Determination of the Cable Span and Cable Deflection of Cable-Driven Parallel Robots

Author(s):  
Andreas Pott
Keyword(s):  
2016 ◽  
Vol 8 (4) ◽  
Author(s):  
Han Yuan ◽  
Eric Courteille ◽  
Dominique Deblaise

This paper addresses the force distribution of redundantly actuated cable-driven parallel robots (CDPRs). A new and efficient method is proposed for the determination of the lower-boundary of cable forces, including the pose-dependent lower-boundaries. In addition, the effect of cable sag is considered in the calculation of the force distribution to improve the computational accuracy. Simulations are made on a 6DOF CDPR driven by eight cables to demonstrate the validity of the proposed method. Results indicate that the pose-dependent lower-boundary method is more efficient than the fixed lower-boundary method in terms of minimizing the motor size and reducing energy consumption.


2006 ◽  
Vol 22 (1) ◽  
pp. 160-167 ◽  
Author(s):  
J.F. O'Brien ◽  
F. Jafari ◽  
J.T. Wen
Keyword(s):  

Author(s):  
Coralie Germain ◽  
Sébastien Briot ◽  
Stéphane Caro ◽  
Philippe Wenger

The characterization of the elastodynamic behavior and natural frequencies of parallel robots is a crucial point. Accurate elastodynamic models of parallel robots are useful at both their design and control stages in order to define their optimal dimensions and shapes while improving their vibratory behavior. Several methods exist to write the elastodynamic model of manipulators. However, those methods do not provide a straightforward way to write the Jacobian matrices related to the kinematic constraints of parallel manipulators. Therefore, the subject of this paper is about a systematic method for the determination of the mass and stiffness matrices of any parallel robot in stationary configurations. The proposed method is used to express the mass and stiffness matrices of the Nantes Variable Actuation Robot (NaVARo), a three-degree-of-freedom (3DOF) planar parallel robot with variable actuation schemes, developed at IRCCyN. Then, its natural frequencies are evaluated and compared with those obtained from both Cast3m software and experimentally.


Author(s):  
X-J Liu ◽  
J Wang ◽  
H Zheng

Parallel robots lead to complex kinematics equations, so determination of their workspaces is a challenging issue. The workspace of a robot is not fully characterized by its volume alone; the workspace shape is an important aspect as well. In this paper, the geometric determination of the workspace for Delta robots is presented. The workspace (workspace volume and workspace shape) for the robots is studied systematically in ‘the physical model of the solution space’, which is a useful tool to express relationships between the performance criteria and all link lengths of one type of robotic mechanism. Performance atlases of the workspace volume for the robots are plotted in the physical model of the solution space. The characteristics of the distribution of the workspace shapes in the physical model of the solution space are presented as well. The physical model of the solution space presents a new method for the computer aided design (CAD) of robotic mechanisms. The results are very useful for obtaining the optimum design of robotic mechanisms.


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