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Biomimetic soft robotic wrist with 3-DOF motion and stiffness tunability based on ring-reinforced pneumatic actuators and a particle jamming joint

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Science China(Technological Sciences) 2024年第3期67卷 774-790页

作者： HU TeTe LU XinJiang YI Jian wang yuhui XU Du State Key Laboratory of Precision Manufacturing for Extreme Service Performance School of Mechanical and Electrical EngineeringCentral South UniversityChangsha 410083China

The human wrist, a complex articulation of skeletal muscles and two-carpal rows, substantially contributes to improvements in maneuverability by agilely performing three-degree-of-freedom(3-DOF) orienting tasks and regulating stiffness according to variations in interaction forces. However, few soft robotic wrists simultaneously demonstrate dexterous 3-DOF motion and variable stiffness;in addition, they do not fully consider a soft-rigid hybrid structure of integrated muscles and two carpal *** this study, we developed a soft-rigid hybrid structure to design a biomimetic soft robotic wrist(BSRW) that is capable of rotating in the x and y directions, twisting around the z-axis, and possessing stiffness-tunable capacity. To actuate the BSRW, a lightweight soft-ring-reinforced bellows-type pneumatic actuator(SRBPA) with large axial, linear deformation(η_(lcmax)=70.6%,η_(lemax)=54.3%) and small radial expansion(η_(demax)=3.7%) is designed to mimic the motion of skeletal muscles. To represent the function of two-carpal rows, a compact particle-jamming joint(PJJ) that combines particles with a membrane-covered ballsocket mechanism is developed to achieve various 3-DOF motions and high axial load-carrying capacity(>60 N). By varying the jamming pressure, the stiffness of the PJJ can be adjusted. Finally, a centrally positioned PJJ and six independently actuated SRBPAs, which are in an inclined and antagonistic arrangement, are sandwiched between two rigid plates to form a flexible,stable, and compact BSRW. Such a structure enables the BSRW to have a dexterous 3-DOF motion, high load-carrying ability,and stiffness tunability. Experimental analysis verify 3-DOF motion of BSRW, producing force of 29.6 N and 36 N and torque of2.2 Nm in corresponding rotations. Moreover, the range of rotational angle and stiffness-tuning properties of BSRW are studied by applying jamming pressure to the PJJ. Finally, a system combining a BSRW and a soft enclosing gripper is proposed to demo

关键词： pneumatic soft actuators particle jamming robotic wrist soft robotics stiffness-tunable

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Autonomous multi-drone racing method based on deep reinforcement learning

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Science China(Information Sciences) 2024年第8期67卷 35-48页

作者： Yu KANG Jian DI Ming LI Yunbo ZHAO yuhui wang Department of Automation University of Science and Technology of China Institute of Advanced Technology University of Science and Technology of China Institute of Artificial Intelligence Hefei Comprehensive National Science Center College of Automation Engineering Nanjing University of Aeronautics and Astronautics

Racing drones have attracted increasing attention due to their remarkable high speed and excellent maneuverability. However, autonomous multi-drone racing is quite difficult since it requires quick and agile flight in intricate surroundings and rich drone interaction. To address these issues, we propose a novel autonomous multi-drone racing method based on deep reinforcement learning. A new set of reward functions is proposed to make racing drones learn the racing skills of human experts. Unlike previous methods that required global information about tracks and track boundary constraints, the proposed method requires only limited localized track information within the range of its own onboard sensors. Further, the dynamic response characteristics of racing drones are incorporated into the training environment, so that the proposed method is more in line with the requirements of real drone racing scenarios. In addition, our method has a low computational cost and can meet the requirements of real-time racing. Finally, the effectiveness and superiority of the proposed method are verified by extensive comparison with the state-of-the-art methods in a series of simulations and real-world experiments.

关键词： racing drone autonomous multi-drone racing sim-to-real deep reinforcement learning Markov game

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A comprehensive review on surface modifications of black phosphorus using biological macromolecules

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Frontiers of Materials Science 2024年第2期18卷 37-59页

作者： Chaiqiong Guo Xuhong He Xuanyu Liu yuhui wang Yan Wei Ziwei Liang Di Huang Department of Biomedical Engineering Research Center for Nano-biomaterials&Regenerative MedicineCollege of Biomedical EngineeringTaiyuan University of TechnologyTaiyuan 030024China Shanxi-Zheda Institute of Advanced Materials and Chemical Engineering Taiyuan 030032China

Black phosphorus(BP),a novel two dimensional material,exhibits remarkable photoelectric characteristics,ultrahigh photothermal conversion efficiency,substantial specific surface area,high carrier mobility,and tunable band gap *** attributes have positioned it as a promising candidate in domains such as energy,medicine,and the ***,its vulnerability to light,oxygen,and water can lead to rapid degradation and loss of crystallinity,thereby limiting its synthesis,preservation,and ***,BP has demonstrated cytotoxic tendencies,substantially constraining its viability in the realm of ***,the imperative for surface modification arises to bolster its stability and biocompatibility,while concurrently expanding its utility *** macromolecules,integral components of living organisms,proffer innate advantages over chemical agents and polymers for the purpose of the BP *** review comprehensively surveys the advancements in utilizing biological macromolecules for the modifications of *** doing so,it aims to pave the way for enhanced stability,biocompatibility,and diversified applications of this material.

关键词： blackphosphorus tumor therapy biocompatibility surface modification biomacromolecule

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Gene expression profiles contribute to robustly predicting prognosis in hepatocellular carcinoma

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Genes & Diseases 2024年第2期11卷 593-596页

作者： Long Liu yuhui wang Yuyuan Zhang Siyuan Weng Hui Xu Zaoqu Liu Xinwei Han Department of Hepatobiliary and Pancreatic Surgery The First Affiliated Hospital of Zhengzhou UniversityZhengzhouHenan 450052China Prenatal Diagnosis Center The Third Affiliated Hospital of Zhengzhou UniversityZhengzhouHenan 450052China Department of Interventional Radiology The First Affiliated Hospital of Zhengzhou UniversityZhengzhouHenan 450052China Interventional Institute of Zhengzhou University ZhengzhouHenan 450052China Interventional Treatment and Clinical Research Center of Henan Province ZhengzhouHenan 450052China

Hepatocellular carcinoma(HCC)is characterized by both inter-and intra-tumor heterogeneity and has distinct clinical outcomes.1 A promising clinical tool to perform patient stratification,prognosis evaluation,and treatment recommendations is ***,we enrolled a total of 1595 tumor patients from 13 independent cohorts,including seven cohorts with survival data,four cohorts with immunotherapy information,and two cohorts with transcatheter arterial chemoembolization(TACE)and Sorafenib information,respectively(Table S1).Using 96 algorithms combinations derived from 10 popular machinelearning approaches,a novel framework was constructed and described in Figure ***,a total of 26 stable consensus prognostic genes were screened in seven cohorts harboring complete survival information via univariate Cox regression analysis(Fig.S2A).

关键词： prognosis clinical arterial

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Effects of in-situZrB_2 nanoparticles and scandium on microstructure and mechanical property of 7N01 aluminum alloy

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Journal of Rare Earths 2024年第3期42卷 612-620,I0007页

作者： Xizhou Kai yuhui wang Ruikun Chen Yanjie Peng Anjun Shi Ran Tao Xiangfeng Liang Guirong Li Gang Chen Xiaojing Xu Yutao Zhao School of Material Science and Engineering Jiangsu UniversityZhenjiang212013China Institute for Advanced Manufacturing and Modern Equipment Technology Jiangsu UniversityZhenjiang212013China

In this study, the in-situ synthesized ZrB_(2) nanoparticles and rare earth Sc were introduced to enhance the strength and ductility of 7N01 aluminum alloy, via the generation of high-melting and uniform nanodispersoids. The microstructure and mechanical property evolution of the prepared composites and the interaction between ZrB_(2) and Sc were studied in detail. The microstructure investigation shows that the introduction of rare earth scandium(Sc) can promote the distribution of ZrB_(2) nanoparticles, by improving their wettability to the Al melt. Meanwhile, the addition of rare earth Sc also modifies the coarse Al Zn Mg Mn Fe precipitated phases, refines the matrix grains and generates high-melting Al_3(Sc,Zr)/Al_3Sc nanodispersoids. Tensile tests of the composites show that with the combinatorial introduction of ZrB_(2) and Sc, the strength and ductility of the composites are improved simultaneously compared with the corresponding 7N01 alloy, ZrB_(2) /7N01 composite and Sc/7N01 alloy. And the optimum contents of ZrB_(2) and Sc are 3 wt% and 0.2 wt% in this study. The yield strength, ultimate strength and elongation of(3 wt% ZrB_(2) +0.2 wt% Sc)/7N01 composite are 477 MPa, 506 MPa and 9.8%, increased about 18.1%, 12.2%and 38% compared to 7N01 alloy. Furthermore, the cooperation strengthening mechanisms of ZrB_(2) and Sc are also discussed.

关键词： 7N01 aluminum alloy In-situ ZrB_(2)nanoparticles Rare earth Sc Microstructure Mechanical property Mechanism

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Fe-Mn-Al-C系奥氏体基低密度钢使役性能研究进展

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机械工程学报 2024年第8期60卷 34-47页

作者：孔玲王玉辉杨浩坤彭艳燕山大学国家冷轧板带装备及工艺工程技术研究中心秦皇岛066004 香港生产力促进局智能制造部中国香港999077

双碳战略催生轻量化材料和技术的蓬勃发展。作为最重要的结构材料之一,钢铁材料在国民经济发展中扮演重要角色。Fe-Mn-Al-C系钢具备优异的轻量化特征、耐腐蚀性、机械强度(抗拉强度600~2000 MPa)和塑性(伸长率30%~100%)匹配,引起国内外... 详细信息

双碳战略催生轻量化材料和技术的蓬勃发展。作为最重要的结构材料之一,钢铁材料在国民经济发展中扮演重要角色。Fe-Mn-Al-C系钢具备优异的轻量化特征、耐腐蚀性、机械强度(抗拉强度600~2000 MPa)和塑性(伸长率30%~100%)匹配,引起国内外极大关注。其中,奥氏体基低密度钢在综合性能和加工方面具有显著优势,是汽车、交通、军事等领域结构件极具潜力的轻量化先进钢铁材料。对近年来国内外发表的Fe-Mn-Al-C系低密度钢典型使役性能进行总结和分析,着重聚焦其作为结构件应用中的“基本力学性能、加工成形性能和重要服役性能”等方面,综述Fe-Mn-Al-C系奥氏体基低密度钢使役过程中的力学行为、变形特征以及冲击、疲劳和腐蚀等使役评价,归纳阻碍该类钢作为结构件工业应用仍需突破的科学与技术问题,提出未来提高奥氏体基Fe-Mn-Al-C系低密度钢使役性能的重点方向和研究路径,以期为奥氏体基低密度钢作为结构件应用研究提供参考。

关键词：奥氏体基低密度钢 Fe-Mn-Al-C 力学性能成形性能服役性能

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pH对锆基底AlCrNbSiTi高熵合金涂层高温电化学行为的影响

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核动力工程 2024年第S01期45卷 123-129页

作者：王宇回刘超胡勇彭德全中国原子能科学研究院北京102413

为了提高压水堆Zr-Sn-Nb合金包壳材料的耐腐蚀性,本文使用电弧离子镀法在Zr-Sn-Nb合金基底上制备了AlCrNbSiTi高熵合金涂层,并分别在3种不同pH的水环境中进行了开路电位和动电位极化电化学的测量,通过微观表征分析了表面氧化膜的形貌、... 详细信息

为了提高压水堆Zr-Sn-Nb合金包壳材料的耐腐蚀性,本文使用电弧离子镀法在Zr-Sn-Nb合金基底上制备了AlCrNbSiTi高熵合金涂层,并分别在3种不同pH的水环境中进行了开路电位和动电位极化电化学的测量,通过微观表征分析了表面氧化膜的形貌、化学成分和结构,研究了pH值变化对AlCrNbSiTi高熵合金涂层高温电化学行为的影响。研究结果表明,随着pH值(7.4~8.5)的增加,涂层的开路电位下降,极化曲线的腐蚀电流密度增加,涂层表面腐蚀程度加剧。因此,AlCrNbSiTi高熵合金涂层的耐腐蚀性随着pH值(7.4~8.5)的增加而下降。

关键词：高熵合金涂层高温电化学腐蚀形貌

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当量比对铝粉/空气旋转爆轰发动机流场影响的数值模拟

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航空动力学报 2024年第5期39卷 80-94页

作者：李世全杨帆王宇辉王健平张国庆北京化工大学机电工程学院北京100029 北京大学工学院北京100871 北京理工大学宇航学院北京100081

以铝粉为燃料,空气为氧化剂,通过一步反应机理,对不同当量比下气固两相旋转爆轰发动机的流场进行二维数值模拟研究。结果表明:由于颗粒注入速度和空气注入速度存在差异,导致反应物区中的颗粒三角区和空气三角区不完全重叠,使得当量比从... 详细信息

以铝粉为燃料,空气为氧化剂,通过一步反应机理,对不同当量比下气固两相旋转爆轰发动机的流场进行二维数值模拟研究。结果表明:由于颗粒注入速度和空气注入速度存在差异,导致反应物区中的颗粒三角区和空气三角区不完全重叠,使得当量比从0.6增加到1.4时,爆轰波前的平均局部当量比从0.929增加到2.093,爆轰波速度从2 070 m/s降低到1 690 m/s,爆轰波压力从5.67 MPa降低到4.87 MPa。燃烧室内基本的流场与气相旋转爆轰发动机相似,但气固两相之间的相互作用使得颗粒呈现出特有的分布特性,包括2个颗粒群和4条颗粒带以及它们之间的间隙。

关键词：旋转爆轰发动机气固两相流当量比铝粉爆燃

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Ti-34Nb-4Zr-0.3O合金时效组织调控及其力学性能

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材料工程 2024年第4期52卷 102-109页

作者：齐欢武祥为张涵雅陈锋王玉会王春阳东南大学材料科学与工程学院南京211189 东南大学江苏省先进金属材料高技术研究重点实验室南京211189 中国航发北京航空材料研究院北京100095

采用真空电弧熔炼、单相区热锻以及冷轧等技术制备亚稳β型Ti-34Nb-4Zr-0.3O(质量分数/%)合金(TNZO),通过对冷轧态TNZO合金进行250℃和300℃的低温时效处理,揭示时效温度和时间对ω相析出行为与合金力学性能的影响规律。结果表明:低温... 详细信息

采用真空电弧熔炼、单相区热锻以及冷轧等技术制备亚稳β型Ti-34Nb-4Zr-0.3O(质量分数/%)合金(TNZO),通过对冷轧态TNZO合金进行250℃和300℃的低温时效处理,揭示时效温度和时间对ω相析出行为与合金力学性能的影响规律。结果表明:低温时效使ω相呈纳米尺寸析出,导致合金的强度和弹性模量提高。300℃时效时,ω相易发生粗化和团聚,使合金的伸长率快速下降和脆化。250℃短时时效可使少量ω相弥散析出,使合金具备高强度、低模量、超高弹性和良好塑性的优异综合性能,在航空航天弹性钛合金和医用植入钛合金领域显示了广阔的应用前景。

关键词：亚稳β钛合金时效 ω相力学性能

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颗粒注射速度对铝粉/空气两相旋转爆轰波的影响

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兵工学报 2024年第4期45卷 1148-1157页

作者：李世全祝文超孙方平王宇辉王健平北京化工大学机电工程学院北京100029 北京大学工学院北京100871

为研究颗粒注射速度对非预混铝粉/空气旋转爆轰波传播特性的影响,通过采用离散相模型、具有有限速率动力学/扩散表面燃烧模型的一步表面反应、多步可逆气相分解反应以及考虑未完全燃烧颗粒的挥发,对注射温度为300 K的铝颗粒和来流总温为... 详细信息

为研究颗粒注射速度对非预混铝粉/空气旋转爆轰波传播特性的影响,通过采用离散相模型、具有有限速率动力学/扩散表面燃烧模型的一步表面反应、多步可逆气相分解反应以及考虑未完全燃烧颗粒的挥发,对注射温度为300 K的铝颗粒和来流总温为900 K的高温空气进行二维数值模拟研究。研究结果表明:由于入口附近颗粒注射速度低于空气的注射速度,空气三角区和颗粒三角区无法完全重合;当颗粒注射速度从1 m/s增加到100 m/s时,爆轰波的速度和温度先减小后增加;颗粒和空气在注入燃烧室时存在较大的温度差异,导致爆轰波不稳定传播;颗粒注射速度为70 m/s时,爆轰波的稳定性最好。

关键词：旋转爆轰波颗粒注射速度气固两相流铝粉传播特性

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