A novel planar parallel manipulator with high orientation capability for a hybrid machine tool: kinematics, dimensional synthesis and performance evaluation

Robotica ◽  
2015 ◽  
Vol 35 (5) ◽  
pp. 1031-1053 ◽  
Author(s):  
Samy F. M. Assal
Keyword(s):  
Performance Evaluation ◽  
Machine Tool ◽  
Parallel Manipulator ◽  
Parallel Manipulators ◽  
Design Parameters ◽  
Dimensional Synthesis ◽  
Hybrid Machine Tool ◽  
Planar Parallel Manipulator ◽  
Hybrid Machine ◽  
High Orientation

SUMMARYIn order to potentially realize the advantages of planar parallel manipulators to be used for hybrid machine tools, the inherently abundant singularities which diminish the usable workspace must be eliminated. Proper structure synthesis and dimensional synthesis can provide a good solution. So, a non-conventional architecture of a three-PPR planar parallel manipulator is proposed in this paper for a hybrid machine tool. The proposed architecture permits a large dexterous workspace with unlimited orientation capability and no singularities. It also provides partially decoupled motion which permits independent actuators control. The kinematic, singularity, orientation capability and workspace analyses of the proposed manipulator are studied to verify those advantages. Based on a non-dimensional design parameter space, the highly important indices for this application namely the workspace index (WI), the motion/force transmission index, the kinematic and dynamic dexterity indices and the stiffness index are selected to be maximized yielding proper dimensions of the design parameters. Those performance indices are proven to be uniform over all the workspace achieving highly important characteristics of uniform accuracy, acceleration characteristics, rigidity and force transmissibility. Performance evaluation is finally presented to verify the high performance of the proposed non-singular planar parallel manipulator with high orientation capability.

Kinematic and dynamic equations of a planar parallel manipulator

2003 ◽  
Vol 217 (5) ◽  
pp. 525-531 ◽  
Author(s):  
L-P Wang ◽  
J-S Wang ◽  
Y-W Li ◽  
Y Lu
Keyword(s):  
Machine Tool ◽  
Parallel Manipulator ◽  
Driving Forces ◽  
Dynamic Modelling ◽  
Parallel Manipulators ◽  
Hybrid Machine Tool ◽  
Dynamic Formulation ◽  
Planar Parallel Manipulator ◽  
Hybrid Machine ◽  
Five Axis

This paper presents an inverse dynamic formulation using the Newton-Euler approach for a planar parallel manipulator, which is used in a new five-axis hybrid machine tool. The inverse kinematics of the manipulator is given and the velocity and the acceleration formulae are derived. The driving forces acting on the legs are determined according to the dynamic formulation. The formulation has been implemented in a program and has been used for some typical trajectories planned for a numerical simulation experiment. The simulation results reveal the nature of the variation of the driving forces in the hybrid machine tool and justify the dynamic control model. The dynamic modelling approach presented in this paper can also be applied to other parallel manipulators with less than six degrees of freedom.

Dynamic Analysis and Counterweight Optimization of the 2-DOF Parallel Manipulator of a Hybrid Machine Tool

2007 ◽  
Vol 2 (4) ◽  
pp. 344-350 ◽  
Author(s):  
Jun Wu ◽  
Jinsong Wang ◽  
Liping Wang ◽  
Tiemin Li ◽  
Yue Liu
Keyword(s):  
Machine Tool ◽  
Parallel Manipulator ◽  
Cutting Tool ◽  
Force Model ◽  
Cutting Force Model ◽  
Dynamic Simulations ◽  
Hybrid Machine Tool ◽  
Planar Parallel Manipulator ◽  
Hybrid Machine ◽  
Two Degree Of Freedom

This paper focuses on the dynamic modeling and counterweight optimization of the two degree of freedom planar parallel manipulator, which is a subpart of a hybrid machine tool. Based on a kinematic analysis, the dynamic equation is derived by using the Newton-Euler approach. Then, three counterweight modes are presented for the parallel manipulator. According to the cutting force model and motion planning of the cutting tool, the dynamic simulations with three counterweight modes are performed, and the mass of counterweight in each counterweight mode is optimized by minimizing the sum of mean square values of actuator forces. The simulations show that the optimal mass of counterweights does not equal the total mass of moving parts of the parallel manipulator, and each counterweight mode has its advantage and disadvantage. Considering the ease in which a counterweight can be implemented, the counterweight mode where two counterweights are connected to two sliders is adopted for the parallel manipulator.

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

2010 ◽  
Vol 132 (3) ◽  
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.

Optimal Kinematic Design and Application of a Redundantly Actuated 3DOF Planar Parallel Manipulator

2008 ◽  
Vol 130 (5) ◽  
Author(s):  
Jun Wu ◽  
Jinsong Wang ◽  
Liping Wang
Keyword(s):  
Machine Tool ◽  
Gas Turbines ◽  
Parallel Manipulator ◽  
Kinematic Model ◽  
Performance Measure ◽  
Kinematic Design ◽  
Hybrid Machine Tool ◽  
Planar Parallel Manipulator ◽  
Redundantly Actuated ◽  
Design And Application

This paper addresses optimal kinematic design and application of a redundantly actuated parallel manipulator with 3DOFs. Based on the kinematic model, the Jacobian matrix is derived and then transferred to a uniform form such that the conditioning index has explicit physical meaning. Based on the task workspace, the width between two columns is determined. Then, a comprehensive performance index, which compromises the conflict between workspace utilization performance measure and conditioning index, is proposed for the optimum design. The parallel manipulator is incorporated into a 4DOF hybrid machine tool, which also includes a feed worktable. Furthermore, a 5DOF machine tool is created by combining the parallel manipulator with a 2DOF worktable to machine blades of gas turbines.

Workspace and singularity analysis of a 3-DOF planar parallel manipulator with actuation redundancy

Robotica ◽  
2009 ◽  
Vol 27 (1) ◽  
pp. 51-57 ◽  
Author(s):  
Jinsong Wang ◽  
Jun Wu ◽  
Tiemin Li ◽  
Xinjun Liu
Keyword(s):  
Parallel Manipulator ◽  
Parallel Manipulators ◽  
Singularity Analysis ◽  
Actuation Redundancy ◽  
Hybrid Machine Tool ◽  
Planar Parallel Manipulator ◽  
Redundantly Actuated ◽  
Value Decomposition ◽  
The Relationship ◽  
Orientation Workspace

SUMMARYThis paper deals with the position workspace, orientation workspace, and singularity of a 3-degree-of-freedom (DOF) planar parallel manipulator with actuation redundancy, which is created by introducing a redundant link with active actuator to a 3-DOF nonredundant parallel manipulator. Based on the kinematic analysis, the position workspace and orientation workspace of the redundantly actuated parallel manipulator and its corresponding nonredundant parallel manipulator are analyzed, respectively. In the singularity analysis phase, the relationship between the generalized input velocity and the generalized output velocity is researched on the basis of the theory of singular value decomposition. Then a method to investigate the singularity of parallel manipulators is presented, which is used to determine the singularity of the redundantly actuated parallel manipulator. In contrast to the corresponding nonredundant parallel manipulator, the redundant one has larger orientation workspace and less singular configurations. The redundantly actuated parallel manipulator is incorporated into a 4-DOF hybrid machine tool which also includes a feed worktable to demonstrate its applicability.

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