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67篇 您的检索式:作者名="Yuefa"
    题名 作者 年代 出处 被引量
1Multi-objective Optimization of a Parallel Ankle Rehabilitation Robot Using Modified Differential Evolution Algorithm显示文摘Dimensional synthesis is one of the most difficult issues in the field of parallel robots with actuation redundancy. To deal with the optimal design of a redundantly actuated parallel robot used for ankle rehabilitation, a methodology of dimensional synthesis based on multi-objective optimization is presented. First, the dimensional synthesis of the redundant parallel robot is formulated as a nonlinear constrained multi-objective optimization problem. Then four objective functions, separately reflecting occupied space, input/output transmission and torque performances, and multi-criteria constraints, such as dimension, interference and kinematics, are defined. In consideration of the passive exercise of plantar/dorsiflexion requiring large output moment, a torque index is proposed. To cope with the actuation redundancy of the parallel robot, a new output transmission index is defined as well. The multi-objective optimization problem is solved by using a modified Differential Evolution(DE) algorithm, which is characterized by new selection and mutation strategies. Meanwhile, a special penalty method is presented to tackle the multi-criteria constraints. Finally, numerical experiments for different optimization algorithms are implemented. The computation results show that the proposed indices of output transmission and torque, and constraint handling are effective for the redundant parallel robot; the modified DE algorithm is superior to the other tested algorithms, in terms of the ability of global search and the number of non-dominated solutions. The proposed methodology of multi-objective optimization can be also applied to the dimensional synthesis of other redundantly actuated parallel robots only with rotational movements.WANG Congzhe FANG Yuefa GUO Sheng 2015Chinese Journal of Mechanical Engineering2015,28,4:13
2Reconfigurable parallel mechanisms with planar five-bar metamorphic linkages显示文摘This paper presents the idea of constructing reconfigurable limbs by integrating metamorphic linkages as subchains.The planar five-bar metamorphic linkages that have three phases resulting from locking of motors are considered.Under the assumption that the constraint exerted by the reconfigurable limb can switch between no constraint,a constraint force,and a constraint couple,the output motions of the metamorphic linkage in its two planar four-bar linkage phases are identified.By adding an appropriate joint to planar four-bar linkages with translational output,four planar five-bar linkages that can be employed in the construction of reconfigurable limbs are enumerated.Serial chains that can provide a constraint couple and a constraint force are synthesized based on screw theory.Reconfigurable limbs that have three configurations associated with the three distinct phases of the metamorphic linkages are assembled with planar five-bar metamorphic linkages and serial chains with four degrees of freedom.A class of reconfigurable parallel mechanisms are constructed by connecting a moving platform and a base with three identical reconfigurable limbs.The degrees of freedom of the reconfigurable parallel mechanism in different configurations with the metamorphic linkages in different phases are given.Finally,the actuation scheme for this kind of mechanisms is addressed.YE Wei FANG YueFa GUO Sheng 2014Science China(Technological Sciences)2014,57,1:12
3Reciprocal Screw Theory Based Singularity Analysis of a Novel 3-DOF Parallel Manipulator显示文摘Singularity analysis is an essential issue for the development and application of parallel manipulators.Most of the existing researches focus on the singularity of parallel manipulators are carried out based on the study of Jacobian matrices.A 3-DOF parallel manipulator with symmetrical structure is presented.The novel parallel manipulator employs only revolute joints and consists of four closed-loop subchains connecting to both base and platform via revolute joints.The closed-loop subchain in each chain-leg is a spherical 6R linkage.The motion characteristics of the output link in the spherical 6R linkage with symmetrical structure are analyzed based on the interrelationships between screw systems.The constraints that are exerted on the platform by each chain-leg are investigated applying the concept of generalized kinematic pair in terms of equivalent screw system.Considering the geometric characteristics of the parallel manipulator,the singularity criteria of the parallel manipulator corresponding to different configurations are revealed based on the dependency of screw system and line geometry.The existing conditions of certain configuration that a singularity must occur are determined.This paper presents a new way of singularity analysis based on disposition of constraint forces on the geometrically identified constraint plane and the proposed approach is capable of avoiding the complexity in solving the Jacobian matrices.FANG Hairong FANG Yuefa ZHANG Ketao 2012Chinese Journal of Mechanical Engineering2012,25,4:7
4Structural Synthesis of a Class of 2R2T Hybrid Mechanisms显示文摘Conventional overconstrained parallel manipulators have been widely studied both in industry and academia,however the structural synthesis of hybrid mechanisms with additional constraints is seldom studied,especially for the four degrees of freedom(DOF) hybrid mechanisms.In order to develop a manipulator with additional constraints,a class of important spatial mechanisms with coupling chains(CCs) whose motion type is two rotations and two translations(2R2T) is presented.Based on screw theory,the combination of different types of limbs which are used to construct parallel mechanisms and coupling chains is proposed.The basic types of the general parallel mechanisms and geometric conditions of the kinematic chains are given using constraint synthesis method.Moreover,the 2R2T motion pattern hybrid mechanisms which are derived by adding coupling chains between different serial kinematic chains(SKCs) of the corresponding parallel mechanisms are presented.According to the constraint analysis of the mechanisms,the movement relationship of the moving platform and the kinematic chains is derived by disassembling the coupling chains.At last,fourteen novel hybrid mechanisms with two or three serial kinematic chains are presented.The proposed novel hybrid mechanisms and construction method enrich the family of the spatial mechanisms and provide an instruction to design more complex hybrid mechanisms.TIAN Chunxu FANG Yuefa GUO Sheng 2016Chinese Journal of Mechanical Engineering2016,29,4:5
5Recent advances in bismuth vanadate-based photocatalysts for photoelectrochemical water splitting显示文摘Photoelectrochemical(PEC)technology is considered to be a promising approach for solar-driven hydrogen production with zero emissions.Bismuth vanadate(BiVO_(4))is a kind of photocatalytic material with strong photoactivity in the visible light region and appropriate band gap for PEC water splitting.However,the solar-to-hydrogen efficiency(STH)of BiVO_(4)is far away from the 10%target needed for practical application due to its poor charge separation ability.Therefore,this review attempts to summarize the strategies for improving the photocurrent density and especially hydrogen production of BiVO_(4)materials through PEC techniques in the last three years,such as doping nonmetal and metal elements,depositing noble metals,constructing heterojunctions,coupling with carbon and metalorganic framework(MOF)materials to further enhance the PEC performance of BiVO_(4)photoanode.This review aims to serve as a general guideline to fabricate highly efficient BiVO_(4)-based materials for PEC water splitting.Lina Wang Xiaoqiang Shi Yuefa Jia Hongfei Cheng Lei Wang Qizhao Wang 2021Chinese Chemical Letters2021,32,6:4
6Theory of Degrees of Freedom for Parallel Mechanisms with Three Spherical Joints and Its Applications显示文摘The analysis of degrees of freedom(DOF) of a moving platform is the fundamental problem in kinematics of parallel mechanism. However, many problems should be considered to correctly perform the DOF calculation by using the traditional DOF criterion, and it is difficult to find a DOF criterion suitable for all kinds of mechanisms. A rule that can be used to determine the position and orientation of the moving platform is presented. Based on the proposed rule, a new form of DOF criterion is proposed, which is suitable for a class of parallel mechanisms with three spherical joints attached to the moving platform. The basic types of generalized limb structures are given based on the possible dimension of achieving the center of spherical joint attached to the moving platform, and the general steps of analyzing the DOF are presented. This proposed formula simplifies the DOF analysis of parallel mechanisms with spherical joints attached to the moving platform, and plays an important role in structural synthesis of such parallel mechanisms.QU Haibo FANG Yuefa GUO Sheng 2015Chinese Journal of Mechanical Engineering2015,28,4:3
7Adaptive control of parallel manipulators via fuzzy-neural network algorithm显示文摘This paper considers adaptive control of parallel manipulators combined with fuzzy-neural network algo- rithms (FNNA). With this algorithm, the robustness is guaranteed by the adaptive control law and the parametric uncertain- ties are eliminated. FNNA is used to handle model uncertainties and external disturbances. In the proposed control scheme, we consider modifying the weight of fuzzy rules and present these rules to a MIMO system of parallel manipulators with more than three degrees-of-freedom (DoF). The algorithm has the advantage of not requiring the inverse of the Jacobian matrix especially for the low DoF parallel manipulators. The validity of the control scheme is shown through numerical simulations of a 6-RPS parallel manipulator with three DoF.Dachang ZHU Yuefa FANG 2007控制理论与应用(英文版)2007,5,3:3
8Design and analysis of a class of redundant collaborative manipulators with 2D large rotational angles显示文摘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(DOFs),a platform with 2D 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.Xiaodong JIN Yuefa FANG Dan ZHANG Xueling LUO 2020Frontiers of Mechanical Engineering2020,15,1:2
9Dimensional synthesis of a novel 5-DOF reconfigurable hybrid perfusion manipulator for large-scale spherical honeycomb perfusion显示文摘A novel hybrid perfusion manipulator(HPM)with five degrees of freedom(DOFs)is introduced by combining the 5PUS-PRPU(P,R,U and S represent prismatic,revolute,universal and spherical joint,respectively)parallel mechanism with the 5PRR reconfigurable base to enhance the perfusion efficiency of the large-scale spherical honeycomb thermal protection layer.This study mainly presents the dimensional synthesis of the proposed HPM.First,the inverse kinematics,including the analytic expression of the rotation angles of the U joint in the PUS limb,is obtained,and mobility analysis is conducted based on screw theory.The Jacobian matrix of 5PUS-PRPU is also determined with screw theory and used for the establishment of the objective function.Second,a global and comprehensive objective function(GCOF)is proposed to represent the Jacobian matrix’s condition number.With the genetic algorithm,dimensional synthesis is conducted by minimizing GCOF subject to the given variable constraints.The values of the designed variables corresponding to different configurations of the reconfigurable base are then obtained.Lastly,the optimal structure parameters of the proposed 5-DOF HPM are determined.Results show that the HPM with the optimized parameters has an enlarged orientation workspace,and the maximum angle of the reconfigurable base is decreased,which is conducive to improving the overall stiffness of HPM.Hui YANG Hairong FANG Yuefa FANG Xiangyun LI 2021Frontiers of Mechanical Engineering2021,16,1:2
10Topological structural synthesis of 4-DOF serial-parallel hybrid mechanisms 显示文摘Qiang Zeng Yuefa Fang 2011Journal of Me- chanical Design2011,133,09:1
11Inverse Velocity and Singularity Analysis of low-DoF Serial Manipulators显示文摘Fang Yuefa Tsai Lung-Wen 2003Journal of Robotic System2003,20,4:1
12Structural synthesis and analysis of serial-parallel hybrid mechanisms with spatial multi-loop kinematic chains 显示文摘Qiang Zeng Yuefa Fang 2011Mechanism and Machine Theory2011,49,:1
13Structure synthesis of a class of 3-DOF rotational parallel manipulators显示文摘FANG Yuefa TSAI L W 0,,01:1
14Structure Synthesis of 4-DoF and 5-DoF Parallel Manipulators with Identical Limb显示文摘Fang Yuefa Tsai Lung-Wen 2002The International Journal of Robotics Research2002,21,9:1
15Structure synthesis of a class of 4-DOF and 5-DOF parallel manipulators with identical limb structures显示文摘Fang Yuefa Tsai Lungwen 2002The International Journal of Robotics Research2002,21,9:1
16Analysis of Instantaneous Motions of Deficient-Rank 3-RPS Parallel Manipulators显示文摘Huang Zhen Wang Jing Fang Yuefa 2002Mechanism and Machine Theory2002,37,2:1
17Experimental method for and theoretical research on defect tolerance of fxed plate based on damage mechanics显示文摘An experimental method and a theoretical analysis based on continuum damage mechanics are applied for the defects tolerance of fxed plate.The defects type studied in this article is scratch,which is considered a typical defect on fxed plate according to the engineering practice.The general approach to the defects tolerance analysis of scratched fxed plate is presented.The method of fatigue life prediction for standard notched specimens has been established on the basis of continuum damage mechanics.For the purpose of obtaining the influence law of fatigue life in consequence of scratches,fatigue experiments of standard notched specimens and scratched specimens have been done.Evaluation of the fatigue life of scratched fxed plate has been carried out.And the value of scratch defects permissible to the condition of safety service life has been worked out.According to the results of theoretical calculations,the fatigue experiment of scratched fxed plate has been performed.The outcome shows that the theoretical prediction tallies with the experimental results.Zhan Zhixin Hu Weiping Zhang Miao Zhu Yuefa Meng Qingchun 2013Chinese Journal of Aeronautics2013,26,5:1
18Kinematic of a three- degree-freedom in-parallel actuated manipulator mechanism显示文摘FANG Yuefa HUANG Zhen 1997Mechanism and Machine Theory1997,32,7:1
19Kinematic characteristics analysis of 3 DOF in-parallel actuated pyramid mechanisms显示文摘HUANG Zhen FANG Yuefa 1996Mechanism and Machine Theory1996,31,8:1
20A convenient approach to ( S )-2-ethylhexan-1-ol mediated by baker’s yeast显示文摘Yikang Huang Fanglin Zhang Yuefa Gong 2005Tetrahedron Letters2005,,42:1
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