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Adaptive Dead Zone Compensation Control Method for Electro-Hydrostatic Actuators Under Low-Speed Conditions

Chinese Journal of Mechanical engineering 2024年第6期37卷 199-211页

作者： Haoyi Jiang Zhenfei Ling Fengqi Zhou Maowen Sun Hao Liu Lilin Xu Yeming Yao Xiaoping Ouyang Huayong Yang State Key Laboratory of Fluid Power and Mechatronic Systems Zhejiang UniversityHangzhou 310027China Aviation Key Laboratory of Science and Technology on Aero Electromechanical System Integration Nanjing Engineering Institute of Aircraft SystemNanjing 210000China

This study proposes an accurate dead zone compensation control method for electro-hydrostatic actuators(EHAs)under low-speed ***,the nonlinear dead zone characteristics under low-speed conditions are summarized based on numerous EHA *** adaptive compensation function(ACF)is then constructed for the dead ***,this study proposes an adaptive dead zone compensation control method for EHAs by integrating the ACF with a virtual decomposition controller(VDC)based on the established EHA *** stability of the proposed control method is also ***,the proposed control method is verified using an EHA *** test results show that the dead zone trajectory tracking errors of EHAs are significantly reduced when combined with the ***,since most EHAs are controlled by adjusting the motor speed,the method presented in this study is simpler and easier to use than methods that employ flow compensation.

关键词： Electro-hydrostatic actuator Dead zone Compensation Control Low-speed

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Gaining Technological Autonomy and Social-emotional Support: A Case Study of How and Why Chinese Older Adults Engage with a Semi-acquaintance Online Community

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Proceedings of the ACM on Human-Computer Interaction 2024年第CSCW2期8卷 1-35页

作者： Qian, Zhigu Fu, Jiaojiao Zhou, Yangfan School of Computer Science Fudan University Shanghai Key Laboratory of Intelligent Information Processing Shanghai China School of Information Science and Engineering East China University of Science and Technology Shanghai China

Older adults are often underserved and marginalized in technology engagement due to their reluctance and the barriers they face in adopting and engaging with mainstream technology. However, Pinxiaoquan, a social feature of an e-commerce platform in China, has gained a large number of older users. This work investigates how and why Chinese older adults use Pinxiaoquan, aiming to unveil the underlying logic and inspire technology-inclusive design for older adults. To this end, we conducted a mixed-methods qualitative study over two years, which included online observation, and semi-interview. We found that Pinxiaoquan’s success among Chinese older adults is mainly due to its ability to inspire technological autonomy and provide social-emotional support. Rather than simply lowering technical barriers or asking them to seek assistance outside the platform, Pinxiaoquan builds a semi-acquaintance online community based on location and social ties that allows older adults to realize technical support mutually. Pinxiaoquan also fulfills their social-emotional needs, such as free online expression, memory creation and preservation, relationship expansion and maintenance, and a sense of value. Our research contributes to the HCI community by highlighting the importance of improving older adults’ technology autonomy following their specific social and cultural background and social-emotional needs. This work also provides unique insights and implications for building inclusive technology for the growing aging population. © 2024 Copyright held by the owner/author(s).

关键词： Marketplaces

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Simulation and Experiment of Windage Power Loss of A Shrouded Spiral Bevel Gears under Oil Injection Lubrication

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Chinese Journal of Mechanical engineering 2025年第2期38卷 413-432页

作者： Bo Li Kai Rong Xuyang Zhang Sanmin Wang U-Xuan Tan Xuanyuan Su Laifa Tao School of Mechanical Engineering Northwestern Polytechnical University Department of Engineering Product Development Singapore University of Technology and Design Hangzhou International Innovation Institute Beihang University National Key Laboratory of Science and Technology on Reliability and Environmental Engineering School of Reliability and Systems Engineering Beihang University

During high-speed rotation, the surface of aeronautic spiral bevel gears will generate significant pressure and viscous forces, which will cause a certain amount of windage power loss and reduce the efficiency of the transmission system. Based on the computational fluid dynamics, this paper analyzes the windage power loss of a single spiral bevel gear and a spiral bevel gear pair under oil injection lubrication. In addition, the shroud is used to suppress gear windage loss, and the clearance size and opening angle of the designed shroud are optimized. Finally, by comparing and analyzing the experimental results, the following conclusions were obtained:(1) For a single gear, the speed is the most important factor affecting windage loss, followed by the hand of spiral, and rotation direction;(2) For gear pairs, under oil injection lubrication, the input speed has the greatest impact on windage power loss, followed by the influence of oil injection port speed, temperature and oil injection port pressure;(3) Installing a shroud is an effective method to reduce windage power loss;(4) In the pure air phase, the smaller the clearance between the shroud and the gear surface, and the smaller the radial direction between the shroud and the shaft, the better the effect of reducing windage;(5) In the two-phase flow of oil and gas, it is necessary to design oil drainage holes on the shroud to ensure the smooth discharge of lubricating oil and improve the drag reduction effect.

关键词： Computational fluid dynamics (CFD) Oil injection lubrication Shroud Spiral bevel gear Windage power loss

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Designing Proportional-Integral Consensus Protocols for Second-Order Multi-Agent systems Using Delayed and Memorized State information

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IEEE/CAA Journal of Automatica Sinica 2024年第4期11卷 878-892页

作者： Honghai Wang Qing-Long Han the College of Information Science and Engineering State Key Laboratory of Synthetical Automation for Process IndustriesNortheastern UniversityShenyang 110819China the School of Science Computing and Engineering TechnologiesSwinburne University of TechnologyMelbourneVIC 3122Australia

This paper is concerned with consensus of a secondorder linear time-invariant multi-agent system in the situation that there exists a communication delay among the agents in the network.A proportional-integral consensus protocol is designed by using delayed and memorized state *** the proportional-integral consensus protocol,the consensus problem of the multi-agent system is transformed into the problem of asymptotic stability of the corresponding linear time-invariant time-delay *** that the location of the eigenvalues of the corresponding characteristic function of the linear time-invariant time-delay system not only determines the stability of the system,but also plays a critical role in the dynamic performance of the *** this paper,based on recent results on the distribution of roots of quasi-polynomials,several necessary conditions for Hurwitz stability for a class of quasi-polynomials are first *** allowable regions of consensus protocol parameters are *** necessary and sufficient conditions for determining effective protocol parameters are *** designed protocol can achieve consensus and improve the dynamic performance of the second-order multi-agent ***,the effects of delays on consensus of systems of harmonic oscillators/double integrators under proportional-integral consensus protocols are ***,some results on proportional-integral consensus are derived for a class of high-order linear time-invariant multi-agent systems.

关键词： Consensus protocol Hurwitz stability multi-agent systems quasi-polynomials time delay

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Radiative cooling for passive thermal management towards sustainable carbon neutrality

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National science Review 2023年第1期10卷 87-97页

作者： Jun Liang Jiawei Wu Jun Guo Huagen Li Xianjun Zhou Sheng Liang Cheng-Wei Qiu Guangming Tao Wuhan National Laboratory for Optoelectronics and Optics Valley Laboratory Huazhong University of Science and Technology Department of Electrical and Computer Engineering National University of Singapore MOE Key Laboratory of Thermo-Fluid Science and Engineering School of Energy and Power Engineering Xi'an Jiaotong University Key Laboratory of Education Ministry on Luminescence and Optical Information Technology National Physical Experiment Teaching Demonstration CenterDepartment of PhysicsSchool of Physical Science and Engineering Beijing Jiaotong University State Key Laboratory of Material Processing and Die &Mould Technology School of Materials Science and Engineering Huazhong University of Science and Technology

Photonic structures at the wavelength scale offer innovative energy solutions for a wide range of applications,from high-efficiency photovoltaics to passive cooling,thus reshaping the global energy *** cooling based on structural and material design presents new opportunities for sustainable carbon neutrality as a zero-energy,ecologically friendly cooling *** this review,in addition to introducing the fundamentals of the basic theory of radiative cooling technology,typical radiative cooling materials alongside their cooling effects over recent years are summarized and the current research status of radiative cooling materials is outlined and ***,technical challenges and potential advancements for radiative cooling are forecast with an outline of future application scenarios and development *** the future,radiative cooling is expected to make a significant contribution to global energy saving and emission reduction.

关键词： photonic structures radiative cooling energy saving and emission reduction carbon neutrality

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Enhancing Image Security With a Novel Chaotic System: A Focus on Multi-Face Image Encryption in Smart Applications

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IEEE Internet of Things Journal 2025年第12期12卷 20087-20098页

作者： Liu, Pengbo Teng, Lin Liu, Huipeng Iu, Herbert Ho-Ching Wang, Mingxu Yan, Xiaopeng Fu, Xianping Dalian Maritime University School of Information Science and Technology Dalian116026 China The University of Western Australia School of Electrical Electronic and Computer Engineering Perth6009 Australia Key Laboratory of Ministry of Fisheries and Education Dalian Ocean University College of Information Engineering Dalian Key Laboratory of Smart Fishery Liaoning Key Laboratory of Marine Information Technology Dalian116023 China

To ensure stringent security strategies for image information involving personal privacy during conveyance and storage, we propose an innovative multi-face privacy protection scheme based on chaos theory. Compared to single-face encryption algorithms, the proposed scheme has broader potential applications in fields such as smart cities and smart transportation. Specifically, a new spatiotemporal chaotic system named the sine-cosine coupled mapping lattice system (SCCML) is designed. It features a larger parameter domain, complexity, and profound unpredictability, yet maintains a simpler construction aimed at providing potential benefits and implementations in the field of information security. In the proposed multi-face privacy protection scheme, multiple faces within an image are rapidly and accurately identified and then encrypted using the proposed SCCML-based digital separation loop encryption algorithm. The encryption algorithm exhibits a synchronous scrambling diffusion mechanism. Additionally, the introduction of mixed multi-base cascade diffusion offers multiple layers of security for facial data, prevents diffusion singularity, and enhances diversity, making it significantly more challenging to crack. Experimental verification on a real multi-face image dataset shows that the algorithm is superior, practical, safe, and efficient. © 2014 IEEE.

关键词： Differential privacy

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MVCE-Net: Multi-View Region Feature and Caption Enhancement Co-Attention Network for Visual Question Answering

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Computers, Materials & Continua 2023年第7期76卷 65-80页

作者： Feng Yan Wushouer Silamu Yanbing Li School of Information Science and Engineering Xinjiang UniversityUrumqi830046China Xinjiang Key Laboratory of Multilingual Information Technology Urumqi830046China

Visual question answering(VQA)requires a deep understanding of images and their corresponding textual questions to answer questions about images more ***,existing models tend to ignore the implicit knowledge in the images and focus only on the visual information in the images,which limits the understanding depth of the image *** images contain more than just visual objects,some images contain textual information about the scene,and slightly more complex images contain relationships between individual visual ***,this paper proposes a model using image description for feature *** model encodes images and their descriptions separately based on the question-guided coattention *** mechanism increases the feature representation of the model,enhancing the model’s ability for *** addition,this paper improves the bottom-up attention model by obtaining two image region *** obtaining the two visual features and the spatial position information corresponding to each feature,concatenating the two features as the final image feature can better represent an ***,the obtained spatial position information is processed to enable the model to perceive the size and relative position of each object in the *** best single model delivers a 74.16%overall accuracy on the VQA 2.0 dataset,our model even outperforms some multi-modal pre-training models with fewer images and a shorter time.

关键词： Bottom-up attention spatial position relationship region feature self-attention

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Rail-Pillar Net:A 3D Detection Network for Railway Foreign Object Based on LiDAR

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Computers, Materials & Continua 2024年第9期80卷 3819-3833页

作者： Fan Li Shuyao Zhang Jie Yang Zhicheng Feng Zhichao Chen School of Electrical Engineering and Automation Jiangxi University of Science and TechnologyGanzhou341000China Jiangxi Provincial Key Laboratory of Maglev Technology Ganzhou341000China School of Information Engineering Jiangxi University of Science and TechnologyGanzhou341000China

Aiming at the limitations of the existing railway foreign object detection methods based on two-dimensional(2D)images,such as short detection distance,strong influence of environment and lack of distance information,we propose Rail-PillarNet,a three-dimensional(3D)LIDAR(Light Detection and Ranging)railway foreign object detection method based on the improvement of ***,the parallel attention pillar encoder(PAPE)is designed to fully extract the features of the pillars and alleviate the problem of local fine-grained information loss in PointPillars pillars ***,a fine backbone network is designed to improve the feature extraction capability of the network by combining the coding characteristics of LIDAR point cloud feature and residual ***,the initial weight parameters of the model were optimised by the transfer learning training method to further improve *** experimental results on the OSDaR23 dataset show that the average accuracy of Rail-PillarNet reaches 58.51%,which is higher than most mainstream models,and the number of parameters is 5.49 *** with PointPillars,the accuracy of each target is improved by 10.94%,3.53%,16.96%and 19.90%,respectively,and the number of parameters only increases by 0.64M,which achieves a balance between the number of parameters and accuracy.

关键词： Railway foreign object light detection and ranging(LiDAR) 3D object detection PointPillars parallel attention mechanism transfer learning

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Colloidal Synthesis of Semiconductor Films for Efficient Photoelectrochemical Hydrogen Generation

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Energy Material Advances 2023年第1期4卷 200-209页

作者： Akang Chen Xinyuan Li Jiale Wang Jiatao Zhang Beijing Key Laboratory of Construction-Tailorable Advanced Functional Materials and Green Applications Key Laboratory of Medical Molecule Science and Pharmaceutical EngineeringMinistry of Industry and Information TechnologyMOE Key Laboratory of Cluster ScienceSchool of Chemistry and Chemical EngineeringSchool of Materials Science&EngineeringBeijing Institute of TechnologyBeijing 100081China

The semiconductor-based photoanodes have shown great potential on photoelectrochemical(PEC)hydrogen *** to the pristine semiconductor,photoanodes fabricated with doped semiconductors exhibit modulated bandgap structure and enhanced charge separation efficiency,demonstrating improved optoelectronic *** this work,we develop a colloidal cation exchange(CE)strategy on versatile synthesis of heterovalent doped chalcogenide semiconductor thin films with high surface *** Ag-doped CdSe(CdSe:Ag)thin films as an example,the organized centimeter-scale CdSe:Ag films with nanometer-scale thickness(thickness around 80 nm,length×width around 1.5 cm×1.2 cm)exhibit enhanced optical absorbance ability and charge carrier density by tuning the energy levels of conduction and valence bands as well as improved electrical conductivity by Ag dopants compared to the pristine CdSe film obtained by the vapor-phase vacuum deposition *** the meantime,the surface roughness of the as-prepared semiconductor thin films is also increased with abundantly exposed active sites to facilitate accessibility to water for hydrogen generation and suppress photogenerated carrier *** CdSe:Ag film photoanodes exhibit superb PEC hydrogen generation performance with a photocurrent density of 0.56 mA/cm^(2) at 1.23 V versus reversible hydrogen electrode,which is nearly 3 times higher than the pristine CdSe *** work provides a new strategy on colloidal synthesis of photoelectrodes with modulated heterovalent doping and surface roughness for PEC applications.

关键词： roughness film synthesis

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Structure-performance relationship between denitration performance and catalytic interface morphologies of MnCeO_(x)/P84 catalytic filters

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Journal of Rare Earths 2025年第3期43卷 516-525,I0004页

作者： Bo Yang Yujie Lei Maosen Ni Liuying Wang Qiong Huang Mindong Chen Jiangsu Collaborative Innovation Center of Atmospheric Environment and Equipment Technology(CICAEET) Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution ControlSchool of Environmental Science and EngineeringNanjing University of Information Science&TechnologyNanjing210044China

MnCeO_(x)/P84 catalytic filters with spherical,flower-like,cubic and rod-like catalytic interfaces were synthesized respectively,and their catalytic activities in the NH_(3)-SCR reaction were *** MnCeO_(x)/P84 catalytic filter with spherical catalytic interfaces(recorded as S-MnCeO_(x)/P84)exhibits the best catalytic denitration *** NO_(x)removal efficiency of S-MnCeO_(x)/P84 reaches the highest value of 98.6%at 160℃when the catalyst loading is 100 g/m^(2).At the same time,S-MnCeO_(x)/P84 exhibits good SO_(2)resistance and stability,achieving a NO_(x)removal rate of 83%at 190℃with 30 ppm SO_(2).The characterization results illustrate that the MnCeO_x active component in S-MnCeO_(x)/P84 is present in weak crystalline states,tightly wrapped around the surface of the filter fiber,and uniformly dispersed,and the mesopore is the main pore structure of the S-MnCeO_(x)/P84,which can provide a channel for the catalytic reaction to *** the same time,transmission electron microscopy(TEM)characterization shows that y-MnO_(2)is the main form of MnO_(2)in the S-MnCeO_(x)/*** analysis of H_(2)temperature programmed reduction(H_(2)-TPR).NH_(3)temperature programmed desorption(NH_(3)-TPD)and in-situ diffuse reflectance infrared spectra(DRIFTS)show that S-MnCeO_(x)/P84 has good redox ability at 100-200℃and has abundant Lewis acid sites and Bronsteds acid sites,which provides an important guarantee for its superior low-temperature NH_(3)-SCR denitration performance.

关键词： Catalytic filter Nitrogen oxides(NO_x) Denitration Catalytic interface Rare earths

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