Kinematic Reliability Analysis of Planar Metamorphic Mechanism with Multi-source Uncertainties

Abstract

Metamorphic mechanism can reorganize and reconstruct itself according to the changes and needs of environment and working conditions, and it has been widely used in the field of robot. The variable topological structure of metamorphic mechanism makes it more difficult to analyze the reliability of full configuration motion of metamorphic mechanism under multi-source uncertainty. A method for reliability analysis of planar five-bar metamorphic mechanism under multiple source uncertainties is presented. The coupling model of link manufacturing tolerance, joint tolerance and thermal deformation is set up under the temperature load, adopting obey truncated normal distribution random parameters and interval parameters to describe the length of link, the uncertainty of the clearance of revolute and prismatic, combined with the metamorphic characteristics to establish full-configuration motion error transfer model, based on interval method and Monte Carlo method, establishing full-configuration motion reliability model with multi-source uncertainties. Based on the proposed method, the kinematic reliability distribution law of the configuration-complete and sub-configuration of the metamorphic mechanism under alternating temperature conditions was analyzed, and the influence law of different joint hole shaft fit, connecting rod tolerance grade and thermal expansion coefficient on the kinematic reliability of the metamorphic mechanism is analyzed.