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

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

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Over-constraint and a Unified Mobility Method for General Spatial Mechanisms Part 1: Essential Principle

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Chinese Journal of Mechanical Engineering 2015年第5期28卷 869-877页

作者： ZENG Daxing lu wenjuan HUANG Zhen School of Mechanical Engineering Yanshan University

Compared with the parallel mechanisms, the mobility analysis of the general multi-loop spatial mechanisms（GMSMs） is more difficult to obtain correct results. The reason is that its multi-loop is formed through several times of closings and there also exists motion coupling even strong coupling, where the over-constraints are concealed. However, the mobility analysis for this kind of mechanisms has been paid few attentions. A new systemic methodology for analyzing mobility is proposed for GMSMs also based on the screw theory. The key issue for mobility analysis is to recognize the over-constraint. Firstly, three theorems are given and point out： the reason and site of over-constraint occurrence, calculating the number of over-constraints by the screw theory, and how to analyze the over-constraints for a single-loop mechanism as well. Then, three closing forms for GMSMs are proposed including rigid closure, movable closure and dynamic closure, and for the three different forms the different analysis methods are also given. Especially, for the most difficult issue of GMSMs with the multi-loop Closure in many times and the inevitable motion coupling, two important methods are proposed：＂recognizing over-constraints by analyzing relative movement＂ and ＂recognizing over-constraints by virtual loop＂. The two methods are well used to solve the issue. Above-mentioned principles are not only systematic and effective but also unified. They provide a theoretical basis for the general multi-loop spatial mechanisms.

关键词： mobility analysis multi-loop over-constraint closing forms virtual loop

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Over-Constraints and a Unified Mobility Method for General Spatial Mechanisms Part 2:Application of the Principle

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Chinese Journal of Mechanical Engineering 2016年第1期29卷 1-10页

作者： lu wenjuan ZENG Daxing HUANG Zhen School of Mechanical Engineering Yanshan University

The pre-research on mobility analysis presented a unified-mobility formula and a methodology based on reciprocal screw theory by HUANG, which focused on classical and modem parallel mechanisms. However its range of application needs to further extend to general multi-loop spatial mechanism. This kind of mechanism is not only more complex in structure but also with strong motion coupling among loops, making the mobility analysis even more complicated, and the relevant research has long been ignored. It is focused on how to apply the new principle for general spatial mechanism to those various multi-loop spatial mechanisms, and some new meaningful knowledge is further found. Several typical examples of the genera/multi-loop spatial mechanisms with motion couple even strong motion couple are considered. These spatial mechanisms include different closing way： over-constraint appearing in rigid closure, in movable closure, and in dynamic closure as well; these examples also include two different new methods to solve this kind of issue： the way to recognize over-constraints by analyzing relative movement between two connected links and by constructing a virtual loop to recognize over-constraints. In addition, over-constraint determination tabulation is brought to analyze the motion couple. The researches above are all based upon the screw theory. All these multi-loop spatial mechanisms with different kinds of structures can completely be solved by following the directions and examples, and the new mobility theory based on the screw theory is also proved to be valid. This study not only enriches and develops the theory and makes the theory more universal, but also has a special meaning for innovation in mechanical engineering.

关键词： mobility analysis over-constraint multi-loop spatial mechanism motion coupling screw theory

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多维CNN耦合的滑坡易发性评价方法

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武汉大学学报（信息科学版） 2024年第8期49卷 1466-1481页

作者：赵占骜王继周毛曦马维军路文娟何毅高轩宇兰州交通大学测绘与地理信息学院甘肃兰州730070 中国测绘科学研究院北京100830 山东科技大学测绘与空间地理信息学院山东青岛266590

卷积神经网络(convolutional neural network,CNN)因其强大的特征提取能力被广泛应用于滑坡易发性评价。然而,随着场景多样化和高精度的需求,CNN算法不断改进,通过加深网络层次或联合其他模型来提高精度的做法往往大幅增加模型参数量和... 详细信息

卷积神经网络(convolutional neural network,CNN)因其强大的特征提取能力被广泛应用于滑坡易发性评价。然而,随着场景多样化和高精度的需求,CNN算法不断改进,通过加深网络层次或联合其他模型来提高精度的做法往往大幅增加模型参数量和计算量,导致模型训练困难或结果过拟合,进而限制其实际应用。提出构建多维CNN耦合模型解决以上问题,通过特征图非对称聚合连结二维CNN(two-dimensional CNN,2D-CNN)和一维CNN(one-dimensional CNN,1D-CNN),维持网络深度而限制模型参数并减少计算量;利用多维卷积核参数共享捕获各滑坡影响因子不同维度及因子之间的深层耦合特征,实现特征充分利用而避免过拟合。以中国西藏自治区色东普沟为实验区,选取11种滑坡影响因子分析该地滑坡易发性。结果表明,因计算量减小,多维CNN耦合结构与参数较少的浅层2D-CNN效率相当,而比参数量近似的深层2D-CNN训练时长大幅减小,模型训练成本降低。此外,耦合模型相比独立1D-CNN和2D-CNN特征学习能力增强,模型精度提升,在测试集数据各混淆矩阵指标下拥有更高评分,进而获得了具有更高可信度的滑坡易发性评价结果。所提出的多维CNN耦合模型是一种适用于滑坡易发性评价的可靠方法,为进一步滑坡灾害监测和预防提供了新的理论指导与技术支持。

关键词： 1D-CNN 2D-CNN 滑坡易发性评价耦合模型

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Comparative Analysis of Characteristics of the Coupled and Decoupled Parallel Mechanisms

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Chinese Journal of Mechanical Engineering 2010年第4期23卷 468-476页

作者： ZENG Daxing HOU Yulei lu wenjuan HUANG Zhen College of Mechanical Engineering Yanshan University Qinhuangdao 066004 China

The existence of coupling makes the parallel mechanism possess some special advantages over the serial mechanism, while it is just the coupling that brings about the parallel mechanism some limitations, such as complex workspace, high nonlinear relationship between input and output, difficulties in static and dynamic analysis, and the development of control system, which restricts its application fields. The decoupled parallel mechanism is currently one of the research focuses of the mechanism fields, while the study on the different characteristics between the deeoupled and coupled parallel mechanisms has not been reported. Therefore, this paper performs the systematic comparative analysis of the 3-RPUR and the 3-CPR parallel mechanisms. The features of the two mechanisms are described and their movement forms are analyzed with screw theory. The inverse and forward displacement solutions are solved and the Jacobian matrices are obtained. According to the Jacobian matrices and by using the theory of physical model of the solution space, the workspace, dexterity, velocity, payload capability, and stiffness of the mechanisms are analyzed with plotting the indices atlases. The research results prove that the effects of the coupling on the parallel mechanism are double-side, and then the adoption of the decoupled parallel mechanism should be determined by the requirements of the concrete application situation. The contents of this paper should be useful for the type synthesis and practical application of the parallel mechanism.

关键词： parallel mechanism couple decouple screw theory index atlas

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Type Synthesis and Characteristic Analysis of a Family of 2-DOF Rotational Decoupled Parallel Mechanisms

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Chinese Journal of Mechanical Engineering 2009年第6期22卷 833-840页

作者： ZENG Daxing Hou Yulei HUANG Zhen lu wenjuan College of Mechanical Engineering Yanshan University Qinhuangdao 066004 China

It is widely used for the rotational parallel mechanism in the field of spatial orientation. While owing to the existence of coupling, the forward kinematic solution and the control of the general rotational parallel mechanism are especially difficult. If decoupling can be realized, the kinematic analysis of the mechanism will be very simple. Presently, the research of the parallel mechanism is focused on the inverse solution and structure optimization, and there is a lack of rotation decoupled parallel mechanisms （DPMs）. So this paper proposes a family of 2 degree of freedom （DOF） rotational DPMs based on the four-bar linkage mechanism, and performs a characteristic analysis. This family of DPMs is composed of a moving platform, a fixed base and three limbs. Taking U_RRU SPU DPM as an example, the motion feature of this DPM is analyzed with the constraint screw method, and its mobility is calculated by using the Modified Kutzbach-Grtibler criterion. The inverse and forward displacement problems of the proposed parallel mechanism are solved. The decoupled feature of the proposed parallel mechanism is validated by the deduction of the expression of the Jaeobian matrix. Three kinds of singularity conditions of this DPM are discussed, and the atlases of the output parameter concerning different geometric parameters are plotted with the theory of the physical model of the solution space. The proposition and characteristic analysis of the novel rotational DPMs in this paper should be useful for further research and application of the parallel mechanisms.

关键词： parallel mechanism rotational decoupled constraint screw method atlases

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Global Dynamic Modeling of Electro-Hydraulic 3-UPS/S Parallel Stabilized Platform by Bond Graph

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Chinese Journal of Mechanical Engineering 2016年第6期29卷 1176-1185页

作者： ZHANG Lijie GUO Fei LI Yongquan lu wenjuan Hebei Provincial Key Laboratory of Heavy Machinery Fluid Power Transmission and Control Yanshan University Key Laboratory of Advanced Forging & Stamping Technology and Science of Ministry of Education Yanshan University Parallel Robot and Mechatronic System Laboratory of Hebei Province Yanshan University

Dynamic modeling of a parallel manipulator（PM） is an important issue. A complete PM system is actually composed of multiple physical domains. As PMs are widely used in various fields, the importance of modeling the global dynamic model of the PM system becomes increasingly prominent. Currently there lacks further research in global dynamic modeling. A unified modeling approach for the multi-energy domains PM system is proposed based on bond graph and a global dynamic model of the 3-UPS/S parallel stabilized platform involving mechanical and electrical-hydraulic elements is built. Firstly, the screw bond graph theory is improved based on the screw theory, the modular joint model is modeled and the normalized dynamic model of the mechanism is established. Secondly, combined with the electro-hydraulic servo system model built by traditional bond graph, the global dynamic model of the system is obtained, and then the motion, force and power of any element can be obtained directly. Lastly, the experiments and simulations of the driving forces, pressure and flow are performed, and the results show that, the theoretical calculation results of the driving forces are in accord with the experimental ones, and the pressure and flow of the first limb and the third limb are symmetry with each other. The results are reasonable and verify the correctness and effectiveness of the model and the method. The proposed dynamic modeling method provides a reference for modeling of other multi-energy domains system which contains complex PM.

关键词： screw bond graph multi-energy domains 3-UPS/S parallel mechanism electro-hydraulic servo system

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基于网络药理学及实验验证探讨敦煌医方小补肝汤抗运动性疲劳的作用机制

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中药药理与临床 2024年第6期40卷 25-32页

作者：芦文娟张禄璐梁永林霍敏峰张李香甘肃中医药大学基础医学院兰州730030 敦煌医学与转化教育部重点实验室兰州730030

目的:运用网络药理学及实验验证的方法探讨小补肝汤干预运动性疲劳的有效成分及可能作用机制。方法:在中药系统药理学分析平台(TCMSP)检索小补肝汤的活性成分;通过人类基因组数据库(Genecards)、药物数据库(Drugbank)、在线人类孟德尔遗... 详细信息

目的:运用网络药理学及实验验证的方法探讨小补肝汤干预运动性疲劳的有效成分及可能作用机制。方法:在中药系统药理学分析平台(TCMSP)检索小补肝汤的活性成分;通过人类基因组数据库(Genecards)、药物数据库(Drugbank)、在线人类孟德尔遗传(OMIM)、遗传药理学与药物基因组学数据库(PharmGkb),获取疾病的靶标基因;利用Venny2.1.0在线工具绘制药物与疾病靶点的韦恩图,获得交集靶点,将其导入STRING数据库,构建蛋白相互作用(PPI)网络图,通过Bioconductor等在线软件进行基因组数据的高通量分析,得到基因本体(GO)生物功能注释图和京都基因与基因组百科全书(KEGG)富集通路图,预测作用通路,并采用动物实验验证网络药理学预测结果。结果:通过筛选得到小补肝汤36种活性成分,药物-疾病共同靶点244个;通过构建药物-成分-靶点-疾病调控网络,筛选出豆甾醇(Stigmasterol)、海风藤酮(Kadsurenone)、β-谷固醇(Beta-sitosterol)、山蒟酮C(Hancinone C)及黄杉素(Taxifolin)等核心成分;通过蛋白互作网络的构建,筛选出AKT1、GNAQ及PTGS2等11个关键靶点;GO富集分析得出生物学过程BP 3675个,包括对药物的反应、对氧含量的反应、对缺氧的反应等;细胞组分379个,包括膜筏、膜微区、线粒体外膜等;分子功能624个,包括DNA-结合转录因子结合、泛素蛋白连接酶结合及G蛋白偶联胺受体活性等;KEGG富集分析得出涉及的信号通路主要有钙信号通路(GNAQ-PLCB2-IP3R1-CAM)、cAMP信号通路和甲状腺激素信号等通路。动物实验结果显示,与正常对照组比较,模型对照组负重游泳力竭时间显著减少,血清中乳酸(LD)、尿素氮(BUN)的含量显著升高,肝糖原与肌糖原的含量显著降低(P<0.01),骨骼肌组织病理可见骨骼肌细胞排列紊乱不均,有较多炎症细胞弥漫浸润,骨骼肌组织GNAQ、PLCB2、IP3RI、CAM蛋白表达显著上调(P<0.01);与模型对照组比较,各给药组小鼠负重游泳力竭时间显著增加(P<0.01),血清中LD、BUN的含量明显降低(P<0.05),肝糖原与肌糖原的含量明显升高(P<0.05),各给药组小鼠骨骼肌纤维排列有所改善,炎性细胞浸润明显减少,骨骼肌组织GNAQ、PLCB2、IP3RI、CAM蛋白表达明显下调(P<0.05)。结论:小补肝汤能下调运动性疲劳小鼠骨骼肌组织中GNAQ、PLCB2、IP3RI、CAM蛋白表达,从而调节胞内钙离子浓度,减轻因钙超载导致的细胞线粒体、肌浆网功能破坏而引起的疲劳。

关键词：小补肝汤网络药理学运动性疲劳鸟嘌呤核苷酸结合蛋白q肽钙离子

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What Kind of＂2004 Plus＂Constitution Ukraine Needs

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学术界 2017年第9期 257-269页

作者： Yang Yousun lu wenjuan Jiangxi University of Finance and Economics Nanchang Jiangxi 330013

Ukraine reinstated 2004 constitution on February 21,2014. Although it is better than 1996 constitution,2004 constitution is far from perfect. T he m ain deficiency of2004 constitution is unbalanced pow er distribution am ong the president,the V erkhovna Rada and the prim e m inister( and the cabinet).Based on the analysis of the deficiencies of2004 constitution,this article puts forw ard som e proposals on the reform of U krainian constitution,such as the establishm ent of a prem ier presidentialism w ith a w eak president,a clearer division of pow er betw een the president,the Rada and the prim e m inister.

关键词：乌克兰宪法总统不平衡权力牧师

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黄河流域气候因子与NDVI相关性的长时序空间异质性研究

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测绘科学 2024年第2期49卷 134-142页

作者：董文洁毛曦路文娟王继周李诚秦瀚中国测绘科学研究院北京100036

针对黄河流域气候的地区差异对植被产生复杂变化的问题,本研究选取了1981—2020年黄河流域的气候数据与NDVI数据,运用重心模型和地理加权回归GWR模型等方法,探究了黄河流域植被NDVI空间变化特征及驱动因素影响的空间异质性。结果表明,... 详细信息

针对黄河流域气候的地区差异对植被产生复杂变化的问题,本研究选取了1981—2020年黄河流域的气候数据与NDVI数据,运用重心模型和地理加权回归GWR模型等方法,探究了黄河流域植被NDVI空间变化特征及驱动因素影响的空间异质性。结果表明,黄河流域植被NDVI分布不均匀,具有显著的空间自相关性;1981年—2020年,植被NDVI重心整体上向东北方向迁移了29.96 km,呈现出“东北—东—东北”的迁移趋势;气候因子对植被NDVI的影响存在空间异质性,降水因子对干旱与半干旱地区均呈现正向影响,回归系数在0.130~1.477之间,而气温对植被NDVI的负向影响占比高达72.3%。

关键词：黄河流域 NDVI 地理加权回归模型莫兰指数空间异质性

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