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Parasitic rotation evaluation and avoidance of 3-UPU parallel mechanism
Haibo QU, Yuefa FANG, Sheng GUO
《机械工程前沿(英文)》 2012年 第7卷 第2期 页码 210-218 doi: 10.1007/s11465-012-0317-4
Based on the prototype of 3-UPU (universal-prismatic-universal joint) parallel mechanism proposed by Tsai [ ], the parasitic rotation evaluation is performed and calculated the bound of instability of SNU Seoul National University 3-UPU parallel mechanism. Through analysis of the terminal constraint system of the 3-UPU parallel mechanism, the equation about the parasitic rotation and limited clearance is presented. Then the norm of possible parasitic rotation is employed to evaluate the mechanism stability with limited clearance. The higher this number the worst is the pose, the lower it is the best it is. And the contour atlas of parasitic rotation is obtained, which can be used for further analysis and design. With the practice experiment result of SUN 3-UPU parallel mechanism, we find it’s bound of instability, which indicates there will appear the parasitic rotation when the number exceeds the bound. Finally, the method for avoidance of possible parasitic motions is presented by adding redundantly actuated limbs.
关键词: parallel mechanism 3-UPU (universal-prismatic-universal joint) parasitic motions limited clearance redundantly actuated limbs
Optimal design of a linkage–cam mechanism-based redundantly actuated parallel manipulator
《机械工程前沿(英文)》 2021年 第16卷 第3期 页码 451-467 doi: 10.1007/s11465-021-0634-6
关键词: redundant actuation parallel manipulator linkage–cam mechanism Jacobian optimal design
Wanghui BU, Zhenyu LIU, Jianrong TAN, Jin CHENG
《机械工程前沿(英文)》 2011年 第6卷 第4期 页码 463-467 doi: 10.1007/s11465-011-0225-z
The shield machine is a heavy construction machine for tunnel excavation, and the segment erector is an important subsystem of the shield machine. It is difficult to achieve precise control in the 6-DOF (degree of freedom) erector in the 2-DOF 5-bar radial mechanism. Hence, this paper proposes a redundantly actuated PRPRP radial mechanism for the segment erector. When the redundant actuator is unlocked, the radial mechanism is able to adjust its posture, which has two degrees of freedom. On the other hand, when the redundant actuator is locked or produces enough pre-tightening tensile force, the PRPRP mechanism can ensure the synchronization of the two driving hydraulic cylinders along the radial direction based on the mechanical structure, which has one degree of freedom. The redundant actuator also facilitates the equal application of two flexural torques at the hydraulic cylinders; thus, preventing the overload of a single cylinder.
关键词: redundant actuation parallel mechanisms five-bar mechanisms segment erectors shield machines
《机械工程前沿(英文)》 2021年 第16卷 第4期 页码 698-710 doi: 10.1007/s11465-021-0646-2
关键词: hydraulic manipulator inverse kinematic redundant design spherical wrist
Preload characteristics identification of the piezoelectric-actuated 1-DOF compliant nanopositioning
Ruizhou WANG, Xianmin ZHANG
《机械工程前沿(英文)》 2015年 第10卷 第1期 页码 20-36 doi: 10.1007/s11465-015-0328-z
Packaged piezoelectric ceramic actuators (PPCAs) and compliant mechanisms are attractive for nanopositioning and nanomanipulation due to their ultra-high precision. The way to create and keep a proper and steady connection between both ends of the PPCA and the compliant mechanism is an essential step to achieve such a high accuracy. The connection status affects the initial position of the terminal moving plate, the positioning accuracy and the dynamic performance of the nanopositioning platform, especially during a long-time or high-frequency positioning procedure. This paper presents a novel external preload mechanism and tests it in a 1-degree of freedom (1-DOF) compliant nanopositioning platform. The 1-DOF platform utilizes a parallelogram guiding mechanism and a parallelogram load mechanism to provide a more accurate actual input displacement and output displacement. The simulation results verify the proposed stiffness model and dynamic model of the platform. The values of the preload displacement, actual input displacement and output displacement can be measured by three capacitive sensors during the whole positioning procedure. The test results show the preload characteristics vary with different types or control modes of the PPCA. Some fitting formulas are derived to describe the preload displacement, actual input displacement and output displacement using the nominal elongation signal of the PPCA. With the identification of the preload characteristics, the actual and comprehensive output characteristics of the PPCA can be obtained by the strain gauge sensor (SGS) embedded in the PPCA.
关键词: nanopositioning preload characteristic packaged piezoelectric ceramic actuator compliant mechanism
Piezoelectric film-actuated motion platform with high resolution
HUA Shunming, ZHANG Hongzhuang, CHENG Guangming, FAN Zunqiang, LIU Jianfang
《机械工程前沿(英文)》 2008年 第3卷 第3期 页码 265-269 doi: 10.1007/s11465-008-0041-2
关键词: mathematical stick-slip mechanism piezoelectric film-actuated analysis terrific
Francesco PENTA,Cesare ROSSI,Sergio SAVINO
《机械工程前沿(英文)》 2016年 第11卷 第2期 页码 184-194 doi: 10.1007/s11465-016-0385-y
This study aims to optimize the geometrical parameters of an under-actuated mechanical finger by conducting a theoretical analysis of these parameters. The finger is actuated by a flexion tendon and an extension tendon. The considered parameters are the tendon guide positions with respect to the hinges. By applying such an optimization, the correct kinematical and dynamical behavior of the closing cycle of the finger can be obtained. The results of this study are useful for avoiding the snap-through and the single joint hyperflexion, which are the two breakdowns most frequently observed during experimentation on prototypes. Diagrams are established to identify the optimum values for the tendon guides position of a finger with specified dimensions. The findings of this study can serve as guide for future finger design.
关键词: tendon-driven fingers mechanical finger design under-actuated mechanical systems
A novel shape memory alloy actuated soft gripper imitated hand behavior
《机械工程前沿(英文)》 2022年 第17卷 第4期 doi: 10.1007/s11465-022-0700-8
关键词: shape memory alloy (SMA) pre bent wire gripper grasping mode lightweight
Structural design of morphing trailing edge actuated by SMA
Qi WANG, Zhiwei XU, Qian ZHU
《机械工程前沿(英文)》 2013年 第8卷 第3期 页码 268-275 doi: 10.1007/s11465-013-0261-y
In this paper, the morphing trailing edge is designed to achieve the up and down deflection under the aerodynamic load. After a detailed and accurate computational analysis to determine the SMA specifications and layout programs, a solid model is created in CATIA and the structures of the morphing wing trailing edge are produced by CNC machining. A set of DSP measurement and control system is designed to accomplish the controlling experiment of the morphing wing trailing edge. At last, via the force analysis, the trailing edge is fabricated with four sections of aluminum alloy, and the arrangement scheme of SMA wires is determined. Experiment of precise control integral has been performed to survey the control effect. The experiment consists of deflection angle tests of the third joint and the integral structure. Primarily, the ultimate deflection angle is tested in these two experiments. Therefore, the controlling experiment of different angles could be performed within this range. The results show that the deflection error is less than 4% and response time is less than 6.7 s, the precise controlling of the morphing trailing edge is preliminary realized.
关键词: morphing wing trailing edge shape memory alloy digital signal processor PID algorithm
Push recovery for the standing under-actuated bipedal robot using the hip strategy
Chao LI,Rong XIONG,Qiu-guo ZHU,Jun WU,Ya-liang WANG,Yi-ming HUANG
《信息与电子工程前沿(英文)》 2015年 第16卷 第7期 页码 579-593 doi: 10.1631/FITEE.14a0230
关键词: Push recovery Balance control Bipedal robot Hip strategy
Motion capability analysis of a quadruped robot as a parallel manipulator
Jingjun YU,Dengfeng LU,Zhongxiang ZHANG,Xu PEI
《机械工程前沿(英文)》 2014年 第9卷 第4期 页码 295-307 doi: 10.1007/s11465-014-0317-7
This paper presents the forward and inverse displacement analysis of a quadruped robot MANA as a parallel manipulator in quadruple stance phase, which is used to obtain the workspace and control the motion of the body. The robot MANA designed on the basis of the structure of quadruped mammal is able to not only walk and turn in the uneven terrain, but also accomplish various manipulating tasks as a parallel manipulator in quadruple stance phase. The latter will be the focus of this paper, however. For this purpose, the leg kinematics is primarily analyzed, which lays the foundation on the gait planning in terms of locomotion and body kinematics analysis as a parallel manipulator. When all four feet of the robot contact on the ground, by assuming there is no slipping at the feet, each contacting point is treated as a passive spherical joint and the kinematic model of parallel manipulator is established. The method for choosing six non-redundant actuated joints for the parallel manipulator from all twelve optional joints is elaborated. The inverse and forward displacement analysis of the parallel manipulator is carried out using the method of coordinate transformation. Finally, based on the inverse and forward kinematic model, two issues on obtaining the reachable workspace of parallel manipulator and planning the motion of the body are implemented and verified by ADAMS simulation.
关键词: quadruped robot actuated joints selection kinematics analysis motion planning parallel manipulator
一种应用于功率放大液压驱动外骨骼的基于物理人机交互估计的控制策略 None
Yi LONG, Zhi-jiang DU, Wei-dong WANG, Long HE, Xi-wang MAO, Wei DONG
《信息与电子工程前沿(英文)》 2018年 第19卷 第9期 页码 1076-1085 doi: 10.1631/FITEE.1601667
标题 作者 时间 类型 操作
Parasitic rotation evaluation and avoidance of 3-UPU parallel mechanism
Haibo QU, Yuefa FANG, Sheng GUO
期刊论文
A redundantly actuated PRPRP radial mechanism in the segment erector of a shield machine for synchronization
Wanghui BU, Zhenyu LIU, Jianrong TAN, Jin CHENG
期刊论文
Development of a redundant anthropomorphic hydraulically actuated manipulator with a roll–pitch–yaw spherical
期刊论文
Preload characteristics identification of the piezoelectric-actuated 1-DOF compliant nanopositioning
Ruizhou WANG, Xianmin ZHANG
期刊论文
Piezoelectric film-actuated motion platform with high resolution
HUA Shunming, ZHANG Hongzhuang, CHENG Guangming, FAN Zunqiang, LIU Jianfang
期刊论文
Analysis of suitable geometrical parameters for designing a tendon-driven under-actuated mechanical finger
Francesco PENTA,Cesare ROSSI,Sergio SAVINO
期刊论文
Push recovery for the standing under-actuated bipedal robot using the hip strategy
Chao LI,Rong XIONG,Qiu-guo ZHU,Jun WU,Ya-liang WANG,Yi-ming HUANG
期刊论文
Motion capability analysis of a quadruped robot as a parallel manipulator
Jingjun YU,Dengfeng LU,Zhongxiang ZHANG,Xu PEI
期刊论文