The Design And Analysis Of A Large Stewart Platform

Stewart platform is a 6-DOF parallel mechanism. Stewart platform particularly suits the circumstances whose space is restricted or workspace is not big but load is big because of its stable structure, high precision, and compact structure. According to the above basic characteristics, a lot of parallel mechanisms have been derived based on different kinematical principles and structures, and Stewart platform is widely applied to many fields of scientific research and industry, such as flight simulator, parallel machine tool, navigation simulator and micro-operation robot.First of all, this subject 3D model of the large Stewart platform has been made according to the engineering requirements, based on Solidworks.And analyzed the structure of this Stewart platform, calculated the degree of freedom. The model was imported into ADAMS with the interface technology of Solidworks and ADAMS.The kinematic equation of Stewart platform was established according to vector transform. The kinematic and dynamic simulation has been made in different motion programs of Stewart platform, actually the driving force curve of the driving links, hinges and ball hinges has been gotten, which supplied the basis for FEA and the control of Stewart platform.According to the collaboration technology of ANSYS and ADAMS, the motion platform of Stewart platform has been transformed into a flexible body, and then the rigid-flexible coupled dynamic simulation has been made in ADAMS. The driving force of six links has been gotten, and compared the results of rigid simulation and rigid-flexible coupled simulation.At the same time, the load file that has been gotten was imported into ANSYS,after that,FEA was made in every pose of the motion platform. With comparing and analyzing every result of load steps, the biggest displacement and stress of the motion platform has been gotten.Finally, the zero pose FEA model of Stewart platform has been established based on ANSYS,whose the modal was analyzed. After that, the frequency and their vibration modes, from 1 to 6 ranks, which has been picked up, which supplied the basis of the vibration control.