Research On The Paramer Design And Experiment Of A Two-dimensional Micro Positioning Platform With Large Travel And Integrated Structure

With the development of nano technology, the micro positioning technology as one of the key technologies of nano technology has become hotspot at home and abroad. The micro positioning mechanism with piezoelectric elements and compliant mechanism is the common micro positioning equipment.In this paper, researches on a kind of large travel integrated structure two-dimensional micro positioning platform (abbr. as micro positioning platform) were carried out, such as configuration design, kinematics analysis, static analysis, parametric finite element analysis, control experiments and so on. The contents and the innovations are listed as follows:(1) According to characteristics of the compliant mechanism, using the micro-positioning parallel mechanism type synthesis theory, a new kind of two freedoms large travel micro positioning platform was designed based on multi-functional micro-drive module and two-dimensional translational parallel mechanism.(2) The structural parameters of micro displacement amplification module were designed by method of pseudo-rigid-body model aiming certain stiffness. Some revisions were also made according to the finite element analysis results. Combined the theoretical stiffness model with the finite element analysis, the structural parameters design method of micro mechanism for the stiffness target was presented. This method made clear the influence of flexible unit on the stiffness of micro mechanism and provided guidance for the optimum design of structural parameters.(3) The element stiffness matrix method was proposed based on the element stiffness matrix of flexible unit and the matrix displacement method. Kinematics and static analysis about the micro positioning platform were completed. Stiffness and kinematics models of the micro positioning platform were both built by the element stiffness matrix method which was comprehensive consideration of deformation of flexible units of the structure.(4) According to the advantages of VC and APDL, parametric finite element analysis of micro positioning platform was studied. The finite element analysis of the micro positioning platform was driven by all parameters through the man-machine information interface and the APDL command files.(5) The hysteresis character and creep properties of the piezoelectric actuator were studied, and the piezoelectric characteristics test program was developed. Workspace and variation curve of output displacements were investigated and performance test program for the micro positioning platform was also developed. And then the control program of the micro positioning platform was designed by adopting closed-loop control strategy.Simulation and experimental results show that the design method of structure parameter is valid. The stiffness model and kinematics model of micro positioning platform are close to the actual working status. The closed-loop control system of micro positioning platform can achieve precise location. Above analysis and research provide basis for the following optimization design of the structure parameter, studying on the dynamic characteristic and ameliorating the control system of the micro positioning platform.