scholarly journals Optimal Design of Parallel Kinematics Machines with 2 Degrees of Freedom

10.5772/5436 ◽  
2008 ◽  
Author(s):  
Sergiu-Dan Stan ◽  
Vistrian Maties ◽  
Radu Bal
Keyword(s):  
Optimal Design ◽  
Degrees Of Freedom ◽  
Parallel Kinematics ◽  
Parallel Kinematics Machines

Full-Mobility Three-CCC Parallel-Kinematics Machines: Kinematics and Isotropic Design

2017 ◽  
Vol 10 (1) ◽  
Author(s):  
Wei Li ◽  
Jorge Angeles
Keyword(s):  
Kinematic Analysis ◽  
Degrees Of Freedom ◽  
Large Region ◽  
Parallel Kinematics ◽  
Six Degrees Of Freedom ◽  
Parallel Kinematics Machines ◽  
The Subject ◽  
Moving Platform

The subject of this paper is twofold: the kinematics and the isotropic design of six degrees-of-freedom (DOF), three-CCC parallel-kinematics machines (PKMs). Upon proper embodiment and dimensioning, the PKMs discussed here, with all actuators mounted on the base, exhibit interesting features, not found elsewhere. One is the existence of an isotropy locus, as opposed to isolated isotropy points in the workspace, thereby guaranteeing the accuracy and the homogeneity of the motion of the moving platform (MP) along different directions within a significantly large region of their workspace. The conditions leading to such a locus are discussed in depth; several typical isotropic designs are brought to the limelight. Moreover, the kinematic analysis shows that rotation and translation of the MP are decoupled, which greatly simplifies not only the kinetostatic analysis but also, most importantly, their control. Moreover, it is shown that the singularity loci of this class of mechanism are determined only by the orientation of their MP, which also simplifies locus evaluation and eases its representation.

Optimal Design of 2 DOF Parallel Kinematics Machines

PAMM ◽  
2006 ◽  
Vol 6 (1) ◽  
pp. 705-706 ◽  
Author(s):  
Sergiu-Dan Stan ◽  
Vistrian Maties ◽  
Radu Balan
Keyword(s):  
Optimal Design ◽  
Parallel Kinematics ◽  
Parallel Kinematics Machines

Configuration Robustness Analysis of the Optimal Design of Cable-Driven Manipulators

2016 ◽  
Vol 8 (6) ◽  
Author(s):  
Joshua T. Bryson ◽  
Xin Jin ◽  
Sunil K. Agrawal
Keyword(s):  
Optimal Design ◽  
Stochastic Optimization ◽  
High Dimension ◽  
Degrees Of Freedom ◽  
Robustness Analysis ◽  
Optimal Solution ◽  
Design Parameters ◽  
Robot Leg ◽  
Robot Performance

Designing an effective cable architecture for a cable-driven robot becomes challenging as the number of cables and degrees of freedom of the robot increase. A methodology has been previously developed to identify the optimal design of a cable-driven robot for a given task using stochastic optimization. This approach is effective in providing an optimal solution for robots with high-dimension design spaces, but does not provide insights into the robustness of the optimal solution to errors in the configuration parameters that arise in the implementation of a design. In this work, a methodology is developed to analyze the robustness of the performance of an optimal design to changes in the configuration parameters. This robustness analysis can be used to inform the implementation of the optimal design into a robot while taking into account the precision and tolerances of the implementation. An optimized cable-driven robot leg is used as a motivating example to illustrate the application of the configuration robustness analysis. Following the methodology, the effect on robot performance due to design variations is analyzed, and a modified design is developed which minimizes the potential performance degradations due to implementation errors in the design parameters. A robot leg is constructed and is used to validate the robustness analysis by demonstrating the predicted effects of variations in the design parameters on the performance of the robot.

Optimal Design of IC Engine Cooling Fins by Using Genetic Algorithm

2014 ◽  
Author(s):  
Terry Yan ◽  
Jason Yobby ◽  
Ravindra Vundavilli
Keyword(s):  
Heat Transfer ◽  
Genetic Algorithms ◽  
Optimal Design ◽  
Degrees Of Freedom ◽  
Combustion Engine ◽  
Local Heat Transfer ◽  
System Component ◽  
Cylinder Wall ◽  
Ic Engine ◽  
Engine Cooling

The analysis for optimal design of an air-cooled internal combustion engine cooling fin array by using genetic algorithms (GA) is presented in this study. Genetic Algorithms are robust, stochastic search techniques which are also used for optimizing highly complex problems. In this study, the fin array is of the traditional circular fin type, which is subject to ambient convective heat transfer. The parameters (degrees of freedom) selected for the analysis include the cylinder wall thickness-to-radius ratio, fin thickness, fin length, the number of fins, and the local heat transfer coefficient. By using a single objective GA procedure, the heat transfer through the fin arrays is set as the objective function to be optimized with each parameter varied within the physical ranges. Proper population size is selected and the mutations, cross-over and selection are conducted in the GA procedure to arrive at the optimal set of parameters after a certain number of generations. The GA proves to be an effective optimization method in the thermal system component designs when the number of independent variables is large.

On the Terminology for Redundant Parallel Manipulators

2008 ◽  
Author(s):  
Andreas Mu¨ller
Keyword(s):  
Dynamic Properties ◽  
Parallel Manipulators ◽  
Point Of View ◽  
Linear Control Systems ◽  
Parallel Kinematics ◽  
Parallel Kinematics Machines ◽  
Geometric Point ◽  
Different Types ◽  
Potential Applications ◽  
General Mathematical Model

Different types of redundancy in parallel kinematics machines (PKM) can be used to improve their kinematic and dynamic properties. The meaning of redundancy of PKM is often differently understood in the literature. In this paper a terminology for redundant PKM is proposed. The basis for this classification is a general mathematical model. With the help of this model PKM are regarded as non-linear control systems. The different types of redundancy are clearly distinguished, and their potential applications are discussed. Redundancy is considered from a geometric point of view. Redundancy is a means to deal with singularities of PKM. The different types of singular configurations are considered in the paper, and the potential of redundancy to cope with such situations is discussed. Again singularities are considered from a geometric point of view.

Designing Statically Determinable Mechanisms of Technological Mechatronic Machines with Parallel Kinematics

2019 ◽  
Vol 20 (7) ◽  
pp. 428-436
Author(s):  
A. K. Tolstosheev ◽  
V. A. Tatarintsev
Keyword(s):  
Structural Analysis ◽  
Hierarchical Structure ◽  
Degrees Of Freedom ◽  
Kinematic Chain ◽  
Parallel Structure ◽  
Parallel Kinematics ◽  
Output Link ◽  
Parallel Connection ◽  
Kinematic Chains ◽  
Chain Increase

The work is devoted to improving the reliability and manufacturability of mechatronic machine designs with parallel kinematics by replacing statically indeterminable manipulators with statically determinable mechanisms. A technique is proposed in which the design of statically determinable manipulators of technological mechatronic machines with parallel kinematics is performed by modifying the structure of prototypes and includes three steps: identifying and analyzing redundant links, eliminating redundant links, checking the correctness of eliminating redundant links. To determine the number of degrees of freedom of the mechanism, identify redundant links, and verify the solution, the authors use the proposed methodology for structural analysis of parallel structure mechanisms. In structural analysis, a manipulator is represented by a hierarchical structure and is considered as a parallel connection of elementary mechanisms with an open kinematic chain; as a kinematic chain consisting of leading and driven parts; as a set of links and kinematic pairs; as a kinematic connection of the output link and the rack. The article implements the following techniques for eliminating redundant links: mobility increase in kinematic pairs; introduction of unloading links and passive kinematic pairs to the kinematic chain; exclusion of extra links and pairs from the kinematic chain; increase in mobility in some kinematic pairs simultaneously with the exclusion of other kinematic pairs that have become superfluous. The authors developed several variants of structural schemes of self-aligning manipulators based on the Orthoglide mechanism, which retain the basic functional proper ties of the prototype. To increase the number of self-aligning mechanism diagrams, the redistribution of mobilities and links within the connecting kinematic chain and between connecting kinematic chains is used. The proposed methodics allow to determine the number of degrees of freedom of the mechanism, the number and type of redundant links, eliminate redundant links and, on an alternative basis, build structural diagrams of statically determinable mechanisms of technological mechatronic machines with parallel kinematics.

scholarly journals The Design of a Novel Prismatic Drive for a Three-DOF Parallel-Kinematics Machine

2005 ◽  
Vol 128 (4) ◽  
pp. 710-718 ◽  
Author(s):  
D. Chablat ◽  
J. Angeles
Keyword(s):  
Parallel Robot ◽  
Rolling Motion ◽  
Parallel Kinematics ◽  
Cam Mechanism ◽  
Pure Rolling ◽  
Parallel Kinematics Machines

The design of a novel prismatic drive is reported in this paper. This transmission is based on Slide-o-Cam, a cam mechanism with multiple rollers mounted on a common translating follower. The design of Slide-o-Cam was reported elsewhere. This drive thus provides pure-rolling motion, thereby reducing the friction of rack-and-pinions and linear drives. Such properties can be used to design new transmissions for parallel-kinematics machines. In this paper, this transmission is intended to replace the ball-screws in Orthoglide, a three-dof parallel robot intended for machining applications.

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