Effect of links deformation on motion precision of parallel manipulator based on flexible dynamics
Abstract
Purpose
Manipulator motion accuracy is a fundamental requirement for precision manufacturing equipment. Light weight manipulators in high speed motions are vulnerable to deformations. The purpose of this work is to analyze the effect of link deformation on the motion precision of parallel manipulators.
Design/methodology/approach
The flexible dynamics model of the links is first established by applying the Euler–Bernoulli beam theory and the assumed modal method. The rigid-flexible coupling equations of the parallel mechanism are further derived by using the Lagrange multiplier approach. The elastic energy resulting from spiral motion and link deformations are computed and analyzed. Motion errors of the 3-link torque-prismatic-torque parallel manipulator are then evaluated based on its inverse kinematics. The validation experiments are also conducted to verify the numerical results.
Findings
The lateral deformation and axial deformation are largest at the middle of the driven links. The axial deformation at the middle of the driven link is approximately one-tenth of the transversal deformation. However, the elastic potential energy of the transversal deformation is much smaller than the elastic force generated from axial deformation.
Practical implications
Knowledge on the relationship between link deformation and motion precision is useful in the design of parallel manipulators for high performing dynamic responses.
Originality/value
This work establishes the relationship between motion precision and the amount of link deformation in parallel manipulators.
Keywords
Acknowledgements
This work was supported by the National Natural Science Foundation of China (Grant No. 51575365 and Grant No. 51105258), the Natural Scientific Foundation of Liaoning Province (Grant No. 2015020127), Program for Liaoning Excellent Talents in University (Grant No. LJQ2014061) and Discipline Content Education Project of Shenyang Jianzhu University (Grant No. XKHY2-31). The authors would like to thank Institute of Advanced Manufacture and Automation Technology in Northeastern University, China, for providing the experimental data.
Citation
Zhu, C., Katupitiya, J. and Wang, J. (2017), "Effect of links deformation on motion precision of parallel manipulator based on flexible dynamics", Industrial Robot, Vol. 44 No. 6, pp. 776-787. https://doi.org/10.1108/IR-12-2016-0368
Publisher
:Emerald Publishing Limited
Copyright © 2017, Emerald Publishing Limited