Mechanical Design And Research On Compound Six-Degree Of Freedom Platform

In view of the common six-degree of freedom(6-DOF)platform with the Stewart structure has a small motion space,large size,complex control system and high development cost.This paper independently designed a compound 6-DOF platform.The mature components of the platform,such as shear-lift mechanism,slewing support and lead screw guide rail,are combined to form a composite motion platform,which has the advantages of wide range of motion,small size,simple control and low cost of research and development.It can be widely used in places with low precision requirements but great demand for motion space,such as simulated driving platform and 4D theater seats,etc.In this paper,the main work with mechanical design,static analysis and calibration,kinematics analysis and simulation and dynamic analysis and simulation had been done.Firstly this design had determined the technical parameters of the platform after referring to the common 6-DOF platform,simulation platform and multi-directional automatic booth.The overall structure scheme of the platform is determined,and the driving mode is electric driving.According to the structural scheme,the models of guide rail,lead screw,motor,slewing support and electric cylinder were selected,and the kinematics and dynamics analysis of lifting mechanism and tumbling mechanism were carried out.Secondly,the main components and the overall structure of the platform were analyzed and checked,including the strength check of the slewing bearing bolt,the strength check of the scissor arm and the stability check of the tension and compression,the shear strength check of the pin and the stability check of the platform against overturning.The 3D model of the platform was established by SolidWorks software and imported it into ANSYS Workbench for finite element static simulation analysis.The equivalent stress cloud diagram,equivalent strain cloud diagram and comprehensive deformation cloud diagram of the platform were obtained,which verified that the mechanical properties of the platform met the requirements.Then the D-H coordinate transformation method was used to establish the linkage coordinate system of the platform,and the kinematics equation of the platform was obtained,and the forward and reverse solution analysis and preliminary verification had been done.Imported the platform SolidWorks 3D model into ADAMS to build the ADAMS model of the platform.The kinematic simulation of the platform was carried out to obtain the displacement,velocity,angular velocity,acceleration and angular acceleration curves of the motion platform in the X,Y and Z directions,which verified the good motion characteristics of the platform,the rationality of the structural design and the correctness of the positive and negative solutions.Finally,the Lagrange equation method was used to construct the platform dynamics equation,and the kinetic energy and potential energy of the platform system were obtained.On the basis of the existing ADAMS model of the platform,the dynamic simulation of the platform was carried out to obtain the force or torque time curves of each joint,which verified that the platform still had good dynamic characteristics under the full load limit state.