Reliability Analysis Of Controllable Metamorphic Palletizing Robot Mechanism Based On Kinematic Failyre

Metamorphic mechanism was proposed as a new type of mechanism more than 20 years ago.It has the characteristics of multi-functional stage change,multi-topological structure change and multi-degree-of-freedom change,and has a good prospect in engineering application.At home and abroad,the research on the metamorphic mechanism mainly focus on the principle,mechanism synthesis,kinematics and dynamics,and the reliability research on the metamorphic mechanism is relatively few.As an important index to measure the quality of machine system,reliability determines whether the machine system works reliably and its performance is stable for a long time under normal conditions.During the configuration transformation of metamorphic mechanism,factors such as kinematic pair clearance and link length error have negative influence on the reliable work of the mechanism.This paper had a two-structural state controlled metamorphic mechanism as the research object,considering respectively the length error and clearance,built the metamorphic moment error model.And on this basis,set up reliability model of metamorphic mechanism.Finally an example analysis was carried out,and this provided the engineering application of metamorphic mechanism with theory reference.Firstly,kinematics analysis and error analysis were carried out under the influence of link length error.Under the condition that the link length error was considered only,the loop vector method was used to construct the motion equations of each configuration for kinematic analysis.On this basis,the function and error equation of each configuration were established by the matrix method,and the error equation of metamorphic moment was constructed by the first order Taylor expansion.Secondly,the kinematics analysis and error analysis of each configuration were carried out by comprehensively considering the link length error and clearance.Through the loop vector method to carry on the kinematics analysis of the state,and Lagrange equation was adopted to establish the dynamics equations of structure state.Selected fourth order Runge-Kutta algorithm to get the kinematics parameters,then under the influence,the matrix method was used to construct the comprehensive error equation of each state,through the first order Taylor expansion,got the error equation of the metamorphic moment.Finally,First-order Second-moment Method was used to establish the general reliability model,and the reliability analysis model was constructed based on the characteristics of the metamorphic mechanism studied in this paper.Then,a numerical analysis was carried out for the reliability of the controllable metamorphic stacking robot mechanism,providing a theoretical reference for the reliability research.