Forward/inverse force transmission capability analyses of fully parallel manipulators

A state of the art survey of ice rubble mechanics is first presented. This survey covers ice rubble morphology, laboratory testing of ice rubble, the study of the load transmission capability of existing rubble fields, and field measurements in ice rubble surrounding offshore structures. Then, the implementation of a new plasticity model for normally consolidated broken ice into an existing finite element stress analysis code is described. The resulting program is validated using triaxial test data. Using this model, a two-dimensional parametric study on ice force transmission through a grounded ice rubble field is performed. The study shows that, in addition to the mechanical properties of ice rubble, the island or berm geometry may significantly affect the ice load. Key words: constitutive model, finite element analysis, ice load, ice rubble, offshore structure, plasticity.

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Evaluation of the Maximum Value of Motion/force Transmission Power in Parallel Manipulators

Journal of Mechanical Engineering ◽

10.3901/jme.2014.03.001 ◽

2014 ◽

Vol 50 (3) ◽

pp. 1 ◽

Cited By ~ 6

Author(s):

Xiang CHEN

Keyword(s):

Parallel Manipulators ◽

Transmission Power ◽

Force Transmission ◽

Maximum Value

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Design of a Three-Axis Articulated Tool Head With Parallel Kinematics Achieving Desired Motion/Force Transmission Characteristics

Journal of Manufacturing Science and Engineering ◽

10.1115/1.4001244 ◽

2010 ◽

Vol 132 (2) ◽

Cited By ~ 24

Author(s):

Xin-Jun Liu ◽

Li-Ping Wang ◽

Fugui Xie ◽

Ilian A. Bonev

Keyword(s):

Parallel Kinematics ◽

Force Transmission ◽

Spherical Joint ◽

Transmission Characteristics ◽

Design Issue ◽

Transmission Capability ◽

High Orientation ◽

Dimensional Optimization

This paper addresses the design issue of a three-axis tool head with three-PRS parallel kinematics (P, R, and S standing for prismatic, revolute, and spherical joint, respectively) by considering their orientation capability and motion/force transmission. The content presented here is actually an improvement on the dimensional optimization of articulated tool heads with parallel kinematics, with emphasis on the three-PRS design to solve the problem of orientational capability. An index that can evaluate the effectiveness of the motion/force transmission is introduced. The orientation capability with which the mechanism has high motion/force transmission capability is then defined. The procedure searching the link lengths with which the mechanism has a high orientation capability and good effectiveness of motion/force transmission is finally presented.

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Optimal Design of Spherical 5R Parallel Manipulators Considering the Motion/Force Transmissibility

Journal of Mechanical Design ◽

10.1115/1.4001129 ◽

2010 ◽

Vol 132 (3) ◽

Cited By ~ 62

Author(s):

Chao Wu ◽

Xin-Jun Liu ◽

Liping Wang ◽

Jinsong Wang

Keyword(s):

Performance Evaluation ◽

Optimal Design ◽

Parallel Manipulator ◽

Screw Theory ◽

Parallel Manipulators ◽

Dimensional Synthesis ◽

Force Transmission ◽

Minimally Invasive Surgical ◽

Pointing Device ◽

Force Transmissibility

The spherical 5R parallel manipulator is a typical parallel manipulator. It can be used as a pointing device or as a minimally invasive surgical robot. This study addresses the motion/force transmission analysis and optimization of the manipulator by taking into account the motion/force transmissibility. The kinematics of the manipulator is analyzed. Several transmission indices are defined by using screw theory for the performance evaluation and dimensional synthesis. The process of determining the optimal angular parameters based on performance charts is presented. The manipulator that has a large workspace and good motion/force transmissibility is identified.

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Force transmission analyses with dimensionally homogeneous Jacobian matrices for parallel manipulators

KSME International Journal ◽

10.1007/bf02990296 ◽

2004 ◽

Vol 18 (5) ◽

pp. 780-788 ◽

Cited By ~ 7

Author(s):

Sung-Gaun Kim ◽

Jeha Ryu

Keyword(s):

Parallel Manipulators ◽

Force Transmission ◽

Jacobian Matrices

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Determination of the closed-form workspace area expression and dimensional optimization of planar parallel manipulators

Robotica ◽

10.1017/s0263574716000710 ◽

2016 ◽

Vol 35 (10) ◽

pp. 2056-2075 ◽

Cited By ~ 4

Author(s):

M. Ganesh ◽

Banke Bihari ◽

Vijay Singh Rathore ◽

Dhiraj Kumar ◽

Chandan Kumar ◽

...

Keyword(s):

Closed Form ◽

Degrees Of Freedom ◽

Solution Space ◽

Optimization Procedure ◽

Parallel Manipulators ◽

Force Transmission ◽

Workspace Analysis ◽

Planar Parallel Manipulator ◽

Transmission Index ◽

Planar Parallel Manipulators

SUMMARYOptimization is an important step in the design and development of a planar parallel manipulator. For optimization processes, workspace analysis is a crucial and preliminary objective. Generally, the workspace analysis for such manipulators is carried out using a non-dimensional approach. For planar parallel manipulators of two degrees of freedom (2-DOF), a non-dimensional workspace analysis is very advantageous. However, it becomes very difficult in the case of 3-DOF and higher DOF manipulators because of the complex shape of the workspace. In this study, the workspace shape is classified as a function of the geometric parameters, and the closed-form area expressions are derived for a constant orientation workspace of a three revolute–revolute–revolute (3-RRR) planar manipulator. The approach is also shown to be feasible for different orientations of a mobile platform. An optimization procedure for the design of planar 3-RRR manipulators is proposed for a prescribed workspace area. It is observed that the closed-form area expression for all the possible shapes of the workspace provides a larger solution space, which is further optimized considering singularity, mass of the manipulator, and a force transmission index.

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