scholarly journals Conceptual design and comparative stiffness analysis of an Exechon-like parallel kinematic machine with lockable spherical joints

2017 ◽  
Vol 14 (4) ◽  
pp. 172988141772413
Author(s):  
Teng-fei Tang ◽  
Jun Zhang
Keyword(s):  
Conceptual Design ◽  
Prediction Accuracy ◽  
Parallel Kinematic Machine ◽  
Stiffness Analysis ◽  
Parallel Kinematic Machines ◽  
Stiffness Model ◽  
Dynamic Analyses ◽  
Parallel Kinematic ◽  
Kinetostatic Model ◽  
Limb Structure

This article proposes two types of lockable spherical joints which can perform three different motion patters by locking or unlocking corresponding rotational axes. Based on the proposed lockable spherical joints, a general reconfigurable limb structure with two passive joints is designed with which the conceptual designs of two types of Exechon-like parallel kinematic machines are completed. To evaluate the stiffness of the proposed Exechon-like parallel kinematic machines, an expanded kinetostatic model is established by including the compliances of all joints and limb structures. The prediction accuracy of the expanded stiffness model is validated by numerical simulations. The comparative stiffness analyses prove that the Exe-Variant parallel kinematic machine claims competitive rigidity performance to the Exechon parallel kinematic machine. The present work can provide useful information for further investigations on structural enhancement, rigidity improvement, and dynamic analyses of other Exechon-like parallel kinematic machines.

Some Implications for Parallel Kinematic Machine Design Based on Kinetostatic Model

2000 ◽  
Author(s):  
Clément M. Gosselin ◽  
Dan Zhang
Keyword(s):  
Material Properties ◽  
Geometric Model ◽  
Design Guidelines ◽  
Machine Design ◽  
Parallel Kinematic Machine ◽  
System Behavior ◽  
New Type ◽  
Link Flexibility ◽  
Parallel Kinematic ◽  
Kinetostatic Model

Abstract In this paper, a new method — named lumped kinetostatic modeling — to analyze the effect of the link flexibility on the mechanism’s stiffness is provided. A new type of mechanism whose degree of freedom (dof) is dependent on a passive constraining leg connecting the base and the platform is introduced and analyzed. With the proposed kinetostatic model, a significant effect of the link flexibility on the mechanism’s precision has been demonstrated. The influence of the changement of structure parameters, including material properties, on the system behavior is discussed. In the paper, the geometric model of this kind of mechanism is first introduced. Then, a lumped kinetostatic model is proposed in order to account for joint and link compliances; some results and design guidelines are obtained. Finally, the optimization of the precision is addressed using a genetic algorithm.

Stiffness Analysis of a Tripod With a Passive Link

2005 ◽  
Author(s):  
Z. M. Bi ◽  
S. Y. T. Lang ◽  
D. Zhang
Keyword(s):  
Constrained Motion ◽  
Motion Platform ◽  
Stiffness Analysis ◽  
Stiffness Model ◽  
Parallel Kinematic Mechanism ◽  
Parallel Kinematic ◽  
Linear Actuators ◽  
Main Components ◽  
Kinematic Mechanism

The system stiffness of a tripod parallel kinematic mechanism (PKM) with 3-DOF is investigated in this paper. The tripod PKM has rotations of a motion platform about the x and y axes and translation along the z axis. The motion on the other axes is constrained by a passive link. The stiffness model considers the compliances of three main components: the fixed-length links, the passive link, and the linear actuators. The modeling procedure for the kinetostatic stiffness model is introduced. A case study is provided to demonstrate evaluation of the stiffness of our prototype tripod machine. The developed model differs from the others in the sense that the stiffness on the motion axes is determined by both the active links and the passive link; but the stiffness on the constrained motion axes depends merely on the passive link.

scholarly journals Parallel Kinematic Machines: Design, Analysis and Simulation in an Integrated Virtual Environment

2004 ◽  
Vol 127 (4) ◽  
pp. 580-588 ◽  
Author(s):  
Dan Zhang ◽  
Lihui Wang ◽  
Sherman Y. T. Lang
Keyword(s):  
Machine Tool ◽  
Virtual Environment ◽  
Collision Detection ◽  
Design Analysis ◽  
Visual Environment ◽  
Parallel Kinematic Machines ◽  
Virtual System ◽  
Parallel Kinematic ◽  
Optimization And Simulation ◽  
Kinetostatic Model

Selecting a configuration for a machine tool that will best suit the needs of a forecast set of requirements can be a difficulty and costly exercise. This problem can now be addressed using an integrated virtual validation system. The system includes kinematic/dynamic analysis, kinetostatic model, CAD module, FEM module, CAM module, optimization module and visual environment for simulation and collision detection of the machining and deburring. It is an integration of the parallel kinematic machines (PKM) design, analysis, optimization and simulation. In this paper, the integrated virtual system is described in detail; a prototype of a 3-dof PKM is modeled, analyzed, optimized and remote controlled with the proposed system. Some results and simulations are also given. Its effectiveness is shown with the results obtained by NRC-IMTI during the design of the 3-dof NRC PKM.

INVESTIGATION ON THE STIFFNESS OF 3-HSS PARALLEL KINEMATIC MACHINE USING FINITE ELEMENT ANALYSIS

2002 ◽  
Vol 26 (3) ◽  
pp. 337-346 ◽  
Author(s):  
Lihua Zhou ◽  
Tian Huang ◽  
Hanfried Kerle
Keyword(s):  
Experimental Data ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Conceptual Design ◽  
Axial Stiffness ◽  
Parallel Kinematic Machine ◽  
Element Analysis ◽  
Fea Model ◽  
Parallel Kinematic ◽  
Good Agreement

A feasible way to estimate the stiffness of a 3-HSS parallel kinematic machine (PKM) by finite element analysis (FEA) is presented. Taking into consideration the base, columns, carriages struts and the mobile platform, a FEA model for the whole machine is established by solving such problems as match between different element types and simulation of moving components. Later on, this approach is applied to a particular 3-HSS PKM, Linapod, and used to steer the conceptual design of the machine. Furthermore, experiments are made on radial and axial stiffness. By comparison, the FE analytical results show good agreement with experimental data.

Sign in / Sign up

Export Citation Format

Share Document