Dimensional Synthesis of Parallel Mechanisms

2013 ◽  
pp. 239-289
Author(s):  
Xin-Jun Liu ◽  
Jinsong Wang
Keyword(s):  
Parallel Mechanisms ◽  
Dimensional Synthesis

The Dimensional Synthesis of Spatial Cable-Driven Parallel Mechanisms

2013 ◽  
Vol 5 (4) ◽  
Author(s):  
K. Azizian ◽  
P. Cardou
Keyword(s):  
Synthesis Method ◽  
Sufficient Condition ◽  
Nonlinear Program ◽  
Parallel Mechanisms ◽  
Dimensional Synthesis ◽  
End Effector ◽  
A Value ◽  
Null Value ◽  
Objective Value

This paper presents a method for the dimensional synthesis of fully constrained spatial cable-driven parallel mechanisms (CDPMs), namely, the problem of finding a geometry whose wrench-closure workspace (WCW) contains a prescribed workspace. The proposed method is an extension to spatial CDPMs of a synthesis method previously published by the authors for planar CDPMs. The WCW of CDPMs is the set of poses for which any wrench can be produced at the end-effector by non-negative cable tensions. A sufficient condition is introduced in order to verify whether a given six-dimensional box, i.e., a box covering point-positions and orientations, is fully inside the WCW of a given spatial CDPM. Then, a nonlinear program is formulated, whose optima represent CDPMs that can reach any point in a set of boxes prescribed by the designer. The objective value of this nonlinear program indicates how well the WCW of the resulting CDPM covers the prescribed box, a null value indicating that none of the WCW is covered and a value greater or equal to one indicating that the full prescribed workspace is covered.

Synthesis of Spatial Parallel Mechanisms for a Vertical and Longitudinal All-Terrain Suspension

2012 ◽  
Vol 162 ◽  
pp. 19-28 ◽  
Author(s):  
Jean Christophe Fauroux
Keyword(s):  
Power Transmission ◽  
Parallel Structure ◽  
Small Scale ◽  
Parallel Mechanisms ◽  
Dimensional Synthesis ◽  
3D Kinematics ◽  
Highly Efficient ◽  
System A ◽  
Original Contribution ◽  
2D And 3D

Fast wheeled motion on unstructured grounds requires highly efficient suspensions that damp shocks vertically but also horizontally, which is an original contribution of the author. This work describes nine 2D and 3D kinematics, most of them with parallel structure, that are suitable for guiding a wheel and providing simultaneous damping in two directions. Steering and power transmission are also included in the most advanced variants, that were previously patented. Both structural and dimensional synthesis are presented, with a kinematic description of each system. A real implementation at a small scale is also described.

GEOMETRIC ANALYSIS OF THE KINEMATIC SENSITIVITY OF PLANAR PARALLEL MECHANISMS

2011 ◽  
Vol 35 (4) ◽  
pp. 477-490 ◽  
Author(s):  
Mohammad Hossein Saadatzi ◽  
Mehdi Tale Masouleh ◽  
Hamid D. Taghirad ◽  
Clément Gosselin ◽  
Philippe Cardou
Keyword(s):  
Physical Meaning ◽  
Performance Index ◽  
Geometric Analysis ◽  
Geometric Approach ◽  
Sensitivity Index ◽  
Parallel Mechanisms ◽  
Dimensional Synthesis ◽  
Kinematic Sensitivity

The kinematic sensitivity is a unit-consistent measure that has been recently proposed as a mechanism performance index to compare robot architectures. This paper presents a robust geometric approach for computing this index for the case of planar parallel mechanisms. The physical meaning of the kinematic sensitivity is investigated through different combinations of the Euclidean and infinity norms and by means of several illustrative examples. Finally, this paper opens some avenues to the dimensional synthesis of parallel mechanisms by exploring the meaning of the global kinematic sensitivity index.

scholarly journals Dimensional (Parametric) Synthesis of the Hexapod-Type Parallel Mechanism with Reconfigurable Design

Machines ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 117
Author(s):  
Alexey Fomin ◽  
Anton Antonov ◽  
Victor Glazunov ◽  
Giuseppe Carbone
Keyword(s):  
Parallel Mechanism ◽  
Optimization Problems ◽  
Equation System ◽  
Synthesis Problem ◽  
Parallel Mechanisms ◽  
Dimensional Synthesis ◽  
Computationally Efficient ◽  
Efficient Manner ◽  
Suggested Approach ◽  
Original Procedure

The study provides a solution to a dimensional synthesis problem for a hexapod-type reconfigurable parallel mechanism, which can change its configuration to realize different trajectories of its output link while having a single drive. The work presents an original procedure to find the dimensions of some mechanism’s links and their initial configuration to reproduce these trajectories. After describing the mechanism, the paper examines kinematic relations representing the basis for the subsequent synthesis algorithm. Next, the obtained expressions are extended and provide a system of equations to be solved. The structure of this equation system allows it to be solved effectively by numerical methods, which is demonstrated with an example. The proposed algorithm of dimensional synthesis does not require solving the optimization problems, in contrast to the familiar methods of dimensional synthesis of parallel mechanisms. Further, the suggested approach to the synthesis problem allows finding solution in a fast and computationally efficient manner.

A Method to Integrate Anthropometry to Davies' Method for Dimensional Synthesis of a Hospital Bed Backrest Mechanism

2019 ◽  
Author(s):  
Rodrigo Luís Pereira Barreto ◽  
Elias Renã Maletz ◽  
André Luís Molgaro ◽  
João Vitor Fernandes Brito ◽  
Daniel Martins
Keyword(s):  
Dimensional Synthesis ◽  
Hospital Bed

scholarly journals Hybrid Seven-bar Press Mechanism

2018 ◽  
Vol 12 (3) ◽  
pp. 181-187
Author(s):  
M. Erkan Kütük ◽  
L. Canan Dülger
Keyword(s):  
Genetic Algorithm ◽  
Objective Function ◽  
Design Optimization ◽  
Hybrid System ◽  
Degrees Of Freedom ◽  
Dimensional Synthesis ◽  
Design Variables ◽  
Optimization Study ◽  
Metal Stamping

An optimization study with kinetostatic analysis is performed on hybrid seven-bar press mechanism. This study is based on previous studies performed on planar hybrid seven-bar linkage. Dimensional synthesis is performed, and optimum link lengths for the mechanism are found. Optimization study is performed by using genetic algorithm (GA). Genetic Algorithm Toolbox is used with Optimization Toolbox in MATLAB®. The design variables and the constraints are used during design optimization. The objective function is determined and eight precision points are used. A seven-bar linkage system with two degrees of freedom is chosen as an example. Metal stamping operation with a dwell is taken as the case study. Having completed optimization, the kinetostatic analysis is performed. All forces on the links and the crank torques are calculated on the hybrid system with the optimized link lengths

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