Research On Macro/Micro Dual Drive Precision Positioning Stage Based On Linear Moroe

With the development of science technology, demands for precision positioning technology over a relatively large range have recently increased in a variety of industries and sciences such as semiconductor photolithography, IC manufacturing and packaging, biomedical. In particular, such demands result in the development of precision stage which achieves a large travel positioning with a high-precision and quick response. But, there is always a contradiction between large travel and high precision, how to coordinate the relationship between the two is very important, in practice often sacrificing stroke to improve accuracy or vice versa. Precision positioning technology over a relatively large range has became one of the key technical problems need to be solved urgently in front edge sciences.In order to better conciliating and solving the contradiction between them, in this paper, starting from the concept of macro and micro combined, further research was taken on such key techniques as the system structure of macro/micro dual drive positioning stage, the implementation method of micron level macro positioning and submicron level micro positioning, the structural design of the permanent magnet linear motor. A linear motor and a PZT actuator are adopted in this system to drive the platform, and a linear encoder is utilized to realize closed-loop displacement feedback, thus, the system gets a large travel and high-precision repeat positioning accuracy. The main research content includes:First. Base on common right circular flexure hinge, a low stress concentration and low coupling displacement composite flexure hinge mechanism was designed. Pseudo-rigid-body model and the theory of mechanics of materials were applied to establish the theoretical model of stiffness. By using finite element analyze the static stiffness, maximum stress at the place of weak section and the inherent frequency of flexure mechanism, the simulation result is consistent with the theoretical analysis, and verifies the feasibility of this method.Second, Design and Research of u-shaped ironless permanent magnet linear motor. Preliminary analysis the structural parameters of the motor magnetic circuit and rotor coil. By making a simple model divided motor magnetic field into three parts of the permanent magnet area, the air gap area and other regions. First solve the magnetic flux density of the single side permanent magnetic, deduce its mathematical expression in each region. And then according to superposition principle of magnetic field, air gap flux density of u-shaped ironless permanent magnet linear motor has been obtained. Moreover, the analytical equations of thrust force and back EMF are derived. A finite element model was established, Analysis the influence of the logarithm of permanent magnet to the magnetic flux density, discuss the influence of the width of unilateral coil to electromagnetic thrust. And the no-load back-EMF, characteristics of flux linkage, cogging force and electromagnetic thrust were obtained by finite element analysis.Last, based on the analysis and simulation, a prototype model is designed and made, and the experiment is carried out. The experimental results agree with the simulation theoretical analysis result, proving the accuracy and feasibility of the design method.