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Disturbances rejection optimization based on improved two-degree-of-freedom LADRC for permanent magnet synchronous motor systems

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Defence Technology（防务技术） 2024年第3期33卷 518-531页

作者： Chenggang Wang Jianhu Yan Wenlong li liang Shan Le Sun School of Automation Nanjing University of Science and TechnologyNanjing 210094China

Permanent magnet synchronous motor(PMSM)speed control systems with conventional linear active disturbance rejection control(CLADRC)strategy encounter issues regarding the coupling between dynamic response and disturbance suppression and have poor performance in suppressing complex nonlinear *** order to address these issues,this paper proposes an improved two-degree-of-freedom LADRC(TDOF-LADRC)strategy,which can enhance the disturbance rejection performance of the system while decoupling entirely the system's dynamic and anti-disturbance performance to boost the system robustness and simplify controller parameter *** models that consider total disturbances are developed to design the TDOF-LADRC speed controller ***,to evaluate the control performance of the TDOF-LADRC strategy,its stability is proven,and the influence of each controller parameter on the system control performance is *** on it,a comparison is made between the disturbance observation ability and anti-disturbance performance of TDOF-LADRC and CLADRC to prove the superiority of TDOF-LADRC in rejecting ***,experiments are performed on a 750 W PMSM experimental platform,and the results demonstrate that the proposed TDOF-LADRC exhibits the properties of two degrees of freedom and improves the disturbance rejection performance of the PMSM system.

关键词： Permanent magnet synchronous motor(PMSM) Active disturbance rejection control(ADRC) Disturbance observer Two-degree-of-freedom control Anti-disturbance

MP-3 microperimeter in early primary open angle glaucoma with a new pattern

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International Journal of Ophthalmology(English edition) 2024年第5期17卷 861-868页

作者： Shuang liang li-Tao Wang Xiao-li liu Jia-liang Duan Dan-Yan liu Department of Ophthalmology of the Second Hospital of Hebei Medical University Shijiazhuang 050000Hebei ProvinceChina Department of Ophthalmology Shijiazhuang People’s HospitalShijiazhuang 050000Hebei ProvinceChina

AIM:To investigate macular microperimetry in patients with early primary open angle glaucoma(POAG)using a new custom-made pattern,and analyze the characteristics of macular ***:This case-control study included 38 patients with POAG,who were divided into pre-perimetric glaucoma(18 eyes of 18 patients),early-stage(20 eyes of 20 patients),and control(20 eyes of 20 patients)*** subjects underwent standard 24-2 humphrey visual field *** MP-3 microperimeter with a new custom-made pattern(28 testing points distributed in four quadrants,covering the central 10°of the retina)was used to evaluate macular *** cell complex(GCC)thicknesses were examined using an RS-3000 Advance OCT *** features of structure and function were analysed per ***:The pre-perimetric glaucoma group had significantly lower inferior hemifield macular sensitivity compared to controls(Plier than conventional perimetry,particularly in pre-perimetric glaucoma cases in which it might be undetectable by conventional me

关键词： early primary open angle glaucoma macular sensitivity microperimetry optical coherence tomography ganglion cell complex

Revealing the key role of non-solvating diluents for fast-charging and low temperature li-ion batteries

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Journal of Energy Chemistry 2024年第7期94卷 171-180页

作者： Yuping Zhang Siyin li Junkai Shi Jiawei Lai Ziyue Zhuang Jingwen liu Wenming Yang liang Ma Yue-Peng Cai Jijian Xu Qifeng Zheng School of Chemistry Guangzhou Key Laboratory of Materials for Energy Conversion and StorageSouth China Normal UniversityGuangzhou 510006GuangdongChina Guangzhou Foreign Language School Guangzhou 511455GuangdongChina Department of Chemistry City University of Hong KongHong Kong 999077China

Fast-charging and low temperature operation are of vital importance for the further development of lithium-ion batteries(liBs),which is hindered by the utilization of conventional carbonate-based electrolytes due to their slow kinetics,narrow operating temperature and voltage ***,an acetonitrile(AN)-based localized high-concentration electrolyte(LHCE)is proposed to retain liquid state and high ionic conductivity at ultra-low temperatures while possessing high oxidation *** originally reveal the excellent thermal shielding effect of non-solvating diluent to prevent the aggregation of li^(+) solvates as temperature drops,maintaining the merits of fast li transport and facile desolvation as at room temperature,which bestows the graphite electrode with remarkable low temperature performance(264 mA h g^(-1) at-20 C).Remarkably,an extremely high capacity retention of 97%is achieved for high-voltage high-energy graphite||NCM batteries after 250 cycles at-20 C,and a high capacity of 110 mA h g^(-1)(71%of its room-temperature capacity)is retained at-30°*** study unveils the key role of the non-solvating diluents and provides instructive guidance in designing electrolytes towards fast-charging and low temperature liBs.

关键词： li-ion battery Fast-charging Low temperature Non-solvating diluent Shielding effect

Flow characteristics and hot workability of a typical low-alloy high-strength steel during multi-pass deformation

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International Journal of Minerals,Metallurgy and Materials 2024年第2期31卷 323-336页

作者： Mingjie Zhao lihong Jiang Changmin li liang Huang Chaoyuan Sun Jianjun li Zhenghua Guo School of Aeronautical Manufacturing Engineering Nanchang Hangkong UniversityNanchang 330063China Jiangxi Key Laboratory of Forming and Joining Technology for Aerospace Components Nanchang Hangkong UniversityNanchang 330063China State Key Laboratory of Materials Processing and Die&Mould Technology School of Materials Science and EngineeringHuazhong University of Science and TechnologyWuhan 430074China China National Erzhong Group Deyang Wanhang Die Forging Co.LTD. Deyang 618000China Hubei Huangshi Mold Industrial Technology Research Institute Huangshi 435007China

Heavy components of low-alloy high-strength(LAHS) steels are generally formed by multi-pass forging. It is necessary to explore the flow characteristics and hot workability of LAHS steels during the multi-pass forging process, which is beneficial to the formulation of actual processing parameters. In the study, the multi-pass hot compression experiments of a typical LAHS steel are carried out at a wide range of deformation temperatures and strain rates. It is found that the work hardening rate of the experimental material depends on deformation parameters and deformation passes, which is ascribed to the impacts of static and dynamic softening behaviors. A new model is established to describe the flow characteristics at various deformation passes. Compared to the classical Arrhenius model and modified Zerilli and Armstrong model, the newly proposed model shows higher prediction accuracy with a confidence level of 0.98565. Furthermore, the connection between power dissipation efficiency(PDE) and deformation parameters is revealed by analyzing the microstructures. The PDE cannot be utilized to reflect the efficiency of energy dissipation for microstructure evolution during the entire deformation process, but only to assess the efficiency of energy dissipation for microstructure evolution in a specific deformation parameter *** a result, an integrated processing map is proposed to better study the hot workability of the LAHS steel, which considers the effects of instability factor(IF), PDE, and distribution and size of grains. The optimized processing parameters for the multi-pass deformation process are the deformation parameters of 1223–1318 K and 0.01–0.08 s^(-1). Complete dynamic recrystallization occurs within the optimized processing parameters with an average grain size of 18.36–42.3 μm. This study will guide the optimization of the forging process of heavy components.

关键词： low-alloy high-strength steel work hardening rate constitutive model hot workability multi-pass deformation

Mechanism of capture section affecting an intake for atmosphere-breathing electric propulsion

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Chinese Journal of Aeronautics 2024年第1期37卷 51-63页

作者： Siyuan ZHANG Jinyuan YANG Cheng li Haolin li liwei ZHANG liang DING Anbang SUN State Key Laboratory of Electrical Insulation and Power Equipment School of Electrical EngineeringXi’an Jiaotong UniversityXi’an 710049China China Academy of Aerospace Science and Innovation Beijing 100049China

Atmosphere-Breathing Electric Propulsion(ABEP)can compensate for lost momentum of spacecraft operating in Very Low Earth Orbit(VLEO)which has been widely concerned due to its excellent commercial *** is a key technology to improve the capture efficiency of intakes,which collect and compress the atmosphere for *** this paper,the mechanism of the capture section affecting capture efficiency is investigated by Test Particle Monte Carlo(TPMC)simulations with 3D intake *** inner surface smoothness and average collision number are determined to be key factors affecting capture efficiency,and a negative effect growth model is accordingly *** the inner surface smoothness is less than 0.2,the highest capture efficiency and its corresponding average collision number interval are independent of the capture section’s geometry and its mesh *** the inner surface smoothness is higher than 0.2,the capture efficiency will decrease by installing any capture *** on the present results,the manufacturing process and material selection are suggested to be prioritized during the intake geometry design in engineering ***,the highest capture efficiency can be achieved by adjusting the length and mesh size of the capture section.

关键词： Atmosphere-breathing electric propulsion Capture efficiency Capture section Intake Test particle Monte Carlo Very low earth orbit

Research on Gait Trajectory Planning of Wall-Climbing Robot Based on Improved PSO Algorithm

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Journal of Bionic Engineering 2024年第4期21卷 1747-1760页

作者： Jian li Xianlin Shi Peng liang Yanjun li Yilin Lv Mingyue Zhong Zezhong Han School of Mechanical and Automotive Engineering Guangxi University of Science and TechnologyLiuzhou545006China

In order to reduce the labor intensity of high-altitude workers and realize the cleaning and maintenance of high-rise building exteriors,this paper proposes a design for a 4-DOF bipedal wall-climbing bionic robot inspired by the inchworm’s *** robot utilizes vacuum adsorption for vertical wall attachment and legged movement for *** enhance the robot’s movement efficiency and reduce wear on the adsorption device,a gait mimicking an inchworm’s movement is planned,and foot trajectory planning is performed using a quintic polynomial *** velocity constraints,foot trajectory optimization is achieved using an improved Particle Swarm Optimization(PSO)algorithm,determining the quintic polynomial function with the best fitness through ***,through comparative experiments,the climbing time of the robot closely matches the simulation results,validating the trajectory planning method’s accuracy.

关键词： Bionic robot Wall-climbing robot PSO Gait planning Trajectory planning

Engineering FeOOH/Ni(OH)_(2) heterostructures on Ni_(3)S_(2)surface to enhance seawater splitting

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Rare Metals 2024年第5期43卷 1989-1998页

作者： Chen Yang Ya-Dong li li-Juan Cao Xi-Long Wang Han-Pu liang Qingdao Institute of Bioenergy and Bioprocess Technology Chinese Academy of SciencesQingdao 266101China Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049China Sino-Danish College University of Chinese Academy of SciencesBeijing 100049China

The construction of highly stable and efficient electrocatalysts is desirable for seawater splitting but remains challenging due to the high concentration of Cl-in ***,FeOOH/Ni(OH)_(2)heterostructure supported on Ni_(3)S_(2)-covered nickel foam(Fe–Ni/Ni_(3)S_(2)/NF)was fabricated by hydrothermal and etching methods,as well as anodic oxidation *** electronic structure of FeOOH and Ni(OH)_(2)could be modulated after depositing FeOOH nanoparticles on Ni(OH)_(2)nanosheet,which greatly boosted the catalytic *** the catalyst used as an electrode for oxygen evolution reaction(OER),it needed low overpotentials of 266 and 368 m V to achieve current densities of 100 and 800 m A·cm^(-2),respectively,in 1 mol·L^(-1)KOH+seawater *** can operate continuously at 100 m A·cm^(-2)for 400 h without obvious ***,in situ generated SO_(4)^(2-)from inner Ni_(3)S_(2)during electrolysis process would accumulate on the surface of active sites to form passivation layers to repel Cl^(-),which seemed to be responsible for superior *** study not only synthesizes an OER catalyst for highly selective and stable seawater splitting,but also gives a novel approach for industrial hydrogen production.

关键词： Anodic oxidation Heterostructure Oxygen evolution reaction Seawater splitting

HWD-YOLO:A New Vision-Based Helmet Wearing Detection Method

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Computers, Materials & Continua 2024年第9期80卷 4543-4560页

作者： licheng Sun Heping li liang Wang College of Information Science and Technology Beijing University of TechnologyBeijing100124China Chinese Institute of Coal Science Beijing100013China State Key Laboratory for Intelligent Coal Mining and Strata Control Beijing100013China Engineering Research Center of Digital Community of Ministry of Education Beijing100124China

It is crucial to ensure workers wear safety helmets when working at a workplace with a high risk of safety accidents,such as construction sites and mine *** existing methods can achieve helmet detection in images,their accuracy and speed still need improvements since complex,cluttered,and large-scale scenes of real workplaces cause server occlusion,illumination change,scale variation,and perspective ***,a new safety helmet-wearing detection method based on deep learning is ***,a new multi-scale contextual aggregation module is proposed to aggregate multi-scale feature information globally and highlight the details of concerned objects in the backbone part of the deep neural ***,a new detection block combining the dilate convolution and attention mechanism is proposed and introduced into the prediction *** block can effectively extract deep featureswhile retaining information on fine-grained details,such as edges and small ***,some newly emerged modules are incorporated into the proposed network to improve safety helmetwearing detection performance *** experiments on open dataset validate the proposed *** reaches better performance on helmet-wearing detection and even outperforms the state-of-the-art *** be more specific,the mAP increases by 3.4%,and the speed increases from17 to 33 fps in comparison with the baseline,You Only Look Once(YOLO)version 5X,and themean average precision increases by 1.0%and the speed increases by 7 fps in comparison with the YOLO version *** generalization ability and portability experiment results show that the proposed improvements could serve as a springboard for deep neural network design to improve object detection performance in complex scenarios.

关键词： Object detection deep learning safety helmet wearing detection feature extraction attention mechanism

Research on Site Planning of Mobile Communication Network

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Computers, Materials & Continua 2024年第8期80卷 3243-3261页

作者： Jiahan He Guangjun liang Meng li KefanYao Bixia Wang Lu li Department of Computer Information and Cyber Security Jiangsu Police InstituteNanjing210000China Engineering Research Center of Electronic Data Forensics Analysis Nanjing210000China Key Laboratory of Digital Forensics Department of Public Security of Jiangsu ProvinceNanjing210000China Basic Course Teaching and Research Department Jiangsu Police InstituteNanjing210000China Communication and Signal College Nanjing Railway Vocational and TechnicalNanjing210000China

In this paper,considering the cost of base station,coverage,call quality,and other practical factors,a multi-objective optimal site planning scheme is ***,based on practical needs,mathematical modeling methods were used to establish mathematical expressions for the three sub-objectives of cost objectives,coverage objectives,and quality ***,a multi-objective optimization model was established by combining threshold and traffic volume *** order to reduce the time complexity of optimization,a non-dominated sorting genetic algorithm(NSGA)is used to solve the multi-objective optimization problem of site ***,a strategy for clustering and optimizing weak coverage areas was *** order to avoid redundant neighborhood retrieval during cluster expansion,the Fast Density-Based Spatial Clustering of Applications with Noise(FDBSCAN)clustering method was *** different sub-objectives as the main objectives,this paper obtained the distribution map of weak coverage areas before and after the establishment of new base stations,as well as relevant site planning maps,and provided three planning schemes for different main *** simulation results show that the traffic coverage of the three station planning schemes is above 90%.The change in the main optimization objective will result in a significant difference between the cost of the three solutions and the coverage of weak coverage points.

关键词： Siting of station multi-objective optimization genetic algorithm NSGA general greed FDBSCAN cluster