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Design and analysis of the gripper mechanism based on generalized parallel mechanisms with configurable

《机械工程前沿（英文）》 2021年 第16卷 第4期   页码 765-781 doi: 10.1007/s11465-021-0655-1

摘要： Generalized parallel mechanisms with a configurable moving platform have become popular in the research field of parallel mechanism. This type of gripper mechanism can be applied to grasp large or heavy objects in different environments that are dangerous and complex for humans. This study proposes a family of novel (5 + 1) degrees of freedom (three translations and two rotations plus an additional grasping motion) gripper mechanisms based on the generalized parallel mechanisms with a configurable moving platform. First, the configurable moving platform, which is a closed loop, is designed for grasping manipulation. The hybrid topological arrangement is determined to improve the stiffness of the manipulator and realize high load-to-weight ratios. A sufficient rule based on Lie group theory is proposed to synthesize the mechanism. The hybrid limb structure is also enumerated. A family of novel gripper mechanisms can be assembled through the hybrid limbs by satisfying the rule. Two examples of the gripper mechanisms with and without parallelogram pairs are shown in this study. A kinematic analysis of the example mechanism is presented. The workspace shows that the mechanism possesses high rotational capability. In addition, a stiffness analysis is performed.

关键词： generalized parallel mechanism     configurable moving platform     gripper mechanism     type synthesis     kinematic analysis    

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Operating mechanism and set pair analysis model of a sustainable water resources system

Chaoyang DU,Jingjie YU,Huaping ZHONG,Dandan WANG

《环境科学与工程前沿（英文）》 2015年 第9卷 第2期   页码 288-297 doi: 10.1007/s11783-014-0642-4

摘要： There is no alternative to the world’s water resources, and their increasing scarcity is making it difficult to meet the world population’s water needs. This paper presents a sustainable water resources system (SWRS) and analyzes the operating mechanism that makes it possible to evaluate the status of such a system. A SWRS can be described as a complex coupling system that integrates water resources, social, economic and ecological systems into a whole. The SWRS’s operating mechanism is composed of dynamic, resistance and coordination components, and it interacts with and controls the system’s evolution process. The study introduces a new approach, set pair analysis theory, to measure the state of a SWRS, and an evaluation index system is established using the subsystems and operating mechanism of a SWRS. The evaluation index system is separated into three levels (goal level, criteria level and index level) and divides the index standard into five grades. An evaluation model of the SWRS based on set pair analysis theory is constructed, and an example of SWRS evaluation in Shanghai is presented. The connection degrees of the index in the three levels are calculated, and the connection degree of the goal index is calculated to be 0.342, which classifies the city’s SWRS condition as grade 2. The sustainable use of water resources in the region is determined to be at a relatively adequate level that meets the requirements of sustainable development.

关键词： sustainable water resources system     operating mechanism     set pair analysis model     Shanghai    

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Inverse Kinematics Analysis of General 6R Serial Robot Mechanism Based on Groebner Base

WANG Yan, HANG Lu-bin, YANG Ting-li

《机械工程前沿（英文）》 2006年 第1卷 第1期   页码 115-124 doi: 10.1007/s11465-005-0022-7

摘要：

This study presents a solution for the inverse kinematics problem in serial 6R manipulator. Using only seven equations composed of Duffy s four kinematical equations containing three angles and three corresponding angles identical equations instead of the traditional 14 equations, the authors reduced the inverse kinematics problem in the general 6R manipulator to a univariate polynomial with a minimum degree based on the Groebner Base method. From that, they concluded that the maximum number of the solutions is 16, generally. Also, the mathematics mechanization method can be extended to solve other mechanism problems involving nonlinear equations symbolically.

关键词： identical     manipulator     univariate polynomial     mechanism     traditional    

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Operation analysis of a Chebyshev-Pantograph leg mechanism for a single DOF biped robot

Conghui LIANG, Marco CECCARELLI, Yukio TAKEDA

《机械工程前沿（英文）》 2012年 第7卷 第4期   页码 357-370 doi: 10.1007/s11465-012-0340-5

摘要：

In this paper, operation analysis of a Chebyshev-Pantograph leg mechanism is presented for a single degree of freedom (DOF) biped robot. The proposed leg mechanism is composed of a Chebyshev four-bar linkage and a pantograph mechanism. In contrast to general fully actuated anthropomorphic leg mechanisms, the proposed leg mechanism has peculiar features like compactness, low-cost, and easy-operation. Kinematic equations of the proposed leg mechanism are formulated for a computer oriented simulation. Simulation results show the operation performance of the proposed leg mechanism with suitable characteristics. A parametric study has been carried out to evaluate the operation performance as function of design parameters. A prototype of a single DOF biped robot equipped with two proposed leg mechanisms has been built at LARM (Laboratory of Robotics and Mechatronics). Experimental test shows practical feasible walking ability of the prototype, as well as drawbacks are discussed for the mechanical design.

关键词： biped robots     leg mechanisms     simulation    

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Regulatory mechanism and functional analysis of

null

《医学前沿（英文）》 2017年 第11卷 第1期   页码 87-96 doi: 10.1007/s11684-016-0469-4

摘要：

S100A9, a calcium-binding protein, participates in the inflammatory process and development of various tumors, thus attracting much attention in the field of cancer biology. This study aimed to investigate the regulatory mechanism of and its function involvement in APL. We used real-time quantitative PCR to determine whether PML/RARα affects the expression of in NB4 and PR9 cells upon ATRA treatment. ChIP-based PCR and dual-luciferase reporter assay system were used to detect how PML/RARα and PU.1 regulate promoter activity. CCK-8 assay and flow cytometry were employed to observe the viability and apoptosis of NB4 cells when was overexpressed. Results showed that was an ATRA-responsive gene, and PML/RARα was necessary for the ATRA-induced expression of in APL cells. In addition, PU.1 could bind to the promoter of , especially when treated with ATRA in NB4 cells, and promote its activity. More importantly, overexpression of induced the apoptosis of NB4 cells and inhibited cell growth. Collectively, our data indicated that PML/RARα and PU.1 were necessary for the ATRA-induced expression of in APL cells. Furthermore, promoted apoptosis in APL cells and affected cell growth.

关键词： S100A9 S100A9     PU.1     PML/RARα     ATRA     APL    

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Theoretical and experimental analysis on super precision grinding of monocrystal silicon

GUO Xiaoguang, GUO Dongming, KANG Renke, JIN Zhuji

《机械工程前沿（英文）》 2007年 第2卷 第2期   页码 137-143 doi: 10.1007/s11465-007-0023-9

摘要： Through investigating the diamond-silicon grinding system, the grinding mechanism, including chip removal and subsurface damage, is discussed with the aid of the molecular dynamics (MD) approach and grinding experiments. Based on MD simulation, nanometric-grinding mechanism is analyzed from the viewpoint of instantaneous distribution of atoms, grinding force, and the potential energy between atoms and the profile of the groove. The simulation results show that some silicon atoms are deformed and piled up in front and on two sides of the abrasive surface because of the extrusion and cutting. When the energy in silicon lattice reaches its maximum value, the bonds of silicon atoms are broken and the material is removed. With the advancement of the abrasive, the silicon lattice under the abrasive surface is fractured, and then the amorphous layers are formed and propagated, which causes the subsurface damage. At the same time, some amorphous atoms are reconstructed and the degenerating layer of the machined surface is formed. Besides, the recovery of elatstic deformation occurs in the machined surface of the workpiece. In addition, the grinding experiment and profile detection with the aid of the measurment for 3D profiling are performed to verify the simulation results. The good agreement in the profile of the groove between the experimental value and the simulating value shows that MD simulation is very effective and reliable, and successful to fulfill the investigation on nanometric machining mechanism.

关键词： machining mechanism     recovery     advancement     mechanism     subsurface    

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Design and locomotion analysis of two kinds of rolling expandable mobile linkages with a single degree

Yanlin HAO, Yaobin TIAN, Jianxu WU, Yezhuo LI, Yan-An YAO

《机械工程前沿（英文）》 2020年 第15卷 第3期   页码 365-373 doi: 10.1007/s11465-020-0585-3

摘要： This study presents two kinds of rolling robots that are able to roll by deforming their outer shapes with a single degree of freedom. Each robot is an essential multi-loop planar expandable linkage constructed by a concave outer loop and several inner parallelogram loops. In this study, the mechanical design of the robots is introduced. Dynamic rolling process is further analyzed on the basis of zero moment point method, and a morphing strategy is proposed to guarantee a stable dynamic rolling process. A novel passive rolling locomotion is also developed, which enables the robots to roll and stand on a slope. To verify the design, two prototypes are manufactured, wherein the dynamic and passive rolling locomotion are carried out.

关键词： rolling locomotion     expandable mechanism     mechanism design     zero moment point (ZMP) analysis    

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Qualitative analysis of direction of public hospital reforms in China

null

《医学前沿（英文）》 2018年 第12卷 第2期   页码 218-223 doi: 10.1007/s11684-017-0534-7

摘要：

Reforms in public hospitals are among the most important improvements in China’s health care system over the last two decades. However, the reforms that should be implemented in public hospitals are unclear. Thus, a feasible direction of reforms in Chinese public hospitals is suggested and reliable policy suggestions are provided for the government to reform public hospitals. The data used in this study were mainly derived from a qualitative study. Focus group discussions and in-depth interviews were conducted in Shanghai, Guangdong, and Gansu between May and December 2014. Government funding accounted for approximately eight percent of the total annual revenue of public hospitals in China, and the insufficient government subsidy considerably affects the operation mechanism of public hospitals. However, solely increasing this subsidy cannot address the inappropriate incentives of public hospitals in China. The most crucial step in setting the direction of reforms in public hospitals in China is transforming inappropriate incentives by implementing a new evaluation index system for directors and physicians in public hospitals.

关键词： public hospital     government hospital     public funding     operation mechanism    

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Flutter control effect and mechanism of central-slotting for long-span bridges

YANG Yongxin, GE Yaojun, XIANG Haifan

《结构与土木工程前沿（英文）》 2007年 第1卷 第3期   页码 298-304 doi: 10.1007/s11709-007-0039-6

摘要： The flutter control effect and mechanism of central-slotting, which have gradually been adopted in the design and construction of long-span bridges as an effective flutter controlling measure, were investigated with theoretical analysis and wind tunnel test. Five basic girder cross-sections representing five typical aerodynamic configurations were selected and central-slotted with two different slot widths. Then, a series of sectional model tests and theoretical analyses based on the two-dimensional three-degrees-of-freedom coupling flutter analysis method (2 dimension-3 degrees of freedom method, 2d-3DOF method) were carried out to investigate the aerodynamic performance, flutter mechanism and flutter modality of the five basic sections and their corresponding central-slotted sections. The results show that central-slotting can not always improve the aerodynamic stability of bridge structure. The control effect of central-slotting depends on the aerodynamic configuration of the original girder section and the corresponding central-slotting width. If the original section is inappropriate or the slot width is unsuitable, central-slotting will even deteriorate the structural flutter performance. Theoretical investigations indicated that the differences in flutter control effects come from the different formation and evolution of aerodynamic damping, and flutter modality especially the participation level of heaving motion also has a significant influence on the control effect of central-slotting.

关键词： aerodynamic configuration     aerodynamic performance     flutter mechanism     aerodynamic stability     theoretical analysis    

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Design, analysis, and neural control of a bionic parallel mechanism

《机械工程前沿（英文）》 2021年 第16卷 第3期   页码 468-486 doi: 10.1007/s11465-021-0640-8

摘要： Although the torso plays an important role in the movement coordination and versatile locomotion of mammals, the structural design and neuromechanical control of a bionic torso have not been fully addressed. In this paper, a parallel mechanism is designed as a bionic torso to improve the agility, coordination, and diversity of robot locomotion. The mechanism consists of 6-degree of freedom actuated parallel joints and can perfectly simulate the bending and stretching of an animal’s torso during walking and running. The overall spatial motion performance of the parallel mechanism is improved by optimizing the structural parameters. Based on this structure, the rhythmic motion of the parallel mechanism is obtained by supporting state analysis. The neural control of the parallel mechanism is realized by constructing a neuromechanical network, which merges the rhythmic signals of the legs and generates the locomotion of the bionic parallel mechanism for different motion patterns. Experimental results show that the complete integrated system can be controlled in real time to achieve proper limb–torso coordination. This coordination enables several different motions with effectiveness and good performance.

关键词： neural control     behavior network     rhythm     motion pattern    

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Design and analysis of partially decoupled translational parallel mechanisms with single-loop structures

《机械工程前沿（英文）》 2022年 第17卷 第3期 doi: 10.1007/s11465-022-0695-1

摘要： This study presents a family of novel translational parallel mechanisms (TPMs) with single-loop topological structures. The proposed mechanism consists of only revolute and prismatic joints. The novel TPMs are simpler in structure and have fewer joints and components than the well-known Delta Robot. Four types of 2-degree of freedom driving systems are applied to different limb structures to avoid the moving actuator that causes the problem of increased moving mass. Four sample TPMs are constructed using the synthesized limbs, and one of them is investigated in terms of kinematic performance. First, a position analysis is performed and validated through numerical simulation to reveal the characteristics of partially decoupled motion, which improves the controllability of TPM. Second, singular configurations are identified, and the resulting singularity curve is obtained. Lastly, the workspace of TPM is analyzed, and the relationship between the singular configurations and the reachable workspace is explored. The workspace of the 3-CRR (C denotes the cylindrical joint and R denotes the revolute joint) translational mechanism is also presented to prove that the proposed TPM has a fairly large workspace.

关键词： translational parallel mechanism     single loop     multiple driving system     workspace analysis     singularity    

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Load-sharing mechanism in timber-steel hybrid shear wall systems

Zheng LI,Minjuan HE,Frank LAM,Minghao LI

《结构与土木工程前沿（英文）》 2015年 第9卷 第2期   页码 203-214 doi: 10.1007/s11709-015-0293-y

摘要： The lateral performance of timber-steel hybrid shear wall systems with regard to the interaction between the steel frame and the infill wood shear wall was investigated in this paper. A numerical model for the timber-steel hybrid shear wall system was developed and verified against test results. Design parameters, such as the lateral infill-to-frame stiffness ratio and the arrangements of wood-steel bolted connections were studied using the numerical model. Some design recommendations were also proposed based on the parametric analysis. In the hybrid shear wall system, the infill wood wall was found to resist a major part of the lateral load within relatively small wall drifts, and then the steel frame provided more lateral resistance. Under seismic loads, the infill wood wall could significantly reduce the inter-story drift of the hybrid system, and a complementary effect between the infill wood wall and the steel frame was observed through different lateral load resisting mechanisms, which provided robustness to the hybrid shear wall systems.

关键词： timer-steel hybrid     shear wall     load sharing mechanism     seismic performance     parametric analysis    

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Reduced kinetic mechanism of -heptane oxidation in modeling polycyclic aromatic hydrocarbon formation

ZHONG Beijing, XI Jun

《能源前沿（英文）》 2008年 第2卷 第3期   页码 326-332 doi: 10.1007/s11708-008-0047-9

摘要： A reduced mechanism, which could couple with the multidimensional computational fluid dynamics code for quantitative description of a reacting flow, was developed for chemical kinetic modeling of polycyclic aromatic hydrocarbon formation in an opposed-flow diffusion flame. The complete kinetic mechanism, which comprises 572 reactions and 108 species, was reduced to a simplified mechanism that includes only 83 reactions and 56 species through sensitivity analysis. The results computed via this reduced mechanism are nearly indistinguishable from those via the detailed mechanism, which demonstrate that the model based on this reduced mechanism can properly describe -heptane oxidation chemistry and quantitatively predict polycyclic aromatic hydrocarbon (such as benzene, naphthalene, phenanthrene and pyrene) formation in opposed-flow diffusion flames.

关键词： phenanthrene     multidimensional computational     sensitivity analysis     polycyclic     mechanism    

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Design and analysis of a class of redundant collaborative manipulators with 2-dimension large rotational

Xiaodong JIN, Yuefa FANG, Dan ZHANG, Xueling LUO

《机械工程前沿（英文）》 2020年 第15卷 第1期   页码 66-80 doi: 10.1007/s11465-019-0570-x

摘要： The parallel spindle heads with high rotational capability are demanded in the area of multi-axis machine tools and 3D printers. This paper focuses on designing a class of 2R1T (R: Rotation; T: Translation) parallel spindle heads and the corresponding collaborative 5-axis manipulators with 2-dimension (2D) large rotational angles. In order to construct 2D rotational degrees of freedom (DOF), a platform with 2-dimension revolute joints is proposed first. Based on the constraint screw theory, the feasible limbs that can be connected in the platform are synthesized. In order to provide constant rotational axis for the platform, a class of redundant limbs are designed. A class of redundant 2R1T parallel spindle heads is obtained by connecting the redundant limbs with the platform and the redundant characteristics are verified by the modified Grübler-Kutzbach criterion. The corresponding 5-axis collaborative manipulators are presented by constructing a 2-DOF series translational bottom moving platform. The inverse kinematics and the orientation workspace as well as the decoupling characteristics of this type of 2R1T parallel spindle heads are analyzed. The results show that these manipulators have large 2D rotational angles than the traditional A3/Z3 heads and can be potentially used in the application of multi-axis machine tools and the 3D printers.

关键词： parallel mechanism     redundant mechanism     large rotational angles     machine tools     2R1T spindle head     collaborative manipulator    

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A study on bearing characteristic and failure mechanism of thin-walled structure of a prefabricated subway

Lianjin TAO; Cheng SHI; Peng DING; Sicheng LI; Shang WU; Yan BAO

《结构与土木工程前沿（英文）》 2022年 第16卷 第3期   页码 359-377 doi: 10.1007/s11709-022-0816-2

摘要： In order to study the bearing performance of a new type of prefabricated subway station structure (PSSS), firstly, a three-dimensional finite element model of the PSSS was established to study the nonlinear mechanics and deformation performance. Secondly, the bearing mechanism of a PSSS was investigated in detail. Finally, the development law of damages to a thin-walled prefabricated component and the failure evolution mechanism of a PSSS were discussed. The results showed that this new type of the PSSS had good bearing capacity. The top arch structure was a three-hinged arch bearing system, and the enclosure structure and the substructure were respectively used as the horizontal and vertical support systems of the three-hinged arch structure to ensure the integrity and stability of the overall structure. Moreover, the tongue-and-groove joints could effectively transmit the internal force between the components and keep the components deformed in harmony. The rigidity degradation of the PSSS caused by the accumulation of damages to the spandrel, hance, arch foot, and enclosure structure was the main reason of its loss of bearing capacity. The existing thin-walled components design had significant advantages in weight reduction, concrete temperature control, components hoisting, transportation and assembly construction, which achieved a good balance between safety, usability and economy.

关键词： prefabricated subway station     thin-walled components     finite element analysis     bearing characteristic     failure mechanism    

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标题 作者 时间 类型 操作

Design and analysis of the gripper mechanism based on generalized parallel mechanisms with configurable

期刊论文

Operating mechanism and set pair analysis model of a sustainable water resources system

Chaoyang DU,Jingjie YU,Huaping ZHONG,Dandan WANG

期刊论文

Inverse Kinematics Analysis of General 6R Serial Robot Mechanism Based on Groebner Base

WANG Yan, HANG Lu-bin, YANG Ting-li

期刊论文

Operation analysis of a Chebyshev-Pantograph leg mechanism for a single DOF biped robot

Conghui LIANG, Marco CECCARELLI, Yukio TAKEDA

期刊论文

Regulatory mechanism and functional analysis of

null

期刊论文

Theoretical and experimental analysis on super precision grinding of monocrystal silicon

GUO Xiaoguang, GUO Dongming, KANG Renke, JIN Zhuji

期刊论文

Design and locomotion analysis of two kinds of rolling expandable mobile linkages with a single degree

Yanlin HAO, Yaobin TIAN, Jianxu WU, Yezhuo LI, Yan-An YAO

期刊论文

Qualitative analysis of direction of public hospital reforms in China

null

期刊论文

Flutter control effect and mechanism of central-slotting for long-span bridges

YANG Yongxin, GE Yaojun, XIANG Haifan

期刊论文

Design, analysis, and neural control of a bionic parallel mechanism

期刊论文

Design and analysis of partially decoupled translational parallel mechanisms with single-loop structures

期刊论文

Load-sharing mechanism in timber-steel hybrid shear wall systems

Zheng LI,Minjuan HE,Frank LAM,Minghao LI

期刊论文

Reduced kinetic mechanism of -heptane oxidation in modeling polycyclic aromatic hydrocarbon formation

ZHONG Beijing, XI Jun

期刊论文

Design and analysis of a class of redundant collaborative manipulators with 2-dimension large rotational

Xiaodong JIN, Yuefa FANG, Dan ZHANG, Xueling LUO

期刊论文

A study on bearing characteristic and failure mechanism of thin-walled structure of a prefabricated subway

Lianjin TAO; Cheng SHI; Peng DING; Sicheng LI; Shang WU; Yan BAO

期刊论文