Study On The Nonlinear Dynamics Of Three Structure Changing Metamorphic Palletizing Robot Mechanism

Metamorphic mechanism,as a new field of mechanism,has been widely concerned by scholars at home and abroad,and has been widely used in life and production.The study of the dynamics of metamorphic mechanisms,especially the nonlinear dynamics,is of great practical value for the promotion of metamorphic mechanisms,so it is necessary to study the nonlinear dynamics of the metamorphic mechanisms.In this paper,a three-tectonic variable palletizing robot mechanism is taken as the object of study.Firstly,the topology analysis of the mechanism is carried out by using the adjacency matrix method,and the state transformation process of the mechanism is described.According to the characteristics of metamorphic mechanism,a kind of electromagnetic cell is designed.By analyzing the kinematics of the mechanism system,the constraint conditions of the system are obtained.Then,based on the beam element,the nonlinear dynamic model of the system is established by finite element method considering the elastic deformation of the component and the impact excitation.Then,the coupling equation of the nonlinear dynamic equation of the system is obtained by using the method of coordinate transformation.The dynamic model is solved by multi-scale method,and the steady state solution of the system is obtained by Newmark method.Based on the analysis of the resonance mechanism under the influence of the impact force,the conditions of the resonance of the system are obtained.On this basis,the main resonance and superharmonic resonance of the system are analyzed.Then,the numerical simulation of the system is carried out by using Matlab software.The dynamic response of the system in both load and no load is discussed.The geometrical simulation of the system is carried out in Adams.The nonlinear resonance phenomena caused by the impact of different frequencies are discussed.The comparison between the time domain and the frequency domain in the Matlab and Adams is obtained by the collision point lateral displacement.The correctness of the analytical model of the system is verified.Finally,the genetic algorithm is used to optimize the cross-section parameters of the rods of the system.The optimal solution of the cross-section parameters of each bar is obtained,which reduces the total weight of the system and improves the stability of the system.The dynamic performance of the system is Improved.