Fully Isotropic Four-Degrees-of-Freedom Parallel Mechanisms for Schoenflies Motion

This paper presents a novel family of fully isotropic parallel mechanisms whose output link is provided with Schoenflies motion, i.e., it can freely translate in space and rotate about a fixed direction. A methodology is proposed that makes use of the theory of screws to synthesize desired forms for both the direct and the inverse Jacobian matrices. In particular, these are made diagonal and constant throughout the workspace. Motors are mounted one per leg and each one of them actuates one of the degrees of freedom of the output body through a constant one-to-one velocity relation. As a consequence, motors may apply, with equal ease, a twist or a wrench of any amplitude (within the motor operation range) to the end-effector around any screw congruous with the admitted motion, so that full isotropy is achieved. Kinematic analysis is trivial and no computation is required for real-time control. Furthermore, actuator motion ranges can be easily related to the theoretical workspace dimensions and the problem of link interference is potentially simplified.

[1]  C. Melchiorri,et al.  Robot manipulability , 1995, IEEE Trans. Robotics Autom..

[2]  Clément Gosselin,et al.  On the Kinematic Design of Spherical Three-Degree-of- Freedom Parallel Manipulators , 1993, Int. J. Robotics Res..

[3]  Marco Carricato,et al.  A Family of 3-DOF Translational Parallel Manipulators , 2003 .

[4]  C. Gosselin,et al.  Type Synthesis of 3-DOF Spherical Parallel Manipulators Based on Screw Theory , 2004 .

[5]  Clément Gosselin,et al.  Constraint singularities of parallel mechanisms , 2002, Proceedings 2002 IEEE International Conference on Robotics and Automation (Cat. No.02CH37292).

[6]  Vincenzo Parenti-Castelli,et al.  Echelon form solution of direct kinematics for the general fully-parallel spherical wrist , 1993 .

[7]  J. M. Hervé.  The Lie group of rigid body displacements, a fundamental tool for mechanism design , 1999 .

[8]  R. Clavel,et al.  A Fast Robot with Parallel Geometry , 1988 .

[9]  D. Stewart.  A Platform with Six Degrees of Freedom , 1965 .

[10]  Qiong Jin,et al.  Structure Synthesis of Parallel Manipulators With 3-Dimension Translation and 1-Dimension Rotation , 2002 .

[11]  Xianwen Kong,et al.  Type Synthesis of 3-DOF Translational Parallel Manipulators Based on Screw Theory , 2004 .

[12]  Q. C. Li,et al.  General Methodology for Type Synthesis of Symmetrical Lower-Mobility Parallel Manipulators and Several Novel Manipulators , 2002, Int. J. Robotics Res..

[13]  Reymond Clavel,et al.  Argos: A Novel 3-DoF Parallel Wrist Mechanism , 2000, Int. J. Robotics Res..

[14]  Xin-Jun Liu,et al.  Some New Parallel Mechanisms Containing the Planar Four-Bar Parallelogram , 2003, Int. J. Robotics Res..

[15]  Jadran Lenarčič,et al.  Advances in Robot Kinematics , 2000 .

[16]  Clément Gosselin,et al.  Type Synthesis of Three-Degree-of-Freedom Spherical Parallel Manipulators , 2004, Int. J. Robotics Res..

[17]  J. M. Hervé,et al.  A Family of Novel Orientational 3-DOF Parallel Robots , 2002 .

[18]  François Pierrot,et al.  A new high-speed 4-DOF parallel robot synthesis and modeling issues , 2003, IEEE Trans. Robotics Autom..

[19]  J. S. Rao,et al.  Mechanism and machine theory , 1989 .

[20]  L. Tsai,et al.  Jacobian Analysis of Limited-DOF Parallel Manipulators , 2002 .

[21]  K. H. Hunt.  Constant-Velocity Shaft Couplings: A General Theory , 1973 .

[22]  Kenneth H. Hunt.  Review: Don't Cross-Thread the Screw! , 2003, J. Field Robotics.

[23]  Marco Carricato,et al.  A Novel Fully Decoupled Two-Degrees-of-Freedom Parallel Wrist , 2004, Int. J. Robotics Res..

[24]  Marco Carricato,et al.  Singularity-Free Fully-Isotropic Translational Parallel Mechanisms , 2002, Int. J. Robotics Res..

[25]  F. Park,et al.  Manipulability of Closed Kinematic Chains , 1998 .

[26]  Yuefa Fang,et al.  Structure Synthesis of a Class of 4-DoF and 5-DoF Parallel Manipulators with Identical Limb Structures , 2002, Int. J. Robotics Res..

[27]  Z. Huang,et al.  Type Synthesis of Symmetrical Lower-Mobility Parallel Mechanisms Using the Constraint-Synthesis Method , 2003, Int. J. Robotics Res..

[28]  Joseph Duffy,et al.  A Direct Determination of the Instantaneous Kinematics of Fully Parallel Robot Manipulators , 1985 .

[29]  K. H. Hunt,et al.  Kinematic geometry of mechanisms , 1978 .

[30]  Antonio Frisoli,et al.  SYNTHESIS BY SCREW ALGEBRA OF TRANSLATING IN-PARALLEL ACTUATED MECHANISMS , 2000 .

[31]  Xianwen Kong,et al.  Type Synthesis of Linear Translational Parallel Manipulators , 2002 .

[32]  L. Tsai,et al.  Kinematics and Optimization of a Spatial 3-UPU Parallel Manipulator , 2000 .

[33]  Clément Gosselin,et al.  Singularity analysis of closed-loop kinematic chains , 1990, IEEE Trans. Robotics Autom..