提升会更加明显。另外,提高轴承锥度虽然能提升承载力,但同时也会增加气体消耗量。

关键词：滑动轴承气体静压轴承承载力耗气量有限元分析优化设计

Design and implementation of a jellyfish otolith-inspired MEMS vector hydrophone for low-frequency detection

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Microsystems & Nanoengineering 2021年第1期7卷 41-50页

作者： Renxin Wang Wei Shen Wenjun zhang Jinlong Song Nansong Li Mengran Liu Guojun zhang Chenyang Xue wendong zhang State Key Laboratory of Dynamic Testing Technology North University of ChinaTaiyuanChina College of Underwater Acoustic Engineering Harbin Engineering UniversityHarbinChina Hubei Key Laboratory of Modern Manufacturing Quantity Engineering School of Mechanical EngineeringHubei University of TechnologyWuhanHubeiChina

Detecting low-frequency underwater acoustic signals can be a challenge for marine *** by the notably strong response of the auditory organs of pectis jellyfish to ultralow frequencies,a kind of otolith-inspired vector hydrophone(OVH)is developed,enabled by hollow buoyant spheres atop *** parametric analysis is performed to optimize the cilium structure in order to balance the resonance frequency and *** the structural parameters of the OVH are determined,the stress distributions of various vector hydrophones are simulated and *** shock resistance of the OVH is also ***,the OVH is fabricated and *** receiving sensitivity of the OVH is measured to be as high as−202.1 dB@100 Hz(0 dB@1 V/μPa),and the average equivalent pressure sensitivity over the frequency range of interest of the OVH reaches−173.8 dB when the frequency ranges from 20 to 200 *** 3 dB polar width of the directivity pattern for the OVH is measured as 87°.Moreover,the OVH is demonstrated to operate under 10 MPa hydrostatic *** results show that the OVH is promising in low-frequency underwater acoustic detection.

关键词： underwater spheres hydrostatic