Stiffness Analysis Of Precision Positioning Platform For Four - DOF Fully Compliant Parallel Mechanism

With the rapid development of science and technology, and thus the accuracy of precision positioning technology are constantly improved. How to design a high-precision micro-positioning platform becomes an inevitable trend of the development of precision positioning technology. The stiffness of the micro-positioning platform is an important factor affecting the accuracy, so it is critical to make the analysis on it.First, The precision positioning platform which are mainly composed of a whole complaint parallel mechanism are designed, based on the theory of the parallel mechanisms and the compliant mechanisms in this paper. Secondly, based on the principle of virtual work and cell kinetic equation, a method for solving the static stiffness of a whole compliant parallel mechanism was designed. Finally, by the analysis software, the result of the demand was verified, that gives the proof of the correctness of the method. The main work of the paper includes:1.Three bodies elected from the three categories (3T1R,2R2T,3R1T)4-DOF parallel mechanism are analyzed about the motion characteristics by screw theory.2.Based on the selected parallel mechanism (Model:4-CRU type,2RPU-2SPS type,4-RPUR type), through the flexible hinge replacement method, compliant mechanisms and other related knowledge, the full supple parallel mechanism are designed, so as to be the main components of the precision positioning platform.3.Application of finite element analysis, models of4-CRU full complaint parallel mechanism、2-RPU-2SPS full complaint parallel mechanism and4-RPUR full complaint parallel mechanism are made and simulated by the Solidworks and ANSYS.4.Compared to the corresponding experimental and calculated data, the correctness that using finite element method analysis the overall stiffness of the full complaint parallel mechanism is verified.Results:1. It is proved that the designed method is correct.2. Through the calculation of the overall stiffness of the three categories four DOF compliant parallel mechanism, a reasonable result comes out, that gives the point that the method not only adapts to a special case, and also the general.3. The design of the compliant parallel mechanism and its stiffness calculation, expand the type of precision positioning platform, improving the accuracy of the precision positioning platform.