Kinematics And Static Stiffness Research Of Six-degree-of-freedom Precision Docking Platform For Bottom Tooling

In the process of assembling the tooling module of the giant laser device,it is very important that carry out the precision docking of the clean holding box and the clean box.Based on this,this paper had designed a precision docking platform with six-degree-of-freedom position adjustment.The platform is a series of two degrees of freedom and is connected in series(3-UPS/PU level adjustment mechanism and 4-PPR plane adjustment mechanism).The main research contents of this paper are as follows:Based on the demand and function analysis of the cleaning and holding box of the bottom-mounted tooling and the clean room,a hybrid mechanism of 3-UPS/PU level adjustment mechanism and 4-PPR plane adjustment mechanism is proposed;the structure of the two parallel mechanisms is respectively The principle is introduced to solve the 3-UPS/PU mechanism and 4-PPR mechanism degrees of freedom.The closed vector of 3-UPS/PU mechanism is established to solve the position inverse solution of the mechanism,and the analytical solution is used to solve the position inverse solution of the 4-PPR plane adjustment mechanism.Based on the position inverse solution of the two mechanisms,the two are Inverse analysis and differential analysis,the analytical expressions of speed and acceleration of 3-UPS/PU mechanism and 4-PPR mechanism are obtained.Finally,the motion simulation of displacement,velocity and acceleration of the two mechanisms is performed by Adams and Matlab software.The simulation results are compared and the simulation error is solved to verify the correctness of the kinematics solution.The dynamic model and simplification of the 3-UPS/PU mechanism horizontal adjustment mechanism and the 4-PPR redundant drive plane adjustment mechanism are established respectively,and the dynamic equations are established by Lagrangian method and virtual work principle.The corresponding driving force is solved by Matlab software.List the constraints affecting the working space,and then analyze the rod length,ball hinge,Hook hinge angle and rod-to-rod distance interference of 3-UPS/PU parallel mechanism.Use Matlab software to carry out space 3D search and make 3-UPS/ PU three-degree-of-freedom work space curve.In order to improve the horizontal adjustment ability of the 3-UPS/PU parallel mechanism of the docking platform,the stiffness matrix method is used to establish the static stiffness analysis model of 3-UPS/PU parallel mechanism.The simulation of static stiffness motion is simulated by Matlab software,and 3-UPS/PU is made.Static stiffness distribution curve of the parallel working mechanism over the entire working space.The static stiffness results are verified by ANSYS software.Finally,the appropriate objective function is selected to solve the optimal stiffness in the workspace.