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Adaptive Robust Servo Control for Vertical Electric Stabilization System of Tank and Experimental Validation

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Defence Technology（防务技术） 2024年第1期31卷 326-342页

作者： Darui Lin Xiuye Wang Yimin Wang Guolai Yang school of mechanical engineering Nanjing University of Science and TechnologyNanjing210094China

A tracking stability control problem for the vertical electric stabilization system of moving tank based on adaptive robust servo control is *** paper mainly focuses on two types of possibly fast timevarying but bounded uncertainty within the vertical electric stabilization system:model parameter uncertainty and uncertain ***,the vertical electric stabilization system is constructed as an uncertain nonlinear dynamic system that can reflect the practical mechanics transfer process of the ***,the dynamical equation in the form of state space is established by designing the angular tracking ***,the comprehensive parameter of system uncertainty is designed to estimate the most conservative effects of ***,an adaptive robust servo control which can effectively handle the combined effects of complex nonlinearity and uncertainty is *** feasibility of the proposed control strategy under the practical physical condition is validated through the tests on the experimental *** paper pioneers the introduction of the internal nonlinearity and uncertainty of the vertical electric stabilization system into the settlement of the tracking stability control problem,and validates the advanced servo control strategy through experiment for the first time.

关键词： Adaptive robust servo control Experimental validation Nonlinearity compensation System uncertainty Vertical electric stabilization system

In-depth analysis of VARTM-based solid-state supercapacitors utilizing CNT-dispersed cobalt-bismuth-samarium ternary hydroxide on woven carbon fiber for enhanced energy storage

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Journal of Energy Chemistry 2024年第10期97卷 498-512,I0010页

作者： Fouzia Mashkoor Mohd Shoeb Hongjun Jeong Mohammad Naved Khan Changyoon Jeong school of mechanical engineering Yeungnam UniversityGyeongsanGyeongbuk 38541Republic of Korea

Multi-metal hydroxides possess unique physical and chemical properties,making them promising candidates for supercapacitor working *** their electrochemical performance can be achieved through a combination with carbon *** this study,we synthesized a composite material by hydrothermally dispersed 4,6,and 10 wt%carbon nanotubes(CNT)into ternary cobaltbismuth-samarium hydroxide(CoBiSm-TOH).These nanocomposites were employed as the material for the working electrode in a *** findings reveal that at 1.5 A/g,the specific capacitance of CNT3@CoBiSm-TOH,using a three-electrode system,was found to be 852.91 F/g,higher than that of CoBi-BOH,CoBiSm-TOH,CNT1@CoBiSm-TOH and CNT5@CoBiSm-TOH-measuring 699.69,750.34,789.54 and 817.79 F/g,***,CNT3@CoBiSm-TOH electrodes exhibited a capacitance retention of around 88%over 10,000 *** demonstrate practical applicability,CNT3@CoBiSm-TOH was grown on woven carbon fiber(WCF),and a solid-state supercapacitor device was developed using the VARTM(vacuum-assisted resin transfer molding).This device displayed a specific capacitance of 272.67 F/g at 2.25 A/***,it achieved a maximum energy density of 53.01 Wh/kg at a power density of 750 W/kg and sustained excellent cycle stability over 50,000 cycles,maintaining 70%of its initial *** results underscore the importance of interfacial nanoengineering and provide crucial insights for the development of future energy storage devices.

关键词： Ternary hydroxide Carbon nanotube Synergistic effect VARTM Supercapacitor

Numerical study on the filtration characteristics of fine particles in granular bed filter at high temperature

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Particuology 2024年第10期93卷 41-53页

作者： Kangning Zhu Jie Cai Yuan Li Xiaoyou Shen Jianfei Xi Yunjun Wang Zhongzhu Gu school of Energy and mechanical engineering Nanjing Normal UniversityNanjing210023China

Granular bed filter(GBF)has become one of the current research hot topics due to its excellent performance in removing fine *** this paper,a three-dimensional fixed bed GBF filtration model was established and its accuracy was ***,the GBF filtration performance at high temperature were *** results demonstrate that elevating the temperature diminishes the filtration efficiency,albeit to a limited *** increasing of inlet gas velocity can significantly improve pressure drop for GBF and the filtration efficiency for fine particles of sizes larger than 5μ*** the diameter of stacked granular particle diameter grows,the filtration efficiency and pressure drop *** density of fine particles almost does not affect the filtration efficiency for fine particles of 1∼7μm,but a higher density leads to a higher filtration efficiency for fine particles of sizes bigger than 9μ***,as the fine particles size increases,the change of the filtration efficiency roughly goes through three stages:Stage 1:the filtration efficiency is basically unchanged;Stage 2:the filtration efficiency increases rapidly;Stage 3:the filtration efficiency increases steadily,but the rate of increase slows *** the increase of the fine particles Stokes number,the filtration efficiency of GBF will pass through two phases of stabilization and rapid increase.

关键词： Granular bed filter Fine particles High temperature Filtration efficiency

Adaptive RISE Control of Winding Tension with Active Disturbance Rejection

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Chinese Journal of mechanical engineering 2024年第4期37卷 135-145页

作者： Junjie Mi Jianyong Yao Wenxiang Deng school of mechanical engineering Nanjing University of Science and TechnologyNanjing 210094China

A winding system is a time-varying system that considers complex nonlinear characteristics,and how to control the stability of the winding tension during the winding process is the primary problem that has hindered development in this field in recent *** nonlinear factors affect the tension in the winding process,such as friction,structured uncertainties,unstructured uncertainties,and external *** terms severely restrict the tension tracking *** tension control strategies are mainly based on the composite control of the tension and speed loops,and previous studies involve complex decoupling *** to the large number of calculations required for this method,it is inconvenient for practical engineering *** simplify the tension generation mechanism and the influence of the nonlinear characteristics of the winding system,a simpler nonlinear dynamic model of the winding tension was *** adaptive method was applied to update the feedback gain of the continuous robust integral of the sign of the error(RISE).Furthermore,an extended state observer was used to estimate modeling errors and external *** model disturbance term can be compensated for in the designed RISE *** asymptotic stability of the system was proven according to the Lyapunov stability ***,a comparative analysis of the proposed nonlinear controller and several other controllers was *** results indicated that the control of the winding tension was significantly enhanced.

关键词： Winding tension Continuous robust integral of the sign of the error(RISE)control Adaptive control Disturbance compensation Extended state observer(ESO) Tension control

Investigation on the Velocity-Dependent Adhesion Hysteresis via Molecular Dynamics Simulation

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Acta Mechanica Solida Sinica 2024年第3期37卷 423-429页

作者： Jinshan He Yiran Li Zhaoyang Ma Ganyun Huang Department of Mechanics School of Mechanical EngineeringTianjin UniversityTianjin300350China

Adhesion plays an important role in miniaturized devices and technologies,which depends not only on indentation depth but also on the history of contact making and breaking,giving rise to adhesion *** the present work,adhesion hysteresis has been investigated via molecular dynamics simulations on approaching and retracting a rigid tip to and from a *** results show that hysteresis in the force-displacement curve that depends on approaching and retraction velocities arises under both elastic and plastic *** underlying mechanisms have been *** implications of the results in friction have been discussed briefly.

关键词： Adhesion hysteresis Molecular dynamics simulation Contact instability Plastic deformation

Effect of Oxygen-Rich Combustion on Flame Propagation of Syngas in a Half-Open Pipe at Elevated Temperatures

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Journal of Thermal Science 2024年第5期33卷 1920-1934页

作者： LI Ningning DENG Haoxin XU Zhuangzhuang YAN Mengmeng WEI Shengnan SUN Guangzhen WEN Xiaoping GAN Haowen WANG Fahui school of mechanical and Power engineering Henan Polytechnic UniversityJiaozuo 454003China

The investigation of syngas flame propagation has great benefits for the effective use of gas *** essay sets out to study the flame propagation of premixed oxygen-rich combustion(oxygen enrichment coefficient in volumeΩ:0.21,0.27,0.32,0.37)of syngas(H_(2):CO=2:8)in half-closed rectangular ducts at elevated temperatures(T:300 K,400 K,500 K)and evaluate the effects of initial temperature and oxygen enrichment coefficient on the LBV from sensitivity analysis and kinetic *** paper presents the effect of the expansion effect on laminar burning velocity for the first time,and separates the effect of the expansion effect on laminar burning velocity by a new *** shows that as the initial temperature goes up,the faster the exponential growth phase of the flame front velocity,the slower the slow growth *** smaller and earlier the maximum flame front velocity arrives,the slower the average flame speed *** the oxygen enrichment coefficient goes up,the peak value of the flame front velocity gradually ***-rich combustion and increasing initial temperature inhibit flame propagation in a half-open tube,but promote laminar burning velocity,which increases the key chemical bond and adiabatic flame *** net reaction rate shows that oxygen-rich combustion mainly promotes the combustion reaction of H_(2)(R2).However,increasing the initial temperature mainly promoted the oxidation of CO(R29).Analysis of the reaction path showed that oxygen-rich combustion and increased initial temperature promoted the reaction of H_(2)and CO with key chemical bonds,increased OH concentration,and inhibited OH cracking reaction.

关键词： gas turbines oxyfuel combustion numerical simulation combustion kinetics fire and flame

Precision motion control for electro-hydraulic axis systems under unknown time-variant parameters and disturbances

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Chinese Journal of Aeronautics 2024年第1期37卷 463-471页

作者： Xiaowei YANG Yaowen GE Wenxiang DENG Jianyong YAO school of mechanical engineering Nanjing University of Science and TechnologyNanjing 210094China

This article focuses on asymptotic precision motion control for electro-hydraulic axis systems under unknown time-variant parameters,mismatched and matched *** from the traditional adaptive results that are applied to dispose of unknown constant parameters only,the unique feature is that an adaptive-gain nonlinear term is introduced into the control design to handle unknown time-variant *** both mismatched and matched disturbances existing in electro-hydraulic axis systems can also be addressed in this *** skillful integration of the backstepping technique and the adaptive control,a synthesized controller framework is successfully developed for electro-hydraulic axis systems,in which the coupled interaction between parameter estimation and disturbance estimation is ***,this designed controller has the capacity of low-computation costs and simpler parameter tuning when compared to the other ones that integrate the adaptive control and observer/estimator-based technique to dividually handle parameter uncertainties and ***,a nonlinear filter is designed to eliminate the“explosion of complexity”issue existing in the classical back-stepping *** stability analysis uncovers that all the closed-loop signals are bounded and the asymptotic tracking performance is also ***,contrastive experiment results validate the superiority of the developed method as well.

关键词： Adaptive control Asymptotic convergence Electro-hydraulic axis system Precision motion control Unknown time-variant parameters and disturbances

Prediction of undeformed chip thickness distribution and surface roughness in ultrasonic vibration grinding of inner hole of bearings

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Journal of Zhejiang University-Science A(Applied Physics & engineering) 2024年第4期25卷 311-323页

作者： Yanqin LI Daohui XIANG Guofu GAO Feng JIAO Bo ZHAO school of mechanical and Power engineering Henan Polytechnic UniversityJiaozuo 454000China

Ultrasonic vibration grinding differs from traditional grinding in terms of its material removal *** randomness of grain-workpiece interaction in ultrasonic vibration grinding can produce variable chips and impact the surface roughness of ***,previous studies used iterative method to calculate the unformed chip thickness(UCT),which has low computational *** this study,a symbolic difference method is proposed to calculate the *** UCT distributions are obtained to describe the stochastic interaction characteristics of ultrasonic grinding ***,the UCT distribution characteristics under different machining parameters are ***,a surface roughness prediction model is established based on the UCT ***,the correctness of the model is verified by *** study provides a quick and accurate method for predicting surface roughness in longitudinal ultrasonic vibration grinding.

关键词： Ultrasonic vibration grinding Undeformed chip thickness(UCT) Distribution characteristics Surface roughness

Bionic functional membranes for separation of oil-in-water emulsions

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Friction 2024年第9期12卷 1909-1928页

作者： Chaolang CHEN Ruisong JIANG Zhiguang GUO school of mechanical engineering Sichuan UniversityChengdu 610065China school of Materials Science and engineering Hubei UniversityWuhan 430062China

The separation of oil-in-water emulsion is an urgent challenge because its massive production and discharge from daily and industrial activities have caused severe hazards to the ecosystem and serious threats to human *** technology is considered an outstanding solution strategy for the separation of oil-in-water emulsions due to its unique advantages of low cost,high efficiency,easy operation,and environmental ***,the membrane is easily fouled by the emulsion oil droplets during the separation process,causing a sharp decline in permeation flux,which greatly inhibits the long-term use of the membrane and largely shortens the membrane’s ***,it was found that endowing the membranes with special wettability e.g.,superhydrophilic and superoleophobic can greatly enhance the permeability of the continuous water phase and inhibit the adhesion of oil droplets,thus promoting the separation performance and anti-oil-fouling property of membrane for oily *** this paper,we review and discuss the recent developments in membranes with special wettability for separating oil-in-water emulsions,including the mechanism analysis of emulsion separation membrane,membrane fouling issues,design strategies,and representative studies for enhancing the membrane’s anti-oil-fouling ability and emulsion separation performance.

关键词： bionic surface membranes wettability oil-in-water emulsions oil-water separation