Dynamic And Error Analysis On A Flexible Parallel Mechanism Considering Clearance

With the progress and development of science,parallel robots mechanisms are using widely in engineering field.At the same time the requirement of the precision and the stability of them is becoming more and more high.The error of product process of parallel robots mechanisms is unavoidable,and the collision and friction of robots move will cause the gap of joint.On the other hand,because of the existence of gravity,external force and inertial force,the robot will product random vibration and elastic deformation while it is move with high speed.All of those will take important influence on dynamic property.So the main research contents of this paper are as follows:Based on the research achievements at home and abroad,taking the 3-RSR parallel mechanism as the research object,studying the dynamic model and error with considering the link flexibility.First of all,establishing the flexible dynamic model of parallel mechanism based on the theory of space beam finite element.Then solve the dynamic model by Matlab software.Analyze the error of the flexible parallel mechanisms according to different material property of bars and different actuating speed.Establish the model of parallel mechanism with joint clearances and the model of flexible parallel mechanism with considering joint clearances by three-dimensional modeling software.Making the bars into flexible by the finite element analysis software,and put the flexible bars into the Adams for the dynamic simulation.And put the data of dynamic simulation into the Matlab to get the displacement,velocity and acceleration curves of different material properties and flexible mechanisms with clearance,and compared with ideal.Study the error of flexible mechanisms with clearances.