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From Concept to Field Trials: Design, Analysis, and Evaluation of a Novel Quadruped robot with Deformable Wheel-Foot Structure

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IEEE Transactions on robotics 2025年 41卷 3143-3161页

作者： Ju, Zhongjin Wei, Ke Xu, Yundou Yanshan University Parallel Robot and Mechatronic System Laboratory of Hebei Province Qinhuangdao066004 China Yanshan University Key Laboratory of Advanced Forging and Stamping Technology and Science Ministry of Education of China Qinhuangdao066004 China

This study introduces a novel quadruped robot, the TerraAdapt, furnished with an innovative deformable wheel-foot integrated structure. This unique design grants the robot the flexibility to alternate between wheeled and footed modes of locomotion, making it efficient in traversing diverse terrains, from smooth indoor floors to challenging outdoor landscapes laden with obstacles. The study delineates an in-depth design and analysis of the deformable wheel and its integrated wheel-foot structure using screw theory. We engineer a 2RRR-RP wheel-foot mode-switching mechanism by modifying a 2RRR spatial six-bar mechanism with an additional RP branch. This mechanism aids in seamless transitioning between different movement modes. Moreover, a 2RRR parallel structure is employed to construct the footed mode *** substantiate the viability and efficacy of the proposed design, we carry out extensive motion simulations and construct an experimental prototype for field testing. The field trials reveal the robot's adeptness in adapting to varied terrains, highlighting the possible advantages of incorporating the proposed deformable wheel into micro mobile robot designs. © 2004-2012 IEEE.

关键词： Machine design

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Experiment of 2×40Gbd PAM8 MISO-FSO system reinforced by high-speed optical signal coupling and precoder-shaped multi-level polar codes

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Optical and Quantum Electronics 2025年第1期57卷 1-18页

作者： Yang, Weiying Liu, Xiaoyu Xiao, Shilin Liu, Zhiyang The State Key Laboratory of Advanced Optical Communication System and Networks Shanghai Jiao Tong University Dongchuan Road Shanghai200240 China

This paper proposes and successfully demonstrates a high-speed optical signal coupling (HS-OSC) of 2x40Gbaud PAM8 with precoder-shaped multi-level polar codes (PS-MLPC) in a gain-oriented multiple-input single-output free space optical (MISO-FSO) system. With the pilot-based correction (PBC), the system gets a multi-path error (MPE) detecting and correcting module, which can minimize the MPE and achieve the gain-oriented HS-OSC. On the other hand, PS-MLPC is deployed in the MISO-FSO system to provide the non-uniform PAM-8 symbols and save the power budget. In the experiment, the PBC module is proven to ensure the HS-OSC process by comparing the captured waveforms. Results in the static FSO channel validate that the bit error rate (BER) of the MISO-FSO system is improved from 4.76×10-3 to below 10-5 and the PS-MLPC PAM-8 saves most 0.85 dB effective signal-to-noise ratio (ESNR). Under turbulent conditions, the gain-oriented MISO-FSO system not only enhances the mean ESNR of about 4.3–5.4 dB but also mitigates the standard deviation of ESNR by 40.6–61.4 %, on which the PS-MLPC provides a Q-factor gain of 1.17–1.64 dB. © The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature 2024.

关键词： Budget control

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A numerical method for predicting bursting strength of composite rocket motor case considering filament winding process-induced stress

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Chinese Journal of Aeronautics 2025年第2期38卷 505-518页

作者： Jiqiu LIANG Fei ZHAO Dan WU Anxin DING Hubei Key Laboratory of Advanced Aerospace Propulsion Technology Wuhan 430040China System Design Institute of Hubei Aerospace Technology Academy Wuhan 430040China School of Materials Science and Engineering Wuhan University of TechnologyWuhan 430070China State Key Laboratory of Advanced Technology for Materials Synthesis and Processing Wuhan University of TechnologyWuhan 430070China

A numerical method to predict the bursting strength of filament wound composite rocket motor case is proposed *** method can evaluate the longitudinal stress evolution of each composite layer as impregnated filaments with fiber tension are wound layer by layer,and consider the effects of accumulated stress and deformation during filament winding on the bursting strength of composite ***∅520 mm composite cases as a case study,the filament-winding-process-induced stress and deformation as well as progressive damage behavior are numerically predicted,followed by a comparison with experimental *** numerical results show that the predicted bursting pressures for composite cases manufactured on the mandrels with and without a flexible component are 14.20 MPa and 21.40 MPa,*** values exhibit slight deviation from the measured pressures of 13.50 MPa and 21.57 ***,the predicted damage locations,situated respectively in the dome and cylinder,agree well with the experimental *** observations indicate that use of flexible component reduces the load-bearing capacity of the ***,it validates the reliability and accuracy of the proposed numerical method in predicting the bursting strength of composite cases.

关键词： Composite case Fiber tension Bursting strengt hProgressive damage analysis Filament winding

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Spatial confinement of free-standing graphene sponge enables excellent stability of conversion-type Fe_(2)O_(3)anode for sodium storage

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Chinese Chemical Letters 2025年第3期36卷 544-549页

作者： Jun Dong Senyuan Tan Sunbin Yang Yalong Jiang Ruxing Wang Jian Ao Zilun Chen Chaohai Zhang Qinyou An Xiaoxing Zhang Hubei Key Laboratory for High-efficiency Utilization of Solar Energy and Operation Control of Energy Storage System Hubei University of TechnologyWuhan 430068China State Key Laboratory of New Textile Materials and Advanced Processing Technologies Wuhan Textile UniversityWuhan 430200China State Key Laboratory of Advanced Technology for Materials Synthesis and Processing Wuhan University of TechnologyWuhan 430070China Nanjing University of Aeronautics and Astronautics Nanjing 210016China

Conversion-type anode materials are highly desirable for Na-ion batteries(NIBs)due to their high theoretical ***,the active materials undergo severe expansion and pulverization during the sodiation,resulting in inferior cycling ***,a self-supporting three-dimensional(3D)graphene sponge decorated with Fe_(2)O_(3)nanocubes(rGO@Fe_(2)O_(3))is ***,the 3D graphene sponge with resilience and high porosity benefits to accommodate the volume expansion of the Fe_(2)O_(3)nanocubes and facilitates the rapid electrons/ions transport,enabling spatial confinement to achieve outstanding ***,the free-standing rGO@Fe_(2)O_(3)can be directly used as an electrode without additional binders and conductive additives,which helps to obtain a higher energy *** on the total mass of the rGO@Fe_(2)O_(3)material,the rGO@Fe_(2)O_(3)anode presents a specific capacity of 859 mAh/g at 0.1 A/*** also delivers an impressive cycling performance(327 mAh/g after 2000 cycles at 1 A/g)and a superior rate capacity(162mAh/g at 20 A/g).The coin-type Na_(3)V_(2)(PO_(4))_(3)@C//rGO@Fe_(2)O_(3)NIB exhibits an energy density of 265.3Wh/*** unique 3D ionic/electronic conductive network may provide new strategies to design advanced conversion-type anode materials for high-performance NIBs.

关键词： Conversion-type anode Spatial confinement Fe_(2)O_(3) Graphene network Self-supporting Sodium-ion batteries

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High-precision trajectory calibration for robot surface machining by meta-heuristic search algorithm from local error in machining area

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International Journal of advanced Manufacturing Technology 2025年第5期138卷 2281-2295页

作者： Bi, Guangde Lu, Lei Zhang, Lei Fan, Cheng Sun, Lining School of Mechanical and Electric Engineering Jiangsu Provincial Key Laboratory of Advanced Robotics Soochow University Suzhou215123 China State Key Laboratory of Robotics and System Harbin Institute of Technology Harbin150001 China

Industrial robots used in complex surface machining are gradually increasing because of their high flexibility and large workspace. However, due to their low geometric accuracy, their application in high-precision surface machining is hindered. In order to improve the machining accuracy, a high-precision robot trajectory calibration method for complex surface machining is proposed. In the machining process, the machining trajectory is usually only within a certain machining area. In the method, high-precision standard balls are set at the boundary of the machining area. Based on the precise position information of these standard balls, the trajectory of the robot in the machining area is calibrated. Compared with the global robot calibration method, the proposed method can calibrate the robot trajectory in the machining area through standard parts, which will improve the trajectory accuracy of the machining robot to the level of repeated positioning accuracy. In this method, a large amount of standard ball data is obtained by the in-place measuring device before the machining process. Then, based on these data, a meta-heuristic search algorithm is used to calibrate the kinematic deviation of the robot measurement and the machining system. The trajectory of the machining robot is adjusted by the kinematic deviation after calibration, and it is applied to the motion control of the machining process to improve the positioning accuracy of the machining trajectory. In the end, to verify the accuracy and practicability of the machining trajectory obtained by this method, measurement and machining experiments are carried out. © The Author(s), under exclusive licence to Springer-Verlag London Ltd., part of Springer Nature 2025.

关键词： Industrial robots

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Main Protection Optimization Scheme for Generator Parallel Operation of Rotating Asynchronous Machine in Nuclear Power Plants

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IEEE Transactions on Power Delivery 2025年第3期40卷 1480-1492页

作者： Wang, Yikai Xu, Chaozheng Qiao, Jian Dai, Zhihui Tan, Liming Yin, Xianggen State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources Baoding071003 China State Grid Hunan Electric Power Company Limited Research Institute Changsha410208 China Huazhong University of Science and Technology State Key Laboratory of Advanced Electromagnetic Technology Wuhan430074 China

The Rotating Asynchronous Machine (RAM) system of a nuclear power plant provides a stable and reliable power supply for the control rod drive mechanism (CRDM) through two parallel generators. At present, the main protection of the generators in the RAM system is only configured with longitudinal differential protection, which cannot reflect the interturn short circuit fault and interbranch short circuit fault of the stator winding. Based on the characteristics of parallel connection of RAM generators in nuclear power plants, this article proposes a dual-generator split phase transverse differential protection and a dual-generator incomplete longitudinal differential protection. Through the internal fault set of the generator and the internal fault potential splitting model of the generator, the quantitative analysis of different main protection configuration schemes is carried out. It is concluded that the existing longitudinal differential protection and the incomplete longitudinal differential protection of two parallel generators can correctly reflect the vast majority of internal short-circuit faults. Finally, the dynamic experiment is carried out to prove the feasibility of the protection method in the actual unit operation. © 1986-2012 IEEE.

关键词： Nuclear power plants

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Experimental Study on Geometry Characteristics of Turbulent Premixed Flames for Natural Gas/Air Mixtures

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Journal of Thermal Science 2025年第1期34卷 268-282页

作者： ZHENG Weilin WANG Qijiao XIAO Huahua CHEN Xiaoxiao XIE Fan ZENG Wen Liaoning Key Lab of Advanced Test Technology for Aerospace Propulsion System Shenyang Aerospace UniversityShenyang 110136China State Key Laboratory of Fire Science University of science and Technology of ChinaHefei 230027China AVIC Shenyang Aircraft Design and Research Institute Shenyang 110035China

In this study,focusing on the geometry characteristics of spherical expanding flame,the turbulent premixed flames of natural gas/air mixtures were investigated in a fan-stirred turbulent *** effects of initial temperature(T=300-400 K),initial pressure(P=0.1-0.3 MPa),turbulence intensity(u'=1.0-2.7 m/s),oxygen volumetric percentage(φ(O_(2))=15%-21%)and carbon dioxide volumetric percentage(φ(CO_(2))=0-20%)were delved *** flame profile under the Cartesian coordinate system was derived from the schlieren images taken by the high-speed ***,from both macroscopic and microscopic perspectives,the influence of experimental conditions on the flame geometry characteristics was explored through flame front extraction,wavelet decomposition and network *** results demonstrate that for significant flame wrinkling,changes in species concentrations and turbulence intensity have more pronounced effects on the flame wrinkling *** wrinkling of the flame front maintains a certain degree of similarity,as evidenced by the locally concentrated distribution of the angles of the maximum fluctuation *** disturbance energy under large-scale(D6-D8)disturbances exhibits relatively high values with a similar trend,exerting a significant impact on the geometry characteristics of the flame *** peaks of correlation degree are scattered either with the decomposition scale or the development of flame radius,indicating no linear correlation between different detail ***,the probability distribution of node degrees in key wrinkled regions exhibits different trends with that of large-scale wrinkling and disturbance energy,especially with changes in initial *** occurs because the number of key wrinkles varies based on the perturbation's strength or the region's ***,an increase in the fluctuation frequency of the flame's local radius may not necessarily lead to an increase in the number of key folded regions.

关键词： geometry characteristics large-scale wrinkling wavelet decomposition network topology fan-stirred turbulent combustor

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Radio Environment Map Reconstruction Via Tensor Completion: Bayesian and Semantic Approaches

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IEEE Transactions on Vehicular Technology 2025年第5期74卷 7897-7913页

作者： Wang, Xuegang Wang, Fanggang He, Boxiang Beijing Jiaotong University State Key Laboratory of Advanced Rail Autonomous Operation Frontiers Science Center for Smart High-Speed Railway System School of Electronics and Information Engineering Beijing100044 China

The radio environment map (REM) is one of the representations of the wireless environments, which consists of the spectrum data and enables the users to understand the electromagnetic situation in temporal, spectral and spatial domains. Generally, the observations of the spectrum data are incomplete due to the insufficient acquisition capability, and even the observed ones could be corrupted by some interferences and white noises. In this paper, we model the REM in all domains using the tensor notation, and propose a Bayesian and a deep-learning approaches to complete the spectrum map from the incomplete and corrupted observed spectrum data. In the first approach, by using the Tucker decomposition on the spectrum tensor, a hierarchical Bayesian framework is modeled to characterize the core tensor, the factor matrices, and the other nuisances. These nodes and their distribution parameters serve as the latent variables in the model. The variational Bayesian method is adopted to compute the posterior probabilities in an iterative manner. Regarding the low-rank property and the correlation of the spectrum, an adaptive compressed tensor decomposition algorithm is proposed to denoise the recovered spectral map in each iteration. In the second approach, the spectrum blanks are initialized by the linear interpolation to obtain the initial complete spectrum tensor. We use the Vision Transformer to solve a semantic segmentation problem in order to identify the semantic regions of the spectrum map in which the power of one emitter dominates. Then, the tensor completion is performed in the individual semantic tensor using the proposed compression algorithm. At last, the simulation results show that both the proposed approaches outperform the existing ones. We further observe that the semantic approach outperforms the Bayesian one for the sparse emitter scenarios while the Bayesian approach exhibits better recovery accuracy as the density of the emitters increases in the normali

关键词： Bayesian networks

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Unveiling the confined dispersion mechanism of nanomaterials by stereocomplex cross-linked networks in polylactic acid

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Journal of Materials Science and Technology 2025年 235卷 293-301页

作者： Su, Xiaolong Pan, Qingchun Zhai, Yaling Jia, Chao Wang, Jinqi Xu, Zhe Li, Jiaxin Zhao, Jian Xiang, Hengxue Wei, Xiaoding Zhu, Meifang State Key Laboratory of Advanced Fiber Materials College of Material Science and Engineering Donghua University Shanghai201620 China State Key Laboratory for Turbulence and Complex System Department of Mechanics and Engineering Science College of Engineering Beijing Innovation Center for Engineering Science and Advanced Technology Peking University Beijing100871 China College of Material Science and Engineering Xinjiang University Urumqi830046 China

Nanomaterials are extensively utilized in a multitude of sectors, but their propensity to aggregate can considerably diminish the efficacy of functional materials. A pivotal challenge in this domain is achieving a homogenous distribution of nanomaterials, which is essential for enhancing their performance while also reducing production costs. In this work, we achieve uniform and stable dispersion of various nanomaterials through the confinement effect generated by the stereocomplex cross-linked network formed by the combination of poly (L-lactic) acid and poly (D-lactic) acid. The unique confinement effect of polylactic acid (PLA) isomers is universal and significantly enhances the dispersion of nanomaterials in both PLA solutions and films. To demonstrate the efficacy of our approach, we disperse aggregation-induced emission (AIE) molecules within PLA, which leads to the production of PLA films exhibiting improved fluorescence property. This work provides an effective solution for the preparation of nanocomposite materials that are both high-performing and cost-efficient. © 2025

关键词： Nanoclay

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Atomically thin MoS_(2)with ultra-low friction properties based on strong interface interaction

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Friction 2025年第4期13卷 139-148页

作者： Xinjian He Tongtong Yu Zishuai Wu Changhe Du Haoyu Deng Yongkang Zhao Shuang Li Yange Feng Liqiang Zhang Zhinan Zhang Daoai Wang State Key Laboratory of Solid Lubrication Lanzhou Institute of Chemical PhysicsChinese Academy of SciencesLanzhou 730000China Center of Materials Science and Optoelectronics Engineering University of ChineseAcademy of SciencesBeijing 100049China Shandong Laboratory of Advanced Materials and Green Manufacturing at Yantai Yantai 265503China State Key Laboratory of Mechanical System and Vibration Shanghai Jiao Tong UniversityShanghai 200240China Qingdao Center of Resource Chemistry and New Materials Qingdao 266100China

Atomically thin lubrication materials with anti-friction properties are crucial for reducing energy consumption and extending the servicelifeofmicro/nanoelectromechanical systems(MEMS/NEMS).However,achieving atomically thin films with ultra-low friction properties at the atomic/nanoscale even at the micrometer scale presents significant *** this study,large-size and high-quality monolayer MoS_(2)(ML MoS_(2))was grown on SiO2/Si substrate by chemical vapor deposition(CVD)*** with mechanically exfoliated ML MoS_(2),the CVD-grown ML MoS,(CVD-MoS_(2))exhibits an ultra-lower friction coefficient(0.00904).Based on the stick-slip effect and Prandtl-Tomlinson(P-T)model,the reduction of puckering effect indicates stronger interaction and lower interface potential barrier in tip,CVD-MoS_(2),and SiO,/Si substrate ***,combining with the density functional theory calculations,the stronger interface adhesion and higher overall charge redistribution degree of CVD-MoS_(2)can also be used to explain its ultralow friction *** work will provide theoretical guidance for designing ultra-thin lubricating materials with ultra-low friction properties.

关键词： chemical vapor deposition(CVD) MoS_(2) ultra-thin ultra-low friction interface interaction

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