Improving the kinematic performance of a planar 3-RRR parallel manipulator through actuation mode conversion

2018 ◽  
Vol 130 ◽  
pp. 86-108 ◽  
Author(s):  
Zhaokun Zhang ◽  
Liping Wang ◽  
Zhufeng Shao
Keyword(s):  
Parallel Manipulator ◽  
Mode Conversion ◽  
Actuation Mode ◽  
Kinematic Performance

Kinematic Optimization of Parallel Manipulators with a Desired Workspace

2015 ◽  
Vol 752-753 ◽  
pp. 973-979 ◽  
Author(s):  
Ze Guo Yang ◽  
Ming Lei Shao ◽  
Dong Ik Shin
Keyword(s):  
Parallel Manipulator ◽  
Parallel Manipulators ◽  
Optimization Method ◽  
Practical Application ◽  
Essential Requirement ◽  
Physical Size ◽  
Kinematic Performance ◽  
The Cost ◽  
Stewart Gough Platform ◽  
Kinematic Optimization

A kinematic optimization method of parallel manipulators is presented in this paper. A desired workspace for a parallel manipulator is usually an essential requirement in a practical application. Additionally, a good kinematic performance and/or a relatively small physical size would be of great significance. A dexterity index is utilized to measure the kinematic performance of parallel manipulators. A method to define the physical size of a parallel manipulator is introduced. The cost function is then formulated as a linear combination of a dexterity index and a physical size measurement. The Optimization Tool Box of MATLAB is applied to solve the optimization problem. Finally, a general Stewart-Gough platform is taken as an example to specify the design methodology.

Algorithm for the Actuation Mode Selection of the Parallel Manipulator NAVARO

2014 ◽  
Author(s):  
Stéphane Caro ◽  
Damien Chablat ◽  
Yue Hu
Keyword(s):  
Parallel Manipulator ◽  
Dynamic Models ◽  
Mode Selection ◽  
Parallel Manipulators ◽  
Control Algorithms ◽  
Planar Parallel Manipulator ◽  
Dynamic Performances ◽  
Actuation Mode ◽  
Three Degree Of Freedom ◽  
Selection Of

Kinematic and dynamic performances of parallel manipulators are usually not homogeneous throughout their operational workspace. This problem is usually solved by introducing actuation redundancy, which involves force control algorithms. Another approach is the selection of the best actuation modes along a trajectory to be followed with regard to the kinetostatic, elastostatic and dynamic performances of the parallel manipulator. Accordingly, this paper introduces a three degree-of-freedom planar parallel manipulator with variable actuation modes, named NAVARO. NAVARO stands for NAntes Variable Actuation RObot and has eight actuation modes. First, the prototype of the manipulator is presented. Then, its transmission systems are presented. The kinematic and dynamic models of the NAVARO are developed. Finally, an algorithm for multiobjective actuation mode selection based on graph theory is detailed.

Kinematic Analysis and Optimal Design of a Novel Schönflies-Motion Parallel Manipulator with Rotational Pitch Motion for Assembly Operations

2021 ◽  
pp. 1-17
Author(s):  
Xiansheng Yang ◽  
Zhilong Zhao ◽  
Hao Xiong ◽  
Qinchuan Li ◽  
Yunjiang Lou
Keyword(s):  
Optimal Design ◽  
Design Optimization ◽  
Cross Sections ◽  
Parallel Manipulator ◽  
Pitch Motion ◽  
Optimization Formulation ◽  
Kinematic Performance ◽  
Schönflies Motion ◽  
Assembly Operations ◽  
Orientation Workspace

Abstract This paper presents a novel Schönflies-motion Parallel Manipulator with Rotational Pitch motion (SPM-RP) based on a single-platform fully-parallel mechanism. The analysis of position, workspace, velocity, and singularity of the SPM-RP is carried out in detail, and a dimensionless Jacobian is proposed to evaluate the manipulability of the SPM-RP. It is shown that the SPM-RP is kinematically position-decoupled, which possesses a large singularity-free workspace and excellent manipulability. The SPM-RP is actuated by four parallel prismatic actuators, enabling the manipulator to provide identical kinematic performance at all generic cross-sections perpendicular to the prismatic joint axes within its workspace. This paper thus proposes a reduced design optimization formulation, where the traditional optimization over the entire workspace is reduced to one on a representative workspace cross-section of the SPM-RP. The design optimization of the SPM-RP has been carried out by maximizing its manipulability over the total orientation workspace, which is crucial for precision assembly. A SPM-RP prototype has been developed based on the achieved optimal design. The mobility, orientation capability, total orientation workspace, and repeatability are tested and verified for the developed SPM-RP prototype. Experiments show that the SPM-RP achieves a large total orientation workspace with excellent precision performance.

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