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Type Synthesis of Self-Alignment Parallel Ankle Rehabilitation robot with Suitable Passive Degrees of Freedom

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Chinese Journal of Mechanical Engineering 2024年第1期37卷 160-175页

作者： Ya Liu Wenjuan Lu Dabao Fan Weijian Tan Bo Hu Daxing Zeng School of Mechanical Engineering Yanshan UniversityQinhuangdao 066004China School of Mechanical Engineering Dongguan University of TechnologyDongguan 523808China Dongguan Engineering Technology Research center for Parallel robot Dongguan 523808China The DGUT Innovation center of robotics and Intelligent Equipment Dongguan 523808China

The current parallel ankle rehabilitation robot(ARR)suffers from the problem of difficult real-time alignment of the human-robot joint center of rotation,which may lead to secondary injuries to the *** study investigates type synthesis of a parallel self-alignment ankle rehabilitation robot(PSAARR)based on the kinematic characteristics of ankle joint rotation center drift from the perspective of introducing"suitable passive degrees of freedom(DOF)"with a suitable number and ***,the self-alignment principle of parallel ARR was proposed by deriving conditions for transforming a human-robot closed chain(HRCC)formed by an ARR and human body into a kinematic suitable constrained system and introducing conditions of"decoupled"and"less limb".Second,the relationship between the self-alignment principle and actuation wrenches(twists)of PSAARR was analyzed with the velocity Jacobian matrix as a"bridge".Subsequently,the type synthesis conditions of PSAARR were ***,a PSAARR synthesis method was proposed based on the screw theory and type of PSAARR synthesis ***,an HRCC kinematic model was established to verify the self-alignment capability of the *** this study,93 types of PSAARR limb structures were synthesized and the self-alignment capability of a human-robot joint axis was verified through kinematic analysis,which provides a theoretical basis for the design of such an ARR.

关键词： Ankle rehabilitation robot Self-alignment Parallel mechanism Type synthesis Screw theory

A novel weld-pool-length monitoring method based on pixel analysis in plasma arc additive manufacturing

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Advances in Manufacturing 2024年第2期12卷 335-348页

作者： Bao-Ri Zhang Yong-Hua Shi Bionic robot Research Department Ji Hua LaboratoryFoshan528200GuangdongPeople’s Republic of China Guangdong Provincial Engineering Research center for Special Welding Technology and Equipment School of Mechanical and Automotive EngineeringSouth China University of TechnologyGuangzhou510640People’s Republic of China

The real-time monitoring of the weld pool during deposition is important for automatic control in plasma arc additive *** obtain a high deposition accuracy,it is essential to maintain a stable weld pool *** this study,a novel passive visual method is proposed to measure the weld pool *** the proposed method,the image quality was improved by designing a special visual system that employed an endoscope and a *** also includes pixel brightness-based and gradient-based algorithms that can adaptively detect feature points at the boundary when the weld pool geometry *** algorithm can also be applied to materials with different solidification *** was performed to measure the real weld pool length in world coordinates,and outlier rejection was performed to increase the accuracy of the ***,tests were carried out on the intersection component,and the results showed that the proposed method performed well in tracking the changing weld pool length and was applicable to the real-time monitoring of different types of materials.

关键词： Plasma arc additive manufacturing(PAAM) Weld pool geometry Gradient analysis Real-time detection

基于知识图谱推理的热轧带钢产品质量缺陷追溯

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计算机集成制造系统 2024年第3期30卷 1105-1114页

作者：张佳琪凌卫青同济大学电子与信息工程学院cims研究中心上海201804

热轧带钢生产面临多工况、机理复杂、工艺参数繁多等问题,造成专家很难及时有效给出生产中导致质量缺陷的原因。由此提出一种基于知识图谱推理的质量缺陷追溯方法。首先通过可解释方法SHAP实现对随机森林模型预测结果的解释,并通过知识... 详细信息

热轧带钢生产面临多工况、机理复杂、工艺参数繁多等问题,造成专家很难及时有效给出生产中导致质量缺陷的原因。由此提出一种基于知识图谱推理的质量缺陷追溯方法。首先通过可解释方法SHAP实现对随机森林模型预测结果的解释,并通过知识图谱将数据挖掘结果与工艺机理、专家经验等知识进行融合,进一步将图谱中表示工艺参数与质量参数依赖关系的子图映射到贝叶斯网络,推断不同工艺参数导致产品质量缺陷的后验概率。实际生产数据验证表明,针对不同生产工况,该方法能有效识别各个批次中导致质量缺陷的工艺参数,表现出良好识别率。

关键词：热轧带钢质量缺陷知识图谱可解释人工智能贝叶斯网络

Neural Network Robust Control Based on Computed Torque for Lower Limb Exoskeleton

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Chinese Journal of Mechanical Engineering 2024年第2期37卷 83-99页

作者： Yibo Han Hongtao Ma Yapeng Wang Di Shi Yanggang Feng Xianzhong Li Yanjun Shi Xilun Ding Wuxiang Zhang School of Mechanical Engineering and Automation Beihang UniversityBeijing 100191China Beihang Goer(WeiFang)Intelligent robot Co. Ltd.Beihang UniversityWeifangChina Research center of Satellite Technology Harbin Institute of TechnologyHarbinChina Beijing Xinfeng Aerospace Equipment Co. LtdBeijingChina

The lower limb exoskeletons are used to assist wearers in various scenarios such as medical and industrial *** modeling errors of the exoskeleton in different application scenarios pose challenges to the robustness and stability of its control *** Radial Basis Function(RBF)neural network is used widely to compensate for modeling *** order to solve the problem that the current RBF neural network controllers cannot guarantee the asymptotic stability,a neural network robust control algorithm based on computed torque method is proposed in this paper,focusing on trajectory *** innovatively incorporates the robust adaptive term while introducing the RBF neural network term,improving the compensation ability for modeling *** stability of the algorithm is proved by Lyapunov method,and the effectiveness of the robust adaptive term is verified by the *** wearing the exoskeleton under different walking speeds and scenarios were carried out,and the results show that the absolute value of tracking errors of the hip and knee joints of the exoskeleton are consistently less than 1.5°and 2.5°,*** proposed control algorithm effectively compensates for modeling errors and exhibits high robustness.

关键词： Lower limb exoskeleton Model compensation RBF neural network Computed torque method

SGT-Net: A Transformer-Based Stratified Graph Convolutional Network for 3D Point Cloud Semantic Segmentation

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Computers, Materials & Continua 2024年第6期79卷 4471-4489页

作者： Suyi Liu Jianning Chi Chengdong Wu Fang Xu Xiaosheng Yu Faculty of robot Science and Engineering Northeastern UniversityShenyang110167China State Key Laboratory of robotics Shenyang Institute of AutomationChinese Academy of SciencesShenyang110016China Institutes for robotics and Intelligent Manufacturing Chinese Academy of SciencesShenyang110169China SIASUN robot&Automation Co. Ltd.Shenyang110169China

In recent years,semantic segmentation on 3D point cloud data has attracted much *** 2D images where pixels distribute regularly in the image domain,3D point clouds in non-Euclidean space are irregular and inherently ***,it is very difficult to extract long-range contexts and effectively aggregate local features for semantic segmentation in 3D point cloud *** current methods either focus on local feature aggregation or long-range context dependency,but fail to directly establish a global-local feature extractor to complete the point cloud semantic segmentation *** this paper,we propose a Transformer-based stratified graph convolutional network(SGT-Net),which enlarges the effective receptive field and builds direct long-range ***,we first propose a novel dense-sparse sampling strategy that provides dense local vertices and sparse long-distance vertices for subsequent graph convolutional network(GCN).Secondly,we propose a multi-key self-attention mechanism based on the Transformer to further weight augmentation for crucial neighboring relationships and enlarge the effective receptive *** addition,to further improve the efficiency of the network,we propose a similarity measurement module to determine whether the neighborhood near the center point is *** demonstrate the validity and superiority of our method on the S3DIS and ShapeNet *** ablation experiments and segmentation visualization,we verify that the SGT model can improve the performance of the point cloud semantic segmentation.

关键词： 3D point cloud semantic segmentation long-range contexts global-local feature graph convolutional network dense-sparse sampling strategy

Multiobjective Differential Evolution for Higher-Dimensional Multimodal Multiobjective Optimization

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IEEE/CAA Journal of Automatica Sinica 2024年第6期11卷 1458-1475页

作者： Jing Liang Hongyu Lin Caitong Yue Ponnuthurai Nagaratnam Suganthan Yaonan Wang School of Electrical and Information Engineering Zhengzhou UniversityZhengzhou 450001 School of Electrical Engineering and Automation Henan Institute of TechnologyXinxiang 453003China School of Electrical and Information Engineering Zhengzhou UniversityZhengzhou 450001China KINDI center for Computing Research Qatar UniversityDohaQatarand also with the Nanyang Technology UniversitySingapore College of Electrical and Information Engineering and also with the National Engineering Research Center for Robot Visual Perception and Control TechnologyHunan UniversityChangsha 410082China IEEE

In multimodal multiobjective optimization problems(MMOPs),there are several Pareto optimal solutions corre-sponding to the identical objective *** paper proposes a new differential evolution algorithm to solve MMOPs with higher-dimensional decision *** to the increase in the dimensions of decision variables in real-world MMOPs,it is diffi-cult for current multimodal multiobjective optimization evolu-tionary algorithms(MMOEAs)to find multiple Pareto optimal *** proposed algorithm adopts a dual-population framework and an improved environmental selection *** utilizes a convergence archive to help the first population improve the quality of *** improved environmental selection method enables the other population to search the remaining decision space and reserve more Pareto optimal solutions through the information of the first *** combination of these two strategies helps to effectively balance and enhance conver-gence and diversity *** addition,to study the per-formance of the proposed algorithm,a novel set of multimodal multiobjective optimization test functions with extensible decision variables is *** proposed MMOEA is certified to be effective through comparison with six state-of-the-art MMOEAs on the test functions.

关键词： Benchmark functions diversity measure evolution-ary algorithms multimodal multiobjective optimization.

Research on DFRP Theory and Application Based on PDM

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High Technology Letters 2001年第3期7卷 46-48页

作者：王晓红 cims and robot center Shanghai University Shanghai 201800 China

Product data management is the foundation and platform to implement Concurrent Engineering. To take manufacturing resource planning of enterprises into account while performing concurrent product design, the paper puts forth a new theory, namely DFRP (Design for Resource Planning), by which fulfills the data intercommunication between PDM (Product Data Management) and MRPII (Manufacturing Resource Planning), thus brings the DFRP into DFX (Design for Something) tools. Finally, the paper analyzes the present problems in the field and points out the development.

关键词： Concurrent engineering PDM DFRP SSPD

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基于知识图谱推荐的钢铁产线智能故障诊断

控制理论与应用 2024年第9期41卷 1548-1558页

作者：朱彦王坚同济大学电子与信息工程学院cims研究中心上海201804

钢铁生产需要经过原料输送、冶炼、热轧、冷轧等多个环节,完成这些流程还需要电力、热风等多种原料与资源的支持.其工艺流程繁复,设备种类众多,设备-故障关系复杂,使得为其进行故障诊断难度也大大增加.为了实现精确高效的故障诊断,本文... 详细信息

钢铁生产需要经过原料输送、冶炼、热轧、冷轧等多个环节,完成这些流程还需要电力、热风等多种原料与资源的支持.其工艺流程繁复,设备种类众多,设备-故障关系复杂,使得为其进行故障诊断难度也大大增加.为了实现精确高效的故障诊断,本文结合上述钢铁产线故障诊断的领域特点,在此基础上提出一种基于知识图谱推荐的钢铁产线故障诊断模型,采用类似水波传播的方式在知识图谱中获取待诊断设备的多阶表示并聚合得到其深度表征以进行故障诊断,并根据钢铁产线故障诊断的特性优化了其中水波集的构建过程以提升最终的诊断效果.同时引入成对关系向量知识表示学习模型(PairRE)进行联合训练以学习知识图谱中的复杂关系.最后通过某大型钢铁公司的热轧产线实际生产数据与多个代表模型进行对比试验和案例分析,验证了所提出方法的科学性和有效性.

关键词：故障诊断知识图谱推荐算法偏好传播

Microstructure Evolution and Mechanical Properties of Friction Stir Welded Al-Cu-Li Alloy

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Acta Metallurgica Sinica(English Letters) 2024年第5期37卷 855-871页

作者： Peng Chen Wenhao Chen Jiaxin Chen Zhiyu Chen Yang Tang Ge Liu Bensheng Huang Zhiqing Zhang School of New Energy and Materials Southwest Petroleum UniversityChengdu 610500China Sichuan Provincial Engineering Research center of Advanced Materials Manufacturing Technology for Shale Gas High-Efficient Exploitation Southwest Petroleum UniversityChengdu 610500China College of Materials Science and Engineering Chongqing UniversityChongqing 400045China School of Mechatronic Engineering Southwest Petroleum UniversityChengdu 610500China School of robot Engineering Yangtze Normal UniversityChongqing 408100China

The investigation concentrates on friction stir welded(FSW)Al-Cu-Li alloy concerning its local microstructural evolution and mechanical *** grain features were characterized by electron back scattered diffraction(EBSD)technology,while precipitate characterization was conducted by using transmission electron microscopy(TEM)aligned along[011]Al and[001]Al zone *** mechanical properties are evaluated through micro-hardness and tensile *** can be found that nugget zones exhibit finely equiaxed grains evolved through complete dynamic recrystallization(DRX),primarily occurring in continuous dynamic recrystallization(CDRX)and discontinuous dynamic recrystallization(DDRX).In the thermal-mechanically affected zone(TMAZ),numerous sub-structured grains,exhibiting an elongated morphology,were created due to partial DRX,signifying the dominance of CDRX,DDRX,and geometric dynamic recrystallization(GDRX)in this region.T_(1)completely dissolves in the nugget zone(NZ)leading to the formation of Guinier-Preston zones and increase ofδ′,β′and S′.Conversely,T_(1)partially solubilizes in TMAZ,the lowest hardness zone(LHZ)and heat affected zone(HAZ),and the residual T_(1)undergoes marked coarsening,revealing various T_(1)*** solubilization and coarsening of T_(1)are primary contributors to the degradation of hardness and strength.θ′primarily dissolves and coarsens in NZ and TMAZ,whilst this precipitate largely coarsens in HAZ and LHZ.σ,TB,grain boundary phases(GBPs)and precipitate-free zone(PFZ)are newly generated during FSW.σexists in the TMAZ,LHZ and HAZ,whereas TB nucleates in *** and PFZ mostly develop in LHZ and HAZ,which can cause strain localization during tensile deformation,potentially leading to LHZ joint fracture.

关键词： Al-Cu-Li alloy Friction stir welding Microstructure evolution Mechanical properties