Analysis of a Novel Fully-isotropy 3T Parallel Mechanism

Abstract

Abstract: To avoid the difficulties in the kinematics analysis and control brought by the existence of coupling in a PM, a novel kind of fully isotropic PM with three translational degrees of freedom was presented. This PM was connected by three limb chains between the moving platform and the fixed base. The first prismatic pairs of three limb chains were in orthogonal distribution, which made the moving platform of the mechanism have three translational degrees of freedom, and there existed a one-to-one correspondence between the input and output displacements. The mechanism’s most prominent advantages are simple kinematic pairs, three translations decoupled, simple kinematics analysis and to facilitate the mechanism motion control design. Using screw theory the degree of freedom and properties were analyzed and the active pair of the mechanism was determined. It also gave out the mechanism's forward and inverse position and velocity analysis, workspace and movement performance. According to the relationship of input and output, Jacobi matrix was solved and fully isotropic of mechanism was verified. Thus it provides a theoretical guidance to the further applications, and also has good application prospects.

Key words: parallel mechanism(PM), kinematics, workspace, isotropy

摘要： 针对并联机构耦合带来运动学分析与控制困难的问题，提出了一种新型完全各向同性的三维移动并联机构，该并联机构动平台和静平台之间由3条支链连接，3条支链的第一个移动副在空间中呈正交分布，使得该机构的动平台具有3个移动自由度，且输入输出一一对应。这种机构最突出的优点是运动副简单，三维移动解耦，运动学分析简单，便于该机构运动控制设计。采用螺旋理论分析了该机构的自由度及性质，确定了机构的主动副，给出了机构的位置和速度正反解，分析了机构工作空间及运动性能。根据机构输入输出关系，求得机构雅可比矩阵，验证了机构具有完全各向同性。研究结果对该机构的进一步应用具有理论指导意义。

关键词: 并联机构, 运动学, 工作空间, 各向同性

CLC Number:

TH112

Cao Haofeng, Cao Yi, Qin Youlei, Ding Rui. Analysis of a Novel Fully-isotropy 3T Parallel Mechanism[J]. China Mechanical Engineering.

曹浩峰, 曹毅, , 秦友蕾, 丁锐. 新型完全各向同性3T并联机构及其特性分析[J]. 中国机械工程.

References

[1]张彦斌, 吴鑫. 完全解耦二移动二转动并联机构结构综合[J]. 农业机械学报, 2013, 44(8):250-256.

Zhang Yanbin, Wu Xin. Structural Synthesis of Fully-decoupled Two-translational and Two-rotational Parallel Mechanisms[J].Transactions of the Chinese Society for Agricultural Machinery, 2013, 44(8):250-256.

[2]Gogu G. Fully-isotropic Parallel Robots with Four Degrees of Freedom T2R2-type[C]// 2005 IEEE/RSJ International Conference on Intelligent Robots and Systems, 2005(IROS 2005). Edmonton: IEEE, 2005:960-965.

[3]Richard P L, Gosselin C M, Kong X. Kinematic Analysis and Prototyping of a Partially Decoupled 4-DoF 3T1R Parallel Manipulator[J]. Journal of Mechanical Design, 2007, 129(6): 611-616.

[4]Li W, Gao F, Zhang J. R-CUBE, a Decoupled Parallel Manipulator Only with Revolute Joints[J]. Mechanism and Machine Theory, 2005, 40(4): 467-473.

[5]Legnani G, Fassi I, Giberti H, et al. A New Isotropic and Decoupled 6-DoF Parallel Manipulator[J]. Mechanism and Machine Theory, 2012, 58: 64-81.

[6]侯雨雷, 张占叶, 胡鑫喆, 等. 新型两转动自由度完全解耦并联机构及其特性[J]. 哈尔滨工业大学学报, 2014, 46(9):80-85.

Hou Yulei, Zhang Zhanye, Hu Xinzhe,et al. A Novel 2-DOF Fully Decoupled Rotational Parallel Mechanism and Its Characteristics[J]. Journal of Harbin Institute of Technology, 2014, 46(9):80-85.

[7]金琼, 杨廷力. 一类新型三平移并联机器人机构的位置分析[J]. 东南大学学报: 自然科学版, 2001, 31(5): 33-38.

Jin Qiong，Yang Tingli. Position Analysis for a Class of Novel 3-DOF Translational Parallel Robot Mechanisms[J]. Journal of Southeast University(Natural Science Edition), 2001, 31(5): 33-38.

[8]Jin Q, Yang T L. Synthesis and Analysis of a Group of 3-degree-of-freedom Partially Decoupled Parallel Manipulators[J]. Journal of Mechanical Design, 2004, 126(2): 301-306.

[9]Glazunov V. Design of Decoupled Parallel Manipulators by Means of the Theory of Screws[J]. Mechanism and Machine Theory, 2010, 45(2): 239-250.

[10]杭鲁滨, 王彦, 吴俊, 等. 基于拓扑解耦准则的球面并联机构解耦条件研究[J]. 机械工程学报, 2006, 41(9): 28-32.

Hang Lubin, Wang Yan, Wu Jun, et al. Study on the Decoupling Conditions of the Spherical Parallel Mechanism Based on the Criterion for Topologically Decoupled Parallel Mechanisms[J]. Journal of Mechanical Engineering, 2006, 41(9): 28-32.

[11]黄真，刘婧芳，李艳文.论机构的自由度[M].北京：科学出版社,2011.

[12]王英, 李秦川, 武传宇,等. 一种具有各向同性的3-PPRRR移动并联机构[J]. 中国机械工程, 2009, 20(10):1135-1140.

Wang Ying, Li Qinchuan, Wu Chuanyu,et al. A 3-DOF 3-PPRRR Translational Parallel Mechanism with Fully-isotropy[J]. China Mechanical Engineering, 2009, 20(10):1135-1140.

[13]杨廷力. 机器人机构拓扑结构学[M]. 北京：机械工业出版社, 2004.

[14]Gogu G. Structural Synthesis of Fully-isotropic Translational Parallel Robots via Theory of Linear Transformations[J]. European Journal of Mechanics-A/Solids, 2004, 23(6):1021-1039.

[15]Chen X, Sun X. Dexterity Analysis of a 4-UPS-RPS Parallel Mechanism[J]. International Journal of Advanced Robotic Systems, 2012, 9(4):467-485.