Performance Analysis And Optimization Research Of 2-RPU&2-SPS 4-DOF Parallel Mechanism Based On ADAMS

The research object of this thesis is the 4-space DOF parallel mechanism proposed by Professor Li Bin——2-RPU&2-SPS.The three-dimensional engineering model diagram is first established,and the reference coordinate system and the dynamic coordinate system are created on the schematic diagram of the mechanism.,Analyzed the kinematics of the organization.The singular configuration of the mechanism is analyzed by the inverse position equation,and the working space of the mechanism is solved by Matlab software in combination with other constraints.Finally,the transmission performance of the mechanism is simply analyzed.In the aspect of mechanism dynamics research,the dynamic inverse solution expression is established,and the influence of structural parameters on the dynamic performance is analyzed.The software Adams is mainly used to simulate and study the kinematics and dynamics,and the structure parameters are analyzed.The influence of kinematics and dynamics performance,and finally the multi-objective function optimization of the mechanism.This paper is mainly divided into the following main research contents:(1)A three-dimensional model of 2-RPU&2-SPS was established,and the nature of the degree of freedom of the mechanism was analyzed by screw theory.Secondly,the position of the mechanism is analyzed,the branch chain coordinate system is established on the rod,and then the speed and acceleration of the upper rod and the lower rod of each motion branch chain are calculated.Finally,Adams was used to verify the correctness of the model and analyze the kinematics performance.(2)The derivation method is used to obtain the Jacobian matrix of the mechanism,the determinant of the forward and inverse Jacobian matrix is used to determine the singular configuration type of the mechanism,and combined with the rod length and rotation angle constraints,the working space of the parallel mechanism is solved by the numerical method.The transmission performance of the mechanism is evaluated by the cosine value of the pressure angle between the branch chains,the dynamic equations of the branch chains and the motion platform are established,and the constraint torque and driving force expressions are obtained,and the Adams software is used to solve the dynamics of the parallel mechanism inversely.numerical simulation.(3)Use Adams software to establish the parametric model and multi-objective function of the parallel mechanism.On the basis of design research,with four parameters as independent variables,when the four objective functions of the mechanism are minimized,a set of optimal solutions that balance multiple objective functions is obtained,which achieves the purpose of optimal design.