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A New Method for Type Synthesis of 2R1T and 2T1R 3-DOF Redundant Actuated Parallel Mechanisms with Closed Loop Units

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Chinese Journal of Mechanical Engineering 2020年第6期33卷 134-157页

作者： Yongquan Li Yang Zhang Lijie Zhang Parallel Robot and Mechatronic System Laboratory of Hebei Province Yanshan UniversityQinhuangdao066004China Key Laboratory of Advanced Forging&Stamping Technology and Science Ministry of Education of ChinaYanshan UniversityQinhuangdao066004China School of Mechanical Engineering and Automation Harbin Institute of TechnologyShenzhen518052China Hebei Provincial Key Laboratory of Heavy Machinery Fluid Power Transmission and Control Yanshan UniversityQinhuangdao066004China

The current type synthesis of the redundant actuated parallel mechanisms is adding active-actuated kinematic branches on the basis of the traditional parallel mechanisms,or using screw theory to perform multiple getting intersection and union to complete type *** number of redundant parallel mechanisms obtained by these two methods is *** this paper,based on Grassmann line geometry and Atlas method,a novel and effective method for type synthesis of redundant actuated parallel mechanisms(PMs)with closed-loop units is ***,the degree of freedom(DOF)and constraint line graph of the moving platform are determined successively,and redundant lines are added in constraint line graph to obtain the redundant constraint line graph and their equivalent line graph,and a branch constraint allocation scheme is formulated based on the allocation ***,a scheme is selected and redundant lines are added in the branch chains DOF graph to construct the redundant actuated branch chains with closed-loop ***,the branch chains that meet the requirements of branch chains configuration criteria and F&C(degree of freedom&constraint)line graph are *** this paper,two types of 2 rotational and 1 translational(2R1T)redundant actuated parallel mechanisms and one type of 2 translational and 1 rotational(2T1R)redundant actuated parallel mechanisms with few branches and closed-loop units were taken as examples,and 238,92 and 15 new configurations were *** the mechanisms contain closed-loop units,and the mechanisms and the actuators both have good ***,all the mechanisms have excellent comprehensive performance,in which the two rotational DOFs of the moving platform of 2R1T redundant actuated parallel mechanism can be independently *** instantaneous analysis shows that all mechanisms are not instantaneous,which proves the feasibility and practicability of the method.

关键词： Redundant actuated Parallel mechanisms Type synthesis Atlas method Instantaneous analysis

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Reliability evaluation of bladder accumulator with no failure data

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High technology Letters 2018年第3期24卷 322-329页

作者：郭锐 Zhang Rongbing Zhao Jingyi Zhou Jinsheng Zhang Zhenmiao Hebei Provincial Key Laboratory of Heavy Machinery Fluid Power Transmission and Control Yanshan UniversityKey Laboratory of Advanced Forging & Stamping Technology and Science (Yanshan University) College of Mechanical Engineering (Yanshan University) Qinhuangdao YSU -Yihua Electrical and Mechanical Engineering Technology Research Institute Co. Ltd.

As a bladder accumulator is a high reliable and long life component in a hydraulic system,its cost is high and it takes a lot of time to test its reliability,therefore,a reliability test with small sample is performed,and no failure data is obtained using the method of fixed time truncation. In the case of Weibull distribution,a life reliability model of bladder energy storage is established by Bayesian method using the optimal confidence intervals method,a model of one-sided lower confidence intervals of the reliability and one-sided lower confidence intervals model of the reliability life are established. Results of experiments show that the evaluation method of no failure data under Weibull distribution is a good way to evaluate the reliability of the accumulator,which is convenient for engineering application,and the reliability of the accumulator has theoretical and practical significance.

关键词： bladder accumulator Weibull distribution fixed time truncation no failure data reliability assessment

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δ-phase precipitation regularity of cold-rolled fine-grained GH4169 alloy plate and its effect on mechanical properties

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Transactions of Nonferrous Metals Society of China 2020年第12期30卷 3287-3295页

作者： Hao XUE Jing-qi ZHAO Yong-kang LIU Chun-xiang ZHANG Jun-ting LUO Key Laboratory of Advanced Forging&Stamping Technology and Science of Ministry of Education Yanshan UniversityQinhuangdao 066004China State Key Laboratory of Metastable Materials Science and Technology Yanshan UniversityQinhuangdao 066004China

Cold rolling and heat-treatment were used for the grain refinement of GH4169 superalloy *** effects of cold rolling reduction ratio and heat-treatment time on the precipitatedδphase,and the effects ofδ-phase content and morphology on the mechanical properties of the GH4169 alloy plates,are *** results demonstrate that coldrolling can promote the precipitation of theδphase and its transformation from theδ-Ni3Nb phase to theδ-NbNi4 *** comprehensive properties of the alloy are better when the heat treatment time is 1 h,with 132 MPa increase in the tensile strength and only 2.9%decrease in the elongation relative to those of the original *** mechanical properties of the alloy are shown to change greatly with the change in theδ-phase morphology.

关键词： fine-grained GH4169 alloy cold rolling δphase mechanical properties

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Influence of liquid film thickness on bearing characteristics of magnetic-liquid suspension guide-way

Influence of liquid film thickness on bearing characteristic...

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19th International Conference of Fluid Power and Mechatronic Control Engineering 2018

作者： Zhao, Jianhua Zhang, Bin Chen, Tao Wang, Qiang Gao, Dianrong Key Laboratory of Advanced Forging and Stamping Technology and Science Hebei Provincial Key Laboratory of Heavy Machinery Fluid Power Transmission and Control Yanshan University Qinhuangdao066004 China

The magnetic-liquid suspension guide-way (MLSG) adopts the double support form of permanent magnetic suspension and hydrostatic pressure. It can greatly enhance the bearing capacity and rigidity of the guide-way system. The liquid film thickness is the main influencing factor on both the bearing capacity of the hydrostatic system and the permanent magnetic force. This paper analysed the effect of liquid film thickness on the static, dynamic and vibration index of MLSG. Firstly, this paper introduced the structural characteristics and supporting mechanism of MLSG. Secondly, based on flow equation, the static pressure equation, the permanent magnetic force equation and the force balance equation, the transfer function of single DOF supporting system of MLSG in constant flow supply mode is presented, and analysed the influence of the thickness of liquid film on single DOF supporting performance of MLSG. The results show that with the increase of the thickness of the liquid film, the bearing capacity of guide-way, the static stiffness, the dynamic stiffness and the natural frequency decrease, and the adjust time, the total power loss, the amplitude amplification coefficient increases, the phase margin is almost unchanged. The study can provide a theoretical basis for the design of MLGS in engineering practice. © 2019 Institution of Engineering and technology. All rights reserved.

关键词： Bearing capacity

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Precision and Flexible Bending Control Strategy Based on Analytical Models and Data Models

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Chinese Journal of Mechanical Engineering 2022年第5期35卷 112-130页

作者： Yongchuan Duan Le Tian Fangfang Zhang Yu Liu Haidi Qiao Liu Yang Yingping Guan Key Laboratory of Advanced Forming&Stamping Technology and Science Ministry of Education of ChinaYanshan UniversityQinhuangdao 066004China College of Mechanical Engineering Yanshan UniversityQinhuangdao 066004China

Forming of various customized bending parts,small batches,as well as numerous types of materials is a new challenges for Industry 4.0,the current control strategies can not meet the precision and flexibility requirement,expected control strategy of bending processes need to not only resist unknown interferences of process condition and models,but also produce various new parts automatically and *** this paper,a precision and flexible bending control strategy based on analytical models and data models is proposed to build adaptive bending *** analytical prediction models for loading and unloading are established and suitable for various materials,a sequential identification strategy is proposed to search nominal properties using the four sub-optimization models.A data-based feedback model is established to prevent over-bending and eliminate online *** models are merged into a precision and flexible control *** system firstly uses sub-optimization models to search the nominal point which is near to target point,secondly the system further uses feedback model to eliminate residual error between the nominal point and target *** with four kinds sheet metals,the allowable ranges for variables are determined for a good *** target bending angles were set to 20°,40°,and 60°.Forty parts were tracked for each kind material,the adaptive bending system converged after one iteration,and exhibited better performances.

关键词： Air bending Springback control Flexible bending control Feedback compensation

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Combination resonances of field modulated magnetic gear system considering eccentricity

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Journal of Information and Computational science 2014年第9期11卷 3037-3046页

作者： Yuan, Xiaoming Hao, Xiuhong Du, Bing Zhang, Lijie Hebei Provincial Key Laboratory of Heavy Machinery Fluid Power Transmission and Control Yanshan University Qinhuangdao 066004 China Key Laboratory of Advanced Forging and Stamping Technology and Science Ministry of Education of China Yanshan University Qinhuangdao 066004 China School of Mechanical Engineering Yanshan University Qinhuangdao 066004 China

Considering the torque ripples caused by the component eccentricities of Field Modulated Magnetic Gear (FMMG) system, a dynamic model and the corresponding dynamic differential equations are founded. The formulae of the resonance responses are deduced and the laws of the combination resonances of FMMG system are discussed. The results show that the component eccentricities have little effects on the maximum torques, but the ripples of the dynamic torques increase, especially the dynamic torque on the inner rotor. The frequencies of the system resonances agree with the excitation frequencies and there are the interactive modulation phenomena between the displacements of all parts. Because the magnetic coupling stiffnesses are much smaller than the supporting stiffnesses of all parts, the relative deflections of two Degree of Freedoms (DOFs) are much bigger than the relative deflections of other DOFs. The resonances will badly deteriorate the dynamic behaviors of FMMG system and must be got much attention. Copyright © 2014 Binary Information Press.

关键词： Dynamic models

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Kinematic,Workspace and Force Analysis of A Five-DOF Hybrid Manipulator R(2RPR)R/SP+RR

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Chinese Journal of Mechanical Engineering 2022年第5期35卷 232-243页

作者： Yundou Xu Fan Yang Youen Mei Dongsheng Zhang Yulin Zhou Yongsheng Zhao Laboratory of Parallel Robot and Mechatronic System of Hebei Province Yanshan UniversityQinhuangdao 066004China Key Laboratory of Advanced Forging&Stamping Technology and Science of Ministry of National Education Yanshan UniversityQinhuangdao 006004China School of Mechanical Engineering Yanshan UniversityQinhuangdao 066004China Tencent Robotics X Tencent HoldingsShenzhen 518057China

In the present study,the over-constrained hybrid manipulator R(2RPR)R/SP+RR is considered as the research *** this paper,kinematics of the hybrid manipulator,including the forward and inverse position,are ***,the workspace is checked based on the inverse position solution to evaluate whether the workspace of the hybrid manipulator meets the requirements,and the actual workspace of the hybrid robot is *** that,the force analysis of the over-constrained parallel mechanism is carried out,and an ADAMS-ANSYS rigid-flexible hybrid body model is established to verify the *** on the obtained results from the force analysis,the manipulator structure is ***,the structure optimization is carried out to improve the robot ***,calibration and workspace verification experiments are performed on the prototype,cutting experiment of an S-shaped aluminum alloy workpiece is completed,and the experiment verifies the machining ability of the *** work conducts kinematics,workspace,force analyses,structural optimization design and experiments on the over-constrained hybrid manipulator R(2RPR)R/SP+RR,providing design basis and technical support for the development of the novel hybrid manipulator in practical engineering.

关键词： Hybrid manipulator Over-constrained Kinematic analysis Stiffness analysis

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Experimental Study on Mechanical Response of Q235 Steel Under Cyclic Stress Loading 13th

Experimental Study on Mechanical Response of Q235 Steel Unde...

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13th International Conference on the technology of Plasticity, ICTP 2021

作者： Zhang, Qingling Jin, Miao Guo, Baofeng Li, Qun School of Mechanical Engineering Yanshan University Qinhuangdao066004 China Key Laboratory of Advanced Forging & Stamping Technology and Science Ministry of Education of China Yanshan University Qinhuangdao066004 China

ISBN: (纸本)9783030753801

The cyclic softening/hardening, ratcheting effect, and Bauschinger effect usually occur in the body structure of large mechanical equipment under cyclic loading. This manuscript focuses on Q235 steel commonly used in the welded frame of large mechanical equipment. The experiments were carried out with mean stress varying from −60 to 60 MPa and stress amplitude varying from 300 to 340 MPa, respectively, and the mechanical responses were analyzed comprehensively. The experimental results show that Q235 steel exhibits cyclic softening characteristics at positive mean stress and cyclic hardening characteristics at negative mean stress. The larger the stress amplitude or the absolute value of the mean stress, the greater the absolute value of ratcheting strain. At the same stress amplitude, when the absolute value of the mean stress is equal, the Bauschinger coefficient is almost equal. Based on the experimental results, the evolution formula of ratcheting strain is established by a phenomenological method. © 2021, The Minerals, Metals & Materials Society.

关键词： Loading

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Error modeling for the leg mechanism of the quadruped walking chair robot

Error modeling for the leg mechanism of the quadruped walkin...

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International Conference on Applied System Innovation, ICASI 2015

作者： Wang, H.B. Wang, S.S. Wen, Y.H. Chen, N. Parallel Robot and Mechatronic System Laboratory of Hebei Province Yanshan University QinhuangdaoHeBei Province China Key Laboratory of Advanced Forging and Stamping Technology and Science Yanshan University QinhuangdaoHeBei Province China

ISBN: (纸本)9781138028937

To reduce the output error of the parallel robot, it is crucial to analyze the pose error of the parallel mechanism. This paper deals with the pose error analysis, and establishes the model for the effects of pose parameters and structural parameters on the accuracy of the leg mechanism. Firstly, based on the research of constraint relations on the leg mechanism of the walking chair robot, the error model is established. Then the influence of structure parameters and pose parameters on the pose error is studied. The results contribute a lot to the determination of the structural parameters and the output error of the control system. © 2016 Taylor & Francis Group, London.

关键词： Errors

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Auto-establishing simulation parallel manipulators with linear legs and auto-solving their workspaces by utilizing CAD variation geometry

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International Journal of Computers and Applications 2017年第4期39卷 220-233页

作者： Lu, Yi Bi, Cuicui Ye, Nijia Bo, Hu College of Mechanical Engineering Yanshan University Qinhuangdao China Parallel Robot and Mechatronic System Laboratory of Hebei Province Key Laboratory of Advanced Forging & Stamping Technology and Science of Ministry of National Education Yanshan University QinhuangdaoHebei China Hebei Hanguang Industry CO. LTD Hebei China

A new approach of CAD variation geometry is proposed for automatically establishing the simulation mechanisms of parallel manipulators (PMs) with linear legs, and automatically solving their forward displacements, workspaces, and Euler angles. First, the basic concepts and techniques of the CAD variation geometry are described. Second, a program is developed by utilizing new approach. In the developed software, an interface is constructed for inputting given parameters and outputting solved results of data and graphs, several sub-programs are compiled for automatically establishing various simulation mechanisms, solving the forward displacements, and solving/ displaying reachable workspaces and Euler angles of various PMs. Third, the three novel and five existing different PMs are illustrated. When the given parameters of the PMs into the interface are inputted, their simulation mechanisms are established automatically. The displacements, the reachable workspaces, and the Euler angles are solved automatically. Finally, the solved results of the developed software are verified by that of the analytic solutions of several existing PMs and the simulation solutions of several novel PMs. © 2017 Informa UK Limited, trading as Taylor & Francis Group.

关键词： Geometry

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